Hi,
I handled this issue as outlined by Jakub in the audit trail. For the
purpose of the bogus div by zero warning just using
c_inhibit_evaluation_warnings appears to work fine.
Tested x86_64-linux.
Thanks,
Paolo.
///
/cp
2012-03-12 Paolo Carlini
PR c++/52299
* pt.c (tsubst_copy_and_build, case COND_EXPR): Avoid bogus
division by zero warnings.
/testsuite
2012-03-12 Paolo Carlini
PR c++/52299
* g++.dg/warn/Wdiv-by-zero-bogus.C: New.
Index: testsuite/g++.dg/warn/Wdiv-by-zero-bogus.C
===
--- testsuite/g++.dg/warn/Wdiv-by-zero-bogus.C (revision 0)
+++ testsuite/g++.dg/warn/Wdiv-by-zero-bogus.C (revision 0)
@@ -0,0 +1,30 @@
+// PR c++/52299
+
+template
+struct test0 {
+ static const unsigned a_
+ = x ? 10 / x : 10;
+};
+
+template
+struct test1 {
+ static const unsigned a_
+ = !x ? 10 : 10 / x;
+};
+
+template
+struct test2 {
+ static const unsigned a_
+ = x ? 10 / x : 10;
+};
+
+template
+struct test3 {
+ static const unsigned a_
+ = !x ? 10 : 10 / x;
+};
+
+unsigned i0 = test0<0>::a_;
+unsigned i1 = test1<0>::a_;
+unsigned i2 = test2::a_;
+unsigned i3 = test3::a_;
Index: cp/pt.c
===
--- cp/pt.c (revision 185247)
+++ cp/pt.c (working copy)
@@ -13943,12 +13943,36 @@ tsubst_copy_and_build (tree t,
}
case COND_EXPR:
- return build_x_conditional_expr
- (RECUR (TREE_OPERAND (t, 0)),
-RECUR (TREE_OPERAND (t, 1)),
-RECUR (TREE_OPERAND (t, 2)),
- complain);
+ {
+ tree cond = RECUR (TREE_OPERAND (t, 0));
+ tree op1, op2;
+ if (TREE_CODE (cond) == INTEGER_CST)
+ {
+ if (integer_zerop (cond))
+ {
+ ++c_inhibit_evaluation_warnings;
+ op1 = RECUR (TREE_OPERAND (t, 1));
+ --c_inhibit_evaluation_warnings;
+ op2 = RECUR (TREE_OPERAND (t, 2));
+ }
+ else
+ {
+ op1 = RECUR (TREE_OPERAND (t, 1));
+ ++c_inhibit_evaluation_warnings;
+ op2 = RECUR (TREE_OPERAND (t, 2));
+ --c_inhibit_evaluation_warnings;
+ }
+ }
+ else
+ {
+ op1 = RECUR (TREE_OPERAND (t, 1));
+ op2 = RECUR (TREE_OPERAND (t, 2));
+ }
+
+ return build_x_conditional_expr (cond, op1, op2, complain);
+ }
+
case PSEUDO_DTOR_EXPR:
return finish_pseudo_destructor_expr
(RECUR (TREE_OPERAND (t, 0)),
