diff options
| -rw-r--r-- | NEWS | 11 | ||||
| -rw-r--r-- | data/c.m4 | 2 | ||||
| -rw-r--r-- | doc/bison.texi | 17 | ||||
| -rw-r--r-- | tests/headers.at | 7 |
4 files changed, 33 insertions, 4 deletions
@@ -14,6 +14,17 @@ GNU Bison NEWS Incorrect definitions of YY_, issued by yacc.c when no parser header is generated, are removed. +** Header guards (yacc.c, glr.c, glr.cc) + + In order to avoid collisions, the header guards are now + YY_<PREFIX>_<FILE>_INCLUDED, instead of merely <PREFIX>_<FILE>. + For instance the header generated from + + %define api.prefix "calc" + %defines "lib/parse.h" + + will use YY_CALC_LIB_PARSE_H_INCLUDED as guard. + * Noteworthy changes in release 2.6.2 (2012-08-03) [stable] ** Bug fixes @@ -30,7 +30,7 @@ m4_define([b4_tocpp], # ------------------ # A valid C macro name to use as a CPP header guard for FILE. m4_define([b4_cpp_guard], -[b4_tocpp(m4_defn([b4_prefix])/[$1])]) +[[YY_]b4_tocpp(m4_defn([b4_prefix])/[$1])[_INCLUDED]]) # b4_cpp_guard_open(FILE) diff --git a/doc/bison.texi b/doc/bison.texi index b8a1aa6d..69836112 100644 --- a/doc/bison.texi +++ b/doc/bison.texi @@ -5124,6 +5124,23 @@ Values, ,Semantic Values of Tokens}. If you have declared @code{%code requires} or @code{%code provides}, the output header also contains their code. @xref{%code Summary}. + +@cindex Header guard +The generated header is protected against multiple inclusions with a C +preprocessor guard: @samp{YY_@var{PREFIX}_@var{FILE}_INCLUDED}, where +@var{PREFIX} and @var{FILE} are the prefix (@pxref{Multiple Parsers, +,Multiple Parsers in the Same Program}) and generated file name turned +uppercase, with each series of non alphanumerical characters converted to a +single underscore. + +For instance with @samp{%define api.prefix "calc"} and @samp{%defines +"lib/parse.h"}, the header will be guarded as follows. +@example +#ifndef YY_CALC_LIB_PARSE_H_INCLUDED +# define YY_CALC_LIB_PARSE_H_INCLUDED +... +#endif /* ! YY_CALC_LIB_PARSE_H_INCLUDED */ +@end example @end deffn @deffn {Directive} %defines @var{defines-file} diff --git a/tests/headers.at b/tests/headers.at index aea0bc9b..0524340e 100644 --- a/tests/headers.at +++ b/tests/headers.at @@ -167,13 +167,14 @@ AT_BISON_CHECK([-d -o AT_SKEL_CC_IF([$1.cc $1.yy], [$1.c $1.y])]) AT_SKEL_CC_IF([], [AT_CHECK([$EGREP yy $1.h], [1])]) -# Ignore comments. Ignore YYPARSE_PARAM (obsolete) and -# YYPUSH_MORE(_DEFINED)? (whose definition is constant). +# Check there is not 'YY' left. +# Ignore comments, YYPARSE_PARAM (obsolete), YYPUSH_MORE(_DEFINED)? +# (constant definition), YY_\w+_INCLUDED (header guards). # # YYDEBUG (not renamed) can be read, but not changed. AT_CHECK([[sed -ne 's,/\*[^*]*\*/,,g;s,//.*,,' \ -e '/YY/p' ]$1.AT_SKEL_CC_IF([hh], [h])[ | - $EGREP -wv 'YY(PARSE_PARAM|PUSH_MORE(_DEFINED)?)|(defined|if) YYDEBUG']], + $EGREP -wv 'YY(PARSE_PARAM|PUSH_MORE(_DEFINED)?|_[0-9A-Z_]+_INCLUDED)|(defined|if) YYDEBUG']], [1]) AT_LANG_COMPILE([$1.o]) |