[RFA-2] Handle GPC specific name for main function

Pierre Muller
2007-10-08T15:43:12Z

Thanks to Joel for all his contribution,
I resubmit a modified version, which is
the same as Joel proposed, to the exception that
I used "const char *" instead of "const char const *"
that I did not find anywhere else in the GDB sources
and seems really strange to me...
I also modified the final comment inside pascal_main_name.

ChangeLog entry:

2007-10-08 Pierre Muller <muller@ics.u-strasbg.fr>

* p-lang.h (pascal_main_name): Add declaration.
* p-lang.c (GPC_P_INITIALIZE, GPC_MAIN_PROGRAM_NAME_1)
(GPC_MAIN_PROGRAM_NAME_2): New constants.
(pascal_main_name): New function.
* symtab.c: Include p-lang.h.
(find_main_name): Add call to pascal_main_name.
* Makefile.in (symtab.o): Add dependency on p-lang.h.

Index: p-lang.h
===================================================================
RCS file: /cvs/src/src/gdb/p-lang.h,v
retrieving revision 1.12
diff -u -p -r1.12 p-lang.h
--- p-lang.h 23 Aug 2007 18:08:36 -0000 1.12
+++ p-lang.h 8 Oct 2007 15:41:43 -0000
@@ -21,6 +21,9 @@

struct value;

+/* Defined in p-lang.c */
+extern const char *pascal_main_name (void);
+
extern int pascal_parse (void); /* Defined in p-exp.y */

extern void pascal_error (char *); /* Defined in p-exp.y */
Index: p-lang.c
===================================================================
RCS file: /cvs/src/src/gdb/p-lang.c,v
retrieving revision 1.33
diff -u -p -r1.33 p-lang.c
--- p-lang.c 23 Sep 2007 16:25:05 -0000 1.33
+++ p-lang.c 8 Oct 2007 15:41:43 -0000
@@ -35,6 +35,56 @@
extern void _initialize_pascal_language (void);

+/* All GPC versions until now (2007-09-27) also define a symbol called
+ '_p_initialize'. Check for the presence of this symbol first. */
+static const char GPC_P_INITIALIZE[] = "_p_initialize";
+
+/* The name of the symbol that GPC uses as the name of the main
+ procedure (since version 20050212). */
+static const char GPC_MAIN_PROGRAM_NAME_1[] = "_p__M0_main_program";
+
+/* Older versions of GPC (versions older than 20050212) were using
+ a different name for the main procedure. */
+static const char GPC_MAIN_PROGRAM_NAME_2[] = "pascal_main_program";
+
+/* Function returning the special symbol name used
+ by GPC for the main procedure in the main program
+ if it is found in minimal symbol list.
+ This function tries to find minimal symbols generated by GPC
+ so that it finds the even if the program was compiled
+ without debugging information.
+ According to information supplied by Waldeck Hebisch,
+ this should work for all versions posterior to June 2000. */
+
+const char *
+pascal_main_name (void)
+{
+ struct minimal_symbol *msym;
+
+ msym = lookup_minimal_symbol (GPC_P_INITIALIZE, NULL, NULL);
+
+ /* If '_p_initialize' was not found, the main program is likely not
+ written in Pascal. */
+ if (msym == NULL)
+ return NULL;
+
+ msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_1, NULL, NULL);
+ if (msym != NULL)
+ {
+ return GPC_MAIN_PROGRAM_NAME_1;
+ }
+
+ msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_2, NULL, NULL);
+ if (msym != NULL)
+ {
+ return GPC_MAIN_PROGRAM_NAME_2;
+ }
+
+ /* No known entry procedure found, the main program is probably
+ not compiled with GPC. */
+ return NULL;
+}
+
/* Determines if type TYPE is a pascal string type.
Returns 1 if the type is a known pascal type
This function is used by p-valprint.c code to allow better string
display.
Index: symtab.c
===================================================================
RCS file: /cvs/src/src/gdb/symtab.c,v
retrieving revision 1.165
diff -u -p -r1.165 symtab.c
--- symtab.c 24 Sep 2007 07:40:32 -0000 1.165
+++ symtab.c 8 Oct 2007 15:41:44 -0000
@@ -40,6 +40,7 @@
#include "filenames.h" /* for FILENAME_CMP */
#include "objc-lang.h"
#include "ada-lang.h"
+#include "p-lang.h"

#include "hashtab.h"

@@ -4126,7 +4127,7 @@ set_main_name (const char *name)
static void
find_main_name (void)
{
- char *new_main_name;
+ const char *new_main_name;

/* Try to see if the main procedure is in Ada. */
/* FIXME: brobecker/2005-03-07: Another way of doing this would
@@ -4151,6 +4152,13 @@ find_main_name (void)
return;
}

+ new_main_name = pascal_main_name ();
+ if (new_main_name != NULL)
+ {
+ set_main_name (new_main_name);
+ return;
+ }
+
/* The languages above didn't identify the name of the main procedure.
Fallback to "main". */
set_main_name ("main");
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.941
diff -u -p -r1.941 Makefile.in
--- Makefile.in 8 Oct 2007 15:09:04 -0000 1.941
+++ Makefile.in 8 Oct 2007 15:41:45 -0000
@@ -2751,7 +2751,7 @@ symtab.o: symtab.c $(defs_h) $(symtab_h)
$(filenames_h) $(objc_lang_h) $(ada_lang_h) $(hashtab_h) \
$(gdb_obstack_h) $(block_h) $(dictionary_h) $(gdb_string_h) \
$(gdb_stat_h) $(cp_abi_h) $(observer_h) $(gdb_assert_h) \
- $(solist_h) $(ada_lang_h)
+ $(solist_h) $(p_lang_h)
target.o: target.c $(defs_h) $(gdb_string_h) $(target_h) $(gdbcmd_h) \
$(symtab_h) $(inferior_h) $(bfd_h) $(symfile_h) $(objfiles_h) \
$(gdb_wait_h) $(dcache_h) $(regcache_h) $(gdb_assert_h) $(gdbcore_h)
\