Hi!
We ICE on the following testcase, because cxx_eval_constant_expression
on COMPOUND_EXPR uses STRIP_NOPS (op1) - needed for the check whether it
is an artificial COMPOUND_EXPR. Unfortunately that means it uses op1
without NOP_EXPRs even if it is a user comma expression.
Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk/4.7?
2012-10-02 Jakub Jelinek <ja...@redhat.com>
PR c++/54777
* semantics.c (cxx_eval_constant_expression) <case COMPOUND_EXPR>: If
not ignoring the second operand, pass the original second operand
and not one with stripped nops to cxx_eval_constant_expression.
* g++.dg/cpp0x/constexpr-ref4.C: New test.
--- gcc/cp/semantics.c.jj 2012-10-01 18:12:01.000000000 +0200
+++ gcc/cp/semantics.c 2012-10-02 12:05:47.229669955 +0200
@@ -7772,6 +7772,7 @@ cxx_eval_constant_expression (const cons
/* Check that the LHS is constant and then discard it. */
cxx_eval_constant_expression (call, op0, allow_non_constant,
false, non_constant_p);
+ op1 = TREE_OPERAND (t, 1);
r = cxx_eval_constant_expression (call, op1, allow_non_constant,
addr, non_constant_p);
}
--- gcc/testsuite/g++.dg/cpp0x/constexpr-ref4.C.jj 2012-10-02
12:11:12.886978774 +0200
+++ gcc/testsuite/g++.dg/cpp0x/constexpr-ref4.C 2012-10-02 12:12:13.085636591
+0200
@@ -0,0 +1,18 @@
+// PR c++/54777
+// { dg-options -std=c++0x }
+
+struct S
+{
+ int s[1];
+ constexpr const int &foo (unsigned i) { return (i < 1 ? 0 : throw 1), s[i]; }
+ constexpr const int &bar (unsigned i) { return i < 1 ? s[i] : (throw 0,
s[i]); }
+};
+
+int
+main ()
+{
+ constexpr S a {};
+ constexpr int i = a.foo (0);
+ constexpr int j = a.bar (0);
+ static_assert (i == j, "Ouch");
+}
Jakub
