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diff --git a/gas/doc/as.texinfo b/gas/doc/as.texinfo deleted file mode 100644 index 330a8b23419..00000000000 --- a/gas/doc/as.texinfo +++ /dev/null @@ -1,5397 +0,0 @@ -\input texinfo @c -*-Texinfo-*- -@c Copyright (c) 1991, 92, 93, 94, 95, 96, 97, 1998 -@c Free Software Foundation, Inc. -@c UPDATE!! On future updates-- -@c (1) check for new machine-dep cmdline options in -@c md_parse_option definitions in config/tc-*.c -@c (2) for platform-specific directives, examine md_pseudo_op -@c in config/tc-*.c -@c (3) for object-format specific directives, examine obj_pseudo_op -@c in config/obj-*.c -@c (4) portable directives in potable[] in read.c -@c %**start of header -@setfilename as.info -@c ---config--- -@c defaults, config file may override: -@set have-stabs -@c --- -@include asconfig.texi -@include gasver.texi -@c --- -@c common OR combinations of conditions -@ifset AOUT -@set aout-bout -@end ifset -@ifset ARM/Thumb -@set ARM -@end ifset -@ifset BOUT -@set aout-bout -@end ifset -@ifset H8/300 -@set H8 -@end ifset -@ifset H8/500 -@set H8 -@end ifset -@ifset SH -@set H8 -@end ifset -@ifset HPPA -@set abnormal-separator -@end ifset -@c ------------ -@ifset GENERIC -@settitle Using @value{AS} -@end ifset -@ifclear GENERIC -@settitle Using @value{AS} (@value{TARGET}) -@end ifclear -@setchapternewpage odd -@c %**end of header - -@c @smallbook -@c @set SMALL -@c WARE! Some of the machine-dependent sections contain tables of machine -@c instructions. Except in multi-column format, these tables look silly. -@c Unfortunately, Texinfo doesn't have a general-purpose multi-col format, so -@c the multi-col format is faked within @example sections. -@c -@c Again unfortunately, the natural size that fits on a page, for these tables, -@c is different depending on whether or not smallbook is turned on. -@c This matters, because of order: text flow switches columns at each page -@c break. -@c -@c The format faked in this source works reasonably well for smallbook, -@c not well for the default large-page format. This manual expects that if you -@c turn on @smallbook, you will also uncomment the "@set SMALL" to enable the -@c tables in question. You can turn on one without the other at your -@c discretion, of course. -@ifinfo -@set SMALL -@c the insn tables look just as silly in info files regardless of smallbook, -@c might as well show 'em anyways. -@end ifinfo - -@ifinfo -@format -START-INFO-DIR-ENTRY -* As: (as). The GNU assembler. -END-INFO-DIR-ENTRY -@end format -@end ifinfo - -@finalout -@syncodeindex ky cp - -@ifinfo -This file documents the GNU Assembler "@value{AS}". - -Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 1998 Free Software Foundation, Inc. - -Permission is granted to make and distribute verbatim copies of -this manual provided the copyright notice and this permission notice -are preserved on all copies. - -@ignore -Permission is granted to process this file through Tex and print the -results, provided the printed document carries copying permission -notice identical to this one except for the removal of this paragraph -(this paragraph not being relevant to the printed manual). - -@end ignore -Permission is granted to copy and distribute modified versions of this manual -under the conditions for verbatim copying, provided that the entire resulting -derived work is distributed under the terms of a permission notice identical to -this one. - -Permission is granted to copy and distribute translations of this manual -into another language, under the above conditions for modified versions. -@end ifinfo - -@titlepage -@title Using @value{AS} -@subtitle The @sc{gnu} Assembler -@ifclear GENERIC -@subtitle for the @value{TARGET} family -@end ifclear -@sp 1 -@subtitle Version @value{VERSION} -@sp 1 -@sp 13 -The Free Software Foundation Inc. thanks The Nice Computer -Company of Australia for loaning Dean Elsner to write the -first (Vax) version of @code{as} for Project @sc{gnu}. -The proprietors, management and staff of TNCCA thank FSF for -distracting the boss while they got some work -done. -@sp 3 -@author Dean Elsner, Jay Fenlason & friends -@page -@tex -{\parskip=0pt -\hfill {\it Using {\tt @value{AS}}}\par -\hfill Edited by Cygnus Support\par -} -%"boxit" macro for figures: -%Modified from Knuth's ``boxit'' macro from TeXbook (answer to exercise 21.3) -\gdef\boxit#1#2{\vbox{\hrule\hbox{\vrule\kern3pt - \vbox{\parindent=0pt\parskip=0pt\hsize=#1\kern3pt\strut\hfil -#2\hfil\strut\kern3pt}\kern3pt\vrule}\hrule}}%box with visible outline -\gdef\ibox#1#2{\hbox to #1{#2\hfil}\kern8pt}% invisible box -@end tex - -@vskip 0pt plus 1filll -Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 1998 Free Software Foundation, Inc. - -Permission is granted to make and distribute verbatim copies of -this manual provided the copyright notice and this permission notice -are preserved on all copies. - -Permission is granted to copy and distribute modified versions of this manual -under the conditions for verbatim copying, provided that the entire resulting -derived work is distributed under the terms of a permission notice identical to -this one. - -Permission is granted to copy and distribute translations of this manual -into another language, under the above conditions for modified versions. -@end titlepage - -@ifinfo -@node Top -@top Using @value{AS} - -This file is a user guide to the @sc{gnu} assembler @code{@value{AS}} version -@value{VERSION}. -@ifclear GENERIC -This version of the file describes @code{@value{AS}} configured to generate -code for @value{TARGET} architectures. -@end ifclear -@menu -* Overview:: Overview -* Invoking:: Command-Line Options -* Syntax:: Syntax -* Sections:: Sections and Relocation -* Symbols:: Symbols -* Expressions:: Expressions -* Pseudo Ops:: Assembler Directives -* Machine Dependencies:: Machine Dependent Features -* Reporting Bugs:: Reporting Bugs -* Acknowledgements:: Who Did What -* Index:: Index -@end menu -@end ifinfo - -@node Overview -@chapter Overview -@iftex -This manual is a user guide to the @sc{gnu} assembler @code{@value{AS}}. -@ifclear GENERIC -This version of the manual describes @code{@value{AS}} configured to generate -code for @value{TARGET} architectures. -@end ifclear -@end iftex - -@cindex invocation summary -@cindex option summary -@cindex summary of options -Here is a brief summary of how to invoke @code{@value{AS}}. For details, -@pxref{Invoking,,Comand-Line Options}. - -@c We don't use deffn and friends for the following because they seem -@c to be limited to one line for the header. -@smallexample -@value{AS} [ -a[cdhlns][=file] ] [ -D ] [ --defsym @var{sym}=@var{val} ] - [ -f ] [ --gstabs ] [ --gdwarf2 ] [ --help ] [ -I @var{dir} ] [ -J ] [ -K ] [ -L ] - [ --keep-locals ] [ -o @var{objfile} ] [ -R ] [ --statistics ] [ -v ] - [ -version ] [ --version ] [ -W ] [ --warn ] [ --fatal-warnings ] - [ -w ] [ -x ] [ -Z ] -@ifset A29K -@c am29k has no machine-dependent assembler options -@end ifset -@ifset ARC - [ -mbig-endian | -mlittle-endian ] -@end ifset -@ifset ARM - [ -m[arm]1 | -m[arm]2 | -m[arm]250 | -m[arm]3 | -m[arm]6 | -m[arm]60 | - -m[arm]600 | -m[arm]610 | -m[arm]620 | -m[arm]7[t][[d]m[i]][fe] | -m[arm]70 | - -m[arm]700 | -m[arm]710[c] | -m[arm]7100 | -m[arm]7500 | -m[arm]8 | - -m[arm]810 | -m[arm]9 | -m[arm]920 | -m[arm]920t | -m[arm]9tdmi | - -mstrongarm | -mstrongarm110 | -mstrongarm1100 ] - [ -m[arm]v2 | -m[arm]v2a | -m[arm]v3 | -m[arm]v3m | -m[arm]v4 | -m[arm]v4t | - -m[arm]v5 | -[arm]v5t ] - [ -mthumb | -mall ] - [ -mfpa10 | -mfpa11 | -mfpe-old | -mno-fpu ] - [ -EB | -EL ] - [ -mapcs-32 | -mapcs-26 | -mapcs-float | -mapcs-reentrant ] - [ -mthumb-interwork ] - [ -moabi ] - [ -k ] -@end ifset -@ifset D10V - [ -O ] -@end ifset -@ifset D30V - [ -O | -n | -N ] -@end ifset -@ifset H8 -@c Hitachi family chips have no machine-dependent assembler options -@end ifset -@ifset HPPA -@c HPPA has no machine-dependent assembler options (yet). -@end ifset -@ifset PJ - [ -mb | -me ] -@end ifset -@ifset SPARC -@c The order here is important. See c-sparc.texi. - [ -Av6 | -Av7 | -Av8 | -Asparclet | -Asparclite - -Av8plus | -Av8plusa | -Av9 | -Av9a ] - [ -xarch=v8plus | -xarch=v8plusa ] [ -bump ] [ -32 | -64 ] -@end ifset -@ifset Z8000 -@c Z8000 has no machine-dependent assembler options -@end ifset -@ifset I960 -@c see md_parse_option in tc-i960.c - [ -ACA | -ACA_A | -ACB | -ACC | -AKA | -AKB | -AKC | -AMC ] - [ -b ] [ -no-relax ] -@end ifset -@ifset M680X0 - [ -l ] [ -m68000 | -m68010 | -m68020 | ... ] -@end ifset -@ifset MCORE - [ -jsri2bsr ] [ -sifilter ] [ -relax ] -@end ifset -@ifset MIPS - [ -nocpp ] [ -EL ] [ -EB ] [ -G @var{num} ] [ -mcpu=@var{CPU} ] - [ -mips1 ] [ -mips2 ] [ -mips3 ] [ -m4650 ] [ -no-m4650 ] - [ --trap ] [ --break ] - [ --emulation=@var{name} ] -@end ifset - [ -- | @var{files} @dots{} ] -@end smallexample - -@table @code -@item -a[cdhlmns] -Turn on listings, in any of a variety of ways: - -@table @code -@item -ac -omit false conditionals - -@item -ad -omit debugging directives - -@item -ah -include high-level source - -@item -al -include assembly - -@item -am -include macro expansions - -@item -an -omit forms processing - -@item -as -include symbols - -@item =file -set the name of the listing file -@end table - -You may combine these options; for example, use @samp{-aln} for assembly -listing without forms processing. The @samp{=file} option, if used, must be -the last one. By itself, @samp{-a} defaults to @samp{-ahls}. - -@item -D -Ignored. This option is accepted for script compatibility with calls to -other assemblers. - -@item --defsym @var{sym}=@var{value} -Define the symbol @var{sym} to be @var{value} before assembling the input file. -@var{value} must be an integer constant. As in C, a leading @samp{0x} -indicates a hexadecimal value, and a leading @samp{0} indicates an octal value. - -@item -f -``fast''---skip whitespace and comment preprocessing (assume source is -compiler output). - -@item --gstabs -Generate stabs debugging information for each assembler line. This -may help debugging assembler code, if the debugger can handle it. - -@item --gdwarf2 -Generate DWARF2 debugging information for each assembler line. This -may help debugging assembler code, if the debugger can handle it. - -@item --help -Print a summary of the command line options and exit. - -@item -I @var{dir} -Add directory @var{dir} to the search list for @code{.include} directives. - -@item -J -Don't warn about signed overflow. - -@item -K -@ifclear DIFF-TBL-KLUGE -This option is accepted but has no effect on the @value{TARGET} family. -@end ifclear -@ifset DIFF-TBL-KLUGE -Issue warnings when difference tables altered for long displacements. -@end ifset - -@item -L -@itemx --keep-locals -Keep (in the symbol table) local symbols. On traditional a.out systems -these start with @samp{L}, but different systems have different local -label prefixes. - -@item -o @var{objfile} -Name the object-file output from @code{@value{AS}} @var{objfile}. - -@item -R -Fold the data section into the text section. - -@item --statistics -Print the maximum space (in bytes) and total time (in seconds) used by -assembly. - -@item --strip-local-absolute -Remove local absolute symbols from the outgoing symbol table. - -@item -v -@itemx -version -Print the @code{as} version. - -@item --version -Print the @code{as} version and exit. - -@item -W -@itemx --no-warn -Suppress warning messages. - -@item --fatal-warnings -Treat warnings as errors. - -@item --warn -Don't suppress warning messages or treat them as errors. - -@item -w -Ignored. - -@item -x -Ignored. - -@item -Z -Generate an object file even after errors. - -@item -- | @var{files} @dots{} -Standard input, or source files to assemble. - -@end table - -@ifset ARC -The following options are available when @value{AS} is configured for -an ARC processor. - -@table @code - -@cindex ARC endianness -@cindex endianness, ARC -@cindex big endian output, ARC -@item -mbig-endian -Generate ``big endian'' format output. - -@cindex little endian output, ARC -@item -mlittle-endian -Generate ``little endian'' format output. - -@end table -@end ifset - -@ifset ARM -The following options are available when @value{AS} is configured for the ARM -processor family. - -@table @code -@item -m[arm][1|2|3|6|7|8|9][...] -Specify which ARM processor variant is the target. -@item -m[arm]v[2|2a|3|3m|4|4t|5|5t] -Specify which ARM architecture variant is used by the target. -@item -mthumb | -mall -Enable or disable Thumb only instruction decoding. -@item -mfpa10 | -mfpa11 | -mfpe-old | -mno-fpu -Select which Floating Point architcture is the target. -@item -mapcs-32 | -mapcs-26 | -mapcs-float | -mapcs-reentrant | -moabi -Select which procedure calling convention is in use. -@item -EB | -EL -Select either big-endian (-EB) or little-endian (-EL) output. -@item -mthumb-interwork -Specify that the code has been generated with interworking between Thumb and -ARM code in mind. -@item -k -Specify that PIC code has been generated. -@end table -@end ifset - -@ifset D10V -The following options are available when @value{AS} is configured for -a D10V processor. -@table @code -@cindex D10V optimization -@cindex optimization, D10V -@item -O -Optimize output by parallelizing instructions. -@end table -@end ifset - -@ifset D30V -The following options are available when @value{AS} is configured for a D30V -processor. -@table @code -@cindex D30V optimization -@cindex optimization, D30V -@item -O -Optimize output by parallelizing instructions. - -@cindex D30V nops -@item -n -Warn when nops are generated. - -@cindex D30V nops after 32-bit multiply -@item -N -Warn when a nop after a 32-bit multiply instruction is generated. -@end table -@end ifset - -@ifset I960 -The following options are available when @value{AS} is configured for the -Intel 80960 processor. - -@table @code -@item -ACA | -ACA_A | -ACB | -ACC | -AKA | -AKB | -AKC | -AMC -Specify which variant of the 960 architecture is the target. - -@item -b -Add code to collect statistics about branches taken. - -@item -no-relax -Do not alter compare-and-branch instructions for long displacements; -error if necessary. - -@end table -@end ifset - - -@ifset M680X0 -The following options are available when @value{AS} is configured for the -Motorola 68000 series. - -@table @code - -@item -l -Shorten references to undefined symbols, to one word instead of two. - -@item -m68000 | -m68008 | -m68010 | -m68020 | -m68030 | -m68040 | -m68060 -@itemx | -m68302 | -m68331 | -m68332 | -m68333 | -m68340 | -mcpu32 | -m5200 -Specify what processor in the 68000 family is the target. The default -is normally the 68020, but this can be changed at configuration time. - -@item -m68881 | -m68882 | -mno-68881 | -mno-68882 -The target machine does (or does not) have a floating-point coprocessor. -The default is to assume a coprocessor for 68020, 68030, and cpu32. Although -the basic 68000 is not compatible with the 68881, a combination of the -two can be specified, since it's possible to do emulation of the -coprocessor instructions with the main processor. - -@item -m68851 | -mno-68851 -The target machine does (or does not) have a memory-management -unit coprocessor. The default is to assume an MMU for 68020 and up. - -@end table -@end ifset - -@ifset PJ -The following options are available when @value{AS} is configured for -a picoJava processor. - -@table @code - -@cindex PJ endianness -@cindex endianness, PJ -@cindex big endian output, PJ -@item -mb -Generate ``big endian'' format output. - -@cindex little endian output, PJ -@item -ml -Generate ``little endian'' format output. - -@end table -@end ifset - - -@ifset SPARC -The following options are available when @code{@value{AS}} is configured -for the SPARC architecture: - -@table @code -@item -Av6 | -Av7 | -Av8 | -Asparclet | -Asparclite -@itemx -Av8plus | -Av8plusa | -Av9 | -Av9a -Explicitly select a variant of the SPARC architecture. - -@samp{-Av8plus} and @samp{-Av8plusa} select a 32 bit environment. -@samp{-Av9} and @samp{-Av9a} select a 64 bit environment. - -@samp{-Av8plusa} and @samp{-Av9a} enable the SPARC V9 instruction set with -UltraSPARC extensions. - -@item -xarch=v8plus | -xarch=v8plusa -For compatibility with the Solaris v9 assembler. These options are -equivalent to -Av8plus and -Av8plusa, respectively. - -@item -bump -Warn when the assembler switches to another architecture. -@end table -@end ifset - -@ifset MIPS -The following options are available when @value{AS} is configured for -a MIPS processor. - -@table @code -@item -G @var{num} -This option sets the largest size of an object that can be referenced -implicitly with the @code{gp} register. It is only accepted for targets that -use ECOFF format, such as a DECstation running Ultrix. The default value is 8. - -@cindex MIPS endianness -@cindex endianness, MIPS -@cindex big endian output, MIPS -@item -EB -Generate ``big endian'' format output. - -@cindex little endian output, MIPS -@item -EL -Generate ``little endian'' format output. - -@cindex MIPS ISA -@item -mips1 -@itemx -mips2 -@itemx -mips3 -Generate code for a particular MIPS Instruction Set Architecture level. -@samp{-mips1} corresponds to the @sc{r2000} and @sc{r3000} processors, -@samp{-mips2} to the @sc{r6000} processor, and @samp{-mips3} to the @sc{r4000} -processor. - -@item -m4650 -@itemx -no-m4650 -Generate code for the MIPS @sc{r4650} chip. This tells the assembler to accept -the @samp{mad} and @samp{madu} instruction, and to not schedule @samp{nop} -instructions around accesses to the @samp{HI} and @samp{LO} registers. -@samp{-no-m4650} turns off this option. - -@item -mcpu=@var{CPU} -Generate code for a particular MIPS cpu. This has little effect on the -assembler, but it is passed by @code{@value{GCC}}. - -@cindex emulation -@item --emulation=@var{name} -This option causes @code{@value{AS}} to emulate @code{@value{AS}} configured -for some other target, in all respects, including output format (choosing -between ELF and ECOFF only), handling of pseudo-opcodes which may generate -debugging information or store symbol table information, and default -endianness. The available configuration names are: @samp{mipsecoff}, -@samp{mipself}, @samp{mipslecoff}, @samp{mipsbecoff}, @samp{mipslelf}, -@samp{mipsbelf}. The first two do not alter the default endianness from that -of the primary target for which the assembler was configured; the others change -the default to little- or big-endian as indicated by the @samp{b} or @samp{l} -in the name. Using @samp{-EB} or @samp{-EL} will override the endianness -selection in any case. - -This option is currently supported only when the primary target -@code{@value{AS}} is configured for is a MIPS ELF or ECOFF target. -Furthermore, the primary target or others specified with -@samp{--enable-targets=@dots{}} at configuration time must include support for -the other format, if both are to be available. For example, the Irix 5 -configuration includes support for both. - -Eventually, this option will support more configurations, with more -fine-grained control over the assembler's behavior, and will be supported for -more processors. - -@item -nocpp -@code{@value{AS}} ignores this option. It is accepted for compatibility with -the native tools. - -@need 900 -@item --trap -@itemx --no-trap -@itemx --break -@itemx --no-break -Control how to deal with multiplication overflow and division by zero. -@samp{--trap} or @samp{--no-break} (which are synonyms) take a trap exception -(and only work for Instruction Set Architecture level 2 and higher); -@samp{--break} or @samp{--no-trap} (also synonyms, and the default) take a -break exception. -@end table -@end ifset - -@ifset MCORE -The following options are available when @value{AS} is configured for -an MCore processor. - -@table @code -@item -jsri2bsr -@itemx -nojsri2bsr -Enable or disable the JSRI to BSR transformation. By default this is enabled. -The command line option @samp{-nojsri2bsr} can be used to disable it. - -@item -sifilter -@itemx -nosifilter -Enable or disable the silicon filter behaviour. By default this is disabled. -The default can be overidden by the @samp{-sifilter} command line option. - -@item -relax -Alter jump instructions for long displacements. - - -@end table -@end ifset - -@menu -* Manual:: Structure of this Manual -* GNU Assembler:: The GNU Assembler -* Object Formats:: Object File Formats -* Command Line:: Command Line -* Input Files:: Input Files -* Object:: Output (Object) File -* Errors:: Error and Warning Messages -@end menu - -@node Manual -@section Structure of this Manual - -@cindex manual, structure and purpose -This manual is intended to describe what you need to know to use -@sc{gnu} @code{@value{AS}}. We cover the syntax expected in source files, including -notation for symbols, constants, and expressions; the directives that -@code{@value{AS}} understands; and of course how to invoke @code{@value{AS}}. - -@ifclear GENERIC -We also cover special features in the @value{TARGET} -configuration of @code{@value{AS}}, including assembler directives. -@end ifclear -@ifset GENERIC -This manual also describes some of the machine-dependent features of -various flavors of the assembler. -@end ifset - -@cindex machine instructions (not covered) -On the other hand, this manual is @emph{not} intended as an introduction -to programming in assembly language---let alone programming in general! -In a similar vein, we make no attempt to introduce the machine -architecture; we do @emph{not} describe the instruction set, standard -mnemonics, registers or addressing modes that are standard to a -particular architecture. -@ifset GENERIC -You may want to consult the manufacturer's -machine architecture manual for this information. -@end ifset -@ifclear GENERIC -@ifset H8/300 -For information on the H8/300 machine instruction set, see @cite{H8/300 -Series Programming Manual} (Hitachi ADE--602--025). For the H8/300H, -see @cite{H8/300H Series Programming Manual} (Hitachi). -@end ifset -@ifset H8/500 -For information on the H8/500 machine instruction set, see @cite{H8/500 -Series Programming Manual} (Hitachi M21T001). -@end ifset -@ifset SH -For information on the Hitachi SH machine instruction set, see -@cite{SH-Microcomputer User's Manual} (Hitachi Micro Systems, Inc.). -@end ifset -@ifset Z8000 -For information on the Z8000 machine instruction set, see @cite{Z8000 CPU Technical Manual} -@end ifset -@end ifclear - -@c I think this is premature---doc@cygnus.com, 17jan1991 -@ignore -Throughout this manual, we assume that you are running @dfn{GNU}, -the portable operating system from the @dfn{Free Software -Foundation, Inc.}. This restricts our attention to certain kinds of -computer (in particular, the kinds of computers that @sc{gnu} can run on); -once this assumption is granted examples and definitions need less -qualification. - -@code{@value{AS}} is part of a team of programs that turn a high-level -human-readable series of instructions into a low-level -computer-readable series of instructions. Different versions of -@code{@value{AS}} are used for different kinds of computer. -@end ignore - -@c There used to be a section "Terminology" here, which defined -@c "contents", "byte", "word", and "long". Defining "word" to any -@c particular size is confusing when the .word directive may generate 16 -@c bits on one machine and 32 bits on another; in general, for the user -@c version of this manual, none of these terms seem essential to define. -@c They were used very little even in the former draft of the manual; -@c this draft makes an effort to avoid them (except in names of -@c directives). - -@node GNU Assembler -@section The GNU Assembler - -@sc{gnu} @code{as} is really a family of assemblers. -@ifclear GENERIC -This manual describes @code{@value{AS}}, a member of that family which is -configured for the @value{TARGET} architectures. -@end ifclear -If you use (or have used) the @sc{gnu} assembler on one architecture, you -should find a fairly similar environment when you use it on another -architecture. Each version has much in common with the others, -including object file formats, most assembler directives (often called -@dfn{pseudo-ops}) and assembler syntax.@refill - -@cindex purpose of @sc{gnu} assembler -@code{@value{AS}} is primarily intended to assemble the output of the -@sc{gnu} C compiler @code{@value{GCC}} for use by the linker -@code{@value{LD}}. Nevertheless, we've tried to make @code{@value{AS}} -assemble correctly everything that other assemblers for the same -machine would assemble. -@ifset VAX -Any exceptions are documented explicitly (@pxref{Machine Dependencies}). -@end ifset -@ifset M680X0 -@c This remark should appear in generic version of manual; assumption -@c here is that generic version sets M680x0. -This doesn't mean @code{@value{AS}} always uses the same syntax as another -assembler for the same architecture; for example, we know of several -incompatible versions of 680x0 assembly language syntax. -@end ifset - -Unlike older assemblers, @code{@value{AS}} is designed to assemble a source -program in one pass of the source file. This has a subtle impact on the -@kbd{.org} directive (@pxref{Org,,@code{.org}}). - -@node Object Formats -@section Object File Formats - -@cindex object file format -The @sc{gnu} assembler can be configured to produce several alternative -object file formats. For the most part, this does not affect how you -write assembly language programs; but directives for debugging symbols -are typically different in different file formats. @xref{Symbol -Attributes,,Symbol Attributes}. -@ifclear GENERIC -@ifclear MULTI-OBJ -On the @value{TARGET}, @code{@value{AS}} is configured to produce -@value{OBJ-NAME} format object files. -@end ifclear -@c The following should exhaust all configs that set MULTI-OBJ, ideally -@ifset A29K -On the @value{TARGET}, @code{@value{AS}} can be configured to produce either -@code{a.out} or COFF format object files. -@end ifset -@ifset I960 -On the @value{TARGET}, @code{@value{AS}} can be configured to produce either -@code{b.out} or COFF format object files. -@end ifset -@ifset HPPA -On the @value{TARGET}, @code{@value{AS}} can be configured to produce either -SOM or ELF format object files. -@end ifset -@end ifclear - -@node Command Line -@section Command Line - -@cindex command line conventions -After the program name @code{@value{AS}}, the command line may contain -options and file names. Options may appear in any order, and may be -before, after, or between file names. The order of file names is -significant. - -@cindex standard input, as input file -@kindex -- -@file{--} (two hyphens) by itself names the standard input file -explicitly, as one of the files for @code{@value{AS}} to assemble. - -@cindex options, command line -Except for @samp{--} any command line argument that begins with a -hyphen (@samp{-}) is an option. Each option changes the behavior of -@code{@value{AS}}. No option changes the way another option works. An -option is a @samp{-} followed by one or more letters; the case of -the letter is important. All options are optional. - -Some options expect exactly one file name to follow them. The file -name may either immediately follow the option's letter (compatible -with older assemblers) or it may be the next command argument (@sc{gnu} -standard). These two command lines are equivalent: - -@smallexample -@value{AS} -o my-object-file.o mumble.s -@value{AS} -omy-object-file.o mumble.s -@end smallexample - -@node Input Files -@section Input Files - -@cindex input -@cindex source program -@cindex files, input -We use the phrase @dfn{source program}, abbreviated @dfn{source}, to -describe the program input to one run of @code{@value{AS}}. The program may -be in one or more files; how the source is partitioned into files -doesn't change the meaning of the source. - -@c I added "con" prefix to "catenation" just to prove I can overcome my -@c APL training... doc@cygnus.com -The source program is a concatenation of the text in all the files, in the -order specified. - -Each time you run @code{@value{AS}} it assembles exactly one source -program. The source program is made up of one or more files. -(The standard input is also a file.) - -You give @code{@value{AS}} a command line that has zero or more input file -names. The input files are read (from left file name to right). A -command line argument (in any position) that has no special meaning -is taken to be an input file name. - -If you give @code{@value{AS}} no file names it attempts to read one input file -from the @code{@value{AS}} standard input, which is normally your terminal. You -may have to type @key{ctl-D} to tell @code{@value{AS}} there is no more program -to assemble. - -Use @samp{--} if you need to explicitly name the standard input file -in your command line. - -If the source is empty, @code{@value{AS}} produces a small, empty object -file. - -@subheading Filenames and Line-numbers - -@cindex input file linenumbers -@cindex line numbers, in input files -There are two ways of locating a line in the input file (or files) and -either may be used in reporting error messages. One way refers to a line -number in a physical file; the other refers to a line number in a -``logical'' file. @xref{Errors, ,Error and Warning Messages}. - -@dfn{Physical files} are those files named in the command line given -to @code{@value{AS}}. - -@dfn{Logical files} are simply names declared explicitly by assembler -directives; they bear no relation to physical files. Logical file names help -error messages reflect the original source file, when @code{@value{AS}} source -is itself synthesized from other files. @code{@value{AS}} understands the -@samp{#} directives emitted by the @code{@value{GCC}} preprocessor. See also -@ref{File,,@code{.file}}. - -@node Object -@section Output (Object) File - -@cindex object file -@cindex output file -@kindex a.out -@kindex .o -Every time you run @code{@value{AS}} it produces an output file, which is -your assembly language program translated into numbers. This file -is the object file. Its default name is -@ifclear BOUT -@code{a.out}. -@end ifclear -@ifset BOUT -@ifset GENERIC -@code{a.out}, or -@end ifset -@code{b.out} when @code{@value{AS}} is configured for the Intel 80960. -@end ifset -You can give it another name by using the @code{-o} option. Conventionally, -object file names end with @file{.o}. The default name is used for historical -reasons: older assemblers were capable of assembling self-contained programs -directly into a runnable program. (For some formats, this isn't currently -possible, but it can be done for the @code{a.out} format.) - -@cindex linker -@kindex ld -The object file is meant for input to the linker @code{@value{LD}}. It contains -assembled program code, information to help @code{@value{LD}} integrate -the assembled program into a runnable file, and (optionally) symbolic -information for the debugger. - -@c link above to some info file(s) like the description of a.out. -@c don't forget to describe @sc{gnu} info as well as Unix lossage. - -@node Errors -@section Error and Warning Messages - -@cindex error messsages -@cindex warning messages -@cindex messages from assembler -@code{@value{AS}} may write warnings and error messages to the standard error -file (usually your terminal). This should not happen when a compiler -runs @code{@value{AS}} automatically. Warnings report an assumption made so -that @code{@value{AS}} could keep assembling a flawed program; errors report a -grave problem that stops the assembly. - -@cindex format of warning messages -Warning messages have the format - -@smallexample -file_name:@b{NNN}:Warning Message Text -@end smallexample - -@noindent -@cindex line numbers, in warnings/errors -(where @b{NNN} is a line number). If a logical file name has been given -(@pxref{File,,@code{.file}}) it is used for the filename, otherwise the name of -the current input file is used. If a logical line number was given -@ifset GENERIC -(@pxref{Line,,@code{.line}}) -@end ifset -@ifclear GENERIC -@ifclear A29K -(@pxref{Line,,@code{.line}}) -@end ifclear -@ifset A29K -(@pxref{Ln,,@code{.ln}}) -@end ifset -@end ifclear -then it is used to calculate the number printed, -otherwise the actual line in the current source file is printed. The -message text is intended to be self explanatory (in the grand Unix -tradition). - -@cindex format of error messages -Error messages have the format -@smallexample -file_name:@b{NNN}:FATAL:Error Message Text -@end smallexample -The file name and line number are derived as for warning -messages. The actual message text may be rather less explanatory -because many of them aren't supposed to happen. - -@node Invoking -@chapter Command-Line Options - -@cindex options, all versions of assembler -This chapter describes command-line options available in @emph{all} -versions of the @sc{gnu} assembler; @pxref{Machine Dependencies}, for options specific -@ifclear GENERIC -to the @value{TARGET}. -@end ifclear -@ifset GENERIC -to particular machine architectures. -@end ifset - -If you are invoking @code{@value{AS}} via the @sc{gnu} C compiler (version 2), -you can use the @samp{-Wa} option to pass arguments through to the assembler. -The assembler arguments must be separated from each other (and the @samp{-Wa}) -by commas. For example: - -@smallexample -gcc -c -g -O -Wa,-alh,-L file.c -@end smallexample - -@noindent -This passes two options to the assembler: @samp{-alh} (emit a listing to -standard output with with high-level and assembly source) and @samp{-L} (retain -local symbols in the symbol table). - -Usually you do not need to use this @samp{-Wa} mechanism, since many compiler -command-line options are automatically passed to the assembler by the compiler. -(You can call the @sc{gnu} compiler driver with the @samp{-v} option to see -precisely what options it passes to each compilation pass, including the -assembler.) - -@menu -* a:: -a[cdhlns] enable listings -* D:: -D for compatibility -* f:: -f to work faster -* I:: -I for .include search path -@ifclear DIFF-TBL-KLUGE -* K:: -K for compatibility -@end ifclear -@ifset DIFF-TBL-KLUGE -* K:: -K for difference tables -@end ifset - -* L:: -L to retain local labels -* M:: -M or --mri to assemble in MRI compatibility mode -* MD:: --MD for dependency tracking -* o:: -o to name the object file -* R:: -R to join data and text sections -* statistics:: --statistics to see statistics about assembly -* traditional-format:: --traditional-format for compatible output -* v:: -v to announce version -* W:: -W, --no-warn, --warn, --fatal-warnings to control warnings -* Z:: -Z to make object file even after errors -@end menu - -@node a -@section Enable Listings: @code{-a[cdhlns]} - -@kindex -a -@kindex -ac -@kindex -ad -@kindex -ah -@kindex -al -@kindex -an -@kindex -as -@cindex listings, enabling -@cindex assembly listings, enabling - -These options enable listing output from the assembler. By itself, -@samp{-a} requests high-level, assembly, and symbols listing. -You can use other letters to select specific options for the list: -@samp{-ah} requests a high-level language listing, -@samp{-al} requests an output-program assembly listing, and -@samp{-as} requests a symbol table listing. -High-level listings require that a compiler debugging option like -@samp{-g} be used, and that assembly listings (@samp{-al}) be requested -also. - -Use the @samp{-ac} option to omit false conditionals from a listing. Any lines -which are not assembled because of a false @code{.if} (or @code{.ifdef}, or any -other conditional), or a true @code{.if} followed by an @code{.else}, will be -omitted from the listing. - -Use the @samp{-ad} option to omit debugging directives from the -listing. - -Once you have specified one of these options, you can further control -listing output and its appearance using the directives @code{.list}, -@code{.nolist}, @code{.psize}, @code{.eject}, @code{.title}, and -@code{.sbttl}. -The @samp{-an} option turns off all forms processing. -If you do not request listing output with one of the @samp{-a} options, the -listing-control directives have no effect. - -The letters after @samp{-a} may be combined into one option, -@emph{e.g.}, @samp{-aln}. - -@node D -@section @code{-D} - -@kindex -D -This option has no effect whatsoever, but it is accepted to make it more -likely that scripts written for other assemblers also work with -@code{@value{AS}}. - -@node f -@section Work Faster: @code{-f} - -@kindex -f -@cindex trusted compiler -@cindex faster processing (@code{-f}) -@samp{-f} should only be used when assembling programs written by a -(trusted) compiler. @samp{-f} stops the assembler from doing whitespace -and comment preprocessing on -the input file(s) before assembling them. @xref{Preprocessing, -,Preprocessing}. - -@quotation -@emph{Warning:} if you use @samp{-f} when the files actually need to be -preprocessed (if they contain comments, for example), @code{@value{AS}} does -not work correctly. -@end quotation - -@node I -@section @code{.include} search path: @code{-I} @var{path} - -@kindex -I @var{path} -@cindex paths for @code{.include} -@cindex search path for @code{.include} -@cindex @code{include} directive search path -Use this option to add a @var{path} to the list of directories -@code{@value{AS}} searches for files specified in @code{.include} -directives (@pxref{Include,,@code{.include}}). You may use @code{-I} as -many times as necessary to include a variety of paths. The current -working directory is always searched first; after that, @code{@value{AS}} -searches any @samp{-I} directories in the same order as they were -specified (left to right) on the command line. - -@node K -@section Difference Tables: @code{-K} - -@kindex -K -@ifclear DIFF-TBL-KLUGE -On the @value{TARGET} family, this option is allowed, but has no effect. It is -permitted for compatibility with the @sc{gnu} assembler on other platforms, -where it can be used to warn when the assembler alters the machine code -generated for @samp{.word} directives in difference tables. The @value{TARGET} -family does not have the addressing limitations that sometimes lead to this -alteration on other platforms. -@end ifclear - -@ifset DIFF-TBL-KLUGE -@cindex difference tables, warning -@cindex warning for altered difference tables -@code{@value{AS}} sometimes alters the code emitted for directives of the form -@samp{.word @var{sym1}-@var{sym2}}; @pxref{Word,,@code{.word}}. -You can use the @samp{-K} option if you want a warning issued when this -is done. -@end ifset - -@node L -@section Include Local Labels: @code{-L} - -@kindex -L -@cindex local labels, retaining in output -Labels beginning with @samp{L} (upper case only) are called @dfn{local -labels}. @xref{Symbol Names}. Normally you do not see such labels when -debugging, because they are intended for the use of programs (like -compilers) that compose assembler programs, not for your notice. -Normally both @code{@value{AS}} and @code{@value{LD}} discard such labels, so you do not -normally debug with them. - -This option tells @code{@value{AS}} to retain those @samp{L@dots{}} symbols -in the object file. Usually if you do this you also tell the linker -@code{@value{LD}} to preserve symbols whose names begin with @samp{L}. - -By default, a local label is any label beginning with @samp{L}, but each -target is allowed to redefine the local label prefix. -@ifset HPPA -On the HPPA local labels begin with @samp{L$}. -@end ifset -@ifset ARM -@samp{;} for the ARM family; -@end ifset - -@node M -@section Assemble in MRI Compatibility Mode: @code{-M} - -@kindex -M -@cindex MRI compatibility mode -The @code{-M} or @code{--mri} option selects MRI compatibility mode. This -changes the syntax and pseudo-op handling of @code{@value{AS}} to make it -compatible with the @code{ASM68K} or the @code{ASM960} (depending upon the -configured target) assembler from Microtec Research. The exact nature of the -MRI syntax will not be documented here; see the MRI manuals for more -information. Note in particular that the handling of macros and macro -arguments is somewhat different. The purpose of this option is to permit -assembling existing MRI assembler code using @code{@value{AS}}. - -The MRI compatibility is not complete. Certain operations of the MRI assembler -depend upon its object file format, and can not be supported using other object -file formats. Supporting these would require enhancing each object file format -individually. These are: - -@itemize @bullet -@item global symbols in common section - -The m68k MRI assembler supports common sections which are merged by the linker. -Other object file formats do not support this. @code{@value{AS}} handles -common sections by treating them as a single common symbol. It permits local -symbols to be defined within a common section, but it can not support global -symbols, since it has no way to describe them. - -@item complex relocations - -The MRI assemblers support relocations against a negated section address, and -relocations which combine the start addresses of two or more sections. These -are not support by other object file formats. - -@item @code{END} pseudo-op specifying start address - -The MRI @code{END} pseudo-op permits the specification of a start address. -This is not supported by other object file formats. The start address may -instead be specified using the @code{-e} option to the linker, or in a linker -script. - -@item @code{IDNT}, @code{.ident} and @code{NAME} pseudo-ops - -The MRI @code{IDNT}, @code{.ident} and @code{NAME} pseudo-ops assign a module -name to the output file. This is not supported by other object file formats. - -@item @code{ORG} pseudo-op - -The m68k MRI @code{ORG} pseudo-op begins an absolute section at a given -address. This differs from the usual @code{@value{AS}} @code{.org} pseudo-op, -which changes the location within the current section. Absolute sections are -not supported by other object file formats. The address of a section may be -assigned within a linker script. -@end itemize - -There are some other features of the MRI assembler which are not supported by -@code{@value{AS}}, typically either because they are difficult or because they -seem of little consequence. Some of these may be supported in future releases. - -@itemize @bullet - -@item EBCDIC strings - -EBCDIC strings are not supported. - -@item packed binary coded decimal - -Packed binary coded decimal is not supported. This means that the @code{DC.P} -and @code{DCB.P} pseudo-ops are not supported. - -@item @code{FEQU} pseudo-op - -The m68k @code{FEQU} pseudo-op is not supported. - -@item @code{NOOBJ} pseudo-op - -The m68k @code{NOOBJ} pseudo-op is not supported. - -@item @code{OPT} branch control options - -The m68k @code{OPT} branch control options---@code{B}, @code{BRS}, @code{BRB}, -@code{BRL}, and @code{BRW}---are ignored. @code{@value{AS}} automatically -relaxes all branches, whether forward or backward, to an appropriate size, so -these options serve no purpose. - -@item @code{OPT} list control options - -The following m68k @code{OPT} list control options are ignored: @code{C}, -@code{CEX}, @code{CL}, @code{CRE}, @code{E}, @code{G}, @code{I}, @code{M}, -@code{MEX}, @code{MC}, @code{MD}, @code{X}. - -@item other @code{OPT} options - -The following m68k @code{OPT} options are ignored: @code{NEST}, @code{O}, -@code{OLD}, @code{OP}, @code{P}, @code{PCO}, @code{PCR}, @code{PCS}, @code{R}. - -@item @code{OPT} @code{D} option is default - -The m68k @code{OPT} @code{D} option is the default, unlike the MRI assembler. -@code{OPT NOD} may be used to turn it off. - -@item @code{XREF} pseudo-op. - -The m68k @code{XREF} pseudo-op is ignored. - -@item @code{.debug} pseudo-op - -The i960 @code{.debug} pseudo-op is not supported. - -@item @code{.extended} pseudo-op - -The i960 @code{.extended} pseudo-op is not supported. - -@item @code{.list} pseudo-op. - -The various options of the i960 @code{.list} pseudo-op are not supported. - -@item @code{.optimize} pseudo-op - -The i960 @code{.optimize} pseudo-op is not supported. - -@item @code{.output} pseudo-op - -The i960 @code{.output} pseudo-op is not supported. - -@item @code{.setreal} pseudo-op - -The i960 @code{.setreal} pseudo-op is not supported. - -@end itemize - -@node MD -@section Dependency tracking: @code{--MD} - -@kindex --MD -@cindex dependency tracking -@cindex make rules - -@code{@value{AS}} can generate a dependency file for the file it creates. This -file consists of a single rule suitable for @code{make} describing the -dependencies of the main source file. - -The rule is written to the file named in its argument. - -This feature is used in the automatic updating of makefiles. - -@node o -@section Name the Object File: @code{-o} - -@kindex -o -@cindex naming object file -@cindex object file name -There is always one object file output when you run @code{@value{AS}}. By -default it has the name -@ifset GENERIC -@ifset I960 -@file{a.out} (or @file{b.out}, for Intel 960 targets only). -@end ifset -@ifclear I960 -@file{a.out}. -@end ifclear -@end ifset -@ifclear GENERIC -@ifset I960 -@file{b.out}. -@end ifset -@ifclear I960 -@file{a.out}. -@end ifclear -@end ifclear -You use this option (which takes exactly one filename) to give the -object file a different name. - -Whatever the object file is called, @code{@value{AS}} overwrites any -existing file of the same name. - -@node R -@section Join Data and Text Sections: @code{-R} - -@kindex -R -@cindex data and text sections, joining -@cindex text and data sections, joining -@cindex joining text and data sections -@cindex merging text and data sections -@code{-R} tells @code{@value{AS}} to write the object file as if all -data-section data lives in the text section. This is only done at -the very last moment: your binary data are the same, but data -section parts are relocated differently. The data section part of -your object file is zero bytes long because all its bytes are -appended to the text section. (@xref{Sections,,Sections and Relocation}.) - -When you specify @code{-R} it would be possible to generate shorter -address displacements (because we do not have to cross between text and -data section). We refrain from doing this simply for compatibility with -older versions of @code{@value{AS}}. In future, @code{-R} may work this way. - -@ifset COFF -When @code{@value{AS}} is configured for COFF output, -this option is only useful if you use sections named @samp{.text} and -@samp{.data}. -@end ifset - -@ifset HPPA -@code{-R} is not supported for any of the HPPA targets. Using -@code{-R} generates a warning from @code{@value{AS}}. -@end ifset - -@node statistics -@section Display Assembly Statistics: @code{--statistics} - -@kindex --statistics -@cindex statistics, about assembly -@cindex time, total for assembly -@cindex space used, maximum for assembly -Use @samp{--statistics} to display two statistics about the resources used by -@code{@value{AS}}: the maximum amount of space allocated during the assembly -(in bytes), and the total execution time taken for the assembly (in @sc{cpu} -seconds). - -@node traditional-format -@section Compatible output: @code{--traditional-format} - -@kindex --traditional-format -For some targets, the output of @code{@value{AS}} is different in some ways -from the output of some existing assembler. This switch requests -@code{@value{AS}} to use the traditional format instead. - -For example, it disables the exception frame optimizations which -@code{@value{AS}} normally does by default on @code{@value{GCC}} output. - -@node v -@section Announce Version: @code{-v} - -@kindex -v -@kindex -version -@cindex assembler version -@cindex version of assembler -You can find out what version of as is running by including the -option @samp{-v} (which you can also spell as @samp{-version}) on the -command line. - -@node W -@section Control Warnings: @code{-W}, @code{--warn}, @code{--no-warn}, @code{--fatal-warnings} - -@code{@value{AS}} should never give a warning or error message when -assembling compiler output. But programs written by people often -cause @code{@value{AS}} to give a warning that a particular assumption was -made. All such warnings are directed to the standard error file. - -@kindex @samp{-W} -@kindex @samp{--no-warn} -@cindex suppressing warnings -@cindex warnings, suppressing -If you use the @code{-W} and @code{--no-warn} options, no warnings are issued. -This only affects the warning messages: it does not change any particular of -how @code{@value{AS}} assembles your file. Errors, which stop the assembly, -are still reported. - -@kindex @samp{--fatal-warnings} -@cindex errors, caused by warnings -@cindex warnings, causing error -If you use the @code{--fatal-warnings} option, @code{@value{AS}} considers -files that generate warnings to be in error. - -@kindex @samp{--warn} -@cindex warnings, switching on -You can switch these options off again by specifying @code{--warn}, which -causes warnings to be output as usual. - -@node Z -@section Generate Object File in Spite of Errors: @code{-Z} -@cindex object file, after errors -@cindex errors, continuing after -After an error message, @code{@value{AS}} normally produces no output. If for -some reason you are interested in object file output even after -@code{@value{AS}} gives an error message on your program, use the @samp{-Z} -option. If there are any errors, @code{@value{AS}} continues anyways, and -writes an object file after a final warning message of the form @samp{@var{n} -errors, @var{m} warnings, generating bad object file.} - -@node Syntax -@chapter Syntax - -@cindex machine-independent syntax -@cindex syntax, machine-independent -This chapter describes the machine-independent syntax allowed in a -source file. @code{@value{AS}} syntax is similar to what many other -assemblers use; it is inspired by the BSD 4.2 -@ifclear VAX -assembler. -@end ifclear -@ifset VAX -assembler, except that @code{@value{AS}} does not assemble Vax bit-fields. -@end ifset - -@menu -* Preprocessing:: Preprocessing -* Whitespace:: Whitespace -* Comments:: Comments -* Symbol Intro:: Symbols -* Statements:: Statements -* Constants:: Constants -@end menu - -@node Preprocessing -@section Preprocessing - -@cindex preprocessing -The @code{@value{AS}} internal preprocessor: -@itemize @bullet -@cindex whitespace, removed by preprocessor -@item -adjusts and removes extra whitespace. It leaves one space or tab before -the keywords on a line, and turns any other whitespace on the line into -a single space. - -@cindex comments, removed by preprocessor -@item -removes all comments, replacing them with a single space, or an -appropriate number of newlines. - -@cindex constants, converted by preprocessor -@item -converts character constants into the appropriate numeric values. -@end itemize - -It does not do macro processing, include file handling, or -anything else you may get from your C compiler's preprocessor. You can -do include file processing with the @code{.include} directive -(@pxref{Include,,@code{.include}}). You can use the @sc{gnu} C compiler driver -to get other ``CPP'' style preprocessing, by giving the input file a -@samp{.S} suffix. @xref{Overall Options,, Options Controlling the Kind of -Output, gcc.info, Using GNU CC}. - -Excess whitespace, comments, and character constants -cannot be used in the portions of the input text that are not -preprocessed. - -@cindex turning preprocessing on and off -@cindex preprocessing, turning on and off -@kindex #NO_APP -@kindex #APP -If the first line of an input file is @code{#NO_APP} or if you use the -@samp{-f} option, whitespace and comments are not removed from the input file. -Within an input file, you can ask for whitespace and comment removal in -specific portions of the by putting a line that says @code{#APP} before the -text that may contain whitespace or comments, and putting a line that says -@code{#NO_APP} after this text. This feature is mainly intend to support -@code{asm} statements in compilers whose output is otherwise free of comments -and whitespace. - -@node Whitespace -@section Whitespace - -@cindex whitespace -@dfn{Whitespace} is one or more blanks or tabs, in any order. -Whitespace is used to separate symbols, and to make programs neater for -people to read. Unless within character constants -(@pxref{Characters,,Character Constants}), any whitespace means the same -as exactly one space. - -@node Comments -@section Comments - -@cindex comments -There are two ways of rendering comments to @code{@value{AS}}. In both -cases the comment is equivalent to one space. - -Anything from @samp{/*} through the next @samp{*/} is a comment. -This means you may not nest these comments. - -@smallexample -/* - The only way to include a newline ('\n') in a comment - is to use this sort of comment. -*/ - -/* This sort of comment does not nest. */ -@end smallexample - -@cindex line comment character -Anything from the @dfn{line comment} character to the next newline -is considered a comment and is ignored. The line comment character is -@ifset A29K -@samp{;} for the AMD 29K family; -@end ifset -@ifset ARC -@samp{;} on the ARC; -@end ifset -@ifset H8/300 -@samp{;} for the H8/300 family; -@end ifset -@ifset H8/500 -@samp{!} for the H8/500 family; -@end ifset -@ifset HPPA -@samp{;} for the HPPA; -@end ifset -@ifset I960 -@samp{#} on the i960; -@end ifset -@ifset PJ -@samp{;} for picoJava; -@end ifset -@ifset SH -@samp{!} for the Hitachi SH; -@end ifset -@ifset SPARC -@samp{!} on the SPARC; -@end ifset -@ifset M32R -@samp{#} on the m32r; -@end ifset -@ifset M680X0 -@samp{|} on the 680x0; -@end ifset -@ifset VAX -@samp{#} on the Vax; -@end ifset -@ifset Z8000 -@samp{!} for the Z8000; -@end ifset -@ifset V850 -@samp{#} on the V850; -@end ifset -see @ref{Machine Dependencies}. @refill -@c FIXME What about i386, m88k, i860? - -@ifset GENERIC -On some machines there are two different line comment characters. One -character only begins a comment if it is the first non-whitespace character on -a line, while the other always begins a comment. -@end ifset - -@ifset V850 -The V850 assembler also supports a double dash as starting a comment that -extends to the end of the line. - -@samp{--}; -@end ifset - -@kindex # -@cindex lines starting with @code{#} -@cindex logical line numbers -To be compatible with past assemblers, lines that begin with @samp{#} have a -special interpretation. Following the @samp{#} should be an absolute -expression (@pxref{Expressions}): the logical line number of the @emph{next} -line. Then a string (@pxref{Strings,, Strings}) is allowed: if present it is a -new logical file name. The rest of the line, if any, should be whitespace. - -If the first non-whitespace characters on the line are not numeric, -the line is ignored. (Just like a comment.) - -@smallexample - # This is an ordinary comment. -# 42-6 "new_file_name" # New logical file name - # This is logical line # 36. -@end smallexample -This feature is deprecated, and may disappear from future versions -of @code{@value{AS}}. - -@node Symbol Intro -@section Symbols - -@cindex characters used in symbols -@ifclear SPECIAL-SYMS -A @dfn{symbol} is one or more characters chosen from the set of all -letters (both upper and lower case), digits and the three characters -@samp{_.$}. -@end ifclear -@ifset SPECIAL-SYMS -@ifclear GENERIC -@ifset H8 -A @dfn{symbol} is one or more characters chosen from the set of all -letters (both upper and lower case), digits and the three characters -@samp{._$}. (Save that, on the H8/300 only, you may not use @samp{$} in -symbol names.) -@end ifset -@end ifclear -@end ifset -@ifset GENERIC -On most machines, you can also use @code{$} in symbol names; exceptions -are noted in @ref{Machine Dependencies}. -@end ifset -No symbol may begin with a digit. Case is significant. -There is no length limit: all characters are significant. Symbols are -delimited by characters not in that set, or by the beginning of a file -(since the source program must end with a newline, the end of a file is -not a possible symbol delimiter). @xref{Symbols}. -@cindex length of symbols - -@node Statements -@section Statements - -@cindex statements, structure of -@cindex line separator character -@cindex statement separator character -@ifclear GENERIC -@ifclear abnormal-separator -A @dfn{statement} ends at a newline character (@samp{\n}) or at a -semicolon (@samp{;}). The newline or semicolon is considered part of -the preceding statement. Newlines and semicolons within character -constants are an exception: they do not end statements. -@end ifclear -@ifset abnormal-separator -@ifset A29K -A @dfn{statement} ends at a newline character (@samp{\n}) or an ``at'' -sign (@samp{@@}). The newline or at sign is considered part of the -preceding statement. Newlines and at signs within character constants -are an exception: they do not end statements. -@end ifset -@ifset HPPA -A @dfn{statement} ends at a newline character (@samp{\n}) or an exclamation -point (@samp{!}). The newline or exclamation point is considered part of the -preceding statement. Newlines and exclamation points within character -constants are an exception: they do not end statements. -@end ifset -@ifset H8 -A @dfn{statement} ends at a newline character (@samp{\n}); or (for the -H8/300) a dollar sign (@samp{$}); or (for the -Hitachi-SH or the -H8/500) a semicolon -(@samp{;}). The newline or separator character is considered part of -the preceding statement. Newlines and separators within character -constants are an exception: they do not end statements. -@end ifset -@end ifset -@end ifclear -@ifset GENERIC -A @dfn{statement} ends at a newline character (@samp{\n}) or line -separator character. (The line separator is usually @samp{;}, unless -this conflicts with the comment character; @pxref{Machine Dependencies}.) The -newline or separator character is considered part of the preceding -statement. Newlines and separators within character constants are an -exception: they do not end statements. -@end ifset - -@cindex newline, required at file end -@cindex EOF, newline must precede -It is an error to end any statement with end-of-file: the last -character of any input file should be a newline.@refill - -An empty statement is allowed, and may include whitespace. It is ignored. - -@cindex instructions and directives -@cindex directives and instructions -@c "key symbol" is not used elsewhere in the document; seems pedantic to -@c @defn{} it in that case, as was done previously... doc@cygnus.com, -@c 13feb91. -A statement begins with zero or more labels, optionally followed by a -key symbol which determines what kind of statement it is. The key -symbol determines the syntax of the rest of the statement. If the -symbol begins with a dot @samp{.} then the statement is an assembler -directive: typically valid for any computer. If the symbol begins with -a letter the statement is an assembly language @dfn{instruction}: it -assembles into a machine language instruction. -@ifset GENERIC -Different versions of @code{@value{AS}} for different computers -recognize different instructions. In fact, the same symbol may -represent a different instruction in a different computer's assembly -language.@refill -@end ifset - -@cindex @code{:} (label) -@cindex label (@code{:}) -A label is a symbol immediately followed by a colon (@code{:}). -Whitespace before a label or after a colon is permitted, but you may not -have whitespace between a label's symbol and its colon. @xref{Labels}. - -@ifset HPPA -For HPPA targets, labels need not be immediately followed by a colon, but -the definition of a label must begin in column zero. This also implies that -only one label may be defined on each line. -@end ifset - -@smallexample -label: .directive followed by something -another_label: # This is an empty statement. - instruction operand_1, operand_2, @dots{} -@end smallexample - -@node Constants -@section Constants - -@cindex constants -A constant is a number, written so that its value is known by -inspection, without knowing any context. Like this: -@smallexample -@group -.byte 74, 0112, 092, 0x4A, 0X4a, 'J, '\J # All the same value. -.ascii "Ring the bell\7" # A string constant. -.octa 0x123456789abcdef0123456789ABCDEF0 # A bignum. -.float 0f-314159265358979323846264338327\ -95028841971.693993751E-40 # - pi, a flonum. -@end group -@end smallexample - -@menu -* Characters:: Character Constants -* Numbers:: Number Constants -@end menu - -@node Characters -@subsection Character Constants - -@cindex character constants -@cindex constants, character -There are two kinds of character constants. A @dfn{character} stands -for one character in one byte and its value may be used in -numeric expressions. String constants (properly called string -@emph{literals}) are potentially many bytes and their values may not be -used in arithmetic expressions. - -@menu -* Strings:: Strings -* Chars:: Characters -@end menu - -@node Strings -@subsubsection Strings - -@cindex string constants -@cindex constants, string -A @dfn{string} is written between double-quotes. It may contain -double-quotes or null characters. The way to get special characters -into a string is to @dfn{escape} these characters: precede them with -a backslash @samp{\} character. For example @samp{\\} represents -one backslash: the first @code{\} is an escape which tells -@code{@value{AS}} to interpret the second character literally as a backslash -(which prevents @code{@value{AS}} from recognizing the second @code{\} as an -escape character). The complete list of escapes follows. - -@cindex escape codes, character -@cindex character escape codes -@table @kbd -@c @item \a -@c Mnemonic for ACKnowledge; for ASCII this is octal code 007. -@c -@cindex @code{\b} (backspace character) -@cindex backspace (@code{\b}) -@item \b -Mnemonic for backspace; for ASCII this is octal code 010. - -@c @item \e -@c Mnemonic for EOText; for ASCII this is octal code 004. -@c -@cindex @code{\f} (formfeed character) -@cindex formfeed (@code{\f}) -@item \f -Mnemonic for FormFeed; for ASCII this is octal code 014. - -@cindex @code{\n} (newline character) -@cindex newline (@code{\n}) -@item \n -Mnemonic for newline; for ASCII this is octal code 012. - -@c @item \p -@c Mnemonic for prefix; for ASCII this is octal code 033, usually known as @code{escape}. -@c -@cindex @code{\r} (carriage return character) -@cindex carriage return (@code{\r}) -@item \r -Mnemonic for carriage-Return; for ASCII this is octal code 015. - -@c @item \s -@c Mnemonic for space; for ASCII this is octal code 040. Included for compliance with -@c other assemblers. -@c -@cindex @code{\t} (tab) -@cindex tab (@code{\t}) -@item \t -Mnemonic for horizontal Tab; for ASCII this is octal code 011. - -@c @item \v -@c Mnemonic for Vertical tab; for ASCII this is octal code 013. -@c @item \x @var{digit} @var{digit} @var{digit} -@c A hexadecimal character code. The numeric code is 3 hexadecimal digits. -@c -@cindex @code{\@var{ddd}} (octal character code) -@cindex octal character code (@code{\@var{ddd}}) -@item \ @var{digit} @var{digit} @var{digit} -An octal character code. The numeric code is 3 octal digits. -For compatibility with other Unix systems, 8 and 9 are accepted as digits: -for example, @code{\008} has the value 010, and @code{\009} the value 011. - -@cindex @code{\@var{xd...}} (hex character code) -@cindex hex character code (@code{\@var{xd...}}) -@item \@code{x} @var{hex-digits...} -A hex character code. All trailing hex digits are combined. Either upper or -lower case @code{x} works. - -@cindex @code{\\} (@samp{\} character) -@cindex backslash (@code{\\}) -@item \\ -Represents one @samp{\} character. - -@c @item \' -@c Represents one @samp{'} (accent acute) character. -@c This is needed in single character literals -@c (@xref{Characters,,Character Constants}.) to represent -@c a @samp{'}. -@c -@cindex @code{\"} (doublequote character) -@cindex doublequote (@code{\"}) -@item \" -Represents one @samp{"} character. Needed in strings to represent -this character, because an unescaped @samp{"} would end the string. - -@item \ @var{anything-else} -Any other character when escaped by @kbd{\} gives a warning, but -assembles as if the @samp{\} was not present. The idea is that if -you used an escape sequence you clearly didn't want the literal -interpretation of the following character. However @code{@value{AS}} has no -other interpretation, so @code{@value{AS}} knows it is giving you the wrong -code and warns you of the fact. -@end table - -Which characters are escapable, and what those escapes represent, -varies widely among assemblers. The current set is what we think -the BSD 4.2 assembler recognizes, and is a subset of what most C -compilers recognize. If you are in doubt, do not use an escape -sequence. - -@node Chars -@subsubsection Characters - -@cindex single character constant -@cindex character, single -@cindex constant, single character -A single character may be written as a single quote immediately -followed by that character. The same escapes apply to characters as -to strings. So if you want to write the character backslash, you -must write @kbd{'\\} where the first @code{\} escapes the second -@code{\}. As you can see, the quote is an acute accent, not a -grave accent. A newline -@ifclear GENERIC -@ifclear abnormal-separator -(or semicolon @samp{;}) -@end ifclear -@ifset abnormal-separator -@ifset A29K -(or at sign @samp{@@}) -@end ifset -@ifset H8 -(or dollar sign @samp{$}, for the H8/300; or semicolon @samp{;} for the -Hitachi SH or -H8/500) -@end ifset -@end ifset -@end ifclear -immediately following an acute accent is taken as a literal character -and does not count as the end of a statement. The value of a character -constant in a numeric expression is the machine's byte-wide code for -that character. @code{@value{AS}} assumes your character code is ASCII: -@kbd{'A} means 65, @kbd{'B} means 66, and so on. @refill - -@node Numbers -@subsection Number Constants - -@cindex constants, number -@cindex number constants -@code{@value{AS}} distinguishes three kinds of numbers according to how they -are stored in the target machine. @emph{Integers} are numbers that -would fit into an @code{int} in the C language. @emph{Bignums} are -integers, but they are stored in more than 32 bits. @emph{Flonums} -are floating point numbers, described below. - -@menu -* Integers:: Integers -* Bignums:: Bignums -* Flonums:: Flonums -@ifclear GENERIC -@ifset I960 -* Bit Fields:: Bit Fields -@end ifset -@end ifclear -@end menu - -@node Integers -@subsubsection Integers -@cindex integers -@cindex constants, integer - -@cindex binary integers -@cindex integers, binary -A binary integer is @samp{0b} or @samp{0B} followed by zero or more of -the binary digits @samp{01}. - -@cindex octal integers -@cindex integers, octal -An octal integer is @samp{0} followed by zero or more of the octal -digits (@samp{01234567}). - -@cindex decimal integers -@cindex integers, decimal -A decimal integer starts with a non-zero digit followed by zero or -more digits (@samp{0123456789}). - -@cindex hexadecimal integers -@cindex integers, hexadecimal -A hexadecimal integer is @samp{0x} or @samp{0X} followed by one or -more hexadecimal digits chosen from @samp{0123456789abcdefABCDEF}. - -Integers have the usual values. To denote a negative integer, use -the prefix operator @samp{-} discussed under expressions -(@pxref{Prefix Ops,,Prefix Operators}). - -@node Bignums -@subsubsection Bignums - -@cindex bignums -@cindex constants, bignum -A @dfn{bignum} has the same syntax and semantics as an integer -except that the number (or its negative) takes more than 32 bits to -represent in binary. The distinction is made because in some places -integers are permitted while bignums are not. - -@node Flonums -@subsubsection Flonums -@cindex flonums -@cindex floating point numbers -@cindex constants, floating point - -@cindex precision, floating point -A @dfn{flonum} represents a floating point number. The translation is -indirect: a decimal floating point number from the text is converted by -@code{@value{AS}} to a generic binary floating point number of more than -sufficient precision. This generic floating point number is converted -to a particular computer's floating point format (or formats) by a -portion of @code{@value{AS}} specialized to that computer. - -A flonum is written by writing (in order) -@itemize @bullet -@item -The digit @samp{0}. -@ifset HPPA -(@samp{0} is optional on the HPPA.) -@end ifset - -@item -A letter, to tell @code{@value{AS}} the rest of the number is a flonum. -@ifset GENERIC -@kbd{e} is recommended. Case is not important. -@ignore -@c FIXME: verify if flonum syntax really this vague for most cases -(Any otherwise illegal letter works here, but that might be changed. Vax BSD -4.2 assembler seems to allow any of @samp{defghDEFGH}.) -@end ignore - -On the H8/300, H8/500, -Hitachi SH, -and AMD 29K architectures, the letter must be -one of the letters @samp{DFPRSX} (in upper or lower case). - -On the ARC, the letter must be one of the letters @samp{DFRS} -(in upper or lower case). - -On the Intel 960 architecture, the letter must be -one of the letters @samp{DFT} (in upper or lower case). - -On the HPPA architecture, the letter must be @samp{E} (upper case only). -@end ifset -@ifclear GENERIC -@ifset A29K -One of the letters @samp{DFPRSX} (in upper or lower case). -@end ifset -@ifset ARC -One of the letters @samp{DFRS} (in upper or lower case). -@end ifset -@ifset H8 -One of the letters @samp{DFPRSX} (in upper or lower case). -@end ifset -@ifset HPPA -The letter @samp{E} (upper case only). -@end ifset -@ifset I960 -One of the letters @samp{DFT} (in upper or lower case). -@end ifset -@end ifclear - -@item -An optional sign: either @samp{+} or @samp{-}. - -@item -An optional @dfn{integer part}: zero or more decimal digits. - -@item -An optional @dfn{fractional part}: @samp{.} followed by zero -or more decimal digits. - -@item -An optional exponent, consisting of: - -@itemize @bullet -@item -An @samp{E} or @samp{e}. -@c I can't find a config where "EXP_CHARS" is other than 'eE', but in -@c principle this can perfectly well be different on different targets. -@item -Optional sign: either @samp{+} or @samp{-}. -@item -One or more decimal digits. -@end itemize - -@end itemize - -At least one of the integer part or the fractional part must be -present. The floating point number has the usual base-10 value. - -@code{@value{AS}} does all processing using integers. Flonums are computed -independently of any floating point hardware in the computer running -@code{@value{AS}}. - -@ifclear GENERIC -@ifset I960 -@c Bit fields are written as a general facility but are also controlled -@c by a conditional-compilation flag---which is as of now (21mar91) -@c turned on only by the i960 config of GAS. -@node Bit Fields -@subsubsection Bit Fields - -@cindex bit fields -@cindex constants, bit field -You can also define numeric constants as @dfn{bit fields}. -specify two numbers separated by a colon--- -@example -@var{mask}:@var{value} -@end example -@noindent -@code{@value{AS}} applies a bitwise @sc{and} between @var{mask} and -@var{value}. - -The resulting number is then packed -@ifset GENERIC -@c this conditional paren in case bit fields turned on elsewhere than 960 -(in host-dependent byte order) -@end ifset -into a field whose width depends on which assembler directive has the -bit-field as its argument. Overflow (a result from the bitwise and -requiring more binary digits to represent) is not an error; instead, -more constants are generated, of the specified width, beginning with the -least significant digits.@refill - -The directives @code{.byte}, @code{.hword}, @code{.int}, @code{.long}, -@code{.short}, and @code{.word} accept bit-field arguments. -@end ifset -@end ifclear - -@node Sections -@chapter Sections and Relocation -@cindex sections -@cindex relocation - -@menu -* Secs Background:: Background -* Ld Sections:: Linker Sections -* As Sections:: Assembler Internal Sections -* Sub-Sections:: Sub-Sections -* bss:: bss Section -@end menu - -@node Secs Background -@section Background - -Roughly, a section is a range of addresses, with no gaps; all data -``in'' those addresses is treated the same for some particular purpose. -For example there may be a ``read only'' section. - -@cindex linker, and assembler -@cindex assembler, and linker -The linker @code{@value{LD}} reads many object files (partial programs) and -combines their contents to form a runnable program. When @code{@value{AS}} -emits an object file, the partial program is assumed to start at address 0. -@code{@value{LD}} assigns the final addresses for the partial program, so that -different partial programs do not overlap. This is actually an -oversimplification, but it suffices to explain how @code{@value{AS}} uses -sections. - -@code{@value{LD}} moves blocks of bytes of your program to their run-time -addresses. These blocks slide to their run-time addresses as rigid -units; their length does not change and neither does the order of bytes -within them. Such a rigid unit is called a @emph{section}. Assigning -run-time addresses to sections is called @dfn{relocation}. It includes -the task of adjusting mentions of object-file addresses so they refer to -the proper run-time addresses. -@ifset H8 -For the H8/300 and H8/500, -and for the Hitachi SH, -@code{@value{AS}} pads sections if needed to -ensure they end on a word (sixteen bit) boundary. -@end ifset - -@cindex standard assembler sections -An object file written by @code{@value{AS}} has at least three sections, any -of which may be empty. These are named @dfn{text}, @dfn{data} and -@dfn{bss} sections. - -@ifset COFF -@ifset GENERIC -When it generates COFF output, -@end ifset -@code{@value{AS}} can also generate whatever other named sections you specify -using the @samp{.section} directive (@pxref{Section,,@code{.section}}). -If you do not use any directives that place output in the @samp{.text} -or @samp{.data} sections, these sections still exist, but are empty. -@end ifset - -@ifset HPPA -@ifset GENERIC -When @code{@value{AS}} generates SOM or ELF output for the HPPA, -@end ifset -@code{@value{AS}} can also generate whatever other named sections you -specify using the @samp{.space} and @samp{.subspace} directives. See -@cite{HP9000 Series 800 Assembly Language Reference Manual} -(HP 92432-90001) for details on the @samp{.space} and @samp{.subspace} -assembler directives. - -@ifset SOM -Additionally, @code{@value{AS}} uses different names for the standard -text, data, and bss sections when generating SOM output. Program text -is placed into the @samp{$CODE$} section, data into @samp{$DATA$}, and -BSS into @samp{$BSS$}. -@end ifset -@end ifset - -Within the object file, the text section starts at address @code{0}, the -data section follows, and the bss section follows the data section. - -@ifset HPPA -When generating either SOM or ELF output files on the HPPA, the text -section starts at address @code{0}, the data section at address -@code{0x4000000}, and the bss section follows the data section. -@end ifset - -To let @code{@value{LD}} know which data changes when the sections are -relocated, and how to change that data, @code{@value{AS}} also writes to the -object file details of the relocation needed. To perform relocation -@code{@value{LD}} must know, each time an address in the object -file is mentioned: -@itemize @bullet -@item -Where in the object file is the beginning of this reference to -an address? -@item -How long (in bytes) is this reference? -@item -Which section does the address refer to? What is the numeric value of -@display -(@var{address}) @minus{} (@var{start-address of section})? -@end display -@item -Is the reference to an address ``Program-Counter relative''? -@end itemize - -@cindex addresses, format of -@cindex section-relative addressing -In fact, every address @code{@value{AS}} ever uses is expressed as -@display -(@var{section}) + (@var{offset into section}) -@end display -@noindent -Further, most expressions @code{@value{AS}} computes have this section-relative -nature. -@ifset SOM -(For some object formats, such as SOM for the HPPA, some expressions are -symbol-relative instead.) -@end ifset - -In this manual we use the notation @{@var{secname} @var{N}@} to mean ``offset -@var{N} into section @var{secname}.'' - -Apart from text, data and bss sections you need to know about the -@dfn{absolute} section. When @code{@value{LD}} mixes partial programs, -addresses in the absolute section remain unchanged. For example, address -@code{@{absolute 0@}} is ``relocated'' to run-time address 0 by -@code{@value{LD}}. Although the linker never arranges two partial programs' -data sections with overlapping addresses after linking, @emph{by definition} -their absolute sections must overlap. Address @code{@{absolute@ 239@}} in one -part of a program is always the same address when the program is running as -address @code{@{absolute@ 239@}} in any other part of the program. - -The idea of sections is extended to the @dfn{undefined} section. Any -address whose section is unknown at assembly time is by definition -rendered @{undefined @var{U}@}---where @var{U} is filled in later. -Since numbers are always defined, the only way to generate an undefined -address is to mention an undefined symbol. A reference to a named -common block would be such a symbol: its value is unknown at assembly -time so it has section @emph{undefined}. - -By analogy the word @emph{section} is used to describe groups of sections in -the linked program. @code{@value{LD}} puts all partial programs' text -sections in contiguous addresses in the linked program. It is -customary to refer to the @emph{text section} of a program, meaning all -the addresses of all partial programs' text sections. Likewise for -data and bss sections. - -Some sections are manipulated by @code{@value{LD}}; others are invented for -use of @code{@value{AS}} and have no meaning except during assembly. - -@node Ld Sections -@section Linker Sections -@code{@value{LD}} deals with just four kinds of sections, summarized below. - -@table @strong - -@ifset COFF -@cindex named sections -@cindex sections, named -@item named sections -@end ifset -@ifset aout-bout -@cindex text section -@cindex data section -@itemx text section -@itemx data section -@end ifset -These sections hold your program. @code{@value{AS}} and @code{@value{LD}} treat them as -separate but equal sections. Anything you can say of one section is -true another. -@ifset aout-bout -When the program is running, however, it is -customary for the text section to be unalterable. The -text section is often shared among processes: it contains -instructions, constants and the like. The data section of a running -program is usually alterable: for example, C variables would be stored -in the data section. -@end ifset - -@cindex bss section -@item bss section -This section contains zeroed bytes when your program begins running. It -is used to hold unitialized variables or common storage. The length of -each partial program's bss section is important, but because it starts -out containing zeroed bytes there is no need to store explicit zero -bytes in the object file. The bss section was invented to eliminate -those explicit zeros from object files. - -@cindex absolute section -@item absolute section -Address 0 of this section is always ``relocated'' to runtime address 0. -This is useful if you want to refer to an address that @code{@value{LD}} must -not change when relocating. In this sense we speak of absolute -addresses being ``unrelocatable'': they do not change during relocation. - -@cindex undefined section -@item undefined section -This ``section'' is a catch-all for address references to objects not in -the preceding sections. -@c FIXME: ref to some other doc on obj-file formats could go here. -@end table - -@cindex relocation example -An idealized example of three relocatable sections follows. -@ifset COFF -The example uses the traditional section names @samp{.text} and @samp{.data}. -@end ifset -Memory addresses are on the horizontal axis. - -@c TEXI2ROFF-KILL -@ifinfo -@c END TEXI2ROFF-KILL -@smallexample - +-----+----+--+ -partial program # 1: |ttttt|dddd|00| - +-----+----+--+ - - text data bss - seg. seg. seg. - - +---+---+---+ -partial program # 2: |TTT|DDD|000| - +---+---+---+ - - +--+---+-----+--+----+---+-----+~~ -linked program: | |TTT|ttttt| |dddd|DDD|00000| - +--+---+-----+--+----+---+-----+~~ - - addresses: 0 @dots{} -@end smallexample -@c TEXI2ROFF-KILL -@end ifinfo -@need 5000 -@tex - -\line{\it Partial program \#1: \hfil} -\line{\ibox{2.5cm}{\tt text}\ibox{2cm}{\tt data}\ibox{1cm}{\tt bss}\hfil} -\line{\boxit{2.5cm}{\tt ttttt}\boxit{2cm}{\tt dddd}\boxit{1cm}{\tt 00}\hfil} - -\line{\it Partial program \#2: \hfil} -\line{\ibox{1cm}{\tt text}\ibox{1.5cm}{\tt data}\ibox{1cm}{\tt bss}\hfil} -\line{\boxit{1cm}{\tt TTT}\boxit{1.5cm}{\tt DDDD}\boxit{1cm}{\tt 000}\hfil} - -\line{\it linked program: \hfil} -\line{\ibox{.5cm}{}\ibox{1cm}{\tt text}\ibox{2.5cm}{}\ibox{.75cm}{}\ibox{2cm}{\tt data}\ibox{1.5cm}{}\ibox{2cm}{\tt bss}\hfil} -\line{\boxit{.5cm}{}\boxit{1cm}{\tt TTT}\boxit{2.5cm}{\tt -ttttt}\boxit{.75cm}{}\boxit{2cm}{\tt dddd}\boxit{1.5cm}{\tt -DDDD}\boxit{2cm}{\tt 00000}\ \dots\hfil} - -\line{\it addresses: \hfil} -\line{0\dots\hfil} - -@end tex -@c END TEXI2ROFF-KILL - -@node As Sections -@section Assembler Internal Sections - -@cindex internal assembler sections -@cindex sections in messages, internal -These sections are meant only for the internal use of @code{@value{AS}}. They -have no meaning at run-time. You do not really need to know about these -sections for most purposes; but they can be mentioned in @code{@value{AS}} -warning messages, so it might be helpful to have an idea of their -meanings to @code{@value{AS}}. These sections are used to permit the -value of every expression in your assembly language program to be a -section-relative address. - -@table @b -@cindex assembler internal logic error -@item ASSEMBLER-INTERNAL-LOGIC-ERROR! -An internal assembler logic error has been found. This means there is a -bug in the assembler. - -@cindex expr (internal section) -@item expr section -The assembler stores complex expression internally as combinations of -symbols. When it needs to represent an expression as a symbol, it puts -it in the expr section. -@c FIXME item debug -@c FIXME item transfer[t] vector preload -@c FIXME item transfer[t] vector postload -@c FIXME item register -@end table - -@node Sub-Sections -@section Sub-Sections - -@cindex numbered subsections -@cindex grouping data -@ifset aout-bout -Assembled bytes -@ifset COFF -conventionally -@end ifset -fall into two sections: text and data. -@end ifset -You may have separate groups of -@ifset GENERIC -data in named sections -@end ifset -@ifclear GENERIC -@ifclear aout-bout -data in named sections -@end ifclear -@ifset aout-bout -text or data -@end ifset -@end ifclear -that you want to end up near to each other in the object file, even though they -are not contiguous in the assembler source. @code{@value{AS}} allows you to -use @dfn{subsections} for this purpose. Within each section, there can be -numbered subsections with values from 0 to 8192. Objects assembled into the -same subsection go into the object file together with other objects in the same -subsection. For example, a compiler might want to store constants in the text -section, but might not want to have them interspersed with the program being -assembled. In this case, the compiler could issue a @samp{.text 0} before each -section of code being output, and a @samp{.text 1} before each group of -constants being output. - -Subsections are optional. If you do not use subsections, everything -goes in subsection number zero. - -@ifset GENERIC -Each subsection is zero-padded up to a multiple of four bytes. -(Subsections may be padded a different amount on different flavors -of @code{@value{AS}}.) -@end ifset -@ifclear GENERIC -@ifset H8 -On the H8/300 and H8/500 platforms, each subsection is zero-padded to a word -boundary (two bytes). -The same is true on the Hitachi SH. -@end ifset -@ifset I960 -@c FIXME section padding (alignment)? -@c Rich Pixley says padding here depends on target obj code format; that -@c doesn't seem particularly useful to say without further elaboration, -@c so for now I say nothing about it. If this is a generic BFD issue, -@c these paragraphs might need to vanish from this manual, and be -@c discussed in BFD chapter of binutils (or some such). -@end ifset -@ifset A29K -On the AMD 29K family, no particular padding is added to section or -subsection sizes; @value{AS} forces no alignment on this platform. -@end ifset -@end ifclear - -Subsections appear in your object file in numeric order, lowest numbered -to highest. (All this to be compatible with other people's assemblers.) -The object file contains no representation of subsections; @code{@value{LD}} and -other programs that manipulate object files see no trace of them. -They just see all your text subsections as a text section, and all your -data subsections as a data section. - -To specify which subsection you want subsequent statements assembled -into, use a numeric argument to specify it, in a @samp{.text -@var{expression}} or a @samp{.data @var{expression}} statement. -@ifset COFF -@ifset GENERIC -When generating COFF output, you -@end ifset -@ifclear GENERIC -You -@end ifclear -can also use an extra subsection -argument with arbitrary named sections: @samp{.section @var{name}, -@var{expression}}. -@end ifset -@var{Expression} should be an absolute expression. -(@xref{Expressions}.) If you just say @samp{.text} then @samp{.text 0} -is assumed. Likewise @samp{.data} means @samp{.data 0}. Assembly -begins in @code{text 0}. For instance: -@smallexample -.text 0 # The default subsection is text 0 anyway. -.ascii "This lives in the first text subsection. *" -.text 1 -.ascii "But this lives in the second text subsection." -.data 0 -.ascii "This lives in the data section," -.ascii "in the first data subsection." -.text 0 -.ascii "This lives in the first text section," -.ascii "immediately following the asterisk (*)." -@end smallexample - -Each section has a @dfn{location counter} incremented by one for every byte -assembled into that section. Because subsections are merely a convenience -restricted to @code{@value{AS}} there is no concept of a subsection location -counter. There is no way to directly manipulate a location counter---but the -@code{.align} directive changes it, and any label definition captures its -current value. The location counter of the section where statements are being -assembled is said to be the @dfn{active} location counter. - -@node bss -@section bss Section - -@cindex bss section -@cindex common variable storage -The bss section is used for local common variable storage. -You may allocate address space in the bss section, but you may -not dictate data to load into it before your program executes. When -your program starts running, all the contents of the bss -section are zeroed bytes. - -The @code{.lcomm} pseudo-op defines a symbol in the bss section; see -@ref{Lcomm,,@code{.lcomm}}. - -The @code{.comm} pseudo-op may be used to declare a common symbol, which is -another form of uninitialized symbol; see @xref{Comm,,@code{.comm}}. - -@ifset GENERIC -When assembling for a target which supports multiple sections, such as ELF or -COFF, you may switch into the @code{.bss} section and define symbols as usual; -see @ref{Section,,@code{.section}}. You may only assemble zero values into the -section. Typically the section will only contain symbol definitions and -@code{.skip} directives (@pxref{Skip,,@code{.skip}}). -@end ifset - -@node Symbols -@chapter Symbols - -@cindex symbols -Symbols are a central concept: the programmer uses symbols to name -things, the linker uses symbols to link, and the debugger uses symbols -to debug. - -@quotation -@cindex debuggers, and symbol order -@emph{Warning:} @code{@value{AS}} does not place symbols in the object file in -the same order they were declared. This may break some debuggers. -@end quotation - -@menu -* Labels:: Labels -* Setting Symbols:: Giving Symbols Other Values -* Symbol Names:: Symbol Names -* Dot:: The Special Dot Symbol -* Symbol Attributes:: Symbol Attributes -@end menu - -@node Labels -@section Labels - -@cindex labels -A @dfn{label} is written as a symbol immediately followed by a colon -@samp{:}. The symbol then represents the current value of the -active location counter, and is, for example, a suitable instruction -operand. You are warned if you use the same symbol to represent two -different locations: the first definition overrides any other -definitions. - -@ifset HPPA -On the HPPA, the usual form for a label need not be immediately followed by a -colon, but instead must start in column zero. Only one label may be defined on -a single line. To work around this, the HPPA version of @code{@value{AS}} also -provides a special directive @code{.label} for defining labels more flexibly. -@end ifset - -@node Setting Symbols -@section Giving Symbols Other Values - -@cindex assigning values to symbols -@cindex symbol values, assigning -A symbol can be given an arbitrary value by writing a symbol, followed -by an equals sign @samp{=}, followed by an expression -(@pxref{Expressions}). This is equivalent to using the @code{.set} -directive. @xref{Set,,@code{.set}}. - -@node Symbol Names -@section Symbol Names - -@cindex symbol names -@cindex names, symbol -@ifclear SPECIAL-SYMS -Symbol names begin with a letter or with one of @samp{._}. On most -machines, you can also use @code{$} in symbol names; exceptions are -noted in @ref{Machine Dependencies}. That character may be followed by any -string of digits, letters, dollar signs (unless otherwise noted in -@ref{Machine Dependencies}), and underscores. -@end ifclear -@ifset A29K -For the AMD 29K family, @samp{?} is also allowed in the -body of a symbol name, though not at its beginning. -@end ifset - -@ifset SPECIAL-SYMS -@ifset H8 -Symbol names begin with a letter or with one of @samp{._}. On the -Hitachi SH or the -H8/500, you can also use @code{$} in symbol names. That character may -be followed by any string of digits, letters, dollar signs (save on the -H8/300), and underscores. -@end ifset -@end ifset - -Case of letters is significant: @code{foo} is a different symbol name -than @code{Foo}. - -Each symbol has exactly one name. Each name in an assembly language program -refers to exactly one symbol. You may use that symbol name any number of times -in a program. - -@subheading Local Symbol Names - -@cindex local symbol names -@cindex symbol names, local -@cindex temporary symbol names -@cindex symbol names, temporary -Local symbols help compilers and programmers use names temporarily. -There are ten local symbol names, which are re-used throughout the -program. You may refer to them using the names @samp{0} @samp{1} -@dots{} @samp{9}. To define a local symbol, write a label of the form -@samp{@b{N}:} (where @b{N} represents any digit). To refer to the most -recent previous definition of that symbol write @samp{@b{N}b}, using the -same digit as when you defined the label. To refer to the next -definition of a local label, write @samp{@b{N}f}---where @b{N} gives you -a choice of 10 forward references. The @samp{b} stands for -``backwards'' and the @samp{f} stands for ``forwards''. - -Local symbols are not emitted by the current @sc{gnu} C compiler. - -There is no restriction on how you can use these labels, but -remember that at any point in the assembly you can refer to at most -10 prior local labels and to at most 10 forward local labels. - -Local symbol names are only a notation device. They are immediately -transformed into more conventional symbol names before the assembler -uses them. The symbol names stored in the symbol table, appearing in -error messages and optionally emitted to the object file have these -parts: - -@table @code -@item L -All local labels begin with @samp{L}. Normally both @code{@value{AS}} and -@code{@value{LD}} forget symbols that start with @samp{L}. These labels are -used for symbols you are never intended to see. If you use the -@samp{-L} option then @code{@value{AS}} retains these symbols in the -object file. If you also instruct @code{@value{LD}} to retain these symbols, -you may use them in debugging. - -@item @var{digit} -If the label is written @samp{0:} then the digit is @samp{0}. -If the label is written @samp{1:} then the digit is @samp{1}. -And so on up through @samp{9:}. - -@item @kbd{C-A} -This unusual character is included so you do not accidentally invent -a symbol of the same name. The character has ASCII value -@samp{\001}. - -@item @emph{ordinal number} -This is a serial number to keep the labels distinct. The first -@samp{0:} gets the number @samp{1}; The 15th @samp{0:} gets the -number @samp{15}; @emph{etc.}. Likewise for the other labels @samp{1:} -through @samp{9:}. -@end table - -For instance, the first @code{1:} is named @code{L1@kbd{C-A}1}, the 44th -@code{3:} is named @code{L3@kbd{C-A}44}. - -@node Dot -@section The Special Dot Symbol - -@cindex dot (symbol) -@cindex @code{.} (symbol) -@cindex current address -@cindex location counter -The special symbol @samp{.} refers to the current address that -@code{@value{AS}} is assembling into. Thus, the expression @samp{melvin: -.long .} defines @code{melvin} to contain its own address. -Assigning a value to @code{.} is treated the same as a @code{.org} -directive. Thus, the expression @samp{.=.+4} is the same as saying -@ifclear no-space-dir -@samp{.space 4}. -@end ifclear -@ifset no-space-dir -@ifset A29K -@samp{.block 4}. -@end ifset -@end ifset - -@node Symbol Attributes -@section Symbol Attributes - -@cindex symbol attributes -@cindex attributes, symbol -Every symbol has, as well as its name, the attributes ``Value'' and -``Type''. Depending on output format, symbols can also have auxiliary -attributes. -@ifset INTERNALS -The detailed definitions are in @file{a.out.h}. -@end ifset - -If you use a symbol without defining it, @code{@value{AS}} assumes zero for -all these attributes, and probably won't warn you. This makes the -symbol an externally defined symbol, which is generally what you -would want. - -@menu -* Symbol Value:: Value -* Symbol Type:: Type -@ifset aout-bout -@ifset GENERIC -* a.out Symbols:: Symbol Attributes: @code{a.out} -@end ifset -@ifclear GENERIC -@ifclear BOUT -* a.out Symbols:: Symbol Attributes: @code{a.out} -@end ifclear -@ifset BOUT -* a.out Symbols:: Symbol Attributes: @code{a.out}, @code{b.out} -@end ifset -@end ifclear -@end ifset -@ifset COFF -* COFF Symbols:: Symbol Attributes for COFF -@end ifset -@ifset SOM -* SOM Symbols:: Symbol Attributes for SOM -@end ifset -@end menu - -@node Symbol Value -@subsection Value - -@cindex value of a symbol -@cindex symbol value -The value of a symbol is (usually) 32 bits. For a symbol which labels a -location in the text, data, bss or absolute sections the value is the -number of addresses from the start of that section to the label. -Naturally for text, data and bss sections the value of a symbol changes -as @code{@value{LD}} changes section base addresses during linking. Absolute -symbols' values do not change during linking: that is why they are -called absolute. - -The value of an undefined symbol is treated in a special way. If it is -0 then the symbol is not defined in this assembler source file, and -@code{@value{LD}} tries to determine its value from other files linked into the -same program. You make this kind of symbol simply by mentioning a symbol -name without defining it. A non-zero value represents a @code{.comm} -common declaration. The value is how much common storage to reserve, in -bytes (addresses). The symbol refers to the first address of the -allocated storage. - -@node Symbol Type -@subsection Type - -@cindex type of a symbol -@cindex symbol type -The type attribute of a symbol contains relocation (section) -information, any flag settings indicating that a symbol is external, and -(optionally), other information for linkers and debuggers. The exact -format depends on the object-code output format in use. - -@ifset aout-bout -@ifclear GENERIC -@ifset BOUT -@c The following avoids a "widow" subsection title. @group would be -@c better if it were available outside examples. -@need 1000 -@node a.out Symbols -@subsection Symbol Attributes: @code{a.out}, @code{b.out} - -@cindex @code{b.out} symbol attributes -@cindex symbol attributes, @code{b.out} -These symbol attributes appear only when @code{@value{AS}} is configured for -one of the Berkeley-descended object output formats---@code{a.out} or -@code{b.out}. - -@end ifset -@ifclear BOUT -@node a.out Symbols -@subsection Symbol Attributes: @code{a.out} - -@cindex @code{a.out} symbol attributes -@cindex symbol attributes, @code{a.out} - -@end ifclear -@end ifclear -@ifset GENERIC -@node a.out Symbols -@subsection Symbol Attributes: @code{a.out} - -@cindex @code{a.out} symbol attributes -@cindex symbol attributes, @code{a.out} - -@end ifset -@menu -* Symbol Desc:: Descriptor -* Symbol Other:: Other -@end menu - -@node Symbol Desc -@subsubsection Descriptor - -@cindex descriptor, of @code{a.out} symbol -This is an arbitrary 16-bit value. You may establish a symbol's -descriptor value by using a @code{.desc} statement -(@pxref{Desc,,@code{.desc}}). A descriptor value means nothing to -@code{@value{AS}}. - -@node Symbol Other -@subsubsection Other - -@cindex other attribute, of @code{a.out} symbol -This is an arbitrary 8-bit value. It means nothing to @code{@value{AS}}. -@end ifset - -@ifset COFF -@node COFF Symbols -@subsection Symbol Attributes for COFF - -@cindex COFF symbol attributes -@cindex symbol attributes, COFF - -The COFF format supports a multitude of auxiliary symbol attributes; -like the primary symbol attributes, they are set between @code{.def} and -@code{.endef} directives. - -@subsubsection Primary Attributes - -@cindex primary attributes, COFF symbols -The symbol name is set with @code{.def}; the value and type, -respectively, with @code{.val} and @code{.type}. - -@subsubsection Auxiliary Attributes - -@cindex auxiliary attributes, COFF symbols -The @code{@value{AS}} directives @code{.dim}, @code{.line}, @code{.scl}, -@code{.size}, and @code{.tag} can generate auxiliary symbol table -information for COFF. -@end ifset - -@ifset SOM -@node SOM Symbols -@subsection Symbol Attributes for SOM - -@cindex SOM symbol attributes -@cindex symbol attributes, SOM - -The SOM format for the HPPA supports a multitude of symbol attributes set with -the @code{.EXPORT} and @code{.IMPORT} directives. - -The attributes are described in @cite{HP9000 Series 800 Assembly -Language Reference Manual} (HP 92432-90001) under the @code{IMPORT} and -@code{EXPORT} assembler directive documentation. -@end ifset - -@node Expressions -@chapter Expressions - -@cindex expressions -@cindex addresses -@cindex numeric values -An @dfn{expression} specifies an address or numeric value. -Whitespace may precede and/or follow an expression. - -The result of an expression must be an absolute number, or else an offset into -a particular section. If an expression is not absolute, and there is not -enough information when @code{@value{AS}} sees the expression to know its -section, a second pass over the source program might be necessary to interpret -the expression---but the second pass is currently not implemented. -@code{@value{AS}} aborts with an error message in this situation. - -@menu -* Empty Exprs:: Empty Expressions -* Integer Exprs:: Integer Expressions -@end menu - -@node Empty Exprs -@section Empty Expressions - -@cindex empty expressions -@cindex expressions, empty -An empty expression has no value: it is just whitespace or null. -Wherever an absolute expression is required, you may omit the -expression, and @code{@value{AS}} assumes a value of (absolute) 0. This -is compatible with other assemblers. - -@node Integer Exprs -@section Integer Expressions - -@cindex integer expressions -@cindex expressions, integer -An @dfn{integer expression} is one or more @emph{arguments} delimited -by @emph{operators}. - -@menu -* Arguments:: Arguments -* Operators:: Operators -* Prefix Ops:: Prefix Operators -* Infix Ops:: Infix Operators -@end menu - -@node Arguments -@subsection Arguments - -@cindex expression arguments -@cindex arguments in expressions -@cindex operands in expressions -@cindex arithmetic operands -@dfn{Arguments} are symbols, numbers or subexpressions. In other -contexts arguments are sometimes called ``arithmetic operands''. In -this manual, to avoid confusing them with the ``instruction operands'' of -the machine language, we use the term ``argument'' to refer to parts of -expressions only, reserving the word ``operand'' to refer only to machine -instruction operands. - -Symbols are evaluated to yield @{@var{section} @var{NNN}@} where -@var{section} is one of text, data, bss, absolute, -or undefined. @var{NNN} is a signed, 2's complement 32 bit -integer. - -Numbers are usually integers. - -A number can be a flonum or bignum. In this case, you are warned -that only the low order 32 bits are used, and @code{@value{AS}} pretends -these 32 bits are an integer. You may write integer-manipulating -instructions that act on exotic constants, compatible with other -assemblers. - -@cindex subexpressions -Subexpressions are a left parenthesis @samp{(} followed by an integer -expression, followed by a right parenthesis @samp{)}; or a prefix -operator followed by an argument. - -@node Operators -@subsection Operators - -@cindex operators, in expressions -@cindex arithmetic functions -@cindex functions, in expressions -@dfn{Operators} are arithmetic functions, like @code{+} or @code{%}. Prefix -operators are followed by an argument. Infix operators appear -between their arguments. Operators may be preceded and/or followed by -whitespace. - -@node Prefix Ops -@subsection Prefix Operator - -@cindex prefix operators -@code{@value{AS}} has the following @dfn{prefix operators}. They each take -one argument, which must be absolute. - -@c the tex/end tex stuff surrounding this small table is meant to make -@c it align, on the printed page, with the similar table in the next -@c section (which is inside an enumerate). -@tex -\global\advance\leftskip by \itemindent -@end tex - -@table @code -@item - -@dfn{Negation}. Two's complement negation. -@item ~ -@dfn{Complementation}. Bitwise not. -@end table - -@tex -\global\advance\leftskip by -\itemindent -@end tex - -@node Infix Ops -@subsection Infix Operators - -@cindex infix operators -@cindex operators, permitted arguments -@dfn{Infix operators} take two arguments, one on either side. Operators -have precedence, but operations with equal precedence are performed left -to right. Apart from @code{+} or @code{-}, both arguments must be -absolute, and the result is absolute. - -@enumerate -@cindex operator precedence -@cindex precedence of operators - -@item -Highest Precedence - -@table @code -@item * -@dfn{Multiplication}. - -@item / -@dfn{Division}. Truncation is the same as the C operator @samp{/} - -@item % -@dfn{Remainder}. - -@item < -@itemx << -@dfn{Shift Left}. Same as the C operator @samp{<<}. - -@item > -@itemx >> -@dfn{Shift Right}. Same as the C operator @samp{>>}. -@end table - -@item -Intermediate precedence - -@table @code -@item | - -@dfn{Bitwise Inclusive Or}. - -@item & -@dfn{Bitwise And}. - -@item ^ -@dfn{Bitwise Exclusive Or}. - -@item ! -@dfn{Bitwise Or Not}. -@end table - -@item -Lowest Precedence - -@table @code -@cindex addition, permitted arguments -@cindex plus, permitted arguments -@cindex arguments for addition -@item + -@dfn{Addition}. If either argument is absolute, the result has the section of -the other argument. You may not add together arguments from different -sections. - -@cindex subtraction, permitted arguments -@cindex minus, permitted arguments -@cindex arguments for subtraction -@item - -@dfn{Subtraction}. If the right argument is absolute, the -result has the section of the left argument. -If both arguments are in the same section, the result is absolute. -You may not subtract arguments from different sections. -@c FIXME is there still something useful to say about undefined - undefined ? -@end table -@end enumerate - -In short, it's only meaningful to add or subtract the @emph{offsets} in an -address; you can only have a defined section in one of the two arguments. - -@node Pseudo Ops -@chapter Assembler Directives - -@cindex directives, machine independent -@cindex pseudo-ops, machine independent -@cindex machine independent directives -All assembler directives have names that begin with a period (@samp{.}). -The rest of the name is letters, usually in lower case. - -This chapter discusses directives that are available regardless of the -target machine configuration for the @sc{gnu} assembler. -@ifset GENERIC -Some machine configurations provide additional directives. -@xref{Machine Dependencies}. -@end ifset -@ifclear GENERIC -@ifset machine-directives -@xref{Machine Dependencies} for additional directives. -@end ifset -@end ifclear - -@menu -* Abort:: @code{.abort} -@ifset COFF -* ABORT:: @code{.ABORT} -@end ifset - -* Align:: @code{.align @var{abs-expr} , @var{abs-expr}} -* Ascii:: @code{.ascii "@var{string}"}@dots{} -* Asciz:: @code{.asciz "@var{string}"}@dots{} -* Balign:: @code{.balign @var{abs-expr} , @var{abs-expr}} -* Byte:: @code{.byte @var{expressions}} -* Comm:: @code{.comm @var{symbol} , @var{length} } -* Data:: @code{.data @var{subsection}} -@ifset COFF -* Def:: @code{.def @var{name}} -@end ifset -@ifset aout-bout -* Desc:: @code{.desc @var{symbol}, @var{abs-expression}} -@end ifset -@ifset COFF -* Dim:: @code{.dim} -@end ifset - -* Double:: @code{.double @var{flonums}} -* Eject:: @code{.eject} -* Else:: @code{.else} -* End:: @code{.end} -@ifset COFF -* Endef:: @code{.endef} -@end ifset - -* Endfunc:: @code{.endfunc} -* Endif:: @code{.endif} -* Equ:: @code{.equ @var{symbol}, @var{expression}} -* Equiv:: @code{.equiv @var{symbol}, @var{expression}} -* Err:: @code{.err} -* Exitm:: @code{.exitm} -* Extern:: @code{.extern} -* Fail:: @code{.fail} -@ifclear no-file-dir -* File:: @code{.file @var{string}} -@end ifclear - -* Fill:: @code{.fill @var{repeat} , @var{size} , @var{value}} -* Float:: @code{.float @var{flonums}} -* Func:: @code{.func} -* Global:: @code{.global @var{symbol}}, @code{.globl @var{symbol}} -* hword:: @code{.hword @var{expressions}} -* Ident:: @code{.ident} -* If:: @code{.if @var{absolute expression}} -* Include:: @code{.include "@var{file}"} -* Int:: @code{.int @var{expressions}} -* Irp:: @code{.irp @var{symbol},@var{values}}@dots{} -* Irpc:: @code{.irpc @var{symbol},@var{values}}@dots{} -* Lcomm:: @code{.lcomm @var{symbol} , @var{length}} -* Lflags:: @code{.lflags} -@ifclear no-line-dir -* Line:: @code{.line @var{line-number}} -@end ifclear - -* Ln:: @code{.ln @var{line-number}} -* Linkonce:: @code{.linkonce [@var{type}]} -* List:: @code{.list} -* Long:: @code{.long @var{expressions}} -@ignore -* Lsym:: @code{.lsym @var{symbol}, @var{expression}} -@end ignore - -* Macro:: @code{.macro @var{name} @var{args}}@dots{} -* MRI:: @code{.mri @var{val}} - -* Nolist:: @code{.nolist} -* Octa:: @code{.octa @var{bignums}} -* Org:: @code{.org @var{new-lc} , @var{fill}} -* P2align:: @code{.p2align @var{abs-expr} , @var{abs-expr}} -* Print:: @code{.print @var{string}} -* Psize:: @code{.psize @var{lines}, @var{columns}} -* Purgem:: @code{.purgem @var{name}} -* Quad:: @code{.quad @var{bignums}} -* Rept:: @code{.rept @var{count}} -* Sbttl:: @code{.sbttl "@var{subheading}"} -@ifset COFF -* Scl:: @code{.scl @var{class}} -* Section:: @code{.section @var{name}, @var{subsection}} -@end ifset - -* Set:: @code{.set @var{symbol}, @var{expression}} -* Short:: @code{.short @var{expressions}} -* Single:: @code{.single @var{flonums}} -@ifset COFF -* Size:: @code{.size} -@end ifset - -* Skip:: @code{.skip @var{size} , @var{fill}} -* Sleb128:: @code{.sleb128 @var{expressions}} -* Space:: @code{.space @var{size} , @var{fill}} -@ifset have-stabs -* Stab:: @code{.stabd, .stabn, .stabs} -@end ifset - -* String:: @code{.string "@var{str}"} -* Struct:: @code{.struct @var{expression}} -@ifset ELF -* Symver:: @code{.symver @var{name},@var{name2@@nodename}} -@end ifset -@ifset COFF -* Tag:: @code{.tag @var{structname}} -@end ifset - -* Text:: @code{.text @var{subsection}} -* Title:: @code{.title "@var{heading}"} -@ifset COFF -* Type:: @code{.type @var{int}} -* Val:: @code{.val @var{addr}} -@end ifset - -* Uleb128:: @code{.uleb128 @var{expressions}} -* Word:: @code{.word @var{expressions}} -* Deprecated:: Deprecated Directives -@end menu - -@node Abort -@section @code{.abort} - -@cindex @code{abort} directive -@cindex stopping the assembly -This directive stops the assembly immediately. It is for -compatibility with other assemblers. The original idea was that the -assembly language source would be piped into the assembler. If the sender -of the source quit, it could use this directive tells @code{@value{AS}} to -quit also. One day @code{.abort} will not be supported. - -@ifset COFF -@node ABORT -@section @code{.ABORT} - -@cindex @code{ABORT} directive -When producing COFF output, @code{@value{AS}} accepts this directive as a -synonym for @samp{.abort}. - -@ifset BOUT -When producing @code{b.out} output, @code{@value{AS}} accepts this directive, -but ignores it. -@end ifset -@end ifset - -@node Align -@section @code{.align @var{abs-expr}, @var{abs-expr}, @var{abs-expr}} - -@cindex padding the location counter -@cindex @code{align} directive -Pad the location counter (in the current subsection) to a particular storage -boundary. The first expression (which must be absolute) is the alignment -required, as described below. - -The second expression (also absolute) gives the fill value to be stored in the -padding bytes. It (and the comma) may be omitted. If it is omitted, the -padding bytes are normally zero. However, on some systems, if the section is -marked as containing code and the fill value is omitted, the space is filled -with no-op instructions. - -The third expression is also absolute, and is also optional. If it is present, -it is the maximum number of bytes that should be skipped by this alignment -directive. If doing the alignment would require skipping more bytes than the -specified maximum, then the alignment is not done at all. You can omit the -fill value (the second argument) entirely by simply using two commas after the -required alignment; this can be useful if you want the alignment to be filled -with no-op instructions when appropriate. - -The way the required alignment is specified varies from system to system. -For the a29k, hppa, m68k, m88k, w65, sparc, and Hitachi SH, and i386 using ELF -format, -the first expression is the -alignment request in bytes. For example @samp{.align 8} advances -the location counter until it is a multiple of 8. If the location counter -is already a multiple of 8, no change is needed. - -For other systems, including the i386 using a.out format, it is the -number of low-order zero bits the location counter must have after -advancement. For example @samp{.align 3} advances the location -counter until it a multiple of 8. If the location counter is already a -multiple of 8, no change is needed. - -This inconsistency is due to the different behaviors of the various -native assemblers for these systems which GAS must emulate. -GAS also provides @code{.balign} and @code{.p2align} directives, -described later, which have a consistent behavior across all -architectures (but are specific to GAS). - -@node Ascii -@section @code{.ascii "@var{string}"}@dots{} - -@cindex @code{ascii} directive -@cindex string literals -@code{.ascii} expects zero or more string literals (@pxref{Strings}) -separated by commas. It assembles each string (with no automatic -trailing zero byte) into consecutive addresses. - -@node Asciz -@section @code{.asciz "@var{string}"}@dots{} - -@cindex @code{asciz} directive -@cindex zero-terminated strings -@cindex null-terminated strings -@code{.asciz} is just like @code{.ascii}, but each string is followed by -a zero byte. The ``z'' in @samp{.asciz} stands for ``zero''. - -@node Balign -@section @code{.balign[wl] @var{abs-expr}, @var{abs-expr}, @var{abs-expr}} - -@cindex padding the location counter given number of bytes -@cindex @code{balign} directive -Pad the location counter (in the current subsection) to a particular -storage boundary. The first expression (which must be absolute) is the -alignment request in bytes. For example @samp{.balign 8} advances -the location counter until it is a multiple of 8. If the location counter -is already a multiple of 8, no change is needed. - -The second expression (also absolute) gives the fill value to be stored in the -padding bytes. It (and the comma) may be omitted. If it is omitted, the -padding bytes are normally zero. However, on some systems, if the section is -marked as containing code and the fill value is omitted, the space is filled -with no-op instructions. - -The third expression is also absolute, and is also optional. If it is present, -it is the maximum number of bytes that should be skipped by this alignment -directive. If doing the alignment would require skipping more bytes than the -specified maximum, then the alignment is not done at all. You can omit the -fill value (the second argument) entirely by simply using two commas after the -required alignment; this can be useful if you want the alignment to be filled -with no-op instructions when appropriate. - -@cindex @code{balignw} directive -@cindex @code{balignl} directive -The @code{.balignw} and @code{.balignl} directives are variants of the -@code{.balign} directive. The @code{.balignw} directive treats the fill -pattern as a two byte word value. The @code{.balignl} directives treats the -fill pattern as a four byte longword value. For example, @code{.balignw -4,0x368d} will align to a multiple of 4. If it skips two bytes, they will be -filled in with the value 0x368d (the exact placement of the bytes depends upon -the endianness of the processor). If it skips 1 or 3 bytes, the fill value is -undefined. - -@node Byte -@section @code{.byte @var{expressions}} - -@cindex @code{byte} directive -@cindex integers, one byte -@code{.byte} expects zero or more expressions, separated by commas. -Each expression is assembled into the next byte. - -@node Comm -@section @code{.comm @var{symbol} , @var{length} } - -@cindex @code{comm} directive -@cindex symbol, common -@code{.comm} declares a common symbol named @var{symbol}. When linking, a -common symbol in one object file may be merged with a defined or common symbol -of the same name in another object file. If @code{@value{LD}} does not see a -definition for the symbol--just one or more common symbols--then it will -allocate @var{length} bytes of uninitialized memory. @var{length} must be an -absolute expression. If @code{@value{LD}} sees multiple common symbols with -the same name, and they do not all have the same size, it will allocate space -using the largest size. - -@ifset ELF -When using ELF, the @code{.comm} directive takes an optional third argument. -This is the desired alignment of the symbol, specified as a byte boundary (for -example, an alignment of 16 means that the least significant 4 bits of the -address should be zero). The alignment must be an absolute expression, and it -must be a power of two. If @code{@value{LD}} allocates uninitialized memory -for the common symbol, it will use the alignment when placing the symbol. If -no alignment is specified, @code{@value{AS}} will set the alignment to the -largest power of two less than or equal to the size of the symbol, up to a -maximum of 16. -@end ifset - -@ifset HPPA -The syntax for @code{.comm} differs slightly on the HPPA. The syntax is -@samp{@var{symbol} .comm, @var{length}}; @var{symbol} is optional. -@end ifset - -@node Data -@section @code{.data @var{subsection}} - -@cindex @code{data} directive -@code{.data} tells @code{@value{AS}} to assemble the following statements onto the -end of the data subsection numbered @var{subsection} (which is an -absolute expression). If @var{subsection} is omitted, it defaults -to zero. - -@ifset COFF -@node Def -@section @code{.def @var{name}} - -@cindex @code{def} directive -@cindex COFF symbols, debugging -@cindex debugging COFF symbols -Begin defining debugging information for a symbol @var{name}; the -definition extends until the @code{.endef} directive is encountered. -@ifset BOUT - -This directive is only observed when @code{@value{AS}} is configured for COFF -format output; when producing @code{b.out}, @samp{.def} is recognized, -but ignored. -@end ifset -@end ifset - -@ifset aout-bout -@node Desc -@section @code{.desc @var{symbol}, @var{abs-expression}} - -@cindex @code{desc} directive -@cindex COFF symbol descriptor -@cindex symbol descriptor, COFF -This directive sets the descriptor of the symbol (@pxref{Symbol Attributes}) -to the low 16 bits of an absolute expression. - -@ifset COFF -The @samp{.desc} directive is not available when @code{@value{AS}} is -configured for COFF output; it is only for @code{a.out} or @code{b.out} -object format. For the sake of compatibility, @code{@value{AS}} accepts -it, but produces no output, when configured for COFF. -@end ifset -@end ifset - -@ifset COFF -@node Dim -@section @code{.dim} - -@cindex @code{dim} directive -@cindex COFF auxiliary symbol information -@cindex auxiliary symbol information, COFF -This directive is generated by compilers to include auxiliary debugging -information in the symbol table. It is only permitted inside -@code{.def}/@code{.endef} pairs. -@ifset BOUT - -@samp{.dim} is only meaningful when generating COFF format output; when -@code{@value{AS}} is generating @code{b.out}, it accepts this directive but -ignores it. -@end ifset -@end ifset - -@node Double -@section @code{.double @var{flonums}} - -@cindex @code{double} directive -@cindex floating point numbers (double) -@code{.double} expects zero or more flonums, separated by commas. It -assembles floating point numbers. -@ifset GENERIC -The exact kind of floating point numbers emitted depends on how -@code{@value{AS}} is configured. @xref{Machine Dependencies}. -@end ifset -@ifclear GENERIC -@ifset IEEEFLOAT -On the @value{TARGET} family @samp{.double} emits 64-bit floating-point numbers -in @sc{ieee} format. -@end ifset -@end ifclear - -@node Eject -@section @code{.eject} - -@cindex @code{eject} directive -@cindex new page, in listings -@cindex page, in listings -@cindex listing control: new page -Force a page break at this point, when generating assembly listings. - -@node Else -@section @code{.else} - -@cindex @code{else} directive -@code{.else} is part of the @code{@value{AS}} support for conditional -assembly; @pxref{If,,@code{.if}}. It marks the beginning of a section -of code to be assembled if the condition for the preceding @code{.if} -was false. - -@node End -@section @code{.end} - -@cindex @code{end} directive -@code{.end} marks the end of the assembly file. @code{@value{AS}} does not -process anything in the file past the @code{.end} directive. - -@ifset COFF -@node Endef -@section @code{.endef} - -@cindex @code{endef} directive -This directive flags the end of a symbol definition begun with -@code{.def}. -@ifset BOUT - -@samp{.endef} is only meaningful when generating COFF format output; if -@code{@value{AS}} is configured to generate @code{b.out}, it accepts this -directive but ignores it. -@end ifset -@end ifset - -@node Endfunc -@section @code{.endfunc} -@cindex @code{endfunc} directive -@code{.endfunc} marks the end of a function specified with @code{.func}. - -@node Endif -@section @code{.endif} - -@cindex @code{endif} directive -@code{.endif} is part of the @code{@value{AS}} support for conditional assembly; -it marks the end of a block of code that is only assembled -conditionally. @xref{If,,@code{.if}}. - -@node Equ -@section @code{.equ @var{symbol}, @var{expression}} - -@cindex @code{equ} directive -@cindex assigning values to symbols -@cindex symbols, assigning values to -This directive sets the value of @var{symbol} to @var{expression}. -It is synonymous with @samp{.set}; @pxref{Set,,@code{.set}}. - -@ifset HPPA -The syntax for @code{equ} on the HPPA is -@samp{@var{symbol} .equ @var{expression}}. -@end ifset - -@node Equiv -@section @code{.equiv @var{symbol}, @var{expression}} -@cindex @code{equiv} directive -The @code{.equiv} directive is like @code{.equ} and @code{.set}, except that -the assembler will signal an error if @var{symbol} is already defined. - -Except for the contents of the error message, this is roughly equivalent to -@smallexample -.ifdef SYM -.err -.endif -.equ SYM,VAL -@end smallexample - -@node Err -@section @code{.err} -@cindex @code{err} directive -If @code{@value{AS}} assembles a @code{.err} directive, it will print an error -message and, unless the @code{-Z} option was used, it will not generate an -object file. This can be used to signal error an conditionally compiled code. - -@node Exitm -@section @code{.exitm} -Exit early from the current macro definition. @xref{Macro}. - -@node Extern -@section @code{.extern} - -@cindex @code{extern} directive -@code{.extern} is accepted in the source program---for compatibility -with other assemblers---but it is ignored. @code{@value{AS}} treats -all undefined symbols as external. - -@node Fail -@section @code{.fail @var{expression}} - -@cindex @code{fail} directive -Generates an error or a warning. If the value of the @var{expression} is 500 -or more, @code{@value{AS}} will print a warning message. If the value is less -than 500, @code{@value{AS}} will print an error message. The message will -include the value of @var{expression}. This can occasionally be useful inside -complex nested macros or conditional assembly. - -@ifclear no-file-dir -@node File -@section @code{.file @var{string}} - -@cindex @code{file} directive -@cindex logical file name -@cindex file name, logical -@code{.file} tells @code{@value{AS}} that we are about to start a new logical -file. @var{string} is the new file name. In general, the filename is -recognized whether or not it is surrounded by quotes @samp{"}; but if you wish -to specify an empty file name, you must give the quotes--@code{""}. This -statement may go away in future: it is only recognized to be compatible with -old @code{@value{AS}} programs. -@ifset A29K -In some configurations of @code{@value{AS}}, @code{.file} has already been -removed to avoid conflicts with other assemblers. @xref{Machine Dependencies}. -@end ifset -@end ifclear - -@node Fill -@section @code{.fill @var{repeat} , @var{size} , @var{value}} - -@cindex @code{fill} directive -@cindex writing patterns in memory -@cindex patterns, writing in memory -@var{result}, @var{size} and @var{value} are absolute expressions. -This emits @var{repeat} copies of @var{size} bytes. @var{Repeat} -may be zero or more. @var{Size} may be zero or more, but if it is -more than 8, then it is deemed to have the value 8, compatible with -other people's assemblers. The contents of each @var{repeat} bytes -is taken from an 8-byte number. The highest order 4 bytes are -zero. The lowest order 4 bytes are @var{value} rendered in the -byte-order of an integer on the computer @code{@value{AS}} is assembling for. -Each @var{size} bytes in a repetition is taken from the lowest order -@var{size} bytes of this number. Again, this bizarre behavior is -compatible with other people's assemblers. - -@var{size} and @var{value} are optional. -If the second comma and @var{value} are absent, @var{value} is -assumed zero. If the first comma and following tokens are absent, -@var{size} is assumed to be 1. - -@node Float -@section @code{.float @var{flonums}} - -@cindex floating point numbers (single) -@cindex @code{float} directive -This directive assembles zero or more flonums, separated by commas. It -has the same effect as @code{.single}. -@ifset GENERIC -The exact kind of floating point numbers emitted depends on how -@code{@value{AS}} is configured. -@xref{Machine Dependencies}. -@end ifset -@ifclear GENERIC -@ifset IEEEFLOAT -On the @value{TARGET} family, @code{.float} emits 32-bit floating point numbers -in @sc{ieee} format. -@end ifset -@end ifclear - -@node Func -@section @code{.func @var{name}[,@var{label}]} -@cindex @code{func} directive -@code{.func} emits debugging information to denote function @var{name}, and -is ignored unless the file is assembled with debugging enabled. -Only @samp{--gstabs} is currently supported. -@var{label} is the entry point of the function and if omitted @var{name} -prepended with the @samp{leading char} is used. -@samp{leading char} is usually @code{_} or nothing, depending on the target. -All functions are currently defined to have @code{void} return type. -The function must be terminated with @code{.endfunc}. - -@node Global -@section @code{.global @var{symbol}}, @code{.globl @var{symbol}} - -@cindex @code{global} directive -@cindex symbol, making visible to linker -@code{.global} makes the symbol visible to @code{@value{LD}}. If you define -@var{symbol} in your partial program, its value is made available to -other partial programs that are linked with it. Otherwise, -@var{symbol} takes its attributes from a symbol of the same name -from another file linked into the same program. - -Both spellings (@samp{.globl} and @samp{.global}) are accepted, for -compatibility with other assemblers. - -@ifset HPPA -On the HPPA, @code{.global} is not always enough to make it accessible to other -partial programs. You may need the HPPA-only @code{.EXPORT} directive as well. -@xref{HPPA Directives,, HPPA Assembler Directives}. -@end ifset - -@node hword -@section @code{.hword @var{expressions}} - -@cindex @code{hword} directive -@cindex integers, 16-bit -@cindex numbers, 16-bit -@cindex sixteen bit integers -This expects zero or more @var{expressions}, and emits -a 16 bit number for each. - -@ifset GENERIC -This directive is a synonym for @samp{.short}; depending on the target -architecture, it may also be a synonym for @samp{.word}. -@end ifset -@ifclear GENERIC -@ifset W32 -This directive is a synonym for @samp{.short}. -@end ifset -@ifset W16 -This directive is a synonym for both @samp{.short} and @samp{.word}. -@end ifset -@end ifclear - -@node Ident -@section @code{.ident} - -@cindex @code{ident} directive -This directive is used by some assemblers to place tags in object files. -@code{@value{AS}} simply accepts the directive for source-file -compatibility with such assemblers, but does not actually emit anything -for it. - -@node If -@section @code{.if @var{absolute expression}} - -@cindex conditional assembly -@cindex @code{if} directive -@code{.if} marks the beginning of a section of code which is only -considered part of the source program being assembled if the argument -(which must be an @var{absolute expression}) is non-zero. The end of -the conditional section of code must be marked by @code{.endif} -(@pxref{Endif,,@code{.endif}}); optionally, you may include code for the -alternative condition, flagged by @code{.else} (@pxref{Else,,@code{.else}}). - -The following variants of @code{.if} are also supported: -@table @code -@cindex @code{ifdef} directive -@item .ifdef @var{symbol} -Assembles the following section of code if the specified @var{symbol} -has been defined. - -@cindex @code{ifc} directive -@item .ifc @var{string1},@var{string2} -Assembles the following section of code if the two strings are the same. The -strings may be optionally quoted with single quotes. If they are not quoted, -the first string stops at the first comma, and the second string stops at the -end of the line. Strings which contain whitespace should be quoted. The -string comparison is case sensitive. - -@cindex @code{ifeq} directive -@item .ifeq @var{absolute expression} -Assembles the following section of code if the argument is zero. - -@cindex @code{ifeqs} directive -@item .ifeqs @var{string1},@var{string2} -Another form of @code{.ifc}. The strings must be quoted using double quotes. - -@cindex @code{ifge} directive -@item .ifge @var{absolute expression} -Assembles the following section of code if the argument is greater than or -equal to zero. - -@cindex @code{ifgt} directive -@item .ifgt @var{absolute expression} -Assembles the following section of code if the argument is greater than zero. - -@cindex @code{ifle} directive -@item .ifle @var{absolute expression} -Assembles the following section of code if the argument is less than or equal -to zero. - -@cindex @code{iflt} directive -@item .iflt @var{absolute expression} -Assembles the following section of code if the argument is less than zero. - -@cindex @code{ifnc} directive -@item .ifnc @var{string1},@var{string2}. -Like @code{.ifc}, but the sense of the test is reversed: this assembles the -following section of code if the two strings are not the same. - -@cindex @code{ifndef} directive -@cindex @code{ifnotdef} directive -@item .ifndef @var{symbol} -@itemx .ifnotdef @var{symbol} -Assembles the following section of code if the specified @var{symbol} -has not been defined. Both spelling variants are equivalent. - -@cindex @code{ifne} directive -@item .ifne @var{absolute expression} -Assembles the following section of code if the argument is not equal to zero -(in other words, this is equivalent to @code{.if}). - -@cindex @code{ifnes} directive -@item .ifnes @var{string1},@var{string2} -Like @code{.ifeqs}, but the sense of the test is reversed: this assembles the -following section of code if the two strings are not the same. -@end table - -@node Include -@section @code{.include "@var{file}"} - -@cindex @code{include} directive -@cindex supporting files, including -@cindex files, including -This directive provides a way to include supporting files at specified -points in your source program. The code from @var{file} is assembled as -if it followed the point of the @code{.include}; when the end of the -included file is reached, assembly of the original file continues. You -can control the search paths used with the @samp{-I} command-line option -(@pxref{Invoking,,Command-Line Options}). Quotation marks are required -around @var{file}. - -@node Int -@section @code{.int @var{expressions}} - -@cindex @code{int} directive -@cindex integers, 32-bit -Expect zero or more @var{expressions}, of any section, separated by commas. -For each expression, emit a number that, at run time, is the value of that -expression. The byte order and bit size of the number depends on what kind -of target the assembly is for. - -@ifclear GENERIC -@ifset H8 -On the H8/500 and most forms of the H8/300, @code{.int} emits 16-bit -integers. On the H8/300H and the Hitachi SH, however, @code{.int} emits -32-bit integers. -@end ifset -@end ifclear - -@node Irp -@section @code{.irp @var{symbol},@var{values}}@dots{} - -@cindex @code{irp} directive -Evaluate a sequence of statements assigning different values to @var{symbol}. -The sequence of statements starts at the @code{.irp} directive, and is -terminated by an @code{.endr} directive. For each @var{value}, @var{symbol} is -set to @var{value}, and the sequence of statements is assembled. If no -@var{value} is listed, the sequence of statements is assembled once, with -@var{symbol} set to the null string. To refer to @var{symbol} within the -sequence of statements, use @var{\symbol}. - -For example, assembling - -@example - .irp param,1,2,3 - move d\param,sp@@- - .endr -@end example - -is equivalent to assembling - -@example - move d1,sp@@- - move d2,sp@@- - move d3,sp@@- -@end example - -@node Irpc -@section @code{.irpc @var{symbol},@var{values}}@dots{} - -@cindex @code{irpc} directive -Evaluate a sequence of statements assigning different values to @var{symbol}. -The sequence of statements starts at the @code{.irpc} directive, and is -terminated by an @code{.endr} directive. For each character in @var{value}, -@var{symbol} is set to the character, and the sequence of statements is -assembled. If no @var{value} is listed, the sequence of statements is -assembled once, with @var{symbol} set to the null string. To refer to -@var{symbol} within the sequence of statements, use @var{\symbol}. - -For example, assembling - -@example - .irpc param,123 - move d\param,sp@@- - .endr -@end example - -is equivalent to assembling - -@example - move d1,sp@@- - move d2,sp@@- - move d3,sp@@- -@end example - -@node Lcomm -@section @code{.lcomm @var{symbol} , @var{length}} - -@cindex @code{lcomm} directive -@cindex local common symbols -@cindex symbols, local common -Reserve @var{length} (an absolute expression) bytes for a local common -denoted by @var{symbol}. The section and value of @var{symbol} are -those of the new local common. The addresses are allocated in the bss -section, so that at run-time the bytes start off zeroed. @var{Symbol} -is not declared global (@pxref{Global,,@code{.global}}), so is normally -not visible to @code{@value{LD}}. - -@ifset GENERIC -Some targets permit a third argument to be used with @code{.lcomm}. This -argument specifies the desired alignment of the symbol in the bss section. -@end ifset - -@ifset HPPA -The syntax for @code{.lcomm} differs slightly on the HPPA. The syntax is -@samp{@var{symbol} .lcomm, @var{length}}; @var{symbol} is optional. -@end ifset - -@node Lflags -@section @code{.lflags} - -@cindex @code{lflags} directive (ignored) -@code{@value{AS}} accepts this directive, for compatibility with other -assemblers, but ignores it. - -@ifclear no-line-dir -@node Line -@section @code{.line @var{line-number}} - -@cindex @code{line} directive -@end ifclear -@ifset no-line-dir -@node Ln -@section @code{.ln @var{line-number}} - -@cindex @code{ln} directive -@end ifset -@cindex logical line number -@ifset aout-bout -Change the logical line number. @var{line-number} must be an absolute -expression. The next line has that logical line number. Therefore any other -statements on the current line (after a statement separator character) are -reported as on logical line number @var{line-number} @minus{} 1. One day -@code{@value{AS}} will no longer support this directive: it is recognized only -for compatibility with existing assembler programs. - -@ifset GENERIC -@ifset A29K -@emph{Warning:} In the AMD29K configuration of @value{AS}, this command is -not available; use the synonym @code{.ln} in that context. -@end ifset -@end ifset -@end ifset - -@ifclear no-line-dir -Even though this is a directive associated with the @code{a.out} or -@code{b.out} object-code formats, @code{@value{AS}} still recognizes it -when producing COFF output, and treats @samp{.line} as though it -were the COFF @samp{.ln} @emph{if} it is found outside a -@code{.def}/@code{.endef} pair. - -Inside a @code{.def}, @samp{.line} is, instead, one of the directives -used by compilers to generate auxiliary symbol information for -debugging. -@end ifclear - -@node Linkonce -@section @code{.linkonce [@var{type}]} -@cindex COMDAT -@cindex @code{linkonce} directive -@cindex common sections -Mark the current section so that the linker only includes a single copy of it. -This may be used to include the same section in several different object files, -but ensure that the linker will only include it once in the final output file. -The @code{.linkonce} pseudo-op must be used for each instance of the section. -Duplicate sections are detected based on the section name, so it should be -unique. - -This directive is only supported by a few object file formats; as of this -writing, the only object file format which supports it is the Portable -Executable format used on Windows NT. - -The @var{type} argument is optional. If specified, it must be one of the -following strings. For example: -@smallexample -.linkonce same_size -@end smallexample -Not all types may be supported on all object file formats. - -@table @code -@item discard -Silently discard duplicate sections. This is the default. - -@item one_only -Warn if there are duplicate sections, but still keep only one copy. - -@item same_size -Warn if any of the duplicates have different sizes. - -@item same_contents -Warn if any of the duplicates do not have exactly the same contents. -@end table - -@node Ln -@section @code{.ln @var{line-number}} - -@cindex @code{ln} directive -@ifclear no-line-dir -@samp{.ln} is a synonym for @samp{.line}. -@end ifclear -@ifset no-line-dir -Tell @code{@value{AS}} to change the logical line number. @var{line-number} -must be an absolute expression. The next line has that logical -line number, so any other statements on the current line (after a -statement separator character @code{;}) are reported as on logical -line number @var{line-number} @minus{} 1. -@ifset BOUT - -This directive is accepted, but ignored, when @code{@value{AS}} is -configured for @code{b.out}; its effect is only associated with COFF -output format. -@end ifset -@end ifset - -@node MRI -@section @code{.mri @var{val}} - -@cindex @code{mri} directive -@cindex MRI mode, temporarily -If @var{val} is non-zero, this tells @code{@value{AS}} to enter MRI mode. If -@var{val} is zero, this tells @code{@value{AS}} to exit MRI mode. This change -affects code assembled until the next @code{.mri} directive, or until the end -of the file. @xref{M, MRI mode, MRI mode}. - -@node List -@section @code{.list} - -@cindex @code{list} directive -@cindex listing control, turning on -Control (in conjunction with the @code{.nolist} directive) whether or -not assembly listings are generated. These two directives maintain an -internal counter (which is zero initially). @code{.list} increments the -counter, and @code{.nolist} decrements it. Assembly listings are -generated whenever the counter is greater than zero. - -By default, listings are disabled. When you enable them (with the -@samp{-a} command line option; @pxref{Invoking,,Command-Line Options}), -the initial value of the listing counter is one. - -@node Long -@section @code{.long @var{expressions}} - -@cindex @code{long} directive -@code{.long} is the same as @samp{.int}, @pxref{Int,,@code{.int}}. - -@ignore -@c no one seems to know what this is for or whether this description is -@c what it really ought to do -@node Lsym -@section @code{.lsym @var{symbol}, @var{expression}} - -@cindex @code{lsym} directive -@cindex symbol, not referenced in assembly -@code{.lsym} creates a new symbol named @var{symbol}, but does not put it in -the hash table, ensuring it cannot be referenced by name during the -rest of the assembly. This sets the attributes of the symbol to be -the same as the expression value: -@smallexample -@var{other} = @var{descriptor} = 0 -@var{type} = @r{(section of @var{expression})} -@var{value} = @var{expression} -@end smallexample -@noindent -The new symbol is not flagged as external. -@end ignore - -@node Macro -@section @code{.macro} - -@cindex macros -The commands @code{.macro} and @code{.endm} allow you to define macros that -generate assembly output. For example, this definition specifies a macro -@code{sum} that puts a sequence of numbers into memory: - -@example - .macro sum from=0, to=5 - .long \from - .if \to-\from - sum "(\from+1)",\to - .endif - .endm -@end example - -@noindent -With that definition, @samp{SUM 0,5} is equivalent to this assembly input: - -@example - .long 0 - .long 1 - .long 2 - .long 3 - .long 4 - .long 5 -@end example - -@ftable @code -@item .macro @var{macname} -@itemx .macro @var{macname} @var{macargs} @dots{} -@cindex @code{macro} directive -Begin the definition of a macro called @var{macname}. If your macro -definition requires arguments, specify their names after the macro name, -separated by commas or spaces. You can supply a default value for any -macro argument by following the name with @samp{=@var{deflt}}. For -example, these are all valid @code{.macro} statements: - -@table @code -@item .macro comm -Begin the definition of a macro called @code{comm}, which takes no -arguments. - -@item .macro plus1 p, p1 -@itemx .macro plus1 p p1 -Either statement begins the definition of a macro called @code{plus1}, -which takes two arguments; within the macro definition, write -@samp{\p} or @samp{\p1} to evaluate the arguments. - -@item .macro reserve_str p1=0 p2 -Begin the definition of a macro called @code{reserve_str}, with two -arguments. The first argument has a default value, but not the second. -After the definition is complete, you can call the macro either as -@samp{reserve_str @var{a},@var{b}} (with @samp{\p1} evaluating to -@var{a} and @samp{\p2} evaluating to @var{b}), or as @samp{reserve_str -,@var{b}} (with @samp{\p1} evaluating as the default, in this case -@samp{0}, and @samp{\p2} evaluating to @var{b}). -@end table - -When you call a macro, you can specify the argument values either by -position, or by keyword. For example, @samp{sum 9,17} is equivalent to -@samp{sum to=17, from=9}. - -@item .endm -@cindex @code{endm} directive -Mark the end of a macro definition. - -@item .exitm -@cindex @code{exitm} directive -Exit early from the current macro definition. - -@cindex number of macros executed -@cindex macros, count executed -@item \@@ -@code{@value{AS}} maintains a counter of how many macros it has -executed in this pseudo-variable; you can copy that number to your -output with @samp{\@@}, but @emph{only within a macro definition}. - -@ignore -@item LOCAL @var{name} [ , @dots{} ] -@emph{Warning: @code{LOCAL} is only available if you select ``alternate -macro syntax'' with @samp{-a} or @samp{--alternate}.} @xref{Alternate,, -Alternate macro syntax}. - -Generate a string replacement for each of the @var{name} arguments, and -replace any instances of @var{name} in each macro expansion. The -replacement string is unique in the assembly, and different for each -separate macro expansion. @code{LOCAL} allows you to write macros that -define symbols, without fear of conflict between separate macro expansions. -@end ignore -@end ftable - -@node Nolist -@section @code{.nolist} - -@cindex @code{nolist} directive -@cindex listing control, turning off -Control (in conjunction with the @code{.list} directive) whether or -not assembly listings are generated. These two directives maintain an -internal counter (which is zero initially). @code{.list} increments the -counter, and @code{.nolist} decrements it. Assembly listings are -generated whenever the counter is greater than zero. - -@node Octa -@section @code{.octa @var{bignums}} - -@c FIXME: double size emitted for "octa" on i960, others? Or warn? -@cindex @code{octa} directive -@cindex integer, 16-byte -@cindex sixteen byte integer -This directive expects zero or more bignums, separated by commas. For each -bignum, it emits a 16-byte integer. - -The term ``octa'' comes from contexts in which a ``word'' is two bytes; -hence @emph{octa}-word for 16 bytes. - -@node Org -@section @code{.org @var{new-lc} , @var{fill}} - -@cindex @code{org} directive -@cindex location counter, advancing -@cindex advancing location counter -@cindex current address, advancing -Advance the location counter of the current section to -@var{new-lc}. @var{new-lc} is either an absolute expression or an -expression with the same section as the current subsection. That is, -you can't use @code{.org} to cross sections: if @var{new-lc} has the -wrong section, the @code{.org} directive is ignored. To be compatible -with former assemblers, if the section of @var{new-lc} is absolute, -@code{@value{AS}} issues a warning, then pretends the section of @var{new-lc} -is the same as the current subsection. - -@code{.org} may only increase the location counter, or leave it -unchanged; you cannot use @code{.org} to move the location counter -backwards. - -@c double negative used below "not undefined" because this is a specific -@c reference to "undefined" (as SEG_UNKNOWN is called in this manual) -@c section. doc@cygnus.com 18feb91 -Because @code{@value{AS}} tries to assemble programs in one pass, @var{new-lc} -may not be undefined. If you really detest this restriction we eagerly await -a chance to share your improved assembler. - -Beware that the origin is relative to the start of the section, not -to the start of the subsection. This is compatible with other -people's assemblers. - -When the location counter (of the current subsection) is advanced, the -intervening bytes are filled with @var{fill} which should be an -absolute expression. If the comma and @var{fill} are omitted, -@var{fill} defaults to zero. - -@node P2align -@section @code{.p2align[wl] @var{abs-expr}, @var{abs-expr}, @var{abs-expr}} - -@cindex padding the location counter given a power of two -@cindex @code{p2align} directive -Pad the location counter (in the current subsection) to a particular -storage boundary. The first expression (which must be absolute) is the -number of low-order zero bits the location counter must have after -advancement. For example @samp{.p2align 3} advances the location -counter until it a multiple of 8. If the location counter is already a -multiple of 8, no change is needed. - -The second expression (also absolute) gives the fill value to be stored in the -padding bytes. It (and the comma) may be omitted. If it is omitted, the -padding bytes are normally zero. However, on some systems, if the section is -marked as containing code and the fill value is omitted, the space is filled -with no-op instructions. - -The third expression is also absolute, and is also optional. If it is present, -it is the maximum number of bytes that should be skipped by this alignment -directive. If doing the alignment would require skipping more bytes than the -specified maximum, then the alignment is not done at all. You can omit the -fill value (the second argument) entirely by simply using two commas after the -required alignment; this can be useful if you want the alignment to be filled -with no-op instructions when appropriate. - -@cindex @code{p2alignw} directive -@cindex @code{p2alignl} directive -The @code{.p2alignw} and @code{.p2alignl} directives are variants of the -@code{.p2align} directive. The @code{.p2alignw} directive treats the fill -pattern as a two byte word value. The @code{.p2alignl} directives treats the -fill pattern as a four byte longword value. For example, @code{.p2alignw -2,0x368d} will align to a multiple of 4. If it skips two bytes, they will be -filled in with the value 0x368d (the exact placement of the bytes depends upon -the endianness of the processor). If it skips 1 or 3 bytes, the fill value is -undefined. - -@node Print -@section @code{.print @var{string}} - -@cindex @code{print} directive -@code{@value{AS}} will print @var{string} on the standard output during -assembly. You must put @var{string} in double quotes. - -@node Psize -@section @code{.psize @var{lines} , @var{columns}} - -@cindex @code{psize} directive -@cindex listing control: paper size -@cindex paper size, for listings -Use this directive to declare the number of lines---and, optionally, the -number of columns---to use for each page, when generating listings. - -If you do not use @code{.psize}, listings use a default line-count -of 60. You may omit the comma and @var{columns} specification; the -default width is 200 columns. - -@code{@value{AS}} generates formfeeds whenever the specified number of -lines is exceeded (or whenever you explicitly request one, using -@code{.eject}). - -If you specify @var{lines} as @code{0}, no formfeeds are generated save -those explicitly specified with @code{.eject}. - -@node Purgem -@section @code{.purgem @var{name}} - -@cindex @code{purgem} directive -Undefine the macro @var{name}, so that later uses of the string will not be -expanded. @xref{Macro}. - -@node Quad -@section @code{.quad @var{bignums}} - -@cindex @code{quad} directive -@code{.quad} expects zero or more bignums, separated by commas. For -each bignum, it emits -@ifclear bignum-16 -an 8-byte integer. If the bignum won't fit in 8 bytes, it prints a -warning message; and just takes the lowest order 8 bytes of the bignum. -@cindex eight-byte integer -@cindex integer, 8-byte - -The term ``quad'' comes from contexts in which a ``word'' is two bytes; -hence @emph{quad}-word for 8 bytes. -@end ifclear -@ifset bignum-16 -a 16-byte integer. If the bignum won't fit in 16 bytes, it prints a -warning message; and just takes the lowest order 16 bytes of the bignum. -@cindex sixteen-byte integer -@cindex integer, 16-byte -@end ifset - -@node Rept -@section @code{.rept @var{count}} - -@cindex @code{rept} directive -Repeat the sequence of lines between the @code{.rept} directive and the next -@code{.endr} directive @var{count} times. - -For example, assembling - -@example - .rept 3 - .long 0 - .endr -@end example - -is equivalent to assembling - -@example - .long 0 - .long 0 - .long 0 -@end example - -@node Sbttl -@section @code{.sbttl "@var{subheading}"} - -@cindex @code{sbttl} directive -@cindex subtitles for listings -@cindex listing control: subtitle -Use @var{subheading} as the title (third line, immediately after the -title line) when generating assembly listings. - -This directive affects subsequent pages, as well as the current page if -it appears within ten lines of the top of a page. - -@ifset COFF -@node Scl -@section @code{.scl @var{class}} - -@cindex @code{scl} directive -@cindex symbol storage class (COFF) -@cindex COFF symbol storage class -Set the storage-class value for a symbol. This directive may only be -used inside a @code{.def}/@code{.endef} pair. Storage class may flag -whether a symbol is static or external, or it may record further -symbolic debugging information. -@ifset BOUT - -The @samp{.scl} directive is primarily associated with COFF output; when -configured to generate @code{b.out} output format, @code{@value{AS}} -accepts this directive but ignores it. -@end ifset -@end ifset - -@node Section -@section @code{.section @var{name}} - -@cindex @code{section} directive -@cindex named section -Use the @code{.section} directive to assemble the following code into a section -named @var{name}. - -This directive is only supported for targets that actually support arbitrarily -named sections; on @code{a.out} targets, for example, it is not accepted, even -with a standard @code{a.out} section name. - -@ifset COFF -For COFF targets, the @code{.section} directive is used in one of the following -ways: -@smallexample -.section @var{name}[, "@var{flags}"] -.section @var{name}[, @var{subsegment}] -@end smallexample - -If the optional argument is quoted, it is taken as flags to use for the -section. Each flag is a single character. The following flags are recognized: -@table @code -@item b -bss section (uninitialized data) -@item n -section is not loaded -@item w -writable section -@item d -data section -@item r -read-only section -@item x -executable section -@item s -shared section (meaningful for PE targets) -@end table - -If no flags are specified, the default flags depend upon the section name. If -the section name is not recognized, the default will be for the section to be -loaded and writable. - -If the optional argument to the @code{.section} directive is not quoted, it is -taken as a subsegment number (@pxref{Sub-Sections}). -@end ifset - -@ifset ELF -For ELF targets, the @code{.section} directive is used like this: -@smallexample -.section @var{name}[, "@var{flags}"[, @@@var{type}]] -@end smallexample -The optional @var{flags} argument is a quoted string which may contain any -combintion of the following characters: -@table @code -@item a -section is allocatable -@item w -section is writable -@item x -section is executable -@end table - -The optional @var{type} argument may contain one of the following constants: -@table @code -@item @@progbits -section contains data -@item @@nobits -section does not contain data (i.e., section only occupies space) -@end table - -If no flags are specified, the default flags depend upon the section name. If -the section name is not recognized, the default will be for the section to have -none of the above flags: it will not be allocated in memory, nor writable, nor -executable. The section will contain data. - -For ELF targets, the assembler supports another type of @code{.section} -directive for compatibility with the Solaris assembler: -@smallexample -.section "@var{name}"[, @var{flags}...] -@end smallexample -Note that the section name is quoted. There may be a sequence of comma -separated flags: -@table @code -@item #alloc -section is allocatable -@item #write -section is writable -@item #execinstr -section is executable -@end table -@end ifset - -@node Set -@section @code{.set @var{symbol}, @var{expression}} - -@cindex @code{set} directive -@cindex symbol value, setting -Set the value of @var{symbol} to @var{expression}. This -changes @var{symbol}'s value and type to conform to -@var{expression}. If @var{symbol} was flagged as external, it remains -flagged (@pxref{Symbol Attributes}). - -You may @code{.set} a symbol many times in the same assembly. - -If you @code{.set} a global symbol, the value stored in the object -file is the last value stored into it. - -@ifset HPPA -The syntax for @code{set} on the HPPA is -@samp{@var{symbol} .set @var{expression}}. -@end ifset - -@node Short -@section @code{.short @var{expressions}} - -@cindex @code{short} directive -@ifset GENERIC -@code{.short} is normally the same as @samp{.word}. -@xref{Word,,@code{.word}}. - -In some configurations, however, @code{.short} and @code{.word} generate -numbers of different lengths; @pxref{Machine Dependencies}. -@end ifset -@ifclear GENERIC -@ifset W16 -@code{.short} is the same as @samp{.word}. @xref{Word,,@code{.word}}. -@end ifset -@ifset W32 -This expects zero or more @var{expressions}, and emits -a 16 bit number for each. -@end ifset -@end ifclear - -@node Single -@section @code{.single @var{flonums}} - -@cindex @code{single} directive -@cindex floating point numbers (single) -This directive assembles zero or more flonums, separated by commas. It -has the same effect as @code{.float}. -@ifset GENERIC -The exact kind of floating point numbers emitted depends on how -@code{@value{AS}} is configured. @xref{Machine Dependencies}. -@end ifset -@ifclear GENERIC -@ifset IEEEFLOAT -On the @value{TARGET} family, @code{.single} emits 32-bit floating point -numbers in @sc{ieee} format. -@end ifset -@end ifclear - -@ifset COFF -@node Size -@section @code{.size} - -@cindex @code{size} directive -This directive is generated by compilers to include auxiliary debugging -information in the symbol table. It is only permitted inside -@code{.def}/@code{.endef} pairs. -@ifset BOUT - -@samp{.size} is only meaningful when generating COFF format output; when -@code{@value{AS}} is generating @code{b.out}, it accepts this directive but -ignores it. -@end ifset -@end ifset - -@node Sleb128 -@section @code{.sleb128 @var{expressions}} - -@cindex @code{sleb128} directive -@var{sleb128} stands for ``signed little endian base 128.'' This is a -compact, variable length representation of numbers used by the DWARF -symbolic debugging format. @xref{Uleb128,@code{.uleb128}}. - -@ifclear no-space-dir -@node Skip -@section @code{.skip @var{size} , @var{fill}} - -@cindex @code{skip} directive -@cindex filling memory -This directive emits @var{size} bytes, each of value @var{fill}. Both -@var{size} and @var{fill} are absolute expressions. If the comma and -@var{fill} are omitted, @var{fill} is assumed to be zero. This is the same as -@samp{.space}. - -@node Space -@section @code{.space @var{size} , @var{fill}} - -@cindex @code{space} directive -@cindex filling memory -This directive emits @var{size} bytes, each of value @var{fill}. Both -@var{size} and @var{fill} are absolute expressions. If the comma -and @var{fill} are omitted, @var{fill} is assumed to be zero. This is the same -as @samp{.skip}. - -@ifset HPPA -@quotation -@emph{Warning:} @code{.space} has a completely different meaning for HPPA -targets; use @code{.block} as a substitute. See @cite{HP9000 Series 800 -Assembly Language Reference Manual} (HP 92432-90001) for the meaning of the -@code{.space} directive. @xref{HPPA Directives,,HPPA Assembler Directives}, -for a summary. -@end quotation -@end ifset -@end ifclear - -@ifset A29K -@ifclear GENERIC -@node Space -@section @code{.space} -@cindex @code{space} directive -@end ifclear -On the AMD 29K, this directive is ignored; it is accepted for -compatibility with other AMD 29K assemblers. - -@quotation -@emph{Warning:} In most versions of the @sc{gnu} assembler, the directive -@code{.space} has the effect of @code{.block} @xref{Machine Dependencies}. -@end quotation -@end ifset - -@ifset have-stabs -@node Stab -@section @code{.stabd, .stabn, .stabs} - -@cindex symbolic debuggers, information for -@cindex @code{stab@var{x}} directives -There are three directives that begin @samp{.stab}. -All emit symbols (@pxref{Symbols}), for use by symbolic debuggers. -The symbols are not entered in the @code{@value{AS}} hash table: they -cannot be referenced elsewhere in the source file. -Up to five fields are required: - -@table @var -@item string -This is the symbol's name. It may contain any character except -@samp{\000}, so is more general than ordinary symbol names. Some -debuggers used to code arbitrarily complex structures into symbol names -using this field. - -@item type -An absolute expression. The symbol's type is set to the low 8 bits of -this expression. Any bit pattern is permitted, but @code{@value{LD}} -and debuggers choke on silly bit patterns. - -@item other -An absolute expression. The symbol's ``other'' attribute is set to the -low 8 bits of this expression. - -@item desc -An absolute expression. The symbol's descriptor is set to the low 16 -bits of this expression. - -@item value -An absolute expression which becomes the symbol's value. -@end table - -If a warning is detected while reading a @code{.stabd}, @code{.stabn}, -or @code{.stabs} statement, the symbol has probably already been created; -you get a half-formed symbol in your object file. This is -compatible with earlier assemblers! - -@table @code -@cindex @code{stabd} directive -@item .stabd @var{type} , @var{other} , @var{desc} - -The ``name'' of the symbol generated is not even an empty string. -It is a null pointer, for compatibility. Older assemblers used a -null pointer so they didn't waste space in object files with empty -strings. - -The symbol's value is set to the location counter, -relocatably. When your program is linked, the value of this symbol -is the address of the location counter when the @code{.stabd} was -assembled. - -@cindex @code{stabn} directive -@item .stabn @var{type} , @var{other} , @var{desc} , @var{value} -The name of the symbol is set to the empty string @code{""}. - -@cindex @code{stabs} directive -@item .stabs @var{string} , @var{type} , @var{other} , @var{desc} , @var{value} -All five fields are specified. -@end table -@end ifset -@c end have-stabs - -@node String -@section @code{.string} "@var{str}" - -@cindex string, copying to object file -@cindex @code{string} directive - -Copy the characters in @var{str} to the object file. You may specify more than -one string to copy, separated by commas. Unless otherwise specified for a -particular machine, the assembler marks the end of each string with a 0 byte. -You can use any of the escape sequences described in @ref{Strings,,Strings}. - -@node Struct -@section @code{.struct @var{expression}} - -@cindex @code{struct} directive -Switch to the absolute section, and set the section offset to @var{expression}, -which must be an absolute expression. You might use this as follows: -@smallexample - .struct 0 -field1: - .struct field1 + 4 -field2: - .struct field2 + 4 -field3: -@end smallexample -This would define the symbol @code{field1} to have the value 0, the symbol -@code{field2} to have the value 4, and the symbol @code{field3} to have the -value 8. Assembly would be left in the absolute section, and you would need to -use a @code{.section} directive of some sort to change to some other section -before further assembly. - -@ifset ELF -@node Symver -@section @code{.symver} -@cindex @code{symver} directive -@cindex symbol versioning -@cindex versions of symbols -Use the @code{.symver} directive to bind symbols to specific version nodes -within a source file. This is only supported on ELF platforms, and is -typically used when assembling files to be linked into a shared library. -There are cases where it may make sense to use this in objects to be bound -into an application itself so as to override a versioned symbol from a -shared library. - -For ELF targets, the @code{.symver} directive is used like this: -@smallexample -.symver @var{name}, @var{name2@@nodename} -@end smallexample -In this case, the symbol @var{name} must exist and be defined within the file -being assembled. The @code{.versym} directive effectively creates a symbol -alias with the name @var{name2@@nodename}, and in fact the main reason that we -just don't try and create a regular alias is that the @var{@@} character isn't -permitted in symbol names. The @var{name2} part of the name is the actual name -of the symbol by which it will be externally referenced. The name @var{name} -itself is merely a name of convenience that is used so that it is possible to -have definitions for multiple versions of a function within a single source -file, and so that the compiler can unambiguously know which version of a -function is being mentioned. The @var{nodename} portion of the alias should be -the name of a node specified in the version script supplied to the linker when -building a shared library. If you are attempting to override a versioned -symbol from a shared library, then @var{nodename} should correspond to the -nodename of the symbol you are trying to override. -@end ifset - -@ifset COFF -@node Tag -@section @code{.tag @var{structname}} - -@cindex COFF structure debugging -@cindex structure debugging, COFF -@cindex @code{tag} directive -This directive is generated by compilers to include auxiliary debugging -information in the symbol table. It is only permitted inside -@code{.def}/@code{.endef} pairs. Tags are used to link structure -definitions in the symbol table with instances of those structures. -@ifset BOUT - -@samp{.tag} is only used when generating COFF format output; when -@code{@value{AS}} is generating @code{b.out}, it accepts this directive but -ignores it. -@end ifset -@end ifset - -@node Text -@section @code{.text @var{subsection}} - -@cindex @code{text} directive -Tells @code{@value{AS}} to assemble the following statements onto the end of -the text subsection numbered @var{subsection}, which is an absolute -expression. If @var{subsection} is omitted, subsection number zero -is used. - -@node Title -@section @code{.title "@var{heading}"} - -@cindex @code{title} directive -@cindex listing control: title line -Use @var{heading} as the title (second line, immediately after the -source file name and pagenumber) when generating assembly listings. - -This directive affects subsequent pages, as well as the current page if -it appears within ten lines of the top of a page. - -@ifset COFF -@node Type -@section @code{.type @var{int}} - -@cindex COFF symbol type -@cindex symbol type, COFF -@cindex @code{type} directive -This directive, permitted only within @code{.def}/@code{.endef} pairs, -records the integer @var{int} as the type attribute of a symbol table entry. -@ifset BOUT - -@samp{.type} is associated only with COFF format output; when -@code{@value{AS}} is configured for @code{b.out} output, it accepts this -directive but ignores it. -@end ifset -@end ifset - -@ifset COFF -@node Val -@section @code{.val @var{addr}} - -@cindex @code{val} directive -@cindex COFF value attribute -@cindex value attribute, COFF -This directive, permitted only within @code{.def}/@code{.endef} pairs, -records the address @var{addr} as the value attribute of a symbol table -entry. -@ifset BOUT - -@samp{.val} is used only for COFF output; when @code{@value{AS}} is -configured for @code{b.out}, it accepts this directive but ignores it. -@end ifset -@end ifset - -@node Uleb128 -@section @code{.uleb128 @var{expressions}} - -@cindex @code{uleb128} directive -@var{uleb128} stands for ``unsigned little endian base 128.'' This is a -compact, variable length representation of numbers used by the DWARF -symbolic debugging format. @xref{Sleb128,@code{.sleb128}}. - -@node Word -@section @code{.word @var{expressions}} - -@cindex @code{word} directive -This directive expects zero or more @var{expressions}, of any section, -separated by commas. -@ifclear GENERIC -@ifset W32 -For each expression, @code{@value{AS}} emits a 32-bit number. -@end ifset -@ifset W16 -For each expression, @code{@value{AS}} emits a 16-bit number. -@end ifset -@end ifclear -@ifset GENERIC - -The size of the number emitted, and its byte order, -depend on what target computer the assembly is for. -@end ifset - -@c on amd29k, i960, sparc the "special treatment to support compilers" doesn't -@c happen---32-bit addressability, period; no long/short jumps. -@ifset DIFF-TBL-KLUGE -@cindex difference tables altered -@cindex altered difference tables -@quotation -@emph{Warning: Special Treatment to support Compilers} -@end quotation - -@ifset GENERIC -Machines with a 32-bit address space, but that do less than 32-bit -addressing, require the following special treatment. If the machine of -interest to you does 32-bit addressing (or doesn't require it; -@pxref{Machine Dependencies}), you can ignore this issue. - -@end ifset -In order to assemble compiler output into something that works, -@code{@value{AS}} occasionlly does strange things to @samp{.word} directives. -Directives of the form @samp{.word sym1-sym2} are often emitted by -compilers as part of jump tables. Therefore, when @code{@value{AS}} assembles a -directive of the form @samp{.word sym1-sym2}, and the difference between -@code{sym1} and @code{sym2} does not fit in 16 bits, @code{@value{AS}} -creates a @dfn{secondary jump table}, immediately before the next label. -This secondary jump table is preceded by a short-jump to the -first byte after the secondary table. This short-jump prevents the flow -of control from accidentally falling into the new table. Inside the -table is a long-jump to @code{sym2}. The original @samp{.word} -contains @code{sym1} minus the address of the long-jump to -@code{sym2}. - -If there were several occurrences of @samp{.word sym1-sym2} before the -secondary jump table, all of them are adjusted. If there was a -@samp{.word sym3-sym4}, that also did not fit in sixteen bits, a -long-jump to @code{sym4} is included in the secondary jump table, -and the @code{.word} directives are adjusted to contain @code{sym3} -minus the address of the long-jump to @code{sym4}; and so on, for as many -entries in the original jump table as necessary. - -@ifset INTERNALS -@emph{This feature may be disabled by compiling @code{@value{AS}} with the -@samp{-DWORKING_DOT_WORD} option.} This feature is likely to confuse -assembly language programmers. -@end ifset -@end ifset -@c end DIFF-TBL-KLUGE - -@node Deprecated -@section Deprecated Directives - -@cindex deprecated directives -@cindex obsolescent directives -One day these directives won't work. -They are included for compatibility with older assemblers. -@table @t -@item .abort -@item .line -@end table - -@ifset GENERIC -@node Machine Dependencies -@chapter Machine Dependent Features - -@cindex machine dependencies -The machine instruction sets are (almost by definition) different on -each machine where @code{@value{AS}} runs. Floating point representations -vary as well, and @code{@value{AS}} often supports a few additional -directives or command-line options for compatibility with other -assemblers on a particular platform. Finally, some versions of -@code{@value{AS}} support special pseudo-instructions for branch -optimization. - -This chapter discusses most of these differences, though it does not -include details on any machine's instruction set. For details on that -subject, see the hardware manufacturer's manual. - -@menu -@ifset A29K -* AMD29K-Dependent:: AMD 29K Dependent Features -@end ifset -@ifset ARC -* ARC-Dependent:: ARC Dependent Features -@end ifset -@ifset ARM -* ARM-Dependent:: ARM Dependent Features -@end ifset -@ifset D10V -* D10V-Dependent:: D10V Dependent Features -@end ifset -@ifset D30V -* D30V-Dependent:: D30V Dependent Features -@end ifset -@ifset H8/300 -* H8/300-Dependent:: Hitachi H8/300 Dependent Features -@end ifset -@ifset H8/500 -* H8/500-Dependent:: Hitachi H8/500 Dependent Features -@end ifset -@ifset HPPA -* HPPA-Dependent:: HPPA Dependent Features -@end ifset -@ifset I80386 -* i386-Dependent:: Intel 80386 Dependent Features -@end ifset -@ifset I960 -* i960-Dependent:: Intel 80960 Dependent Features -@end ifset -@ifset M680X0 -* M68K-Dependent:: M680x0 Dependent Features -@end ifset -@ifset MIPS -* MIPS-Dependent:: MIPS Dependent Features -@end ifset -@ifset SH -* SH-Dependent:: Hitachi SH Dependent Features -@end ifset -@ifset PJ -* PJ-Dependent:: picoJava Dependent Features -@end ifset -@ifset SPARC -* Sparc-Dependent:: SPARC Dependent Features -@end ifset -@ifset V850 -* V850-Dependent:: V850 Dependent Features -@end ifset -@ifset Z8000 -* Z8000-Dependent:: Z8000 Dependent Features -@end ifset -@ifset VAX -* Vax-Dependent:: VAX Dependent Features -@end ifset -@end menu - -@lowersections -@end ifset - -@c The following major nodes are *sections* in the GENERIC version, *chapters* -@c in single-cpu versions. This is mainly achieved by @lowersections. There is a -@c peculiarity: to preserve cross-references, there must be a node called -@c "Machine Dependencies". Hence the conditional nodenames in each -@c major node below. Node defaulting in makeinfo requires adjacency of -@c node and sectioning commands; hence the repetition of @chapter BLAH -@c in both conditional blocks. - -@ifset ARC -@ifset GENERIC -@page -@node ARC-Dependent -@chapter ARC Dependent Features -@end ifset -@ifclear GENERIC -@node Machine Dependencies -@chapter ARC Dependent Features -@end ifclear - -@cindex ARC support -@menu -* ARC-Opts:: Options -* ARC-Float:: Floating Point -* ARC-Directives:: Sparc Machine Directives -@end menu - -@node ARC-Opts -@section Options - -@cindex options for ARC -@cindex ARC options -@cindex architectures, ARC -@cindex ARC architectures -The ARC chip family includes several successive levels (or other -variants) of chip, using the same core instruction set, but including -a few additional instructions at each level. - -By default, @code{@value{AS}} assumes the core instruction set (ARC -base). The @code{.cpu} pseudo-op is intended to be used to select -the variant. - -@table @code -@cindex @code{-mbig-endian} option (ARC) -@cindex @code{-mlittle-endian} option (ARC) -@cindex ARC big-endian output -@cindex ARC little-endian output -@cindex big-endian output, ARC -@cindex little-endian output, ARC -@item -mbig-endian -@itemx -mlittle-endian -Any @sc{arc} configuration of @code{@value{AS}} can select big-endian or -little-endian output at run time (unlike most other @sc{gnu} development -tools, which must be configured for one or the other). Use -@samp{-mbig-endian} to select big-endian output, and @samp{-mlittle-endian} -for little-endian. -@end table - -@node ARC-Float -@section Floating Point - -@cindex floating point, ARC (@sc{ieee}) -@cindex ARC floating point (@sc{ieee}) -The ARC cpu family currently does not have hardware floating point -support. Software floating point support is provided by @code{GCC} -and uses @sc{ieee} floating-point numbers. - -@node ARC-Directives -@section ARC Machine Directives - -@cindex ARC machine directives -@cindex machine directives, ARC -The ARC version of @code{@value{AS}} supports the following additional -machine directives: - -@table @code -@item .cpu -@cindex @code{cpu} directive, SPARC -This must be followed by the desired cpu. -The ARC is intended to be customizable, @code{.cpu} is used to -select the desired variant [though currently there are none]. - -@end table - -@end ifset - -@ifset A29K -@include c-a29k.texi -@end ifset - -@ifset ARM -@include c-arm.texi -@end ifset - -@ifset Hitachi-all -@ifclear GENERIC -@node Machine Dependencies -@chapter Machine Dependent Features - -The machine instruction sets are different on each Hitachi chip family, -and there are also some syntax differences among the families. This -chapter describes the specific @code{@value{AS}} features for each -family. - -@menu -* H8/300-Dependent:: Hitachi H8/300 Dependent Features -* H8/500-Dependent:: Hitachi H8/500 Dependent Features -* SH-Dependent:: Hitachi SH Dependent Features -@end menu -@lowersections -@end ifclear -@end ifset - -@ifset D10V -@include c-d10v.texi -@end ifset - -@ifset D30V -@include c-d30v.texi -@end ifset - -@ifset H8/300 -@include c-h8300.texi -@end ifset - -@ifset H8/500 -@include c-h8500.texi -@end ifset - -@ifset HPPA -@include c-hppa.texi -@end ifset - -@ifset I80386 -@include c-i386.texi -@end ifset - -@ifset I960 -@include c-i960.texi -@end ifset - - -@ifset M680X0 -@include c-m68k.texi -@end ifset - -@ifset MIPS -@include c-mips.texi -@end ifset - -@ifset NS32K -@include c-ns32k.texi -@end ifset - -@ifset PJ -@include c-pj.texi -@end ifset - -@ifset SH -@include c-sh.texi -@end ifset - -@ifset SPARC -@include c-sparc.texi -@end ifset - -@ifset Z8000 -@include c-z8k.texi -@end ifset - -@ifset VAX -@include c-vax.texi -@end ifset - -@ifset V850 -@include c-v850.texi -@end ifset - -@ifset GENERIC -@c reverse effect of @down at top of generic Machine-Dep chapter -@raisesections -@end ifset - -@node Reporting Bugs -@chapter Reporting Bugs -@cindex bugs in assembler -@cindex reporting bugs in assembler - -Your bug reports play an essential role in making @code{@value{AS}} reliable. - -Reporting a bug may help you by bringing a solution to your problem, or it may -not. But in any case the principal function of a bug report is to help the -entire community by making the next version of @code{@value{AS}} work better. -Bug reports are your contribution to the maintenance of @code{@value{AS}}. - -In order for a bug report to serve its purpose, you must include the -information that enables us to fix the bug. - -@menu -* Bug Criteria:: Have you found a bug? -* Bug Reporting:: How to report bugs -@end menu - -@node Bug Criteria -@section Have you found a bug? -@cindex bug criteria - -If you are not sure whether you have found a bug, here are some guidelines: - -@itemize @bullet -@cindex fatal signal -@cindex assembler crash -@cindex crash of assembler -@item -If the assembler gets a fatal signal, for any input whatever, that is a -@code{@value{AS}} bug. Reliable assemblers never crash. - -@cindex error on valid input -@item -If @code{@value{AS}} produces an error message for valid input, that is a bug. - -@cindex invalid input -@item -If @code{@value{AS}} does not produce an error message for invalid input, that -is a bug. However, you should note that your idea of ``invalid input'' might -be our idea of ``an extension'' or ``support for traditional practice''. - -@item -If you are an experienced user of assemblers, your suggestions for improvement -of @code{@value{AS}} are welcome in any case. -@end itemize - -@node Bug Reporting -@section How to report bugs -@cindex bug reports -@cindex assembler bugs, reporting - -A number of companies and individuals offer support for @sc{gnu} products. If -you obtained @code{@value{AS}} from a support organization, we recommend you -contact that organization first. - -You can find contact information for many support companies and -individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs -distribution. - -In any event, we also recommend that you send bug reports for @code{@value{AS}} -to @samp{bug-gnu-utils@@gnu.org}. - -The fundamental principle of reporting bugs usefully is this: -@strong{report all the facts}. If you are not sure whether to state a -fact or leave it out, state it! - -Often people omit facts because they think they know what causes the problem -and assume that some details do not matter. Thus, you might assume that the -name of a symbol you use in an example does not matter. Well, probably it does -not, but one cannot be sure. Perhaps the bug is a stray memory reference which -happens to fetch from the location where that name is stored in memory; -perhaps, if the name were different, the contents of that location would fool -the assembler into doing the right thing despite the bug. Play it safe and -give a specific, complete example. That is the easiest thing for you to do, -and the most helpful. - -Keep in mind that the purpose of a bug report is to enable us to fix the bug if -it is new to us. Therefore, always write your bug reports on the assumption -that the bug has not been reported previously. - -Sometimes people give a few sketchy facts and ask, ``Does this ring a -bell?'' Those bug reports are useless, and we urge everyone to -@emph{refuse to respond to them} except to chide the sender to report -bugs properly. - -To enable us to fix the bug, you should include all these things: - -@itemize @bullet -@item -The version of @code{@value{AS}}. @code{@value{AS}} announces it if you start -it with the @samp{--version} argument. - -Without this, we will not know whether there is any point in looking for -the bug in the current version of @code{@value{AS}}. - -@item -Any patches you may have applied to the @code{@value{AS}} source. - -@item -The type of machine you are using, and the operating system name and -version number. - -@item -What compiler (and its version) was used to compile @code{@value{AS}}---e.g. -``@code{gcc-2.7}''. - -@item -The command arguments you gave the assembler to assemble your example and -observe the bug. To guarantee you will not omit something important, list them -all. A copy of the Makefile (or the output from make) is sufficient. - -If we were to try to guess the arguments, we would probably guess wrong -and then we might not encounter the bug. - -@item -A complete input file that will reproduce the bug. If the bug is observed when -the assembler is invoked via a compiler, send the assembler source, not the -high level language source. Most compilers will produce the assembler source -when run with the @samp{-S} option. If you are using @code{@value{GCC}}, use -the options @samp{-v --save-temps}; this will save the assembler source in a -file with an extension of @file{.s}, and also show you exactly how -@code{@value{AS}} is being run. - -@item -A description of what behavior you observe that you believe is -incorrect. For example, ``It gets a fatal signal.'' - -Of course, if the bug is that @code{@value{AS}} gets a fatal signal, then we -will certainly notice it. But if the bug is incorrect output, we might not -notice unless it is glaringly wrong. You might as well not give us a chance to -make a mistake. - -Even if the problem you experience is a fatal signal, you should still say so -explicitly. Suppose something strange is going on, such as, your copy of -@code{@value{AS}} is out of synch, or you have encountered a bug in the C -library on your system. (This has happened!) Your copy might crash and ours -would not. If you told us to expect a crash, then when ours fails to crash, we -would know that the bug was not happening for us. If you had not told us to -expect a crash, then we would not be able to draw any conclusion from our -observations. - -@item -If you wish to suggest changes to the @code{@value{AS}} source, send us context -diffs, as generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p} -option. Always send diffs from the old file to the new file. If you even -discuss something in the @code{@value{AS}} source, refer to it by context, not -by line number. - -The line numbers in our development sources will not match those in your -sources. Your line numbers would convey no useful information to us. -@end itemize - -Here are some things that are not necessary: - -@itemize @bullet -@item -A description of the envelope of the bug. - -Often people who encounter a bug spend a lot of time investigating -which changes to the input file will make the bug go away and which -changes will not affect it. - -This is often time consuming and not very useful, because the way we -will find the bug is by running a single example under the debugger -with breakpoints, not by pure deduction from a series of examples. -We recommend that you save your time for something else. - -Of course, if you can find a simpler example to report @emph{instead} -of the original one, that is a convenience for us. Errors in the -output will be easier to spot, running under the debugger will take -less time, and so on. - -However, simplification is not vital; if you do not want to do this, -report the bug anyway and send us the entire test case you used. - -@item -A patch for the bug. - -A patch for the bug does help us if it is a good one. But do not omit -the necessary information, such as the test case, on the assumption that -a patch is all we need. We might see problems with your patch and decide -to fix the problem another way, or we might not understand it at all. - -Sometimes with a program as complicated as @code{@value{AS}} it is very hard to -construct an example that will make the program follow a certain path through -the code. If you do not send us the example, we will not be able to construct -one, so we will not be able to verify that the bug is fixed. - -And if we cannot understand what bug you are trying to fix, or why your -patch should be an improvement, we will not install it. A test case will -help us to understand. - -@item -A guess about what the bug is or what it depends on. - -Such guesses are usually wrong. Even we cannot guess right about such -things without first using the debugger to find the facts. -@end itemize - -@node Acknowledgements -@chapter Acknowledgements - -If you have contributed to @code{@value{AS}} and your name isn't listed here, -it is not meant as a slight. We just don't know about it. Send mail to the -maintainer, and we'll correct the situation. Currently -@c (January 1994), -the maintainer is Ken Raeburn (email address @code{raeburn@@cygnus.com}). - -Dean Elsner wrote the original @sc{gnu} assembler for the VAX.@footnote{Any -more details?} - -Jay Fenlason maintained GAS for a while, adding support for GDB-specific debug -information and the 68k series machines, most of the preprocessing pass, and -extensive changes in @file{messages.c}, @file{input-file.c}, @file{write.c}. - -K. Richard Pixley maintained GAS for a while, adding various enhancements and -many bug fixes, including merging support for several processors, breaking GAS -up to handle multiple object file format back ends (including heavy rewrite, -testing, an integration of the coff and b.out back ends), adding configuration -including heavy testing and verification of cross assemblers and file splits -and renaming, converted GAS to strictly ANSI C including full prototypes, added -support for m680[34]0 and cpu32, did considerable work on i960 including a COFF -port (including considerable amounts of reverse engineering), a SPARC opcode -file rewrite, DECstation, rs6000, and hp300hpux host ports, updated ``know'' -assertions and made them work, much other reorganization, cleanup, and lint. - -Ken Raeburn wrote the high-level BFD interface code to replace most of the code -in format-specific I/O modules. - -The original VMS support was contributed by David L. Kashtan. Eric Youngdale -has done much work with it since. - -The Intel 80386 machine description was written by Eliot Dresselhaus. - -Minh Tran-Le at IntelliCorp contributed some AIX 386 support. - -The Motorola 88k machine description was contributed by Devon Bowen of Buffalo -University and Torbjorn Granlund of the Swedish Institute of Computer Science. - -Keith Knowles at the Open Software Foundation wrote the original MIPS back end -(@file{tc-mips.c}, @file{tc-mips.h}), and contributed Rose format support -(which hasn't been merged in yet). Ralph Campbell worked with the MIPS code to -support a.out format. - -Support for the Zilog Z8k and Hitachi H8/300 and H8/500 processors (tc-z8k, -tc-h8300, tc-h8500), and IEEE 695 object file format (obj-ieee), was written by -Steve Chamberlain of Cygnus Support. Steve also modified the COFF back end to -use BFD for some low-level operations, for use with the H8/300 and AMD 29k -targets. - -John Gilmore built the AMD 29000 support, added @code{.include} support, and -simplified the configuration of which versions accept which directives. He -updated the 68k machine description so that Motorola's opcodes always produced -fixed-size instructions (e.g. @code{jsr}), while synthetic instructions -remained shrinkable (@code{jbsr}). John fixed many bugs, including true tested -cross-compilation support, and one bug in relaxation that took a week and -required the proverbial one-bit fix. - -Ian Lance Taylor of Cygnus Support merged the Motorola and MIT syntax for the -68k, completed support for some COFF targets (68k, i386 SVR3, and SCO Unix), -added support for MIPS ECOFF and ELF targets, wrote the initial RS/6000 and -PowerPC assembler, and made a few other minor patches. - -Steve Chamberlain made @code{@value{AS}} able to generate listings. - -Hewlett-Packard contributed support for the HP9000/300. - -Jeff Law wrote GAS and BFD support for the native HPPA object format (SOM) -along with a fairly extensive HPPA testsuite (for both SOM and ELF object -formats). This work was supported by both the Center for Software Science at -the University of Utah and Cygnus Support. - -Support for ELF format files has been worked on by Mark Eichin of Cygnus -Support (original, incomplete implementation for SPARC), Pete Hoogenboom and -Jeff Law at the University of Utah (HPPA mainly), Michael Meissner of the Open -Software Foundation (i386 mainly), and Ken Raeburn of Cygnus Support (sparc, -and some initial 64-bit support). - -Richard Henderson rewrote the Alpha assembler. Klaus Kaempf wrote GAS and BFD -support for openVMS/Alpha. - -Several engineers at Cygnus Support have also provided many small bug fixes and -configuration enhancements. - -Many others have contributed large or small bugfixes and enhancements. If -you have contributed significant work and are not mentioned on this list, and -want to be, let us know. Some of the history has been lost; we are not -intentionally leaving anyone out. - -@node Index -@unnumbered Index - -@printindex cp - -@contents -@bye -@c Local Variables: -@c fill-column: 79 -@c End: |