c-decl.c (grokdeclarator): Instead of looking at TREE_OVERFLOW check if the…

c-decl.c (grokdeclarator): Instead of looking at TREE_OVERFLOW check if the constant fits in the index type.

2011-05-03  Richard Guenther  <rguenther@suse.de>

	* c-decl.c (grokdeclarator): Instead of looking at
	TREE_OVERFLOW check if the constant fits in the index type.

	* gcc.dg/large-size-array-5.c: New testcase.

From-SVN: r173297

gcc/ChangeLog

+2011-05-03  Richard Guenther  <rguenther@suse.de>
+
+	* c-decl.c (grokdeclarator): Instead of looking at
+	TREE_OVERFLOW check if the constant fits in the index type.
+
 2011-05-03  Richard Sandiford  <richard.sandiford@linaro.org>
 
 	* config/arm/neon.md (vec_load_lanes<mode><mode>): New expanders,

gcc/c-decl.c

@@ -5368,15 +5368,13 @@ grokdeclarator (const struct c_declarator *declarator,
 					     convert (index_type,
 						      size_one_node));
 
-		    /* If that overflowed, the array is too big.  ???
-		       While a size of INT_MAX+1 technically shouldn't
-		       cause an overflow (because we subtract 1), the
-		       overflow is recorded during the conversion to
-		       index_type, before the subtraction.  Handling
-		       this case seems like an unnecessary
-		       complication.  */
-		    if (TREE_CODE (itype) == INTEGER_CST
-			&& TREE_OVERFLOW (itype))
+		    /* The above overflows when size does not fit
+		       in index_type.
+		       ???  While a size of INT_MAX+1 technically shouldn't
+		       cause an overflow (because we subtract 1), handling
+		       this case seems like an unnecessary complication.  */
+		    if (TREE_CODE (size) == INTEGER_CST
+			&& !int_fits_type_p (size, index_type))
 		      {
 			if (name)
 			  error_at (loc, "size of array %qE is too large",

gcc/testsuite/ChangeLog

+2011-05-03  Richard Guenther  <rguenther@suse.de>
+
+	* gcc.dg/large-size-array-5.c: New testcase.
+
 2011-05-03  Richard Sandiford  <richard.sandiford@linaro.org>
 
 	* gcc.dg/vect/vect-strided-u16-i3.c: New test.

gcc/testsuite/gcc.dg/large-size-array-5.c

+/* { dg-do compile } */
+/* { dg-options "-Wno-overflow" } */
+
+typedef __SIZE_TYPE__ size_t;
+
+extern char a[((size_t)-1 >> 1) + 1]; /* { dg-error "too large" } */
+extern char b[((size_t)-1 >> 1)];
+extern int c[(((size_t)-1 >> 1) + 1) / sizeof(int)]; /* { dg-error "too large" } */
+extern int d[((size_t)-1 >> 1) / sizeof(int)];