Bug 54103 is a C front-end regression involving ICEs in certain cases
of expressions such as 0 / 0 being converted to truthvalues.
c_common_truthvalue_conversion, or
c_objc_common_truthvalue_conversion, received 0 / 0 directly as a
TRUNC_DIV_EXPR, without any wrapping C_MAYBE_CONST_EXPR to indicate
that the expression has integer constant operands, so did not know
that it had to produce a result valid for an expression with integer
constant operands (that is, one satisfying EXPR_INT_CONST_OPERANDS -
meaning either an INTEGER_CST, or a C_MAYBE_CONST_EXPR with
C_MAYBE_CONST_EXPR_INT_OPERANDS set, but not anything with
C_MAYBE_CONST_EXPR deeper in the expression). As a result it returned
an expression with a C_MAYBE_CONST_EXPR not at top level - but the
callers assumed this could not occur, so created their own wrapping
C_MAYBE_CONST_EXPR (and C_MAYBE_CONST_EXPR should never be nested).
This is fixed by ensuring that a properly marked expression gets
passed to c_objc_common_truthvalue_conversion; ensuring
c_objc_common_truthvalue_conversion handes such expressions directly
so c_common_truthvalue_conversion doesn't have to; and avoiding direct
calls to c_common_truthvalue_conversion in relevant places.
Bootstrapped with no regressions on x86_64-unknown-linux-gnu. Applied
to mainline. Will apply to 4.7 (when not frozen) and 4.6 branches
subject to testing there.
c:
2012-09-14 Joseph Myers <jos...@codesourcery.com>
PR c/54103
* c-typeck.c (build_unary_op): Pass original argument of
TRUTH_NOT_EXPR to c_objc_common_truthvalue_conversion, then remove
any C_MAYBE_CONST_EXPR, if it has integer operands.
(build_binary_op): Pass original arguments of TRUTH_ANDIF_EXPR,
TRUTH_ORIF_EXPR, TRUTH_AND_EXPR, TRUTH_OR_EXPR and TRUTH_XOR_EXPR
to c_objc_common_truthvalue_conversion, then remove any
C_MAYBE_CONST_EXPR, if they have integer operands. Use
c_objc_common_truthvalue_conversion not
c_common_truthvalue_conversion.
(c_objc_common_truthvalue_conversion): Build NE_EXPR directly and
call note_integer_operands for arguments with integer operands
that are not integer constants.
testsuite:
2012-09-14 Joseph Myers <jos...@codesourcery.com>
PR c/54103
* gcc.c-torture/compile/pr54103-1.c,
gcc.c-torture/compile/pr54103-2.c,
gcc.c-torture/compile/pr54103-3.c,
gcc.c-torture/compile/pr54103-4.c,
gcc.c-torture/compile/pr54103-5.c,
gcc.c-torture/compile/pr54103-6.c: New tests.
* gcc.dg/c90-const-expr-8.c: Update expected column number.
Index: c/c-typeck.c
===================================================================
--- c/c-typeck.c (revision 191291)
+++ c/c-typeck.c (working copy)
@@ -3553,7 +3553,13 @@ build_unary_op (location_t location,
"wrong type argument to unary exclamation mark");
return error_mark_node;
}
- arg = c_objc_common_truthvalue_conversion (location, arg);
+ if (int_operands)
+ {
+ arg = c_objc_common_truthvalue_conversion (location, xarg);
+ arg = remove_c_maybe_const_expr (arg);
+ }
+ else
+ arg = c_objc_common_truthvalue_conversion (location, arg);
ret = invert_truthvalue_loc (location, arg);
/* If the TRUTH_NOT_EXPR has been folded, reset the location. */
if (EXPR_P (ret) && EXPR_HAS_LOCATION (ret))
@@ -9807,8 +9813,20 @@ build_binary_op (location_t location, enum tree_co
but that does not mean the operands should be
converted to ints! */
result_type = integer_type_node;
- op0 = c_common_truthvalue_conversion (location, op0);
- op1 = c_common_truthvalue_conversion (location, op1);
+ if (op0_int_operands)
+ {
+ op0 = c_objc_common_truthvalue_conversion (location, orig_op0);
+ op0 = remove_c_maybe_const_expr (op0);
+ }
+ else
+ op0 = c_objc_common_truthvalue_conversion (location, op0);
+ if (op1_int_operands)
+ {
+ op1 = c_objc_common_truthvalue_conversion (location, orig_op1);
+ op1 = remove_c_maybe_const_expr (op1);
+ }
+ else
+ op1 = c_objc_common_truthvalue_conversion (location, op1);
converted = 1;
boolean_op = true;
}
@@ -10520,13 +10538,18 @@ c_objc_common_truthvalue_conversion (location_t lo
int_const = (TREE_CODE (expr) == INTEGER_CST && !TREE_OVERFLOW (expr));
int_operands = EXPR_INT_CONST_OPERANDS (expr);
- if (int_operands)
- expr = remove_c_maybe_const_expr (expr);
+ if (int_operands && TREE_CODE (expr) != INTEGER_CST)
+ {
+ expr = remove_c_maybe_const_expr (expr);
+ expr = build2 (NE_EXPR, integer_type_node, expr,
+ convert (TREE_TYPE (expr), integer_zero_node));
+ expr = note_integer_operands (expr);
+ }
+ else
+ /* ??? Should we also give an error for vectors rather than leaving
+ those to give errors later? */
+ expr = c_common_truthvalue_conversion (location, expr);
- /* ??? Should we also give an error for vectors rather than leaving
- those to give errors later? */
- expr = c_common_truthvalue_conversion (location, expr);
-
if (TREE_CODE (expr) == INTEGER_CST && int_operands && !int_const)
{
if (TREE_OVERFLOW (expr))
Index: testsuite/gcc.c-torture/compile/pr54103-2.c
===================================================================
--- testsuite/gcc.c-torture/compile/pr54103-2.c (revision 0)
+++ testsuite/gcc.c-torture/compile/pr54103-2.c (revision 0)
@@ -0,0 +1,5 @@
+void
+f (void)
+{
+ 0 / 0 || 0 ? : 0;
+}
Index: testsuite/gcc.c-torture/compile/pr54103-4.c
===================================================================
--- testsuite/gcc.c-torture/compile/pr54103-4.c (revision 0)
+++ testsuite/gcc.c-torture/compile/pr54103-4.c (revision 0)
@@ -0,0 +1,5 @@
+void
+f (void)
+{
+ 0 / 0 && 1 ? : 0;
+}
Index: testsuite/gcc.c-torture/compile/pr54103-6.c
===================================================================
--- testsuite/gcc.c-torture/compile/pr54103-6.c (revision 0)
+++ testsuite/gcc.c-torture/compile/pr54103-6.c (revision 0)
@@ -0,0 +1,5 @@
+void
+f (void)
+{
+ 0 || 65536*65536 ? : 0;
+}
Index: testsuite/gcc.c-torture/compile/pr54103-1.c
===================================================================
--- testsuite/gcc.c-torture/compile/pr54103-1.c (revision 0)
+++ testsuite/gcc.c-torture/compile/pr54103-1.c (revision 0)
@@ -0,0 +1,5 @@
+void
+f (void)
+{
+ 0 || 0 / 0 ? : 0;
+}
Index: testsuite/gcc.c-torture/compile/pr54103-3.c
===================================================================
--- testsuite/gcc.c-torture/compile/pr54103-3.c (revision 0)
+++ testsuite/gcc.c-torture/compile/pr54103-3.c (revision 0)
@@ -0,0 +1,5 @@
+void
+f (void)
+{
+ 1 && 0 / 0 ? : 0;
+}
Index: testsuite/gcc.c-torture/compile/pr54103-5.c
===================================================================
--- testsuite/gcc.c-torture/compile/pr54103-5.c (revision 0)
+++ testsuite/gcc.c-torture/compile/pr54103-5.c (revision 0)
@@ -0,0 +1,5 @@
+void
+f (void)
+{
+ !(0 / 0);
+}
Index: testsuite/gcc.dg/c90-const-expr-8.c
===================================================================
--- testsuite/gcc.dg/c90-const-expr-8.c (revision 191291)
+++ testsuite/gcc.dg/c90-const-expr-8.c (working copy)
@@ -22,6 +22,6 @@ enum e {
E5 = 0 * -INT_MIN, /* { dg-warning "12:integer overflow in expression" } */
/* { dg-error "3:overflow in constant expression" "constant" { target *-*-*
} 22 } */
E6 = 0 * !-INT_MIN, /* { dg-warning "13:integer overflow in expression" } */
- /* { dg-error "3:not an integer constant" "constant" { target *-*-* } 24 } */
+ /* { dg-error "8:not an integer constant" "constant" { target *-*-* } 24 } */
E7 = INT_MIN % -1 /* Not an overflow. */
};
--
Joseph S. Myers
jos...@codesourcery.com
