re PR c++/13764 (c++ front-end creates extra blocks)

        PR c++/13764
        * c-common.c (finish_fname_decls): Use append_to_statement_list_force.
        * cp/cp-tree.h (FUNCTION_NEEDS_BODY_BLOCK): New macro.
        * cp/name-lookup.c (pushdecl_maybe_friend): Check it.
        * cp/decl.c (begin_function_body): Do nothing if it's false.
        (finish_function_body): Ditto.
        (outer_curly_brace_block): New fn.
        (finish_function): Use it.

From-SVN: r104698

gcc/ChangeLog

 2005-09-26  Jason Merrill  <jason@redhat.com>
 
+	PR c++/13764
+	* c-common.c (finish_fname_decls): Use append_to_statement_list_force.
+
 	* doc/invoke.texi: Clarify documentation of -fno-enforce-eh-specs.
 
 2005-09-26  James E Wilson  <wilson@specifix.com>

gcc/c-common.c

@@ -695,7 +695,7 @@ finish_fname_decls (void)
       if (TREE_CODE (*bodyp) == BIND_EXPR)
 	bodyp = &BIND_EXPR_BODY (*bodyp);
 
-      append_to_statement_list (*bodyp, &stmts);
+      append_to_statement_list_force (*bodyp, &stmts);
       *bodyp = stmts;
     }
 

gcc/cp/ChangeLog

+2005-09-26  Jason Merrill  <jason@redhat.com>
+
+	PR c++/13764
+	* cp-tree.h (FUNCTION_NEEDS_BODY_BLOCK): New macro.
+	* name-lookup.c (pushdecl_maybe_friend): Check it.
+	* decl.c (begin_function_body): Do nothing if it's false.
+	(finish_function_body): Ditto.
+	(outer_curly_brace_block): New fn.
+	(finish_function): Use it.
+
 2005-09-26  Richard Guenther  <rguenther@suse.de>
 
 	PR middle-end/15855

gcc/cp/cp-tree.h

@@ -255,6 +255,8 @@ typedef struct ptrmem_cst * ptrmem_cst_t;
 /* Used to mark the block around the member initializers and cleanups.  */
 #define BIND_EXPR_BODY_BLOCK(NODE) \
   TREE_LANG_FLAG_3 (BIND_EXPR_CHECK (NODE))
+#define FUNCTION_NEEDS_BODY_BLOCK(NODE) \
+  (DECL_CONSTRUCTOR_P (NODE) || DECL_DESTRUCTOR_P (NODE))
 
 #define STATEMENT_LIST_NO_SCOPE(NODE) \
   TREE_LANG_FLAG_0 (STATEMENT_LIST_CHECK (NODE))

gcc/cp/decl.c

@@ -10656,14 +10656,16 @@ finish_destructor_body (void)
 /* Do the necessary processing for the beginning of a function body, which
    in this case includes member-initializers, but not the catch clauses of
    a function-try-block.  Currently, this means opening a binding level
-   for the member-initializers (in a ctor) and member cleanups (in a dtor).
-   In other functions, this isn't necessary, but it doesn't hurt.  */
+   for the member-initializers (in a ctor) and member cleanups (in a dtor).  */
 
 tree
 begin_function_body (void)
 {
   tree stmt;
 
+  if (! FUNCTION_NEEDS_BODY_BLOCK (current_function_decl))
+    return NULL_TREE;
+
   if (processing_template_decl)
     /* Do nothing now.  */;
   else
@@ -10694,6 +10696,9 @@ begin_function_body (void)
 void
 finish_function_body (tree compstmt)
 {
+  if (compstmt == NULL_TREE)
+    return;
+  
   /* Close the block.  */
   finish_compound_stmt (compstmt);
 
@@ -10705,6 +10710,20 @@ finish_function_body (tree compstmt)
     finish_destructor_body ();
 }
 
+/* Given a function, returns the BLOCK corresponding to the outermost level
+   of curly braces, skipping the artificial block created for constructor
+   initializers.  */
+
+static tree
+outer_curly_brace_block (tree fndecl)
+{
+  tree block = BLOCK_SUBBLOCKS (DECL_INITIAL (fndecl));
+  if (FUNCTION_NEEDS_BODY_BLOCK (current_function_decl))
+    /* Skip the artificial function body block.  */
+    block = BLOCK_SUBBLOCKS (block);
+  return block;
+}
+
 /* Finish up a function declaration and compile that function
    all the way to assembler language output.  The free the storage
    for the function definition.
@@ -10836,9 +10855,7 @@ finish_function (int flags)
 	     the function so we know that their lifetime always ends with a
 	     return; see g++.dg/opt/nrv6.C.  We could be more flexible if
 	     we were to do this optimization in tree-ssa.  */
-	  && (outer = BLOCK_SUBBLOCKS (DECL_INITIAL (fndecl)))
-	  /* Skip the artificial function body block.  */
-	  && (outer = BLOCK_SUBBLOCKS (outer))
+	  && (outer = outer_curly_brace_block (fndecl))
 	  && chain_member (r, BLOCK_VARS (outer)))
 	finalize_nrv (&DECL_SAVED_TREE (fndecl), r, DECL_RESULT (fndecl));
 

gcc/cp/name-lookup.c

@@ -935,8 +935,9 @@ pushdecl_maybe_friend (tree x, bool is_friend)
 		     them there.  */
 		  struct cp_binding_level *b = current_binding_level->level_chain;
 
-		  /* Skip the ctor/dtor cleanup level.  */
-		  b = b->level_chain;
+		  if (FUNCTION_NEEDS_BODY_BLOCK (current_function_decl))
+		    /* Skip the ctor/dtor cleanup level.  */
+		    b = b->level_chain;
 
 		  /* ARM $8.3 */
 		  if (b->kind == sk_function_parms)

gcc/testsuite/g++.dg/tree-ssa/block1.C

+// PR 13764: We were inserting an extra body block in all functions, but
+// it's only really necessary for [cd]tors.
+// { dg-options "-fdump-tree-gimple" }
+
+void bar (void)
+{
+  int a;
+}
+
+// { dg-final { scan-tree-dump-times "\{" 1 "gimple" } }
+// { dg-final { cleanup-tree-dump "gimple" } }