Re: [RFC] lookup problem in blockframe.c:inside_main_func()

[Joel Brobecker <brobecker@gnat.com>]

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> > 2003-10-06  J. Brobecker  <brobecker@gnat.com>
> > 
> > 	* blockframe.c (inside_main_func): No longer use symbol_lookup()
> >         to lookup the main function symbol.
> 
> This is OK.

Thank you Daniel. Attached is what I ended up commiting (added the dated
comment - let me know if you'd like to see it reworked).

-- 
Joel

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Index: blockframe.c
===================================================================
RCS file: /cvs/src/src/gdb/blockframe.c,v
retrieving revision 1.80
diff -u -p -r1.80 blockframe.c
--- blockframe.c	14 Sep 2003 16:32:12 -0000	1.80
+++ blockframe.c	10 Oct 2003 20:21:02 -0000
@@ -83,22 +83,35 @@ deprecated_inside_entry_file (CORE_ADDR 
 int
 inside_main_func (CORE_ADDR pc)
 {
+  struct minimal_symbol *msymbol;
+
   if (pc == 0)
     return 1;
   if (symfile_objfile == 0)
     return 0;
 
+  msymbol = lookup_minimal_symbol (main_name (), NULL, symfile_objfile);
+
   /* If the addr range is not set up at symbol reading time, set it up
      now.  This is for DEPRECATED_FRAME_CHAIN_VALID_ALTERNATE. I do
      this for coff, because it is unable to set it up and symbol
      reading time. */
 
-  if (symfile_objfile->ei.main_func_lowpc == INVALID_ENTRY_LOWPC &&
-      symfile_objfile->ei.main_func_highpc == INVALID_ENTRY_HIGHPC)
+  if (msymbol != NULL
+      && symfile_objfile->ei.main_func_lowpc == INVALID_ENTRY_LOWPC
+      && symfile_objfile->ei.main_func_highpc == INVALID_ENTRY_HIGHPC)
     {
-      struct symbol *mainsym;
+      /* brobecker/2003-10-10: We used to rely on lookup_symbol() to search
+         the symbol associated to the main function.  Unfortunately,
+         lookup_symbol() uses the current-language la_lookup_symbol_nonlocal
+         function to do the global symbol search.  Depending on the language,
+         this can introduce certain side-effects, because certain languages
+         such as Ada for instance may find more than one match.  So we prefer
+         to search the main function symbol using its address rather than
+         its name.  */
+      struct symbol *mainsym
+        = find_pc_function (SYMBOL_VALUE_ADDRESS (msymbol));
 
-      mainsym = lookup_symbol (main_name (), NULL, VAR_DOMAIN, NULL, NULL);
       if (mainsym && SYMBOL_CLASS (mainsym) == LOC_BLOCK)
 	{
 	  symfile_objfile->ei.main_func_lowpc =
@@ -111,8 +124,6 @@ inside_main_func (CORE_ADDR pc)
   /* Not in the normal symbol tables, see if "main" is in the partial
      symbol table.  If it's not, then give up.  */
   {
-    struct minimal_symbol *msymbol
-      = lookup_minimal_symbol (main_name (), NULL, symfile_objfile);
     if (msymbol != NULL && MSYMBOL_TYPE (msymbol) == mst_text)
       {
 	struct obj_section *osect