PATCH: PR middle-end/17982/20218: stop calling assemble_external before final assembly output time

["H. J. Lu" <hjl at lucon dot org>]

We are calling assemble_external before final assembly output time. It
is bad due to PR middle-end/17982. It is delayed for unit at a time.
This patch always delays it to the very end. It simplifies ia64 and
also generates assembler visibility directives for locally bound
symbols to fix PR 20218.


H.J.
----
2005-07-23  H.J. Lu  <hongjiu.lu@intel.com>

	PR middle-end/17982
	PR middle-end/20218
	* cgraphunit.c (cgraph_optimize): Remove call to
	process_pending_assemble_externals.

	* config/elfos.h (ASM_OUTPUT_EXTERNAL): New.

	* config/ia64/hpux.h (TARGET_ASM_FILE_END): Removed.

	* config/ia64/ia64.c (ia64_asm_output_external): Rewritten.
	(ia64_hpux_add_extern_decl): Removed.
	(ia64_hpux_file_end): Likewise.
	(extern_func_list): Likewise.
	(extern_func_head): Likewise.

	* output.h (assemble_external): Update comments.
	(default_elf_asm_output_external): New.
	(maybe_assemble_visibility): New.

	* toplev.c (compile_file): Call
	process_pending_assemble_externals.

	* varasm.c (maybe_assemble_visibility): Make it extern and
	return int.
	(default_elf_asm_output_external): New.

--- gcc/cgraphunit.c.global	2005-07-22 14:54:33.000000000 -0700
+++ gcc/cgraphunit.c	2005-07-23 11:46:23.000000000 -0700
@@ -1214,8 +1214,6 @@ cgraph_optimize (void)
       return;
     }
 
-  process_pending_assemble_externals ();
-  
   /* Frontend may output common variables after the unit has been finalized.
      It is safe to deal with them here as they are always zero initialized.  */
   cgraph_varpool_analyze_pending_decls ();
--- gcc/config/elfos.h.global	2005-07-04 10:08:42.000000000 -0700
+++ gcc/config/elfos.h	2005-07-23 14:52:40.000000000 -0700
@@ -487,3 +487,13 @@ Boston, MA 02110-1301, USA.  */
         fprintf ((FILE), "\"\n");					\
     }									\
   while (0)
+
+/* A C statement (sans semicolon) to output to the stdio stream STREAM
+   any text necessary for declaring the name of an external symbol
+   named NAME whch is referenced in this compilation but not defined.
+   It is needed to properly support non-default visibility.  */
+
+#ifndef ASM_OUTPUT_EXTERNAL
+#define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME) \
+  default_elf_asm_output_external (FILE, DECL, NAME)
+#endif
--- gcc/config/ia64/hpux.h.global	2005-07-04 10:08:43.000000000 -0700
+++ gcc/config/ia64/hpux.h	2005-07-22 15:10:25.000000000 -0700
@@ -147,10 +147,6 @@ do {								\
    definitions, so do not use them in gthr-posix.h.  */
 #define GTHREAD_USE_WEAK 0
 
-/* Put out the needed function declarations at the end.  */
-
-#define TARGET_ASM_FILE_END ia64_hpux_file_end
-
 #undef CTORS_SECTION_ASM_OP
 #define CTORS_SECTION_ASM_OP  "\t.section\t.init_array,\t\"aw\",\"init_array\""
 
--- gcc/config/ia64/ia64.c.global	2005-07-22 14:54:48.000000000 -0700
+++ gcc/config/ia64/ia64.c	2005-07-23 15:08:22.000000000 -0700
@@ -243,10 +243,6 @@ static void ia64_rwreloc_select_rtx_sect
 					     unsigned HOST_WIDE_INT)
      ATTRIBUTE_UNUSED;
 static unsigned int ia64_section_type_flags (tree, const char *, int);
-static void ia64_hpux_add_extern_decl (tree decl)
-     ATTRIBUTE_UNUSED;
-static void ia64_hpux_file_end (void)
-     ATTRIBUTE_UNUSED;
 static void ia64_init_libfuncs (void)
      ATTRIBUTE_UNUSED;
 static void ia64_hpux_init_libfuncs (void)
@@ -4820,49 +4816,6 @@ ia64_secondary_reload_class (enum reg_cl
 }
 
 
-/* Emit text to declare externally defined variables and functions, because
-   the Intel assembler does not support undefined externals.  */
-
-void
-ia64_asm_output_external (FILE *file, tree decl, const char *name)
-{
-  int save_referenced;
-
-  /* GNU as does not need anything here, but the HP linker does need
-     something for external functions.  */
-
-  if (TARGET_GNU_AS
-      && (!TARGET_HPUX_LD
-	  || TREE_CODE (decl) != FUNCTION_DECL
-	  || strstr (name, "__builtin_") == name))
-    return;
-
-  /* ??? The Intel assembler creates a reference that needs to be satisfied by
-     the linker when we do this, so we need to be careful not to do this for
-     builtin functions which have no library equivalent.  Unfortunately, we
-     can't tell here whether or not a function will actually be called by
-     expand_expr, so we pull in library functions even if we may not need
-     them later.  */
-  if (! strcmp (name, "__builtin_next_arg")
-      || ! strcmp (name, "alloca")
-      || ! strcmp (name, "__builtin_constant_p")
-      || ! strcmp (name, "__builtin_args_info"))
-    return;
-
-  if (TARGET_HPUX_LD)
-    ia64_hpux_add_extern_decl (decl);
-  else
-    {
-      /* assemble_name will set TREE_SYMBOL_REFERENCED, so we must save and
-         restore it.  */
-      save_referenced = TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl));
-      if (TREE_CODE (decl) == FUNCTION_DECL)
-        ASM_OUTPUT_TYPE_DIRECTIVE (file, name, "function");
-      (*targetm.asm_out.globalize_label) (file, name);
-      TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)) = save_referenced;
-    }
-}
-
 /* Parse the -mfixed-range= option string.  */
 
 static void
@@ -8216,55 +8169,33 @@ ia64_hpux_function_arg_padding (enum mac
    return DEFAULT_FUNCTION_ARG_PADDING (mode, type);
 }
 
-/* Linked list of all external functions that are to be emitted by GCC.
-   We output the name if and only if TREE_SYMBOL_REFERENCED is set in
-   order to avoid putting out names that are never really used.  */
-
-struct extern_func_list GTY(())
-{
-  struct extern_func_list *next;
-  tree decl;
-};
-
-static GTY(()) struct extern_func_list *extern_func_head;
-
-static void
-ia64_hpux_add_extern_decl (tree decl)
-{
-  struct extern_func_list *p = ggc_alloc (sizeof (struct extern_func_list));
-
-  p->decl = decl;
-  p->next = extern_func_head;
-  extern_func_head = p;
-}
-
-/* Print out the list of used global functions.  */
+/* Emit text to declare externally defined variables and functions, because
+   the Intel assembler does not support undefined externals.  */
 
-static void
-ia64_hpux_file_end (void)
+void
+ia64_asm_output_external (FILE *file, tree decl, const char *name)
 {
-  struct extern_func_list *p;
-
-  for (p = extern_func_head; p; p = p->next)
-    {
-      tree decl = p->decl;
-      tree id = DECL_ASSEMBLER_NAME (decl);
-
-      gcc_assert (id);
-
-      if (!TREE_ASM_WRITTEN (decl) && TREE_SYMBOL_REFERENCED (id))
-        {
-	  const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
-
-	  TREE_ASM_WRITTEN (decl) = 1;
-	  (*targetm.asm_out.globalize_label) (asm_out_file, name);
-	  fputs (TYPE_ASM_OP, asm_out_file);
-	  assemble_name (asm_out_file, name);
-	  fprintf (asm_out_file, "," TYPE_OPERAND_FMT "\n", "function");
-        }
+  /* We output the name if and only if TREE_SYMBOL_REFERENCED is
+     set in order to avoid putting out names that are never really
+     used. */
+  if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)))
+    {
+      /* maybe_assemble_visibility will return 1 if the assembler
+	 visibility directive is outputed.  */
+      int need_visibility = ((*targetm.binds_local_p) (decl)
+			     && maybe_assemble_visibility (decl));
+
+      /* GNU as does not need anything here, but the HP linker does
+	 need something for external functions.  */
+      if ((TARGET_HPUX_LD || !TARGET_GNU_AS)
+	  && TREE_CODE (decl) == FUNCTION_DECL)
+	{
+	  ASM_OUTPUT_TYPE_DIRECTIVE (file, name, "function");
+	  (*targetm.asm_out.globalize_label) (file, name);
+	}
+      else if (need_visibility && !TARGET_GNU_AS)
+	(*targetm.asm_out.globalize_label) (file, name);
     }
-
-  extern_func_head = 0;
 }
 
 /* Set SImode div/mod functions, init_integral_libfuncs only initializes
--- gcc/output.h.global	2005-07-04 10:08:33.000000000 -0700
+++ gcc/output.h	2005-07-23 14:52:10.000000000 -0700
@@ -270,9 +270,9 @@ extern void assemble_end_function (tree,
    initial value (that will be done by the caller).  */
 extern void assemble_variable (tree, int, int, int);
 
-/* Output something to declare an external symbol to the assembler.
-   (Most assemblers don't need this, so we normally output nothing.)
-   Do nothing if DECL is not external.  */
+/* Queue for outputing something to declare an external symbol to the
+   assembler.  (Most assemblers don't need this, so we normally output
+   nothing.)  Do nothing if DECL is not external.  */
 extern void assemble_external (tree);
 
 /* Assemble code to leave SIZE bytes of zeros.  */
@@ -543,6 +543,10 @@ extern void default_file_start (void);
 extern void file_end_indicate_exec_stack (void);
 extern bool default_valid_pointer_mode (enum machine_mode);
 
+extern void default_elf_asm_output_external (FILE *file, tree,
+					     const char *);
+extern int maybe_assemble_visibility (tree);
+
 extern int default_address_cost (rtx);
 
 /* When performing hot/cold basic block partitioning, insert note in
--- gcc/toplev.c.global	2005-07-22 14:54:36.000000000 -0700
+++ gcc/toplev.c	2005-07-23 11:43:24.000000000 -0700
@@ -1027,6 +1027,9 @@ compile_file (void)
 	     IDENT_ASM_OP, version_string);
 #endif
 
+  /* Output external symbols.  */
+  process_pending_assemble_externals ();
+
   /* This must be at the end.  Some target ports emit end of file directives
      into the assembly file here, and hence we can not output anything to the
      assembly file after this point.  */
--- gcc/varasm.c.global	2005-07-22 14:54:37.000000000 -0700
+++ gcc/varasm.c	2005-07-23 15:07:57.000000000 -0700
@@ -126,7 +126,6 @@ static unsigned HOST_WIDE_INT array_size
 static unsigned min_align (unsigned, unsigned);
 static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int);
 static void globalize_decl (tree);
-static void maybe_assemble_visibility (tree);
 static int in_named_entry_eq (const void *, const void *);
 static hashval_t in_named_entry_hash (const void *);
 static void initialize_cold_section_name (void);
@@ -1921,11 +1920,8 @@ assemble_external (tree decl ATTRIBUTE_U
   if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
     return;
 
-  if (flag_unit_at_a_time)
-    pending_assemble_externals = tree_cons (0, decl,
-					    pending_assemble_externals);
-  else
-    assemble_external_real (decl);
+  pending_assemble_externals = tree_cons (0, decl,
+					  pending_assemble_externals);
 #endif
 }
 
@@ -4709,13 +4705,18 @@ default_assemble_visibility (tree decl, 
 
 /* A helper function to call assemble_visibility when needed for a decl.  */
 
-static void
+int
 maybe_assemble_visibility (tree decl)
 {
   enum symbol_visibility vis = DECL_VISIBILITY (decl);
 
   if (vis != VISIBILITY_DEFAULT)
-    targetm.asm_out.visibility (decl, vis);
+    {
+      targetm.asm_out.visibility (decl, vis);
+      return 1;
+    }
+  else
+    return 0;
 }
 
 /* Returns 1 if the target configuration supports defining public symbols
@@ -5522,4 +5523,19 @@ file_end_indicate_exec_stack (void)
   named_section_flags (".note.GNU-stack", flags);
 }
 
+/* Emit text to declare externally defined symbols. It is needed to
+   properly support non-default visibility.  */
+void
+default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
+				 tree decl,
+				 const char *name ATTRIBUTE_UNUSED)
+{
+  /* We output the name if and only if TREE_SYMBOL_REFERENCED is
+     set in order to avoid putting out names that are never really
+     used. */
+  if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
+      && targetm.binds_local_p (decl))
+    maybe_assemble_visibility (decl);
+}
+
 #include "gt-varasm.h"