Re: RFA: PATCH to add id_strcmp helper function

[Jason Merrill <jason@redhat.com>]

[-- Attachment #1: Type: text/plain, Size: 792 bytes --]

On Thu, May 18, 2017 at 11:03 PM, Martin Sebor <msebor@gmail.com> wrote:
> On 05/18/2017 08:30 PM, Jason Merrill wrote:
>>
>> I got tired of writing strcmp (IDENTIFIER_POINTER and decided to wrap
>> it in an inline function.  I decided to use "id_strcmp" instead of
>> just overloading strcmp, but I don't feel strongly about that choice.
>>
>> The second patch changes all existing uses of that pattern to use the
>> new function.
>>
>> OK for trunk?
>
>
> Since all the uses are of the form !id_strcmp(), would taking
> a step further and introducing a bool id_equal() be going too
> far?
>
> Besides being (arguably) easier to read, it would get around
> the question of whether it should be !id_strcmp() or
> id_strcmp == 0, or perhaps even 0 == id_strcmp().

Makes sense.

OK for trunk?

[-- Attachment #2: id-equal.diff --]
[-- Type: text/plain, Size: 15114 bytes --]

commit ca96d8533f808e8b8ebcd35ee699a90dcc2bf8cf
Author: Jason Merrill <jason@redhat.com>
Date:   Thu May 18 15:23:27 2017 -0400

            * tree.h (id_equal): New.
    
            * dwarf2out.c, hsa-gen.c, ipa-devirt.c, omp-expand.c,
            omp-simd-clone.c, read-rtl-function.c, tree-chkp.c, tree.c: Use it
            instead of strcmp of IDENTIFIER_POINTER.
    c-family/
            * c-ada-spec.c, c-pragma.c: Use it.
    cp/
            * cp-tree.h, decl2.c, mangle.c, parser.c, pt.c, semantics.c: Use it.
            * error.c: Use is_this_parameter.

diff --git a/gcc/c-family/c-ada-spec.c b/gcc/c-family/c-ada-spec.c
index 18c5ccf..6cf298a 100644
--- a/gcc/c-family/c-ada-spec.c
+++ b/gcc/c-family/c-ada-spec.c
@@ -1799,7 +1799,7 @@ is_char_array (tree t)
 
   tmp = TREE_TYPE (tmp);
   return num_dim == 1 && TREE_CODE (tmp) == INTEGER_TYPE
-    && !strcmp (IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (tmp))), "char");
+    && id_equal (DECL_NAME (TYPE_NAME (tmp)), "char");
 }
 
 /* Dump in BUFFER an array type T in Ada syntax.  Assume that the "type"
diff --git a/gcc/c-family/c-pragma.c b/gcc/c-family/c-pragma.c
index bc36626..48b02b8 100644
--- a/gcc/c-family/c-pragma.c
+++ b/gcc/c-family/c-pragma.c
@@ -514,7 +514,7 @@ handle_pragma_redefine_extname (cpp_reader * ARG_UNUSED (dummy))
 	      const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
 	      name = targetm.strip_name_encoding (name);
 
-	      if (strcmp (name, IDENTIFIER_POINTER (newname)))
+	      if (!id_equal (newname, name))
 		warning (OPT_Wpragmas, "#pragma redefine_extname ignored due to "
 			 "conflict with previous rename");
 	    }
@@ -587,7 +587,7 @@ maybe_apply_renaming_pragma (tree decl, tree asmname)
 	if (DECL_NAME (decl) == p->oldname)
 	  {
 	    /* Only warn if there is a conflict.  */
-	    if (strcmp (IDENTIFIER_POINTER (p->newname), oldname))
+	    if (!id_equal (p->newname, oldname))
 	      warning (OPT_Wpragmas, "#pragma redefine_extname ignored due to "
 		       "conflict with previous rename");
 
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 98ef023..7c46cad 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -2960,7 +2960,7 @@ struct GTY(()) lang_decl {
    template function.  */
 #define DECL_PRETTY_FUNCTION_P(NODE) \
   (DECL_NAME (NODE) \
-   && !strcmp (IDENTIFIER_POINTER (DECL_NAME (NODE)), "__PRETTY_FUNCTION__"))
+   && id_equal (DECL_NAME (NODE), "__PRETTY_FUNCTION__"))
 
 /* Nonzero if the variable was declared to be thread-local.
    We need a special C++ version of this test because the middle-end
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index 85310e0..29883da 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -827,7 +827,7 @@ grokfield (const cp_declarator *declarator,
 	}
 
       if (IDENTIFIER_POINTER (name)[0] == '_'
-	  && ! strcmp (IDENTIFIER_POINTER (name), "_vptr"))
+	  && id_equal (name, "_vptr"))
 	error ("member %qD conflicts with virtual function table field name",
 	       value);
     }
diff --git a/gcc/cp/error.c b/gcc/cp/error.c
index 1ae25bb..b65cee4 100644
--- a/gcc/cp/error.c
+++ b/gcc/cp/error.c
@@ -2149,8 +2149,7 @@ dump_expr (cxx_pretty_printer *pp, tree t, int flags)
                            flags | TFF_EXPR_IN_PARENS);
 		pp_cxx_dot (pp);
 	      }
-	    else if (TREE_CODE (ob) != PARM_DECL
-		     || strcmp (IDENTIFIER_POINTER (DECL_NAME (ob)), "this"))
+	    else if (!is_this_parameter (ob))
 	      {
 		dump_expr (pp, ob, flags | TFF_EXPR_IN_PARENS);
 		pp_cxx_arrow (pp);
@@ -2231,9 +2230,7 @@ dump_expr (cxx_pretty_printer *pp, tree t, int flags)
 	if (INDIRECT_REF_P (ob))
 	  {
 	    ob = TREE_OPERAND (ob, 0);
-	    if (TREE_CODE (ob) != PARM_DECL
-		|| (DECL_NAME (ob)
-		    && strcmp (IDENTIFIER_POINTER (DECL_NAME (ob)), "this")))
+	    if (!is_this_parameter (ob))
 	      {
 		dump_expr (pp, ob, flags | TFF_EXPR_IN_PARENS);
 		if (TREE_CODE (TREE_TYPE (ob)) == REFERENCE_TYPE)
diff --git a/gcc/cp/mangle.c b/gcc/cp/mangle.c
index 42290fe..e866675 100644
--- a/gcc/cp/mangle.c
+++ b/gcc/cp/mangle.c
@@ -2900,7 +2900,7 @@ write_expression (tree expr)
     write_template_arg_literal (expr);
   else if (code == PARM_DECL && DECL_ARTIFICIAL (expr))
     {
-      gcc_assert (!strcmp ("this", IDENTIFIER_POINTER (DECL_NAME (expr))));
+      gcc_assert (id_equal (DECL_NAME (expr), "this"));
       write_string ("fpT");
     }
   else if (code == PARM_DECL)
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 4f2c2d5..a1ada02 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -3201,7 +3201,7 @@ cp_parser_diagnose_invalid_type_name (cp_parser *parser, tree id,
 		"-std=c++11 or -std=gnu++11");
       else if (cxx_dialect < cxx11
 	       && TREE_CODE (id) == IDENTIFIER_NODE
-	       && !strcmp (IDENTIFIER_POINTER (id), "thread_local"))
+	       && id_equal (id, "thread_local"))
 	inform (location, "C++11 %<thread_local%> only available with "
 		"-std=c++11 or -std=gnu++11");
       else if (!flag_concepts && id == ridpointers[(int)RID_CONCEPT])
@@ -7823,7 +7823,7 @@ cp_parser_unary_expression (cp_parser *parser, cp_id_kind * pidk,
 		/* ISO C++ defines alignof only with types, not with
 		   expressions. So pedwarn if alignof is used with a non-
 		   type expression. However, __alignof__ is ok.  */
-		if (!strcmp (IDENTIFIER_POINTER (token->u.value), "alignof"))
+		if (id_equal (token->u.value, "alignof"))
 		  pedwarn (token->location, OPT_Wpedantic,
 			   "ISO C++ does not allow %<alignof%> "
 			   "with a non-type");
@@ -20397,17 +20397,17 @@ cp_parser_virt_specifier_seq_opt (cp_parser* parser)
       /* See if it's a virt-specifier-qualifier.  */
       if (token->type != CPP_NAME)
         break;
-      if (!strcmp (IDENTIFIER_POINTER(token->u.value), "override"))
+      if (id_equal (token->u.value, "override"))
         {
           maybe_warn_cpp0x (CPP0X_OVERRIDE_CONTROLS);
           virt_specifier = VIRT_SPEC_OVERRIDE;
         }
-      else if (!strcmp (IDENTIFIER_POINTER(token->u.value), "final"))
+      else if (id_equal (token->u.value, "final"))
         {
           maybe_warn_cpp0x (CPP0X_OVERRIDE_CONTROLS);
           virt_specifier = VIRT_SPEC_FINAL;
         }
-      else if (!strcmp (IDENTIFIER_POINTER(token->u.value), "__final"))
+      else if (id_equal (token->u.value, "__final"))
         {
           virt_specifier = VIRT_SPEC_FINAL;
         }
@@ -27644,7 +27644,7 @@ static bool
 token_is__thread (cp_token *token)
 {
   gcc_assert (token->keyword == RID_THREAD);
-  return !strcmp (IDENTIFIER_POINTER (token->u.value), "__thread");
+  return id_equal (token->u.value, "__thread");
 }
 
 /* Set the location for a declarator specifier and check if it is
@@ -31254,7 +31254,7 @@ cp_parser_oacc_shape_clause (cp_parser *parser, omp_clause_code kind,
 	    }
 	  /* Worker num: argument and vector length: arguments.  */
 	  else if (cp_lexer_next_token_is (lexer, CPP_NAME)
-		   && strcmp (id, IDENTIFIER_POINTER (next->u.value)) == 0
+		   && id_equal (next->u.value, id)
 		   && cp_lexer_nth_token_is (lexer, 2, CPP_COLON))
 	    {
 	      cp_lexer_consume_token (lexer);  /* id  */
@@ -37125,10 +37125,8 @@ cp_parser_omp_declare_reduction (cp_parser *parser, cp_token *pragma_tok,
       else if (ARITHMETIC_TYPE_P (type)
 	       && (orig_reduc_id == NULL_TREE
 		   || (TREE_CODE (type) != COMPLEX_TYPE
-		       && (strcmp (IDENTIFIER_POINTER (orig_reduc_id),
-				   "min") == 0
-			   || strcmp (IDENTIFIER_POINTER (orig_reduc_id),
-				      "max") == 0))))
+		       && (id_equal (orig_reduc_id, "min")
+			   || id_equal (orig_reduc_id, "max")))))
 	error_at (loc, "predeclared arithmetic type %qT in "
 		       "%<#pragma omp declare reduction%>", type);
       else if (TREE_CODE (type) == FUNCTION_TYPE
@@ -38665,15 +38663,15 @@ cp_parser_cilk_simd_clause_name (cp_parser *parser)
     clause_type = PRAGMA_CILK_CLAUSE_PRIVATE;
   else if (!token->u.value || token->type != CPP_NAME)
     return PRAGMA_CILK_CLAUSE_NONE;
-  else if (!strcmp (IDENTIFIER_POINTER (token->u.value), "vectorlength"))
+  else if (id_equal (token->u.value, "vectorlength"))
     clause_type = PRAGMA_CILK_CLAUSE_VECTORLENGTH;
-  else if (!strcmp (IDENTIFIER_POINTER (token->u.value), "linear"))
+  else if (id_equal (token->u.value, "linear"))
     clause_type = PRAGMA_CILK_CLAUSE_LINEAR;
-  else if (!strcmp (IDENTIFIER_POINTER (token->u.value), "firstprivate"))
+  else if (id_equal (token->u.value, "firstprivate"))
     clause_type = PRAGMA_CILK_CLAUSE_FIRSTPRIVATE;
-  else if (!strcmp (IDENTIFIER_POINTER (token->u.value), "lastprivate"))
+  else if (id_equal (token->u.value, "lastprivate"))
     clause_type = PRAGMA_CILK_CLAUSE_LASTPRIVATE;
-  else if (!strcmp (IDENTIFIER_POINTER (token->u.value), "reduction"))
+  else if (id_equal (token->u.value, "reduction"))
     clause_type = PRAGMA_CILK_CLAUSE_REDUCTION;
   else
     return PRAGMA_CILK_CLAUSE_NONE;
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 54de34b..49957f9 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -3426,7 +3426,7 @@ builtin_pack_fn_p (tree fn)
       || !DECL_IS_BUILTIN (fn))
     return false;
 
-  if (strcmp (IDENTIFIER_POINTER (DECL_NAME (fn)), "__integer_pack") == 0)
+  if (id_equal (DECL_NAME (fn), "__integer_pack"))
     return true;
 
   return false;
@@ -3504,7 +3504,7 @@ expand_builtin_pack_call (tree call, tree args, tsubst_flags_t complain,
 
   tree fn = CALL_EXPR_FN (call);
 
-  if (strcmp (IDENTIFIER_POINTER (DECL_NAME (fn)), "__integer_pack") == 0)
+  if (id_equal (DECL_NAME (fn), "__integer_pack"))
     return expand_integer_pack (call, args, complain, in_decl);
 
   return NULL_TREE;
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 1ba961e..0e9e348 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -2882,7 +2882,7 @@ begin_class_definition (tree t)
       if (ns && TREE_CODE (ns) == NAMESPACE_DECL
 	  && DECL_CONTEXT (ns) == std_node
 	  && DECL_NAME (ns)
-	  && !strcmp (IDENTIFIER_POINTER (DECL_NAME (ns)), "decimal"))
+	  && id_equal (DECL_NAME (ns), "decimal"))
 	{
 	  const char *n = TYPE_NAME_STRING (t);
 	  if ((strcmp (n, "decimal32") == 0)
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 5ff45eb..7a42f8f 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -20621,7 +20621,7 @@ add_calling_convention_attribute (dw_die_ref subr_die, tree decl)
 	   targetm.dwarf_calling_convention (TREE_TYPE (decl)));
 
   if (is_fortran ()
-      && !strcmp (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)), "MAIN__"))
+      && id_equal (DECL_ASSEMBLER_NAME (decl), "MAIN__"))
     {
       /* DWARF 2 doesn't provide a way to identify a program's source-level
 	entry point.  DW_AT_calling_convention attributes are only meant
diff --git a/gcc/hsa-gen.c b/gcc/hsa-gen.c
index c5d8a6e..3aa65f3 100644
--- a/gcc/hsa-gen.c
+++ b/gcc/hsa-gen.c
@@ -3924,7 +3924,7 @@ get_hsa_kernel_dispatch_offset (const char *field_name)
 
   for (tree chain = TYPE_FIELDS (*hsa_kernel_dispatch_type);
        chain != NULL_TREE; chain = TREE_CHAIN (chain))
-    if (strcmp (field_name, IDENTIFIER_POINTER (DECL_NAME (chain))) == 0)
+    if (id_equal (DECL_NAME (chain), field_name))
       return int_byte_position (chain);
 
   gcc_unreachable ();
diff --git a/gcc/ipa-devirt.c b/gcc/ipa-devirt.c
index c7460ca..dc9232c 100644
--- a/gcc/ipa-devirt.c
+++ b/gcc/ipa-devirt.c
@@ -2359,7 +2359,7 @@ is_cxa_pure_virtual_p (tree target)
 {
   return target && TREE_CODE (TREE_TYPE (target)) != METHOD_TYPE
 	 && DECL_NAME (target)
-	 && !strcmp (IDENTIFIER_POINTER (DECL_NAME (target)),
+	 && id_equal (DECL_NAME (target),
 		     "__cxa_pure_virtual");
 }
 
diff --git a/gcc/omp-expand.c b/gcc/omp-expand.c
index 7a7c747..53d3d3f 100644
--- a/gcc/omp-expand.c
+++ b/gcc/omp-expand.c
@@ -4366,9 +4366,9 @@ expand_cilk_for (struct omp_region *region, struct omp_for_data *fd)
   tree t, low_val = NULL_TREE, high_val = NULL_TREE;
   for (t = DECL_ARGUMENTS (child_fndecl); t; t = TREE_CHAIN (t))
     {
-      if (!strcmp (IDENTIFIER_POINTER (DECL_NAME (t)), "__high"))
+      if (id_equal (DECL_NAME (t), "__high"))
 	high_val = t;
-      else if (!strcmp (IDENTIFIER_POINTER (DECL_NAME (t)), "__low"))
+      else if (id_equal (DECL_NAME (t), "__low"))
 	low_val = t;
     }
   gcc_assert (low_val && high_val);
diff --git a/gcc/omp-simd-clone.c b/gcc/omp-simd-clone.c
index 99589d4..3aa8b13 100644
--- a/gcc/omp-simd-clone.c
+++ b/gcc/omp-simd-clone.c
@@ -417,8 +417,7 @@ simd_clone_mangle (struct cgraph_node *node,
      if the simdlen is assumed to be 8 for the first one, etc.  */
   for (struct cgraph_node *clone = node->simd_clones; clone;
        clone = clone->simdclone->next_clone)
-    if (strcmp (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (clone->decl)),
-		str) == 0)
+    if (id_equal (DECL_ASSEMBLER_NAME (clone->decl), str))
       return NULL_TREE;
 
   return get_identifier (str);
diff --git a/gcc/read-rtl-function.c b/gcc/read-rtl-function.c
index c5027971..ec25051 100644
--- a/gcc/read-rtl-function.c
+++ b/gcc/read-rtl-function.c
@@ -536,7 +536,7 @@ static tree
 find_param_by_name (tree fndecl, const char *name)
 {
   for (tree arg = DECL_ARGUMENTS (fndecl); arg; arg = TREE_CHAIN (arg))
-    if (strcmp (name, IDENTIFIER_POINTER (DECL_NAME (arg))) == 0)
+    if (id_equal (DECL_NAME (arg), name))
       return arg;
   return NULL_TREE;
 }
@@ -1324,7 +1324,7 @@ function_reader::parse_mem_expr (const char *desc)
   int i;
   tree t;
   FOR_EACH_VEC_ELT (m_fake_scope, i, t)
-    if (strcmp (desc, IDENTIFIER_POINTER (DECL_NAME (t))) == 0)
+    if (id_equal (DECL_NAME (t), desc))
       return t;
 
   /* Not found?  Create it.
diff --git a/gcc/tree-chkp.c b/gcc/tree-chkp.c
index 2300e98..172c28e 100644
--- a/gcc/tree-chkp.c
+++ b/gcc/tree-chkp.c
@@ -2379,8 +2379,7 @@ chkp_get_bound_for_parm (tree parm)
 	 to use zero bounds for input arguments of main
 	 function.  */
       else if (flag_chkp_zero_input_bounds_for_main
-	       && strcmp (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (orig_decl)),
-			  "main") == 0)
+	       && id_equal (DECL_ASSEMBLER_NAME (orig_decl), "main"))
 	bounds = chkp_get_zero_bounds ();
       else if (BOUNDED_P (parm))
 	{
diff --git a/gcc/tree.c b/gcc/tree.c
index db31620..d87d585 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -6050,7 +6050,7 @@ private_is_attribute_p (const char *attr_name, size_t attr_len, const_tree ident
 
   if (ident_len == attr_len)
     {
-      if (strcmp (attr_name, IDENTIFIER_POINTER (ident)) == 0)
+      if (id_equal (ident, attr_name))
 	return true;
     }
   else if (ident_len == attr_len + 4)
diff --git a/gcc/tree.h b/gcc/tree.h
index c6e883c..c23a370 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -3618,6 +3618,20 @@ tree_operand_check_code (const_tree __t, enum tree_code __code, int __i,
 
 #endif
 
+/* True iff an identifier matches a C string.  */
+
+inline bool
+id_equal (const_tree id, const char *str)
+{
+  return !strcmp (IDENTIFIER_POINTER (id), str);
+}
+
+inline bool
+id_equal (const char *str, const_tree id)
+{
+  return !strcmp (str, IDENTIFIER_POINTER (id));
+}
+
 #define error_mark_node			global_trees[TI_ERROR_MARK]
 
 #define intQI_type_node			global_trees[TI_INTQI_TYPE]