re PR target/40483 (gcc 4.x needs to utilize better COMDAT mechanism under Solaris)

	PR target/40483
	* configure.ac (gcc_cv_as_comdat_group_group): Check for Sun as
	COMDAT group syntax, both SPARC and x86 variants.
	(HAVE_COMDAT_GROUP): Also define if gcc_cv_as_comdat_group_group.
	* configure: Regenerate.
	* config/sol2.h (TARGET_SOLARIS): Define.
	(PUSHSECTION_FORMAT): Remove.
	(SECTION_NAME_FORMAT): Define.
	* config/sol2.c: Include hashtab.h.
	(solaris_output_init_fini): Replace PUSHSECTION_FORMAT by its
	expansion, using SECTION_NAME_FORMAT.
	(solaris_comdat_htab): New variable.
	(struct comdat_entry): Define.
	(comdat_hash): New function.
	(comdat_eq): New function.
	(solaris_elf_asm_comdat_section): New function.
	(solaris_define_comdat_signature): New function.
	(solaris_code_end): New function.
	* config/sol2-protos.h (solaris_elf_asm_comdat_section): Declare.
	(solaris_code_end): Declare.
	* config/t-sol2 (sol2.o): Add $HASHTAB_H dependency.
	* config/i386/i386.c (ix86_code_end) [TARGET_SOLARIS]: Call
	solaris_code_end.
	(i386_solaris_elf_named_section): Wrap in TARGET_SOLARIS.
	Remove ATTRIBUTE_UNUSED.
	[!USE_GAS]: Call solaris_elf_asm_comdat_section for
	SECTION_LINKONCE sections if HAVE_COMDAT_GROUP.
	* config/sparc/sparc.c (sparc_solaris_elf_asm_named_section):
	Likewise.
	* config/i386/sol2-10.h (TARGET_ASM_NAMED_SECTION): Moved ...
	* config/i386/sol2.h (TARGET_ASM_NAMED_SECTION): ... here.
	* config/sparc/sol2.h (TARGET_ASM_CODE_END): Redefine.
	(PUSHSECTION_FORMAT): Remove.
	(SECTION_NAME_FORMAT): Redefine.

From-SVN: r173913

1 files changed, 129 insertions, 2 deletions

diff --git a/gcc/config/sol2.c b/gcc/config/sol2.c
index decde2f..7fed184 100644
--- a/gcc/config/sol2.c
+++ b/gcc/config/sol2.c
@@ -29,6 +29,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tm_p.h"
 #include "diagnostic-core.h"
 #include "ggc.h"
+#include "hashtab.h"
 
 tree solaris_pending_aligns, solaris_pending_inits, solaris_pending_finis;
 
@@ -106,14 +107,14 @@ solaris_output_init_fini (FILE *file, tree decl)
 {
   if (lookup_attribute ("init", DECL_ATTRIBUTES (decl)))
     {
-      fprintf (file, PUSHSECTION_FORMAT, ".init");
+      fprintf (file, "\t.pushsection\t" SECTION_NAME_FORMAT "\n", ".init");
       ASM_OUTPUT_CALL (file, decl);
       fprintf (file, "\t.popsection\n");
     }
 
   if (lookup_attribute ("fini", DECL_ATTRIBUTES (decl)))
     {
-      fprintf (file, PUSHSECTION_FORMAT, ".fini");
+      fprintf (file, "\t.pushsection\t" SECTION_NAME_FORMAT "\n", ".fini");
       ASM_OUTPUT_CALL (file, decl);
       fprintf (file, "\t.popsection\n");
     }
@@ -155,3 +156,129 @@ solaris_assemble_visibility (tree decl ATTRIBUTE_UNUSED,
 	   "in this configuration; ignored");
 #endif
 }
+
+/* Hash table of group signature symbols.  */
+
+static htab_t solaris_comdat_htab;
+
+/* Group section information entry stored in solaris_comdat_htab.  */
+
+typedef struct comdat_entry
+{
+  const char *name;
+  unsigned int flags;
+  tree decl;
+  const char *sig;
+} comdat_entry;
+
+/* Helper routines for maintaining solaris_comdat_htab.  */
+
+static hashval_t
+comdat_hash (const void *p)
+{
+  const comdat_entry *entry = (const comdat_entry *) p;
+
+  return htab_hash_string (entry->sig);
+}
+
+static int
+comdat_eq (const void *p1, const void *p2)
+{
+  const comdat_entry *entry1 = (const comdat_entry *) p1;
+  const comdat_entry *entry2 = (const comdat_entry *) p2;
+
+  return strcmp (entry1->sig, entry2->sig) == 0;
+}
+
+/* Output assembly to switch to COMDAT group section NAME with attributes
+   FLAGS and group signature symbol DECL, using Sun as syntax.  */
+
+void
+solaris_elf_asm_comdat_section (const char *name, unsigned int flags, tree decl)
+{
+  const char *signature;
+  char *section;
+  comdat_entry entry, **slot;
+
+  if (TREE_CODE (decl) == IDENTIFIER_NODE)
+    signature = IDENTIFIER_POINTER (decl);
+  else
+    signature = IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl));
+
+  /* Sun as requires group sections to be fragmented, i.e. to have names of
+     the form <section>%<fragment>.  Strictly speaking this is only
+     necessary to support cc -xF, but is enforced globally in violation of
+     the ELF gABI.  We keep the section names generated by GCC (generally
+     of the form .text.<signature>) and append %<signature> to pacify as,
+     despite the redundancy.  */
+  section = concat (name, "%", signature, NULL);
+
+  /* Clear SECTION_LINKONCE flag so targetm.asm_out.named_section only
+     emits this as a regular section.  Emit section before .group
+     directive since Sun as treats undeclared sections as @progbits,
+     which conflicts with .bss* sections which are @nobits.  */
+  targetm.asm_out.named_section (section, flags & ~SECTION_LINKONCE, decl);
+  
+  /* Sun as separates declaration of a group section and of the group
+     itself, using the .group directive and the #comdat flag.  */
+  fprintf (asm_out_file, "\t.group\t%s," SECTION_NAME_FORMAT ",#comdat\n",
+	   signature, section);
+
+  /* Unlike GNU as, group signature symbols need to be defined explicitly
+     for Sun as.  With a few exceptions, this is already the case.  To
+     identify the missing ones without changing the affected frontents,
+     remember the signature symbols and emit those not marked
+     TREE_SYMBOL_REFERENCED in solaris_code_end.  */
+  if (solaris_comdat_htab == NULL)
+    solaris_comdat_htab = htab_create_alloc (37, comdat_hash, comdat_eq, NULL,
+					     xcalloc, free);
+
+  entry.sig = signature;
+  slot = (comdat_entry **) htab_find_slot (solaris_comdat_htab, &entry, INSERT);
+
+  if (*slot == NULL)
+    {
+      *slot = XCNEW (comdat_entry);
+      /* Remember fragmented section name.  */
+      (*slot)->name = section;
+      /* Emit as regular section, .group declaration has already been done.  */
+      (*slot)->flags = flags & ~SECTION_LINKONCE;
+      (*slot)->decl = decl;
+      (*slot)->sig = signature;
+    }
+}
+
+/* Define unreferenced COMDAT group signature symbol corresponding to SLOT.  */
+
+static int
+solaris_define_comdat_signature (void **slot, void *aux ATTRIBUTE_UNUSED)
+{
+  comdat_entry *entry = *(comdat_entry **) slot;
+  tree decl = entry->decl;
+
+  if (TREE_CODE (decl) != IDENTIFIER_NODE)
+    decl = DECL_COMDAT_GROUP (decl);
+
+  if (!TREE_SYMBOL_REFERENCED (decl))
+    {
+      /* Switch to group section, otherwise Sun as complains
+	 `Group Id symbol defined outside of group'.  */
+      switch_to_section (get_section (entry->name, entry->flags, entry->decl));
+
+      ASM_OUTPUT_LABEL (asm_out_file, entry->sig);
+    }
+
+  /* Continue with scan.  */
+  return 1;
+}
+
+/* Emit unreferenced COMDAT group signature symbols for Sun as.  */
+
+void
+solaris_code_end (void)
+{
+  if (solaris_comdat_htab == NULL)
+    return;
+
+  htab_traverse (solaris_comdat_htab, solaris_define_comdat_signature, NULL);
+}