* xcoffread.c (xcoff_sym_fns): Update.

	* symfile.h (struct sym_fns) <sym_read_psymbols>: New field.
	(enum symfile_add_flags) <SYMFILE_NO_READ>: New constant.
	* symfile.c (syms_from_objfile): Handle SYMFILE_NO_READ.
	(symbol_file_add_with_addrs_or_offsets): Likewise.
	(reread_symbols): Handle OBJF_PSYMTABS_READ.
	* somread.c (som_sym_fns): Update.
	* psymtab.h (require_partial_symbols): Declare.
	* psymtab.c (require_partial_symbols): New function.
	(ALL_OBJFILE_PSYMTABS_REQUIRED): New macro.
	(ALL_OBJFILE_PSYMTABS): Undef.
	(ALL_PSYMTABS): Move from psympriv.h.
	(lookup_partial_symtab, find_pc_sect_psymtab)
	(lookup_symbol_aux_psymtabs, relocate_psymtabs)
	(find_last_source_symtab_from_partial)
	(forget_cached_source_info_partial)
	(print_psymtab_stats_for_objfile, read_symtabs_for_function)
	(expand_partial_symbol_tables, read_psymtabs_with_filename)
	(map_symbol_names_psymtab, map_symbol_filenames_psymtab)
	(find_symbol_file_from_partial, map_matching_symbols_psymtab)
	(expand_symtabs_matching_via_partial, maintenance_info_psymtabs):
	Use ALL_OBJFILE_PSYMTABS_REQUIRED.
	* psympriv.h (ALL_PSYMTABS): Move to psymtab.c.
	* objfiles.h (OBJF_PSYMTABS_READ): New macro.
	* objfiles.c (objfile_has_partial_symbols): Handle lazily-read
	psymtabs.
	* mipsread.c (ecoff_sym_fns): Update.
	* machoread.c (macho_sym_fns): Update.
	* elfread.c (elf_symfile_read): Set up for lazy psymtab reading.
	(read_psyms): New function.
	(elf_sym_fns, elf_sym_fns_gdb_index): Update.
	(elf_sym_fns_lazy_psyms): New global.
	* dwarf2read.c (dwarf2_initialize_objfile): Don't call
	dwarf2_build_psymtabs.
	* dbxread.c (aout_sym_fns): Update.
	* coffread.c (coff_sym_fns): Update.

16 files changed, 214 insertions, 37 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 9b2637a..7149bbf 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,44 @@
 2011-03-07  Tom Tromey  <tromey@redhat.com>
 
+	* xcoffread.c (xcoff_sym_fns): Update.
+	* symfile.h (struct sym_fns) <sym_read_psymbols>: New field.
+	(enum symfile_add_flags) <SYMFILE_NO_READ>: New constant.
+	* symfile.c (syms_from_objfile): Handle SYMFILE_NO_READ.
+	(symbol_file_add_with_addrs_or_offsets): Likewise.
+	(reread_symbols): Handle OBJF_PSYMTABS_READ.
+	* somread.c (som_sym_fns): Update.
+	* psymtab.h (require_partial_symbols): Declare.
+	* psymtab.c (require_partial_symbols): New function.
+	(ALL_OBJFILE_PSYMTABS_REQUIRED): New macro.
+	(ALL_OBJFILE_PSYMTABS): Undef.
+	(ALL_PSYMTABS): Move from psympriv.h.
+	(lookup_partial_symtab, find_pc_sect_psymtab)
+	(lookup_symbol_aux_psymtabs, relocate_psymtabs)
+	(find_last_source_symtab_from_partial)
+	(forget_cached_source_info_partial)
+	(print_psymtab_stats_for_objfile, read_symtabs_for_function)
+	(expand_partial_symbol_tables, read_psymtabs_with_filename)
+	(map_symbol_names_psymtab, map_symbol_filenames_psymtab)
+	(find_symbol_file_from_partial, map_matching_symbols_psymtab)
+	(expand_symtabs_matching_via_partial, maintenance_info_psymtabs):
+	Use ALL_OBJFILE_PSYMTABS_REQUIRED.
+	* psympriv.h (ALL_PSYMTABS): Move to psymtab.c.
+	* objfiles.h (OBJF_PSYMTABS_READ): New macro.
+	* objfiles.c (objfile_has_partial_symbols): Handle lazily-read
+	psymtabs.
+	* mipsread.c (ecoff_sym_fns): Update.
+	* machoread.c (macho_sym_fns): Update.
+	* elfread.c (elf_symfile_read): Set up for lazy psymtab reading.
+	(read_psyms): New function.
+	(elf_sym_fns, elf_sym_fns_gdb_index): Update.
+	(elf_sym_fns_lazy_psyms): New global.
+	* dwarf2read.c (dwarf2_initialize_objfile): Don't call
+	dwarf2_build_psymtabs.
+	* dbxread.c (aout_sym_fns): Update.
+	* coffread.c (coff_sym_fns): Update.
+
+2011-03-07  Tom Tromey  <tromey@redhat.com>
+
 	* infrun.c (print_exited_reason): Include inferior id and pid in
 	message.
 
diff --git a/gdb/coffread.c b/gdb/coffread.c
index 9df775d..85a5553 100644
--- a/gdb/coffread.c
+++ b/gdb/coffread.c
@@ -2191,6 +2191,7 @@ static const struct sym_fns coff_sym_fns =
 				   for sym_read() */
   coff_symfile_read,		/* sym_read: read a symbol file into
 				   symtab */
+  NULL,				/* sym_read_psymbols */
   coff_symfile_finish,		/* sym_finish: finished with file,
 				   cleanup */
   default_symfile_offsets,	/* sym_offsets: xlate external to
diff --git a/gdb/dbxread.c b/gdb/dbxread.c
index b68aa80..2e32f38 100644
--- a/gdb/dbxread.c
+++ b/gdb/dbxread.c
@@ -3587,6 +3587,7 @@ static const struct sym_fns aout_sym_fns =
   dbx_new_init,			/* init anything gbl to entire symtab */
   dbx_symfile_init,		/* read initial info, setup for sym_read() */
   dbx_symfile_read,		/* read a symbol file into symtab */
+  NULL,				/* sym_read_psymbols */
   dbx_symfile_finish,		/* finished with file, cleanup */
   default_symfile_offsets, 	/* parse user's offsets to internal form */
   default_symfile_segments,	/* Get segment information from a file.  */
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index d12028f..2a47c7d 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -2767,7 +2767,6 @@ dwarf2_initialize_objfile (struct objfile *objfile)
   if (dwarf2_read_index (objfile))
     return 1;
 
-  dwarf2_build_psymtabs (objfile);
   return 0;
 }
 
diff --git a/gdb/elfread.c b/gdb/elfread.c
index 54c7fa3..59a1f7c 100644
--- a/gdb/elfread.c
+++ b/gdb/elfread.c
@@ -40,8 +40,9 @@
 
 extern void _initialize_elfread (void);
 
-/* Forward declaration.  */
+/* Forward declarations.  */
 static const struct sym_fns elf_sym_fns_gdb_index;
+static const struct sym_fns elf_sym_fns_lazy_psyms;
 
 /* The struct elfinfo is available only during ELF symbol table and
    psymtab reading.  It is destroyed at the completion of psymtab-reading.
@@ -887,14 +888,24 @@ elf_symfile_read (struct objfile *objfile, int symfile_flags)
 				bfd_section_size (abfd, str_sect));
     }
 
-  if (dwarf2_has_info (objfile) && dwarf2_initialize_objfile (objfile))
-    objfile->sf = &elf_sym_fns_gdb_index;
-
+  if (dwarf2_has_info (objfile))
+    {
+      if (dwarf2_initialize_objfile (objfile))
+	objfile->sf = &elf_sym_fns_gdb_index;
+      else
+	{
+	  /* It is ok to do this even if the stabs reader made some
+	     partial symbols, because OBJF_PSYMTABS_READ has not been
+	     set, and so our lazy reader function will still be called
+	     when needed.  */
+	  objfile->sf = &elf_sym_fns_lazy_psyms;
+	}
+    }
   /* If the file has its own symbol tables it has no separate debug
      info.  `.dynsym'/`.symtab' go to MSYMBOLS, `.debug_info' goes to
      SYMTABS/PSYMTABS.  `.gnu_debuglink' may no longer be present with
      `.note.gnu.build-id'.  */
-  if (!objfile_has_partial_symbols (objfile))
+  else if (!objfile_has_partial_symbols (objfile))
     {
       char *debugfile;
 
@@ -913,6 +924,15 @@ elf_symfile_read (struct objfile *objfile, int symfile_flags)
     }
 }
 
+/* Callback to lazily read psymtabs.  */
+
+static void
+read_psyms (struct objfile *objfile)
+{
+  if (dwarf2_has_info (objfile))
+    dwarf2_build_psymtabs (objfile);
+}
+
 /* This cleans up the objfile's deprecated_sym_stab_info pointer, and
    the chain of stab_section_info's, that might be dangling from
    it.  */
@@ -1057,6 +1077,25 @@ static const struct sym_fns elf_sym_fns =
   elf_new_init,			/* init anything gbl to entire symtab */
   elf_symfile_init,		/* read initial info, setup for sym_read() */
   elf_symfile_read,		/* read a symbol file into symtab */
+  NULL,				/* sym_read_psymbols */
+  elf_symfile_finish,		/* finished with file, cleanup */
+  default_symfile_offsets,	/* Translate ext. to int. relocation */
+  elf_symfile_segments,		/* Get segment information from a file.  */
+  NULL,
+  default_symfile_relocate,	/* Relocate a debug section.  */
+  &psym_functions
+};
+
+/* The same as elf_sym_fns, but not registered and lazily reads
+   psymbols.  */
+
+static const struct sym_fns elf_sym_fns_lazy_psyms =
+{
+  bfd_target_elf_flavour,
+  elf_new_init,			/* init anything gbl to entire symtab */
+  elf_symfile_init,		/* read initial info, setup for sym_read() */
+  elf_symfile_read,		/* read a symbol file into symtab */
+  read_psyms,			/* sym_read_psymbols */
   elf_symfile_finish,		/* finished with file, cleanup */
   default_symfile_offsets,	/* Translate ext. to int. relocation */
   elf_symfile_segments,		/* Get segment information from a file.  */
@@ -1073,6 +1112,7 @@ static const struct sym_fns elf_sym_fns_gdb_index =
   elf_new_init,			/* init anything gbl to entire symab */
   elf_symfile_init,		/* read initial info, setup for sym_red() */
   elf_symfile_read,		/* read a symbol file into symtab */
+  NULL,				/* sym_read_psymbols */
   elf_symfile_finish,		/* finished with file, cleanup */
   default_symfile_offsets,	/* Translate ext. to int. relocatin */
   elf_symfile_segments,		/* Get segment information from a file.  */
diff --git a/gdb/machoread.c b/gdb/machoread.c
index ad33f63..dbf9ae4 100644
--- a/gdb/machoread.c
+++ b/gdb/machoread.c
@@ -843,6 +843,7 @@ static const struct sym_fns macho_sym_fns = {
   macho_new_init,               /* init anything gbl to entire symtab */
   macho_symfile_init,           /* read initial info, setup for sym_read() */
   macho_symfile_read,           /* read a symbol file into symtab */
+  NULL,				/* sym_read_psymbols */
   macho_symfile_finish,         /* finished with file, cleanup */
   macho_symfile_offsets,        /* xlate external to internal form */
   default_symfile_segments,	/* Get segment information from a file.  */
diff --git a/gdb/mipsread.c b/gdb/mipsread.c
index 697f784..74d795d 100644
--- a/gdb/mipsread.c
+++ b/gdb/mipsread.c
@@ -396,6 +396,7 @@ static const struct sym_fns ecoff_sym_fns =
   mipscoff_new_init,		/* init anything gbl to entire symtab */
   mipscoff_symfile_init,	/* read initial info, setup for sym_read() */
   mipscoff_symfile_read,	/* read a symbol file into symtab */
+  NULL,				/* sym_read_psymbols */
   mipscoff_symfile_finish,	/* finished with file, cleanup */
   default_symfile_offsets,	/* dummy FIXME til implem sym reloc */
   default_symfile_segments,	/* Get segment information from a file.  */
diff --git a/gdb/objfiles.c b/gdb/objfiles.c
index 2223038..f3259dd 100644
--- a/gdb/objfiles.c
+++ b/gdb/objfiles.c
@@ -907,7 +907,14 @@ objfile_relocate (struct objfile *objfile, struct section_offsets *new_offsets)
 int
 objfile_has_partial_symbols (struct objfile *objfile)
 {
-  return objfile->sf ? objfile->sf->qf->has_symbols (objfile) : 0;
+  if (!objfile->sf)
+    return 0;
+  /* If we have not read psymbols, but we have a function capable of
+     reading them, then that is an indication that they are in fact
+     available.  */
+  if ((objfile->flags & OBJF_PSYMTABS_READ) == 0)
+    return objfile->sf->sym_read_psymbols != NULL;
+  return objfile->sf->qf->has_symbols (objfile);
 }
 
 /* Return non-zero if OBJFILE has full symbols.  */
diff --git a/gdb/objfiles.h b/gdb/objfiles.h
index 759c2f9..275c2ac 100644
--- a/gdb/objfiles.h
+++ b/gdb/objfiles.h
@@ -436,6 +436,11 @@ struct objfile
 
 #define OBJF_USERLOADED	(1 << 3)	/* User loaded */
 
+/* Set if we have tried to read partial symtabs for this objfile.
+   This is used to allow lazy reading of partial symtabs.  */
+
+#define OBJF_PSYMTABS_READ (1 << 4)
+
 /* The object file that contains the runtime common minimal symbols
    for SunOS4.  Note that this objfile has no associated BFD.  */
 
diff --git a/gdb/psympriv.h b/gdb/psympriv.h
index 8e8e15c..95d7676 100644
--- a/gdb/psympriv.h
+++ b/gdb/psympriv.h
@@ -183,10 +183,4 @@ extern void discard_psymtab (struct partial_symtab *);
 #define	ALL_OBJFILE_PSYMTABS(objfile, p) \
     for ((p) = (objfile) -> psymtabs; (p) != NULL; (p) = (p) -> next)
 
-/* Traverse all psymtabs in all objfiles.  */
-
-#define	ALL_PSYMTABS(objfile, p) \
-  ALL_OBJFILES (objfile)	 \
-    ALL_OBJFILE_PSYMTABS (objfile, p)
-
 #endif /* PSYMPRIV_H */
diff --git a/gdb/psymtab.c b/gdb/psymtab.c
index 6a0c563..eeae03b 100644
--- a/gdb/psymtab.c
+++ b/gdb/psymtab.c
@@ -69,6 +69,60 @@ static struct partial_symbol *fixup_psymbol_section (struct partial_symbol
 
 static struct symtab *psymtab_to_symtab (struct partial_symtab *pst);
 
+/* Ensure that the partial symbols for OBJFILE have been loaded.  This
+   function always returns its argument, as a convenience.  */
+
+struct objfile *
+require_partial_symbols (struct objfile *objfile, int verbose)
+{
+  if ((objfile->flags & OBJF_PSYMTABS_READ) == 0)
+    {
+      objfile->flags |= OBJF_PSYMTABS_READ;
+
+      if (objfile->sf->sym_read_psymbols)
+	{
+	  if (verbose)
+	    {
+	      printf_unfiltered (_("Reading symbols from %s..."),
+				 objfile->name);
+	      gdb_flush (gdb_stdout);
+	    }
+	  (*objfile->sf->sym_read_psymbols) (objfile);
+	  if (verbose)
+	    {
+	      if (!objfile_has_symbols (objfile))
+		{
+		  wrap_here ("");
+		  printf_unfiltered (_("(no debugging symbols found)..."));
+		  wrap_here ("");
+		}
+
+	      printf_unfiltered (_("done.\n"));
+	    }
+	}
+    }
+
+  return objfile;
+}
+
+/* Traverse all psymtabs in one objfile, requiring that the psymtabs
+   be read in.  */
+
+#define ALL_OBJFILE_PSYMTABS_REQUIRED(objfile, p)		\
+    for ((p) = require_partial_symbols (objfile, 1)->psymtabs;	\
+	 (p) != NULL;						\
+	 (p) = (p)->next)
+
+/* We want to make sure this file always requires psymtabs.  */
+
+#undef ALL_OBJFILE_PSYMTABS
+
+/* Traverse all psymtabs in all objfiles.  */
+
+#define ALL_PSYMTABS(objfile, p) \
+  ALL_OBJFILES (objfile)	 \
+    ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, p)
+
 /* Lookup the partial symbol table of a source file named NAME.
    *If* there is no '/' in the name, a match after a '/'
    in the psymtab filename will also work.  */
@@ -79,7 +133,7 @@ lookup_partial_symtab (struct objfile *objfile, const char *name,
 {
   struct partial_symtab *pst;
 
-  ALL_OBJFILE_PSYMTABS (objfile, pst)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, pst)
   {
     if (FILENAME_CMP (name, pst->filename) == 0)
       {
@@ -117,7 +171,7 @@ lookup_partial_symtab (struct objfile *objfile, const char *name,
   /* Now, search for a matching tail (only if name doesn't have any dirs).  */
 
   if (lbasename (name) == name)
-    ALL_OBJFILE_PSYMTABS (objfile, pst)
+    ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, pst)
     {
       if (FILENAME_CMP (lbasename (pst->filename), name) == 0)
 	return (pst);
@@ -280,7 +334,7 @@ find_pc_sect_psymtab (struct objfile *objfile, CORE_ADDR pc,
      its CUs may be missing in PSYMTABS_ADDRMAP as they may be varying
      debug info type in single OBJFILE.  */
 
-  ALL_OBJFILE_PSYMTABS (objfile, pst)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, pst)
     if (pc >= pst->textlow && pc < pst->texthigh)
       {
 	struct partial_symtab *best_pst;
@@ -423,7 +477,7 @@ lookup_symbol_aux_psymtabs (struct objfile *objfile,
   struct partial_symtab *ps;
   const int psymtab_index = (block_index == GLOBAL_BLOCK ? 1 : 0);
 
-  ALL_OBJFILE_PSYMTABS (objfile, ps)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, ps)
   {
     if (!ps->readin && lookup_partial_symbol (ps, name, psymtab_index, domain))
       return PSYMTAB_TO_SYMTAB (ps);
@@ -635,7 +689,7 @@ relocate_psymtabs (struct objfile *objfile,
   struct partial_symbol **psym;
   struct partial_symtab *p;
 
-  ALL_OBJFILE_PSYMTABS (objfile, p)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, p)
     {
       p->textlow += ANOFFSET (delta, SECT_OFF_TEXT (objfile));
       p->texthigh += ANOFFSET (delta, SECT_OFF_TEXT (objfile));
@@ -667,7 +721,7 @@ find_last_source_symtab_from_partial (struct objfile *ofp)
   struct partial_symtab *ps;
   struct partial_symtab *cs_pst = 0;
 
-  ALL_OBJFILE_PSYMTABS (ofp, ps)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (ofp, ps)
     {
       const char *name = ps->filename;
       int len = strlen (name);
@@ -696,7 +750,7 @@ forget_cached_source_info_partial (struct objfile *objfile)
 {
   struct partial_symtab *pst;
 
-  ALL_OBJFILE_PSYMTABS (objfile, pst)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, pst)
     {
       if (pst->fullname != NULL)
 	{
@@ -873,7 +927,7 @@ print_psymtab_stats_for_objfile (struct objfile *objfile)
   struct partial_symtab *ps;
 
   i = 0;
-  ALL_OBJFILE_PSYMTABS (objfile, ps)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, ps)
     {
       if (ps->readin == 0)
 	i++;
@@ -915,7 +969,7 @@ read_symtabs_for_function (struct objfile *objfile, const char *func_name)
 {
   struct partial_symtab *ps;
 
-  ALL_OBJFILE_PSYMTABS (objfile, ps)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, ps)
   {
     if (ps->readin)
       continue;
@@ -933,7 +987,7 @@ expand_partial_symbol_tables (struct objfile *objfile)
 {
   struct partial_symtab *psymtab;
 
-  ALL_OBJFILE_PSYMTABS (objfile, psymtab)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, psymtab)
     {
       psymtab_to_symtab (psymtab);
     }
@@ -944,7 +998,7 @@ read_psymtabs_with_filename (struct objfile *objfile, const char *filename)
 {
   struct partial_symtab *p;
 
-  ALL_OBJFILE_PSYMTABS (objfile, p)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, p)
     {
       if (strcmp (filename, p->filename) == 0)
 	PSYMTAB_TO_SYMTAB (p);
@@ -957,7 +1011,7 @@ map_symbol_names_psymtab (struct objfile *objfile,
 {
   struct partial_symtab *ps;
 
-  ALL_OBJFILE_PSYMTABS (objfile, ps)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, ps)
     {
       struct partial_symbol **psym;
 
@@ -995,7 +1049,7 @@ map_symbol_filenames_psymtab (struct objfile *objfile,
 {
   struct partial_symtab *ps;
 
-  ALL_OBJFILE_PSYMTABS (objfile, ps)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, ps)
     {
       const char *fullname;
 
@@ -1044,7 +1098,7 @@ find_symbol_file_from_partial (struct objfile *objfile, const char *name)
 {
   struct partial_symtab *pst;
 
-  ALL_OBJFILE_PSYMTABS (objfile, pst)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, pst)
     {
       if (lookup_partial_symbol (pst, name, 1, VAR_DOMAIN))
 	return pst->filename;
@@ -1095,7 +1149,7 @@ map_matching_symbols_psymtab (const char *name, domain_enum namespace,
   const int block_kind = global ? GLOBAL_BLOCK : STATIC_BLOCK;
   struct partial_symtab *ps;
 
-  ALL_OBJFILE_PSYMTABS (objfile, ps)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, ps)
     {
       QUIT;
       if (ps->readin
@@ -1128,7 +1182,7 @@ expand_symtabs_matching_via_partial (struct objfile *objfile,
 {
   struct partial_symtab *ps;
 
-  ALL_OBJFILE_PSYMTABS (objfile, ps)
+  ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, ps)
     {
       struct partial_symbol **psym;
       struct partial_symbol **bound, **gbound, **sbound;
@@ -1640,7 +1694,7 @@ maintenance_info_psymtabs (char *regexp, int from_tty)
          actually find a symtab whose name matches.  */
       int printed_objfile_start = 0;
 
-      ALL_OBJFILE_PSYMTABS (objfile, psymtab)
+      ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, psymtab)
 	{
 	  QUIT;
 
diff --git a/gdb/psymtab.h b/gdb/psymtab.h
index 4a1e8e4..73e0a81 100644
--- a/gdb/psymtab.h
+++ b/gdb/psymtab.h
@@ -38,4 +38,12 @@ extern const struct quick_symbol_functions psym_functions;
 
 extern const struct quick_symbol_functions dwarf2_gdb_index_functions;
 
+/* Ensure that the partial symbols for OBJFILE have been loaded.  If
+   VERBOSE is non-zero, then this will print a message when symbols
+   are loaded.  This function always returns its argument, as a
+   convenience.  */
+
+extern struct objfile *require_partial_symbols (struct objfile *objfile,
+						int verbose);
+
 #endif /* PSYMTAB_H */
diff --git a/gdb/somread.c b/gdb/somread.c
index fbbe356..70831a0 100644
--- a/gdb/somread.c
+++ b/gdb/somread.c
@@ -433,6 +433,7 @@ static const struct sym_fns som_sym_fns =
   som_new_init,			/* init anything gbl to entire symtab */
   som_symfile_init,		/* read initial info, setup for sym_read() */
   som_symfile_read,		/* read a symbol file into symtab */
+  NULL,				/* sym_read_psymbols */
   som_symfile_finish,		/* finished with file, cleanup */
   som_symfile_offsets,		/* Translate ext. to int. relocation */
   default_symfile_segments,	/* Get segment information from a file.  */
diff --git a/gdb/symfile.c b/gdb/symfile.c
index de0b369..06b5dec 100644
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -1019,6 +1019,9 @@ syms_from_objfile (struct objfile *objfile,
 
   (*objfile->sf->sym_read) (objfile, add_flags);
 
+  if ((add_flags & SYMFILE_NO_READ) == 0)
+    require_partial_symbols (objfile, 0);
+
   /* Discard cleanups as symbol reading was successful.  */
 
   discard_cleanups (old_chain);
@@ -1079,9 +1082,15 @@ symbol_file_add_with_addrs_or_offsets (bfd *abfd,
   struct cleanup *my_cleanups;
   const char *name = bfd_get_filename (abfd);
   const int from_tty = add_flags & SYMFILE_VERBOSE;
+  const int should_print = ((from_tty || info_verbose)
+			    && (readnow_symbol_files
+				|| (add_flags & SYMFILE_NO_READ) == 0));
 
   if (readnow_symbol_files)
-    flags |= OBJF_READNOW;
+    {
+      flags |= OBJF_READNOW;
+      add_flags &= ~SYMFILE_NO_READ;
+    }
 
   my_cleanups = make_cleanup_bfd_close (abfd);
 
@@ -1100,7 +1109,7 @@ symbol_file_add_with_addrs_or_offsets (bfd *abfd,
   /* We either created a new mapped symbol table, mapped an existing
      symbol table file which has not had initial symbol reading
      performed, or need to read an unmapped symbol table.  */
-  if (from_tty || info_verbose)
+  if (should_print)
     {
       if (deprecated_pre_add_symbol_hook)
 	deprecated_pre_add_symbol_hook (name);
@@ -1121,7 +1130,7 @@ symbol_file_add_with_addrs_or_offsets (bfd *abfd,
 
   if ((flags & OBJF_READNOW))
     {
-      if (from_tty || info_verbose)
+      if (should_print)
 	{
 	  printf_unfiltered (_("expanding to full symbols..."));
 	  wrap_here ("");
@@ -1132,15 +1141,14 @@ symbol_file_add_with_addrs_or_offsets (bfd *abfd,
 	objfile->sf->qf->expand_all_symtabs (objfile);
     }
 
-  if ((from_tty || info_verbose)
-      && !objfile_has_symbols (objfile))
+  if (should_print && !objfile_has_symbols (objfile))
     {
       wrap_here ("");
       printf_unfiltered (_("(no debugging symbols found)..."));
       wrap_here ("");
     }
 
-  if (from_tty || info_verbose)
+  if (should_print)
     {
       if (deprecated_post_add_symbol_hook)
 	deprecated_post_add_symbol_hook ();
@@ -2497,6 +2505,12 @@ reread_symbols (void)
 	  /* Do not set flags as this is safe and we don't want to be
              verbose.  */
 	  (*objfile->sf->sym_read) (objfile, 0);
+	  if ((objfile->flags & OBJF_PSYMTABS_READ) != 0)
+	    {
+	      objfile->flags &= ~OBJF_PSYMTABS_READ;
+	      require_partial_symbols (objfile, 0);
+	    }
+
 	  if (!objfile_has_symbols (objfile))
 	    {
 	      wrap_here ("");
diff --git a/gdb/symfile.h b/gdb/symfile.h
index 4d56341..a0151ea 100644
--- a/gdb/symfile.h
+++ b/gdb/symfile.h
@@ -326,6 +326,13 @@ struct sym_fns
 
   void (*sym_read) (struct objfile *, int);
 
+  /* Read the partial symbols for an objfile.  This may be NULL, in
+     which case gdb assumes that sym_read already read the partial
+     symbols.  This may only be non-NULL if the objfile actually does
+     have debuginfo available.  */
+
+  void (*sym_read_psymbols) (struct objfile *);
+
   /* Called when we are finished with an objfile.  Should do all
      cleanup that is specific to the object file format for the
      particular objfile.  */
@@ -408,7 +415,11 @@ enum symfile_add_flags
     SYMFILE_MAINLINE = 1 << 2,
 
     /* Do not call breakpoint_re_set when adding this symbol file.  */
-    SYMFILE_DEFER_BP_RESET = 1 << 3
+    SYMFILE_DEFER_BP_RESET = 1 << 3,
+
+    /* Do not immediately read symbols for this file.  By default,
+       symbols are read when the objfile is created.  */
+    SYMFILE_NO_READ = 1 << 4
   };
 
 extern void syms_from_objfile (struct objfile *,
diff --git a/gdb/xcoffread.c b/gdb/xcoffread.c
index a794f61..081080c 100644
--- a/gdb/xcoffread.c
+++ b/gdb/xcoffread.c
@@ -3084,6 +3084,7 @@ static const struct sym_fns xcoff_sym_fns =
   xcoff_new_init,		/* init anything gbl to entire symtab */
   xcoff_symfile_init,		/* read initial info, setup for sym_read() */
   xcoff_initial_scan,		/* read a symbol file into symtab */
+  NULL,				/* sym_read_psymbols */
   xcoff_symfile_finish,		/* finished with file, cleanup */
   xcoff_symfile_offsets,	/* xlate offsets ext->int form */
   default_symfile_segments,	/* Get segment information from a file.  */