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C++ PATCH for c++/91962 - ICE with reference binding and qualification conversion
- From: Marek Polacek <polacek at redhat dot com>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>, Jason Merrill <jason at redhat dot com>
- Date: Thu, 24 Oct 2019 15:24:03 -0400
- Subject: C++ PATCH for c++/91962 - ICE with reference binding and qualification conversion
When fixing c++/91889 (r276251) I was assuming that we couldn't have a ck_qual
under a ck_ref_bind, and I was introducing it in the patch and so this
+ if (next_conversion (convs)->kind == ck_qual)
+ {
+ gcc_assert (same_type_p (TREE_TYPE (expr),
+ next_conversion (convs)->type));
+ /* Strip the cast created by the ck_qual; cp_build_addr_expr
+ below expects an lvalue. */
+ STRIP_NOPS (expr);
+ }
in convert_like_real was supposed to handle it. But that assumption was wrong
as this test shows; here we have "(int *)f" where f is of type long int, and
we're converting it to "const int *const &", so we have both ck_ref_bind and
ck_qual. That means that the new STRIP_NOPS strips an expression it shouldn't
have, and that then breaks when creating a TARGET_EXPR. So we want to limit
the stripping to the new case only. This I do by checking need_temporary_p,
which will be 0 in the new case. Yes, we can set need_temporary_p when
binding a reference directly, but then we won't have a qualification
conversion. It is possible to have a bit-field, convert it to a pointer,
and then convert that pointer to a more-qualified pointer, but in that case
we're not dealing with an lvalue, so gl_kind is 0, so we won't enter this
block in reference_binding:
1747 if ((related_p || compatible_p) && gl_kind)
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2019-10-24 Marek Polacek <polacek@redhat.com>
PR c++/91962 - ICE with reference binding and qualification conversion.
* call.c (convert_like_real) <case ck_ref_bind>: Check need_temporary_p.
* g++.dg/cpp0x/ref-bind7.C: New test.
diff --git gcc/cp/call.c gcc/cp/call.c
index 55d2abaaddd..d4674a77078 100644
--- gcc/cp/call.c
+++ gcc/cp/call.c
@@ -7386,7 +7386,8 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
/* direct_reference_binding might have inserted a ck_qual under
this ck_ref_bind for the benefit of conversion sequence ranking.
Ignore the conversion; we'll create our own below. */
- if (next_conversion (convs)->kind == ck_qual)
+ if (next_conversion (convs)->kind == ck_qual
+ && !convs->need_temporary_p)
{
gcc_assert (same_type_p (TREE_TYPE (expr),
next_conversion (convs)->type));
diff --git gcc/testsuite/g++.dg/cpp0x/ref-bind7.C gcc/testsuite/g++.dg/cpp0x/ref-bind7.C
new file mode 100644
index 00000000000..e3675bc560d
--- /dev/null
+++ gcc/testsuite/g++.dg/cpp0x/ref-bind7.C
@@ -0,0 +1,13 @@
+// PR c++/91962 - ICE with reference binding and qualification conversion.
+// { dg-do compile { target c++11 } }
+
+template <typename a> class b {
+public:
+ void c(const a &);
+};
+class B {
+ void d();
+ b<const int *> e;
+};
+long f;
+void B::d() { e.c((const int *)f); }