[C++ PATCH] Fix set but not used warnings in C++ FE

[Jakub Jelinek <jakub@redhat.com>]

Hi!

This patch fixes set but not used warnings in C++ FE.  Most cases are quite
obvious, though I'd appreciate if you could go through these and tell
whether in some cases it wasn't just a bug that the variables aren't used
anywhere and instead of dropping the variable we should actually use it.
The build_vec_init change I'm particularly unsure about, size_in_bytes
has side-effects (diagnosing incomplete types), I wonder if we need to
preserve the call or if incomplete type in the build_vec_init case will be
already diagnosed earlier.

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2009-11-27  Jakub Jelinek  <jakub@redhat.com>

	* g++spec.c (lang_specific_driver): Remove unused saw_verbose_flag
	variable.
	* pt.c (tsubst_pack_expansion): Remove unused first_arg_pack variable.
	* init.c (build_vec_init): Remove unused size variable.
	* typeck2.c (check_narrowing): Remove unused was_decl variable.
	* decl.c (poplevel): Remove unused tmp and real_functionbody
	variables.
	(decls_match): Remove unused tree_name variable.
	(start_decl): Remove unused type variable.
	* parser.c (cp_parser_type_parameter): Remove unused parameter_list
	variable.
	(cp_parser_template_id, cp_parser_explicit_instantiation,
	cp_parser_declarator): Remove unused token variable.
	(cp_parser_simple_type_specifier): Remove unused id variable.
	(cp_parser_parameter_declaration): Remove unused
	greater_than_is_operator_p variable.
	(cp_parser_check_declarator_template_parameters): Remove unused
	member variable.
	(c_parse_file): Remove unused error_occurred variable.
	* cp-gimplify.c (cp_gimplify_init_expr): Remove unused slot variable.
	* typeck.c (cp_build_function_call_vec): Remove unused name variable.
	* class.c (resolve_address_of_overloaded_function): Remove unused
	is_reference variable.
	(build_rtti_vtbl_entries): Remove unused basetype variable.
	* mangle.c (write_template_param): Remove unused parm_level and
	parm_type variables.

--- gcc/cp/g++spec.c.jj	2009-07-03 11:14:44.000000000 +0200
+++ gcc/cp/g++spec.c	2009-11-26 17:36:35.000000000 +0100
@@ -59,9 +59,6 @@ lang_specific_driver (int *in_argc, cons
   /* If nonzero, the user gave us the `-p' or `-pg' flag.  */
   int saw_profile_flag = 0;
 
-  /* If nonzero, the user gave us the `-v' flag.  */
-  int saw_verbose_flag = 0;
-
   /* What do with libstdc++:
      -1 means we should not link in libstdc++
      0  means we should link in libstdc++ if it is needed
@@ -153,8 +150,6 @@ lang_specific_driver (int *in_argc, cons
 	    args[i] |= WITHLIBC;
 	  else if (strcmp (argv[i], "-pg") == 0 || strcmp (argv[i], "-p") == 0)
 	    saw_profile_flag++;
-	  else if (strcmp (argv[i], "-v") == 0)
-	    saw_verbose_flag = 1;
 	  else if (strncmp (argv[i], "-x", 2) == 0)
 	    {
 	      const char * arg;
--- gcc/cp/pt.c.jj	2009-11-25 10:50:09.000000000 +0100
+++ gcc/cp/pt.c	2009-11-26 17:36:35.000000000 +0100
@@ -7993,7 +7993,7 @@ tsubst_pack_expansion (tree t, tree args
 {
   tree pattern;
   tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
-  tree first_arg_pack; int i, len = -1;
+  int i, len = -1;
   tree result;
   int incomplete = 0;
   bool very_local_specializations = false;
@@ -8077,10 +8077,7 @@ tsubst_pack_expansion (tree t, tree args
             incomplete = 1;
 
           if (len < 0)
-            {
-              len = my_len;
-              first_arg_pack = arg_pack;
-            }
+	    len = my_len;
           else if (len != my_len)
             {
 	      if (incomplete)
--- gcc/cp/init.c.jj	2009-11-13 11:13:20.000000000 +0100
+++ gcc/cp/init.c	2009-11-26 17:36:35.000000000 +0100
@@ -2666,7 +2666,6 @@ build_vec_init (tree base, tree maxindex
 {
   tree rval;
   tree base2 = NULL_TREE;
-  tree size;
   tree itype = NULL_TREE;
   tree iterator;
   /* The type of BASE.  */
@@ -2724,7 +2723,7 @@ build_vec_init (tree base, tree maxindex
     }
 
   maxindex = cp_convert (ptrdiff_type_node, maxindex);
-  size = size_in_bytes (type);
+  size_in_bytes (type);
   if (TREE_CODE (atype) == ARRAY_TYPE)
     {
       ptype = build_pointer_type (type);
--- gcc/cp/typeck2.c.jj	2009-11-23 13:04:26.000000000 +0100
+++ gcc/cp/typeck2.c	2009-11-26 17:36:35.000000000 +0100
@@ -655,13 +655,9 @@ check_narrowing (tree type, tree init)
   tree ftype = unlowered_expr_type (init);
   bool ok = true;
   REAL_VALUE_TYPE d;
-  bool was_decl = false;
 
   if (DECL_P (init))
-    {
-      was_decl = true;
-      init = decl_constant_value (init);
-    }
+    init = decl_constant_value (init);
 
   if (TREE_CODE (type) == INTEGER_TYPE
       && TREE_CODE (ftype) == REAL_TYPE)
--- gcc/cp/decl.c.jj	2009-11-23 16:14:32.000000000 +0100
+++ gcc/cp/decl.c	2009-11-26 17:36:35.000000000 +0100
@@ -520,8 +520,6 @@ poplevel (int keep, int reverse, int fun
   /* The chain of decls was accumulated in reverse order.
      Put it into forward order, just for cleanliness.  */
   tree decls;
-  int tmp = functionbody;
-  int real_functionbody;
   tree subblocks;
   tree block;
   tree decl;
@@ -535,8 +533,8 @@ poplevel (int keep, int reverse, int fun
 
   gcc_assert (current_binding_level->kind != sk_class);
 
-  real_functionbody = (current_binding_level->kind == sk_cleanup
-		       ? ((functionbody = 0), tmp) : functionbody);
+  if (current_binding_level->kind == sk_cleanup)
+    functionbody = 0;
   subblocks = functionbody >= 0 ? current_binding_level->blocks : 0;
 
   gcc_assert (!VEC_length(cp_class_binding,
@@ -1035,8 +1033,6 @@ decls_match (tree newdecl, tree olddecl)
 void
 warn_extern_redeclared_static (tree newdecl, tree olddecl)
 {
-  tree name;
-
   if (TREE_CODE (newdecl) == TYPE_DECL
       || TREE_CODE (newdecl) == TEMPLATE_DECL
       || TREE_CODE (newdecl) == CONST_DECL
@@ -1059,7 +1055,6 @@ warn_extern_redeclared_static (tree newd
       && DECL_ARTIFICIAL (olddecl))
     return;
 
-  name = DECL_ASSEMBLER_NAME (newdecl);
   permerror (input_location, "%qD was declared %<extern%> and later %<static%>", newdecl);
   permerror (input_location, "previous declaration of %q+D", olddecl);
 }
@@ -4071,7 +4066,6 @@ start_decl (const cp_declarator *declara
 	    tree *pushed_scope_p)
 {
   tree decl;
-  tree type;
   tree context;
   bool was_public;
   int flags;
@@ -4094,8 +4088,6 @@ start_decl (const cp_declarator *declara
       || decl == error_mark_node)
     return error_mark_node;
 
-  type = TREE_TYPE (decl);
-
   context = DECL_CONTEXT (decl);
 
   if (context)
--- gcc/cp/parser.c.jj	2009-11-25 10:50:09.000000000 +0100
+++ gcc/cp/parser.c	2009-11-26 17:36:35.000000000 +0100
@@ -10650,14 +10650,13 @@ cp_parser_type_parameter (cp_parser* par
 
     case RID_TEMPLATE:
       {
-	tree parameter_list;
 	tree identifier;
 	tree default_argument;
 
 	/* Look for the `<'.  */
 	cp_parser_require (parser, CPP_LESS, "%<<%>");
 	/* Parse the template-parameter-list.  */
-	parameter_list = cp_parser_template_parameter_list (parser);
+	cp_parser_template_parameter_list (parser);
 	/* Look for the `>'.  */
 	cp_parser_require (parser, CPP_GREATER, "%<>%>");
 	/* Look for the `class' keyword.  */
@@ -10791,7 +10790,7 @@ cp_parser_template_id (cp_parser *parser
   cp_token_position start_of_id = 0;
   deferred_access_check *chk;
   VEC (deferred_access_check,gc) *access_check;
-  cp_token *next_token = NULL, *next_token_2 = NULL, *token = NULL;
+  cp_token *next_token = NULL, *next_token_2 = NULL;
   bool is_identifier;
 
   /* If the next token corresponds to a template-id, there is no need
@@ -10839,7 +10838,6 @@ cp_parser_template_id (cp_parser *parser
 
   /* Parse the template-name.  */
   is_identifier = false;
-  token = cp_lexer_peek_token (parser->lexer);
   templ = cp_parser_template_name (parser, template_keyword_p,
 				   check_dependency_p,
 				   is_declaration,
@@ -11516,7 +11514,6 @@ cp_parser_explicit_instantiation (cp_par
   int declares_class_or_enum;
   cp_decl_specifier_seq decl_specifiers;
   tree extension_specifier = NULL_TREE;
-  cp_token *token;
 
   /* Look for an (optional) storage-class-specifier or
      function-specifier.  */
@@ -11539,7 +11536,6 @@ cp_parser_explicit_instantiation (cp_par
      control while processing explicit instantiation directives.  */
   push_deferring_access_checks (dk_no_check);
   /* Parse a decl-specifier-seq.  */
-  token = cp_lexer_peek_token (parser->lexer);
   cp_parser_decl_specifier_seq (parser,
 				CP_PARSER_FLAGS_OPTIONAL,
 				&decl_specifiers,
@@ -11996,8 +11992,6 @@ cp_parser_simple_type_specifier (cp_pars
   /* If the type-specifier was for a built-in type, we're done.  */
   if (type)
     {
-      tree id;
-
       /* Record the type.  */
       if (decl_specs
 	  && (token->keyword != RID_SIGNED
@@ -12012,7 +12006,7 @@ cp_parser_simple_type_specifier (cp_pars
 	decl_specs->any_specifiers_p = true;
 
       /* Consume the token.  */
-      id = cp_lexer_consume_token (parser->lexer)->u.value;
+      cp_lexer_consume_token (parser->lexer);
 
       /* There is no valid C++ program where a non-template type is
 	 followed by a "<".  That usually indicates that the user thought
@@ -13800,7 +13794,6 @@ cp_parser_declarator (cp_parser* parser,
 		      bool* parenthesized_p,
 		      bool member_p)
 {
-  cp_token *token;
   cp_declarator *declarator;
   enum tree_code code;
   cp_cv_quals cv_quals;
@@ -13815,9 +13808,6 @@ cp_parser_declarator (cp_parser* parser,
   if (cp_parser_allow_gnu_extensions_p (parser))
     attributes = cp_parser_attributes_opt (parser);
 
-  /* Peek at the next token.  */
-  token = cp_lexer_peek_token (parser->lexer);
-
   /* Check for the ptr-operator production.  */
   cp_parser_parse_tentatively (parser);
   /* Parse the ptr-operator.  */
@@ -15012,7 +15002,6 @@ cp_parser_parameter_declaration (cp_pars
 				 bool *parenthesized_p)
 {
   int declares_class_or_enum;
-  bool greater_than_is_operator_p;
   cp_decl_specifier_seq decl_specifiers;
   cp_declarator *declarator;
   tree default_argument;
@@ -15027,7 +15016,6 @@ cp_parser_parameter_declaration (cp_pars
      template-parameter, the first non-nested `>' is taken as the end
      of the template parameter-list rather than a greater-than
      operator.  */
-  greater_than_is_operator_p = !template_parm_p;
 
   /* Type definitions may not appear in parameter types.  */
   saved_message = parser->type_definition_forbidden_message;
@@ -18221,10 +18209,8 @@ cp_parser_check_declarator_template_para
       if (declarator->u.id.qualifying_scope)
 	{
 	  tree scope;
-	  tree member;
 
 	  scope = declarator->u.id.qualifying_scope;
-	  member = declarator->u.id.unqualified_name;
 
 	  while (scope && CLASS_TYPE_P (scope))
 	    {
@@ -23123,7 +23109,6 @@ pragma_lex (tree *value)
 void
 c_parse_file (void)
 {
-  bool error_occurred;
   static bool already_called = false;
 
   if (already_called)
@@ -23136,7 +23121,7 @@ c_parse_file (void)
   the_parser = cp_parser_new ();
   push_deferring_access_checks (flag_access_control
 				? dk_no_deferred : dk_no_check);
-  error_occurred = cp_parser_translation_unit (the_parser);
+  cp_parser_translation_unit (the_parser);
   the_parser = NULL;
 }
 
--- gcc/cp/cp-gimplify.c.jj	2009-09-30 12:19:17.000000000 +0200
+++ gcc/cp/cp-gimplify.c	2009-11-26 17:36:35.000000000 +0100
@@ -429,17 +429,13 @@ cp_gimplify_init_expr (tree *expr_p, gim
   tree from = TREE_OPERAND (*expr_p, 1);
   tree to = TREE_OPERAND (*expr_p, 0);
   tree t;
-  tree slot = NULL_TREE;
 
   /* What about code that pulls out the temp and uses it elsewhere?  I
      think that such code never uses the TARGET_EXPR as an initializer.  If
      I'm wrong, we'll abort because the temp won't have any RTL.  In that
      case, I guess we'll need to replace references somehow.  */
   if (TREE_CODE (from) == TARGET_EXPR)
-    {
-      slot = TARGET_EXPR_SLOT (from);
-      from = TARGET_EXPR_INITIAL (from);
-    }
+    from = TARGET_EXPR_INITIAL (from);
 
   /* Look through any COMPOUND_EXPRs, since build_compound_expr pushes them
      inside the TARGET_EXPR.  */
--- gcc/cp/typeck.c.jj	2009-11-23 13:04:26.000000000 +0100
+++ gcc/cp/typeck.c	2009-11-26 17:36:35.000000000 +0100
@@ -3021,7 +3021,6 @@ cp_build_function_call_vec (tree functio
 			    tsubst_flags_t complain)
 {
   tree fntype, fndecl;
-  tree name = NULL_TREE;
   int is_method;
   tree original = function;
   int nargs;
@@ -3044,8 +3043,6 @@ cp_build_function_call_vec (tree functio
 
   if (TREE_CODE (function) == FUNCTION_DECL)
     {
-      name = DECL_NAME (function);
-
       mark_used (function);
       fndecl = function;
 
--- gcc/cp/class.c.jj	2009-11-23 13:04:26.000000000 +0100
+++ gcc/cp/class.c	2009-11-26 17:36:35.000000000 +0100
@@ -6059,7 +6059,6 @@ resolve_address_of_overloaded_function (
        selected function.  */
 
   int is_ptrmem = 0;
-  int is_reference = 0;
   /* We store the matches in a TREE_LIST rooted here.  The functions
      are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
      interoperability with most_specialized_instantiation.  */
@@ -6082,12 +6081,9 @@ resolve_address_of_overloaded_function (
     /* This is OK, too.  */
     is_ptrmem = 1;
   else if (TREE_CODE (target_type) == FUNCTION_TYPE)
-    {
-      /* This is OK, too.  This comes from a conversion to reference
-	 type.  */
-      target_type = build_reference_type (target_type);
-      is_reference = 1;
-    }
+    /* This is OK, too.  This comes from a conversion to reference
+       type.  */
+    target_type = build_reference_type (target_type);
   else
     {
       if (flags & tf_error)
@@ -8043,12 +8039,10 @@ build_rtti_vtbl_entries (tree binfo, vtb
 {
   tree b;
   tree t;
-  tree basetype;
   tree offset;
   tree decl;
   tree init;
 
-  basetype = BINFO_TYPE (binfo);
   t = BINFO_TYPE (vid->rtti_binfo);
 
   /* To find the complete object, we will first convert to our most
--- gcc/cp/mangle.c.jj	2009-11-02 15:54:23.000000000 +0100
+++ gcc/cp/mangle.c	2009-11-26 17:36:35.000000000 +0100
@@ -2809,8 +2809,6 @@ static void
 write_template_param (const tree parm)
 {
   int parm_index;
-  int parm_level;
-  tree parm_type = NULL_TREE;
 
   MANGLE_TRACE_TREE ("template-parm", parm);
 
@@ -2820,13 +2818,10 @@ write_template_param (const tree parm)
     case TEMPLATE_TEMPLATE_PARM:
     case BOUND_TEMPLATE_TEMPLATE_PARM:
       parm_index = TEMPLATE_TYPE_IDX (parm);
-      parm_level = TEMPLATE_TYPE_LEVEL (parm);
       break;
 
     case TEMPLATE_PARM_INDEX:
       parm_index = TEMPLATE_PARM_IDX (parm);
-      parm_level = TEMPLATE_PARM_LEVEL (parm);
-      parm_type = TREE_TYPE (TEMPLATE_PARM_DECL (parm));
       break;
 
     default:

	Jakub