re PR c/90628 (__builtin_mul_overflow writes to const qualified integer)

	PR c/90628
	* c-common.c (check_builtin_function_arguments)
	<case BUILTIN_*_OVERFLOW>: Diagnose pointer to const qualified integer
	as last argument.

	* c-c++-common/builtin-arith-overflow-3.c: New test.

From-SVN: r271732

gcc/c-family/ChangeLog

+2019-05-29  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/90628
+	* c-common.c (check_builtin_function_arguments)
+	<case BUILTIN_*_OVERFLOW>: Diagnose pointer to const qualified integer
+	as last argument.
+
 2019-05-23  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* c-ada-spec.c (compare_node): Compare the DECL_UIDs as a last resort.

gcc/c-family/c-common.c

@@ -5995,6 +5995,13 @@ check_builtin_function_arguments (location_t loc, vec<location_t> arg_loc,
 			"has pointer to boolean type", fndecl);
 	      return false;
 	    }
+	  else if (TYPE_READONLY (TREE_TYPE (TREE_TYPE (args[2]))))
+	    {
+	      error_at (ARG_LOCATION (2), "argument 3 in call to function %qE "
+			"has pointer to %<const%> type (%qT)", fndecl,
+			TREE_TYPE (args[2]));
+	      return false;
+	    }
 	  return true;
 	}
       return false;

gcc/testsuite/ChangeLog

 2019-05-29  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c/90628
+	* c-c++-common/builtin-arith-overflow-3.c: New test.
+
 	P1091R3 - Extending structured bindings to be more like var decls
 	P1381R1 - Reference capture of structured bindings
 	* g++.dg/cpp1z/decomp3.C (test): For static, expect only warning

gcc/testsuite/c-c++-common/builtin-arith-overflow-3.c

+/* PR c/90628 */
+/* { dg-do compile } */
+
+const int a = 1, b = 2, c = 3;
+const long d = 4, e = 5, f = 6;
+const long long g = 7, h = 8, i = 9;
+
+void
+f1 ()
+{
+  __builtin_add_overflow (a, b, &c);	/* { dg-error "argument 3 in call to function '__builtin_add_overflow' has pointer to 'const' type" } */
+}
+
+void
+f2 ()
+{
+  __builtin_sub_overflow (d, e, &f);	/* { dg-error "argument 3 in call to function '__builtin_sub_overflow' has pointer to 'const' type" } */
+}
+
+void
+f3 ()
+{
+  __builtin_mul_overflow (g, h, &i);	/* { dg-error "argument 3 in call to function '__builtin_mul_overflow' has pointer to 'const' type" } */
+}
+
+void
+f4 ()
+{
+  __builtin_sadd_overflow (a, b, &c);	/* { dg-warning "passing argument 3 of '__builtin_sadd_overflow' discards 'const' qualifier from pointer target type" "" { target c } } */
+}	/* { dg-error "invalid conversion from 'const int\\*' to 'int\\*'" "" { target c++ } .-1 } */
+
+void
+f5 ()
+{
+  __builtin_ssubl_overflow (d, e, &f);	/* { dg-warning "passing argument 3 of '__builtin_ssubl_overflow' discards 'const' qualifier from pointer target type" "" { target c } } */
+}	/* { dg-error "invalid conversion from 'const long int\\*' to 'long int\\*'" "" { target c++ } .-1 } */
+
+void
+f6 ()
+{
+  __builtin_smulll_overflow (g, h, &i);	/* { dg-warning "passing argument 3 of '__builtin_smulll_overflow' discards 'const' qualifier from pointer target type" "" { target c } } */
+}	/* { dg-error "invalid conversion from 'const long long int\\*' to 'long long int\\*'" "" { target c++ } .-1 } */