Makde gcc handle __stack_smash_handler similarly to memcpy and memset when

creating calls: cache the RTL, let a declaration alter the asm spec, and
set the same RTL attributes.  For all three, let a declaration set the ELF
visibility.

ok miod@

5 files changed, 71 insertions, 39 deletions

diff --git a/gnu/gcc/gcc/c-common.c b/gnu/gcc/gcc/c-common.c
index 68db97e8c05..be20dd52c65 100644
--- a/gnu/gcc/gcc/c-common.c
+++ b/gnu/gcc/gcc/c-common.c
@@ -3416,9 +3416,9 @@ set_builtin_user_assembler_name (tree decl, const char *asmspec)
   builtin = built_in_decls [DECL_FUNCTION_CODE (decl)];
   set_user_assembler_name (builtin, asmspec);
   if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMCPY)
-    init_block_move_fn (asmspec);
+    init_block_move_fn (decl, asmspec);
   else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMSET)
-    init_block_clear_fn (asmspec);
+    init_block_clear_fn (decl, asmspec);
 }
 
 /* The number of named compound-literals generated thus far.  */
diff --git a/gnu/gcc/gcc/c-decl.c b/gnu/gcc/gcc/c-decl.c
index 042a2e1291c..f09ffd96a04 100644
--- a/gnu/gcc/gcc/c-decl.c
+++ b/gnu/gcc/gcc/c-decl.c
@@ -3484,16 +3484,6 @@ finish_decl (tree decl, tree init, tree asmspec_tree)
 	TREE_USED (decl) = 1;
     }
 
-  /* If this is a function and an assembler name is specified, reset DECL_RTL
-     so we can give it its new name.  Also, update built_in_decls if it
-     was a normal built-in.  */
-  if (TREE_CODE (decl) == FUNCTION_DECL && asmspec)
-    {
-      if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
-	set_builtin_user_assembler_name (decl, asmspec);
-      set_user_assembler_name (decl, asmspec);
-    }
-
   /* If #pragma weak was used, mark the decl weak now.  */
   maybe_apply_pragma_weak (decl);
 
@@ -3513,12 +3503,24 @@ finish_decl (tree decl, tree init, tree asmspec_tree)
 
       if (asmspec)
 	{
+          /* If this is a function and an assembler name is specified,
+             reset DECL_RTL so we can give it its new name.  Also,
+             update built_in_decls if it was a normal built-in.  */
+          if (TREE_CODE (decl) == FUNCTION_DECL)
+            {
+              if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
+	        set_builtin_user_assembler_name (decl, asmspec);
+              else if (strcmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
+	          "__stack_smash_handler") == 0)
+	        init_stack_smash_fn (decl, asmspec);
+              set_user_assembler_name (decl, asmspec);
+            }
 	  /* If this is not a static variable, issue a warning.
 	     It doesn't make any sense to give an ASMSPEC for an
 	     ordinary, non-register local variable.  Historically,
 	     GCC has accepted -- but ignored -- the ASMSPEC in
 	     this case.  */
-	  if (!DECL_FILE_SCOPE_P (decl)
+	  else if (!DECL_FILE_SCOPE_P (decl)
 	      && TREE_CODE (decl) == VAR_DECL
 	      && !C_DECL_REGISTER (decl)
 	      && !TREE_STATIC (decl))
diff --git a/gnu/gcc/gcc/expr.c b/gnu/gcc/gcc/expr.c
index c6bc4263b86..8c5c80e1f66 100644
--- a/gnu/gcc/gcc/expr.c
+++ b/gnu/gcc/gcc/expr.c
@@ -1393,7 +1393,7 @@ emit_block_move_via_libcall (rtx dst, rtx src, rtx size, bool tailcall)
 static GTY(()) tree block_move_fn;
 
 void
-init_block_move_fn (const char *asmspec)
+init_block_move_fn (tree decl, const char *asmspec)
 {
   if (!block_move_fn)
     {
@@ -1409,7 +1409,10 @@ init_block_move_fn (const char *asmspec)
       TREE_PUBLIC (fn) = 1;
       DECL_ARTIFICIAL (fn) = 1;
       TREE_NOTHROW (fn) = 1;
-      DECL_VISIBILITY (fn) = VISIBILITY_DEFAULT;
+      if (decl != NULL_TREE && DECL_VISIBILITY_SPECIFIED (decl))
+	DECL_VISIBILITY (fn) = DECL_VISIBILITY (decl);
+      else
+	DECL_VISIBILITY (fn) = VISIBILITY_DEFAULT;
       DECL_VISIBILITY_SPECIFIED (fn) = 1;
 
       block_move_fn = fn;
@@ -1425,7 +1428,7 @@ emit_block_move_libcall_fn (int for_call)
   static bool emitted_extern;
 
   if (!block_move_fn)
-    init_block_move_fn (NULL);
+    init_block_move_fn (NULL_TREE, NULL);
 
   if (for_call && !emitted_extern)
     {
@@ -2597,7 +2600,7 @@ clear_storage_via_libcall (rtx object, rtx size, bool tailcall)
 static GTY(()) tree block_clear_fn;
 
 void
-init_block_clear_fn (const char *asmspec)
+init_block_clear_fn (tree decl, const char *asmspec)
 {
   if (!block_clear_fn)
     {
@@ -2613,7 +2616,10 @@ init_block_clear_fn (const char *asmspec)
       TREE_PUBLIC (fn) = 1;
       DECL_ARTIFICIAL (fn) = 1;
       TREE_NOTHROW (fn) = 1;
-      DECL_VISIBILITY (fn) = VISIBILITY_DEFAULT;
+      if (decl != NULL_TREE && DECL_VISIBILITY_SPECIFIED (decl))
+	DECL_VISIBILITY (fn) = DECL_VISIBILITY (decl);
+      else
+	DECL_VISIBILITY (fn) = VISIBILITY_DEFAULT;
       DECL_VISIBILITY_SPECIFIED (fn) = 1;
 
       block_clear_fn = fn;
@@ -2629,7 +2635,7 @@ clear_storage_libcall_fn (int for_call)
   static bool emitted_extern;
 
   if (!block_clear_fn)
-    init_block_clear_fn (NULL);
+    init_block_clear_fn (NULL_TREE, NULL);
 
   if (for_call && !emitted_extern)
     {
diff --git a/gnu/gcc/gcc/expr.h b/gnu/gcc/gcc/expr.h
index 42b98937a82..c4434850c93 100644
--- a/gnu/gcc/gcc/expr.h
+++ b/gnu/gcc/gcc/expr.h
@@ -373,8 +373,9 @@ enum block_op_methods
   BLOCK_OP_TAILCALL
 };
 
-extern void init_block_move_fn (const char *);
-extern void init_block_clear_fn (const char *);
+extern void init_block_move_fn (tree, const char *);
+extern void init_block_clear_fn (tree, const char *);
+extern void init_stack_smash_fn (tree, const char *);
 
 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
 
diff --git a/gnu/gcc/gcc/targhooks.c b/gnu/gcc/gcc/targhooks.c
index 802df49b2cd..ce7bdbd9fa3 100644
--- a/gnu/gcc/gcc/targhooks.c
+++ b/gnu/gcc/gcc/targhooks.c
@@ -393,10 +393,49 @@ static GTY(()) int stack_protect_labelno;
 
 #include "c-common.h"
 
+static GTY(()) tree stack_smash_fn;
+
+void
+init_stack_smash_fn (tree decl, const char *asmspec)
+{
+  if (!stack_smash_fn)
+    {
+      tree args, fn;
+
+      fn = get_identifier ("__stack_smash_handler");
+      args = build_function_type_list (void_type_node, ptr_type_node,
+				       NULL_TREE);
+      fn = build_decl (FUNCTION_DECL, fn, args);
+      DECL_EXTERNAL (fn) = 1;
+      TREE_PUBLIC (fn) = 1;
+      DECL_ARTIFICIAL (fn) = 1;
+      TREE_THIS_VOLATILE (fn) = 1;
+      TREE_NOTHROW (fn) = 1;
+      if (decl != NULL_TREE && DECL_VISIBILITY_SPECIFIED (decl))
+	DECL_VISIBILITY (fn) = DECL_VISIBILITY (decl);
+      else
+        DECL_VISIBILITY (fn) = VISIBILITY_DEFAULT;
+      DECL_VISIBILITY_SPECIFIED (fn) = 1;
+      stack_smash_fn = fn;
+    }
+
+  if (asmspec)
+    set_user_assembler_name (stack_smash_fn, asmspec);
+}
+
+static tree
+emit_stack_smash_libcall_fn (void)
+{
+  if (!stack_smash_fn)
+    init_stack_smash_fn (NULL_TREE, NULL);
+
+  return stack_smash_fn;
+}
+
 tree 
 default_external_stack_protect_fail (void)
 {
-  tree t, func, type, init, stack_smash_handler;
+  tree t, func, type, init;
   const char *name = fname_as_string (0);
   size_t length = strlen (name);
   char name_buf[32];
@@ -420,26 +459,10 @@ default_external_stack_protect_fail (void)
 
   assemble_variable (func, 0, 0, 0);
 
-  /* Build a decl for __stack_smash_handler.  */
-  t = build_pointer_type (TREE_TYPE (func));
-  t = build_function_type_list (void_type_node, t, NULL);
-  t = build_decl (FUNCTION_DECL, get_identifier ("__stack_smash_handler"), t);
-  TREE_STATIC (t) = 1;
-  TREE_PUBLIC (t) = 1;
-  DECL_EXTERNAL (t) = 1;
-  TREE_USED (t) = 1;
-  TREE_THIS_VOLATILE (t) = 1;
-  TREE_NOTHROW (t) = 1;
-  DECL_ARTIFICIAL (t) = 1;
-  DECL_IGNORED_P (t) = 1;
-  DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
-  DECL_VISIBILITY_SPECIFIED (t) = 1;
-  stack_smash_handler = t;
-
   /* Generate a call to __stack_smash_handler(__func__).  */
   t = build_fold_addr_expr (func);
   t = tree_cons (NULL, t, NULL);
-  return build_function_call_expr (stack_smash_handler, t);
+  return build_function_call_expr (emit_stack_smash_libcall_fn (), t);
 }
 
 tree