c-common.c (c_common_type_for_size): Use NULL_TREE instead of 0.

	* c-common.c (c_common_type_for_size): Use NULL_TREE instead of 0.
	(c_common_fixed_point_type_for_size): Likewise.
	(c_common_type_for_mode): Likewise.
	(shorten_compare): Likewise.
	(c_promoting_integer_type_p): Use false/true instead of 0/1.
	* c-pragma.c (maybe_apply_renaming_pragma): Use NULL_TREE instead of 0.

	* c-decl.c (match_builtin_function_types): Use NULL_TREE instead of 0.
	(check_earlier_gotos): Likewise.
	(define_label): Likewise.
	(pending_xref_error): Likewise.
	(smallest_type_quals_location): Likewise.
	(grokdeclarator): Likewise.
	(grokparms): Likewise.
	(identifier_global_value): Likewise.
	* c-typeck.c (set_nonincremental_init_from_string): Likewise.
	(find_init_member): Likewise.

From-SVN: r248195

gcc/c-family/ChangeLog

 2017-05-18  Marek Polacek  <polacek@redhat.com>
 
+	* c-common.c (c_common_type_for_size): Use NULL_TREE instead of 0.
+	(c_common_fixed_point_type_for_size): Likewise.
+	(c_common_type_for_mode): Likewise.
+	(shorten_compare): Likewise.
+	(c_promoting_integer_type_p): Use false/true instead of 0/1.
+	* c-pragma.c (maybe_apply_renaming_pragma): Use NULL_TREE instead of 0.
+
+2017-05-18  Marek Polacek  <polacek@redhat.com>
+
 	* c-common.c (self_promoting_args_p): Change the return type to bool.
 	Use false/true instead of 0/1.
 	* c-common.h (self_promoting_args_p): Update.

gcc/c-family/c-common.c

@@ -2112,7 +2112,7 @@ c_common_type_for_size (unsigned int bits, int unsignedp)
   if (bits <= TYPE_PRECISION (intDI_type_node))
     return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
 
-  return 0;
+  return NULL_TREE;
 }
 
 /* Return a fixed-point type that has at least IBIT ibits and FBIT fbits
@@ -2138,7 +2138,7 @@ c_common_fixed_point_type_for_size (unsigned int ibit, unsigned int fbit,
       sorry ("GCC cannot support operators with integer types and "
 	     "fixed-point types that have too many integral and "
 	     "fractional bits together");
-      return 0;
+      return NULL_TREE;
     }
 
   return c_common_type_for_mode (mode, satp);
@@ -2359,7 +2359,7 @@ c_common_type_for_mode (machine_mode mode, int unsignedp)
 	&& !!unsignedp == !!TYPE_UNSIGNED (TREE_VALUE (t)))
       return TREE_VALUE (t);
 
-  return 0;
+  return NULL_TREE;
 }
 
 tree
@@ -2690,7 +2690,7 @@ expr_original_type (tree expr)
 
    LOC is the location of the comparison.
 
-   If this function returns nonzero, it means that the comparison has
+   If this function returns non-NULL_TREE, it means that the comparison has
    a constant value.  What this function returns is an expression for
    that value.  */
 
@@ -2944,7 +2944,7 @@ shorten_compare (location_t loc, tree *op0_ptr, tree *op1_ptr,
   else if (real1 && real2
 	   && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0)))
 	       || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1)))))
-    return 0;
+    return NULL_TREE;
 
   else if (real1 && real2
 	   && (TYPE_PRECISION (TREE_TYPE (primop0))
@@ -3038,7 +3038,7 @@ shorten_compare (location_t loc, tree *op0_ptr, tree *op1_ptr,
 
   *restype_ptr = truthvalue_type_node;
 
-  return 0;
+  return NULL_TREE;
 }
 
 /* Return a tree for the sum or difference (RESULTCODE says which)
@@ -4630,10 +4630,10 @@ c_promoting_integer_type_p (const_tree t)
       return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node);
 
     case BOOLEAN_TYPE:
-      return 1;
+      return true;
 
     default:
-      return 0;
+      return false;
     }
 }
 

gcc/c-family/c-pragma.c

@@ -594,7 +594,7 @@ maybe_apply_renaming_pragma (tree decl, tree asmname)
 	    pending_redefine_extname->unordered_remove (ix);
 	    break;
 	  }
-      return 0;
+      return NULL_TREE;
     }
 
   /* Find out if we have a pending #pragma redefine_extname.  */
@@ -643,7 +643,7 @@ maybe_apply_renaming_pragma (tree decl, tree asmname)
     }
 
   /* Nada.  */
-  return 0;
+  return NULL_TREE;
 }
 
 

gcc/c/ChangeLog

 2017-05-18  Marek Polacek  <polacek@redhat.com>
 
+	* c-decl.c (match_builtin_function_types): Use NULL_TREE instead of 0.
+	(check_earlier_gotos): Likewise.
+	(define_label): Likewise.
+	(pending_xref_error): Likewise.
+	(smallest_type_quals_location): Likewise.
+	(grokdeclarator): Likewise.
+	(grokparms): Likewise.
+	(identifier_global_value): Likewise.
+	* c-typeck.c (set_nonincremental_init_from_string): Likewise.
+	(find_init_member): Likewise.
+
+2017-05-18  Marek Polacek  <polacek@redhat.com>
+
 	* c-decl.c (start_decl): Use false/true instead of 0/1.
 	(grokdeclarator): Likewise.
 	(finish_struct): Likewise.

gcc/c/c-decl.c

@@ -1630,7 +1630,7 @@ match_builtin_function_types (tree newtype, tree oldtype)
   newrettype = TREE_TYPE (newtype);
 
   if (TYPE_MODE (oldrettype) != TYPE_MODE (newrettype))
-    return 0;
+    return NULL_TREE;
 
   oldargs = TYPE_ARG_TYPES (oldtype);
   newargs = TYPE_ARG_TYPES (newtype);
@@ -1644,7 +1644,7 @@ match_builtin_function_types (tree newtype, tree oldtype)
 	  || !TREE_VALUE (newargs)
 	  || TYPE_MODE (TREE_VALUE (oldargs))
 	     != TYPE_MODE (TREE_VALUE (newargs)))
-	return 0;
+	return NULL_TREE;
 
       oldargs = TREE_CHAIN (oldargs);
       newargs = TREE_CHAIN (newargs);
@@ -3755,7 +3755,7 @@ check_earlier_gotos (tree label, struct c_label_vars* label_vars)
 
 /* Define a label, specifying the location in the source file.
    Return the LABEL_DECL node for the label, if the definition is valid.
-   Otherwise return 0.  */
+   Otherwise return NULL_TREE.  */
 
 tree
 define_label (location_t location, tree name)
@@ -3774,7 +3774,7 @@ define_label (location_t location, tree name)
     {
       error_at (location, "duplicate label %qD", label);
       locate_old_decl (label);
-      return 0;
+      return NULL_TREE;
     }
   else if (label && DECL_CONTEXT (label) == current_function_decl)
     {
@@ -3971,7 +3971,7 @@ pending_xref_error (void)
 /* Look up NAME in the current scope and its superiors
    in the namespace of variables, functions and typedefs.
    Return a ..._DECL node of some kind representing its definition,
-   or return 0 if it is undefined.  */
+   or return NULL_TREE if it is undefined.  */
 
 tree
 lookup_name (tree name)
@@ -5516,7 +5516,7 @@ smallest_type_quals_location (const location_t *locations,
    determine the name and type of the object declared
    and construct a ..._DECL node for it.
    (In one case we can return a ..._TYPE node instead.
-    For invalid input we sometimes return 0.)
+    For invalid input we sometimes return NULL_TREE.)
 
    DECLSPECS is a c_declspecs structure for the declaration specifiers.
 
@@ -5662,7 +5662,7 @@ grokdeclarator (const struct c_declarator *declarator,
      a function declarator.  */
 
   if (funcdef_flag && !funcdef_syntax)
-    return 0;
+    return NULL_TREE;
 
   /* If this looks like a function definition, make it one,
      even if it occurs where parms are expected.
@@ -6833,7 +6833,7 @@ grokdeclarator (const struct c_declarator *declarator,
 		if (funcdef_flag)
 		  storage_class = declspecs->storage_class = csc_none;
 		else
-		  return 0;
+		  return NULL_TREE;
 	      }
 	  }
 
@@ -7073,20 +7073,22 @@ grokparms (struct c_arg_info *arg_info, bool funcdef_flag)
 	     "function declaration isn%'t a prototype");
 
   if (arg_types == error_mark_node)
-    return 0;  /* don't set TYPE_ARG_TYPES in this case */
+    /* Don't set TYPE_ARG_TYPES in this case.  */
+    return NULL_TREE;
 
   else if (arg_types && TREE_CODE (TREE_VALUE (arg_types)) == IDENTIFIER_NODE)
     {
       if (!funcdef_flag)
 	{
-	  pedwarn (input_location, 0, "parameter names (without types) in function declaration");
+	  pedwarn (input_location, 0, "parameter names (without types) in "
+		   "function declaration");
 	  arg_info->parms = NULL_TREE;
 	}
       else
 	arg_info->parms = arg_info->types;
 
       arg_info->types = NULL_TREE;
-      return 0;
+      return NULL_TREE;
     }
   else
     {
@@ -9599,7 +9601,7 @@ identifier_global_value	(tree t)
     if (B_IN_FILE_SCOPE (b) || B_IN_EXTERNAL_SCOPE (b))
       return b->decl;
 
-  return 0;
+  return NULL_TREE;
 }
 
 /* In C, the only C-linkage public declaration is at file scope.  */

gcc/c/c-typeck.c

@@ -8774,7 +8774,7 @@ set_nonincremental_init_from_string (tree str,
   constructor_incremental = 0;
 }
 
-/* Return value of FIELD in pending initializer or zero if the field was
+/* Return value of FIELD in pending initializer or NULL_TREE if the field was
    not initialized yet.  */
 
 static tree
@@ -8826,7 +8826,7 @@ find_init_member (tree field, struct obstack * braced_init_obstack)
 	  && (constructor_elements->last ().index == field))
 	return constructor_elements->last ().value;
     }
-  return 0;
+  return NULL_TREE;
 }
 
 /* "Output" the next constructor element.
@@ -14007,7 +14007,7 @@ c_build_va_arg (location_t loc1, tree expr, location_t loc2, tree type)
 }
 
 /* Return truthvalue of whether T1 is the same tree structure as T2.
-   Return 1 if they are the same. Return 0 if they are different.  */
+   Return 1 if they are the same. Return false if they are different.  */
 
 bool
 c_tree_equal (tree t1, tree t2)