Add first preprocessor macro-expansion files.

* macroexp.c, macroexp.h, macrotab.c, macrotab.h: New files.
* Makefile.in (SFILES): Add macrotab.c, macroexp.c.
(splay_tree_h, macroexp_h, macrotab_h): New variable.
(HFILES_NO_SRCDIR): Add macrotab.h, macroexp.h.
(COMMON_OBS): Add macrotab.o, macroexp.o.
(macroexp.o, macrotab.o): New rules.

1 files changed, 295 insertions, 0 deletions

diff --git a/gdb/macrotab.h b/gdb/macrotab.h
new file mode 100644
index 00000000000..cbc6d1b53d7
--- /dev/null
+++ b/gdb/macrotab.h
@@ -0,0 +1,295 @@
+/* Interface to C preprocessor macro tables for GDB.
+   Copyright 2002 Free Software Foundation, Inc.
+   Contributed by Red Hat, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifndef MACROTAB_H
+#define MACROTAB_H
+
+#include "obstack.h"
+#include "bcache.h"
+
+/* How do we represent a source location?  I mean, how should we
+   represent them within GDB; the user wants to use all sorts of
+   ambiguous abbreviations, like "break 32" and "break foo.c:32"
+   ("foo.c" may have been #included into several compilation units),
+   but what do we disambiguate those things to?
+
+   - Answer 1: "Filename and line number."  (Or column number, if
+   you're picky.)  That's not quite good enough.  For example, the
+   same source file can be #included into several different
+   compilation units --- which #inclusion do you mean?
+
+   - Answer 2: "Compilation unit, filename, and line number."  This is
+   a pretty good answer; GDB's `struct symtab_and_line' basically
+   embodies this representation.  But it's still ambiguous; what if a
+   given compilation unit #includes the same file twice --- how can I
+   set a breakpoint on line 12 of the fifth #inclusion of "foo.c"?
+
+   - Answer 3: "Compilation unit, chain of #inclusions, and line
+   number."  This is analogous to the way GCC reports errors in
+   #include files:
+
+        $ gcc -c base.c
+        In file included from header2.h:8,
+                         from header1.h:3,
+                         from base.c:5:
+        header3.h:1: parse error before ')' token
+        $
+
+   GCC tells you exactly what path of #inclusions led you to the
+   problem.  It gives you complete information, in a way that the
+   following would not:
+
+        $ gcc -c base.c
+        header3.h:1: parse error before ')' token
+        $
+
+   Converting all of GDB to use this is a big task, and I'm not really
+   suggesting it should be a priority.  But this module's whole
+   purpose is to maintain structures describing the macro expansion
+   process, so I think it's appropriate for us to take a little care
+   to do that in a complete fashion.
+
+   In this interface, the first line of a file is numbered 1, not 0.
+   This is the same convention the rest of GDB uses.  */
+
+
+/* A table of all the macro definitions for a given compilation unit.  */
+struct macro_table;
+
+
+/* A source file that participated in a compilation unit --- either a
+   main file, or an #included file.  If a file is #included more than
+   once, the presence of the `included_from' and `included_at_line'
+   members means that we need to make one instance of this structure
+   for each #inclusion.  Taken as a group, these structures form a
+   tree mapping the #inclusions that contributed to the compilation
+   unit, with the main source file as its root.
+
+   It's worth noting that libcpp has a simpler way of representing all
+   this, which we should consider switching to.  It might even be
+   suitable for ordinary non-macro line number info.
+
+   Suppose you take your main source file, and after each line
+   containing an #include directive you insert the text of the
+   #included file.  The result is a big file that pretty much
+   corresponds to the full text the compiler's going to see.  There's
+   a one-to-one correspondence between lines in the big file and
+   per-inclusion lines in the source files.  (Obviously, #include
+   directives that are #if'd out don't count.  And you'll need to
+   append a newline to any file that doesn't end in one, to avoid
+   splicing the last #included line with the next line of the
+   #including file.)
+
+   Libcpp calls line numbers in this big imaginary file "logical line
+   numbers", and has a data structure called a "line map" that can map
+   logical line numbers onto actual source filenames and line numbers,
+   and also tell you the chain of #inclusions responsible for any
+   particular logical line number.  Basically, this means you can pass
+   around a single line number and some kind of "compilation unit"
+   object and you get nice, unambiguous source code locations that
+   distinguish between multiple #inclusions of the same file, etc.
+
+   Pretty neat, huh?  */
+
+struct macro_source_file
+{
+
+  /* The macro table for the compilation unit this source location is
+     a part of.  */
+  struct macro_table *table;
+
+  /* A source file --- possibly a header file.  */
+  const char *filename;
+
+  /* The location we were #included from, or zero if we are the
+     compilation unit's main source file.  */
+  struct macro_source_file *included_by;
+
+  /* If `included_from' is non-zero, the line number in that source
+     file at which we were included.  */
+  int included_at_line;
+
+  /* Head of a linked list of the source files #included by this file;
+     our children in the #inclusion tree.  This list is sorted by its
+     elements' `included_at_line' values, which are unique.  (The
+     macro splay tree's ordering function needs this property.)  */
+  struct macro_source_file *includes;
+
+  /* The next file #included by our `included_from' file; our sibling
+     in the #inclusion tree.  */
+  struct macro_source_file *next_included;
+};
+
+
+/* Create a new, empty macro table.  Allocate it in OBSTACK, or use
+   xmalloc if OBSTACK is zero.  Use BCACHE to store all macro names,
+   arguments, definitions, and anything else that might be the same
+   amongst compilation units in an executable file; if BCACHE is zero,
+   don't cache these things.
+
+   Note that, if either OBSTACK or BCACHE are non-zero, then you
+   should only ever add information the macro table --- you should
+   never remove things from it.  You'll get an error if you try.  At
+   the moment, since we only provide obstacks and bcaches for macro
+   tables for symtabs, this restriction makes a nice sanity check.
+   Obstacks and bcaches are pretty much grow-only structures anyway.
+   However, if we find that it's occasionally useful to delete things
+   even from the symtab's tables, and the storage leak isn't a
+   problem, this restriction could be lifted.  */
+struct macro_table *new_macro_table (struct obstack *obstack,
+                                     struct bcache *bcache);
+
+
+/* Free TABLE, and any macro definitions, source file structures,
+   etc. it owns.  This will raise an internal error if TABLE was
+   allocated on an obstack, or if it uses a bcache.  */
+void free_macro_table (struct macro_table *table);
+
+
+/* Set FILENAME as the main source file of TABLE.  Return a source
+   file structure describing that file; if we record the #definition
+   of macros, or the #inclusion of other files into FILENAME, we'll
+   use that source file structure to indicate the context.
+
+   The "main source file" is the one that was given to the compiler;
+   all other source files that contributed to the compilation unit are
+   #included, directly or indirectly, from this one.
+
+   The macro table makes its own copy of FILENAME; the caller is
+   responsible for freeing FILENAME when it is no longer needed.  */
+struct macro_source_file *macro_set_main (struct macro_table *table,
+                                          const char *filename);
+
+
+/* Return the main source file of the macro table TABLE.  */
+struct macro_source_file *macro_main (struct macro_table *table);
+
+
+/* Record a #inclusion.
+   Record in SOURCE's macro table that, at line number LINE in SOURCE,
+   we #included the file INCLUDED.  Return a source file structure we
+   can use for symbols #defined or files #included into that.  If we've
+   already created a source file structure for this #inclusion, return
+   the same structure we created last time.
+
+   The first line of the source file has a line number of 1, not 0.
+
+   The macro table makes its own copy of INCLUDED; the caller is
+   responsible for freeing INCLUDED when it is no longer needed.  */
+struct macro_source_file *macro_include (struct macro_source_file *source,
+                                         int line,
+                                         const char *included);
+
+
+/* Find any source file structure for a file named NAME, either
+   included into SOURCE, or SOURCE itself.  Return zero if we have
+   none.  NAME is only the final portion of the filename, not the full
+   path.  e.g., `stdio.h', not `/usr/include/stdio.h'.  If NAME
+   appears more than once in the inclusion tree, return the
+   least-nested inclusion --- the one closest to the main source file.  */
+struct macro_source_file *(macro_lookup_inclusion
+                           (struct macro_source_file *source,
+                            const char *name));
+
+
+/* Record an object-like #definition (i.e., one with no parameter list).
+   Record in SOURCE's macro table that, at line number LINE in SOURCE,
+   we #defined a preprocessor symbol named NAME, whose replacement
+   string is REPLACEMENT.  This function makes copies of NAME and
+   REPLACEMENT; the caller is responsible for freeing them.  */
+void macro_define_object (struct macro_source_file *source, int line,
+                          const char *name, const char *replacement);
+
+
+/* Record an function-like #definition (i.e., one with a parameter list).
+
+   Record in SOURCE's macro table that, at line number LINE in SOURCE,
+   we #defined a preprocessor symbol named NAME, with ARGC arguments
+   whose names are given in ARGV, whose replacement string is REPLACEMENT.  If
+   the macro takes a variable number of arguments, then ARGC should be
+   one greater than the number of named arguments, and ARGV[ARGC-1]
+   should be the string "...".  This function makes its own copies of
+   NAME, ARGV, and REPLACEMENT; the caller is responsible for freeing
+   them.  */
+void macro_define_function (struct macro_source_file *source, int line,
+                            const char *name, int argc, const char **argv,
+                            const char *replacement);
+
+
+/* Record an #undefinition.
+   Record in SOURCE's macro table that, at line number LINE in SOURCE,
+   we removed the definition for the preprocessor symbol named NAME.  */
+void macro_undef (struct macro_source_file *source, int line,
+                  const char *name);
+
+
+/* Different kinds of macro definitions.  */
+enum macro_kind
+{
+  macro_object_like,
+  macro_function_like
+};
+
+
+/* A preprocessor symbol definition.  */
+struct macro_definition
+{
+  /* The table this definition lives in.  */
+  struct macro_table *table;
+
+  /* What kind of macro it is.  */
+  enum macro_kind kind;
+
+  /* If `kind' is `macro_function_like', the number of arguments it
+     takes, and their names.  The names, and the array of pointers to
+     them, are in the table's bcache, if it has one.  */
+  int argc;
+  const char * const *argv;
+
+  /* The replacement string (body) of the macro.  This is in the
+     table's bcache, if it has one.  */
+  const char *replacement;
+};
+
+
+/* Return a pointer to the macro definition for NAME in scope at line
+   number LINE of SOURCE.  If LINE is -1, return the definition in
+   effect at the end of the file.  The macro table owns the structure;
+   the caller need not free it.  Return zero if NAME is not #defined
+   at that point.  */
+struct macro_definition *(macro_lookup_definition
+                          (struct macro_source_file *source,
+                           int line, const char *name));
+
+
+/* Return the source location of the definition for NAME in scope at
+   line number LINE of SOURCE.  Set *DEFINITION_LINE to the line
+   number of the definition, and return a source file structure for
+   the file.  Return zero if NAME has no definition in scope at that
+   point, and leave *DEFINITION_LINE unchanged.  */
+struct macro_source_file *(macro_definition_location
+                           (struct macro_source_file *source,
+                            int line,
+                            const char *name,
+                            int *definition_line));
+
+
+#endif /* MACROTAB_H */