[rfa] eliminate some annoying mdebug-related symtab crashes

[Daniel Jacobowitz <dmj+ at andrew dot cmu dot edu>]

I'm really looking forward to getting away from mdebug and back to straight
ELF stabs, but I need mdebug for one last project.  This patch addresses two
of the crashes I've been having - properly, this time.

The init_header_files fix is almost trivial, although it might be preferable
to rename the functions now that I've had to make them non-static.  The list
was NULL, mdebugread's psymtab_to_symtab_1 was calling dbxread's
process_one_symbol which called add_new_header_file, and we crashed.  I'm
not sure if the extra:

+  stabsread_new_init ();
+  buildsym_new_init ();

is really necessary, since elfread_new_init() calls them, but analogy with
every other existing symbol reader suggests that it is correct, or at least
customary.


The init_psymbol_list is a little trickier.  Normally, both the global and
static symbol lists for an objfile are pre-allocated based on the expected
number of symbols.  mdebugread does not do that, which is, I think, fine. 
If global symbols are read but no static symbols are read, which has
happened to me in the startfiles several times, we should not be
re-initializing the list of symbols - there are psymtabs pointing in to what
we're freeing.  We only want to do that if neither global nor static symbols
have been read.


Are these OK to commit?

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer
2001-07-07  Daniel Jacobowitz  <drow@mvista.com>

	* dbxread.c (dbx_symfile_read): Only reinitialize
	the psymbol list if mainline or if both static
	and global lists are empty.
	* dwarf2read.c (dwarf2_build_psymtabs): Likewise.
	* dwarfread.c (dwarf_build_psymtabs): Likewise.
	* xcoffread.c (xcoff_initial_scan): Likewise.
	* os9kread.c (os9k_symfile_read): Likewise.

	* dbxread.c (free_header_files): Make global.
	(init_header_files): Likewise.
	* stabsread.h (free_header_files): Add prototype.
	(init_header_files): Likewise.
	* mdebugread.c (mdebug_build_psymtabs): Initialize
	properly before using the stabs debug reader.

Index: dbxread.c
===================================================================
RCS file: /cvs/src/src/gdb/dbxread.c,v
retrieving revision 1.19
diff -u -r1.19 dbxread.c
--- dbxread.c	2001/07/07 17:19:50	1.19
+++ dbxread.c	2001/07/09 21:46:34
@@ -270,10 +270,6 @@
 
 static void process_now (struct objfile *);
 
-static void free_header_files (void);
-
-static void init_header_files (void);
-
 static void read_ofile_symtab (struct partial_symtab *);
 
 static void dbx_psymtab_to_symtab (struct partial_symtab *);
@@ -319,7 +315,7 @@
 
 /* Free up old header file tables */
 
-static void
+void
 free_header_files (void)
 {
   if (this_object_header_files)
@@ -332,7 +328,7 @@
 
 /* Allocate new header file tables */
 
-static void
+void
 init_header_files (void)
 {
   n_allocated_this_object_header_files = 10;
@@ -582,8 +578,8 @@
 
   /* If we are reinitializing, or if we have never loaded syms yet, init */
   if (mainline
-      || objfile->global_psymbols.size == 0
-      || objfile->static_psymbols.size == 0)
+      || (objfile->global_psymbols.size == 0
+	  &&  objfile->static_psymbols.size == 0))
     init_psymbol_list (objfile, DBX_SYMCOUNT (objfile));
 
   symbol_size = DBX_SYMBOL_SIZE (objfile);
Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.29
diff -u -r1.29 dwarf2read.c
--- dwarf2read.c	2001/07/05 16:45:48	1.29
+++ dwarf2read.c	2001/07/09 21:46:38
@@ -869,8 +869,9 @@
 					   dwarf_line_offset,
 					   dwarf_line_size);
 
-  if (mainline || objfile->global_psymbols.size == 0 ||
-      objfile->static_psymbols.size == 0)
+  if (mainline
+      || (objfile->global_psymbols.size == 0
+	  && objfile->static_psymbols.size == 0))
     {
       init_psymbol_list (objfile, 1024);
     }
Index: dwarfread.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarfread.c,v
retrieving revision 1.7
diff -u -r1.7 dwarfread.c
--- dwarfread.c	2001/03/06 08:21:07	1.7
+++ dwarfread.c	2001/07/09 21:46:41
@@ -706,8 +706,9 @@
      Since we have no idea how many DIES we are looking at, we just guess
      some arbitrary value. */
 
-  if (mainline || objfile->global_psymbols.size == 0 ||
-      objfile->static_psymbols.size == 0)
+  if (mainline
+      || (objfile->global_psymbols.size == 0
+	  && objfile->static_psymbols.size == 0))
     {
       init_psymbol_list (objfile, 1024);
     }
Index: mdebugread.c
===================================================================
RCS file: /cvs/src/src/gdb/mdebugread.c,v
retrieving revision 1.13
diff -u -r1.13 mdebugread.c
--- mdebugread.c	2001/05/29 10:45:10	1.13
+++ mdebugread.c	2001/07/09 21:46:46
@@ -491,6 +491,11 @@
   debug_swap = swap;
   debug_info = info;
 
+  stabsread_new_init ();
+  buildsym_new_init ();
+  free_header_files ();
+  init_header_files ();
+        
   /* Make sure all the FDR information is swapped in.  */
   if (info->fdr == (FDR *) NULL)
     {
Index: os9kread.c
===================================================================
RCS file: /cvs/src/src/gdb/os9kread.c,v
retrieving revision 1.9
diff -u -r1.9 os9kread.c
--- os9kread.c	2001/03/07 02:57:08	1.9
+++ os9kread.c	2001/07/09 21:46:49
@@ -320,8 +320,9 @@
 
   sym_bfd = objfile->obfd;
   /* If we are reinitializing, or if we have never loaded syms yet, init */
-  if (mainline || objfile->global_psymbols.size == 0 ||
-      objfile->static_psymbols.size == 0)
+  if (mainline
+      || (objfile->global_psymbols.size == 0
+	  && objfile->static_psymbols.size == 0))
     init_psymbol_list (objfile, DBX_SYMCOUNT (objfile));
 
   free_pending_blocks ();
Index: stabsread.h
===================================================================
RCS file: /cvs/src/src/gdb/stabsread.h,v
retrieving revision 1.5
diff -u -r1.5 stabsread.h
--- stabsread.h	2001/03/06 08:21:17	1.5
+++ stabsread.h	2001/07/09 21:46:50
@@ -219,4 +219,8 @@
 extern int resolve_cfront_continuation
   (struct objfile *objfile, struct symbol *sym, char *p);
 
+extern void free_header_files (void);
+
+extern void init_header_files (void);
+
 #undef EXTERN
Index: xcoffread.c
===================================================================
RCS file: /cvs/src/src/gdb/xcoffread.c,v
retrieving revision 1.14
diff -u -r1.14 xcoffread.c
--- xcoffread.c	2001/05/01 19:36:11	1.14
+++ xcoffread.c	2001/07/09 21:46:52
@@ -2684,8 +2684,8 @@
 
   /* If we are reinitializing, or if we have never loaded syms yet, init */
   if (mainline
-      || objfile->global_psymbols.size == 0
-      || objfile->static_psymbols.size == 0)
+      || (objfile->global_psymbols.size == 0
+	  && objfile->static_psymbols.size == 0))
     /* I'm not sure how how good num_symbols is; the rule of thumb in
        init_psymbol_list was developed for a.out.  On the one hand,
        num_symbols includes auxents.  On the other hand, it doesn't