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

8 files changed, 173 insertions, 12 deletions

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 87d5650..15dde25 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -8768,6 +8768,10 @@ ix86_code_end (void)
   rtx xops[2];
   int regno;
 
+#ifdef TARGET_SOLARIS
+  solaris_code_end ();
+#endif
+
   for (regno = AX_REG; regno <= SP_REG; regno++)
     {
       char name[32];
@@ -32148,9 +32152,10 @@ void ix86_emit_swsqrtsf (rtx res, rtx a, enum machine_mode mode,
 			  gen_rtx_MULT (mode, e2, e3)));
 }
 
+#ifdef TARGET_SOLARIS
 /* Solaris implementation of TARGET_ASM_NAMED_SECTION.  */
 
-static void ATTRIBUTE_UNUSED
+static void
 i386_solaris_elf_named_section (const char *name, unsigned int flags,
 				tree decl)
 {
@@ -32164,8 +32169,18 @@ i386_solaris_elf_named_section (const char *name, unsigned int flags,
 	       flags & SECTION_WRITE ? "aw" : "a");
       return;
     }
+
+#ifndef USE_GAS
+  if (HAVE_COMDAT_GROUP && flags & SECTION_LINKONCE)
+    {
+      solaris_elf_asm_comdat_section (name, flags, decl);
+      return;
+    }
+#endif
+
   default_elf_asm_named_section (name, flags, decl);
 }
+#endif /* TARGET_SOLARIS */
 
 /* Return the mangling of TYPE if it is an extended fundamental type.  */
 
diff --git a/gcc/config/i386/sol2-10.h b/gcc/config/i386/sol2-10.h
index c3decd2..04a7132 100644
--- a/gcc/config/i386/sol2-10.h
+++ b/gcc/config/i386/sol2-10.h
@@ -133,6 +133,3 @@ along with GCC; see the file COPYING3.  If not see
 
 /* We do not need to search a special directory for startup files.  */
 #undef MD_STARTFILE_PREFIX
-
-#undef TARGET_ASM_NAMED_SECTION
-#define TARGET_ASM_NAMED_SECTION i386_solaris_elf_named_section
diff --git a/gcc/config/i386/sol2.h b/gcc/config/i386/sol2.h
index baddbb0..36ca62f 100644
--- a/gcc/config/i386/sol2.h
+++ b/gcc/config/i386/sol2.h
@@ -154,6 +154,9 @@ along with GCC; see the file COPYING3.  If not see
     }								\
   while (0)
 
+#undef TARGET_ASM_NAMED_SECTION
+#define TARGET_ASM_NAMED_SECTION i386_solaris_elf_named_section
+
 /* We do not need NT_VERSION notes.  */
 #undef X86_FILE_START_VERSION_DIRECTIVE
 #define X86_FILE_START_VERSION_DIRECTIVE false
diff --git a/gcc/config/sol2-protos.h b/gcc/config/sol2-protos.h
index 800629a..25753ff 100644
--- a/gcc/config/sol2-protos.h
+++ b/gcc/config/sol2-protos.h
@@ -22,3 +22,5 @@ extern void solaris_insert_attributes (tree, tree *);
 extern void solaris_register_pragmas (void);
 extern void solaris_output_init_fini (FILE *, tree);
 extern void solaris_assemble_visibility (tree, int);
+extern void solaris_elf_asm_comdat_section (const char *, unsigned int, tree);
+extern void solaris_code_end (void);
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);
+}
diff --git a/gcc/config/sol2.h b/gcc/config/sol2.h
index 7e42ddb..f3394fd 100644
--- a/gcc/config/sol2.h
+++ b/gcc/config/sol2.h
@@ -19,6 +19,9 @@ You should have received a copy of the GNU General Public License
 along with GCC; see the file COPYING3.  If not see
 <http://www.gnu.org/licenses/>.  */
 
+/* We are compiling for Solaris 2 now.  */
+#define TARGET_SOLARIS 1
+
 /* We use stabs-in-elf for debugging, because that is what the native
    toolchain uses.  */
 #undef PREFERRED_DEBUGGING_TYPE
@@ -257,9 +260,8 @@ __enable_execute_stack (void *addr)					\
   { "init",      0, 0, true,  false,  false, NULL, false },		\
   { "fini",      0, 0, true,  false,  false, NULL, false }
 
-/* Solaris/x86 as and gas support the common ELF .section/.pushsection
-   syntax.  */
-#define PUSHSECTION_FORMAT	"\t.pushsection\t%s\n"
+/* Solaris/x86 as and gas support unquoted section names.  */
+#define SECTION_NAME_FORMAT	"%s"
 
 /* This is how to declare the size of a function.  For Solaris, we output
    any .init or .fini entries here.  */
diff --git a/gcc/config/sparc/sol2.h b/gcc/config/sparc/sol2.h
index 73355ca..a53b82a 100644
--- a/gcc/config/sparc/sol2.h
+++ b/gcc/config/sparc/sol2.h
@@ -188,9 +188,16 @@ along with GCC; see the file COPYING3.  If not see
 #undef TARGET_ASM_NAMED_SECTION
 #define TARGET_ASM_NAMED_SECTION sparc_solaris_elf_asm_named_section
 
-/* And SPARC non-standard pushsection syntax.  */
-#undef PUSHSECTION_FORMAT
-#define PUSHSECTION_FORMAT "\t.pushsection\t\"%s\"\n"
+/* Emit COMDAT group signature symbols for Sun as.  */
+#undef TARGET_ASM_CODE_END
+#define TARGET_ASM_CODE_END solaris_code_end
+
+/* Solaris/SPARC as requires doublequoted section names.  While gas
+   supports that, too, we prefer the standard variant.  */
+#ifndef USE_GAS
+#undef SECTION_NAME_FORMAT
+#define SECTION_NAME_FORMAT	"\"%s\""
+#endif
 
 /* Static stack checking is supported by means of probes.  */
 #define STACK_CHECK_STATIC_BUILTIN 1
diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
index e2443d7..10b35f2 100644
--- a/gcc/config/sparc/sparc.c
+++ b/gcc/config/sparc/sparc.c
@@ -8537,12 +8537,19 @@ sparc_profile_hook (int labelno)
     }
 }
 
+#ifdef TARGET_SOLARIS
 /* Solaris implementation of TARGET_ASM_NAMED_SECTION.  */
 
 static void
 sparc_solaris_elf_asm_named_section (const char *name, unsigned int flags,
 				     tree decl ATTRIBUTE_UNUSED)
 {
+  if (HAVE_COMDAT_GROUP && flags & SECTION_LINKONCE)
+    {
+      solaris_elf_asm_comdat_section (name, flags, decl);
+      return;
+    }
+
   fprintf (asm_out_file, "\t.section\t\"%s\"", name);
 
   if (!(flags & SECTION_DEBUG))
@@ -8558,6 +8565,7 @@ sparc_solaris_elf_asm_named_section (const char *name, unsigned int flags,
 
   fputc ('\n', asm_out_file);
 }
+#endif /* TARGET_SOLARIS */
 
 /* We do not allow indirect calls to be optimized into sibling calls.