[Bug c++/91678] [9/10 Regression] decltype returns wrong type under certain conditions
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91678 --- Comment #6 from Marek Polacek --- Author: mpolacek Date: Sat Dec 7 17:35:54 2019 New Revision: 279077 URL: https://gcc.gnu.org/viewcvs?rev=279077=gcc=rev Log: PR c++/91678 - wrong error with decltype and location wrapper. Compiling this testcase results in a bogus "invalid cast" error; this occurs since the introduction of location wrappers in finish_id_expression. Here we are parsing the decltype expression via cp_parser_decltype_expr which can lead to calling various fold_* and c-family routines. They use non_lvalue_loc, but that won't create a NON_LVALUE_EXPR wrapper around a location wrapper. So before the location wrappers addition cp_parser_decltype_expr would return NON_LVALUE_EXPR . Now it returns VIEW_CONVERT_EXPR(c), but the STRIP_ANY_LOCATION_WRAPPER immediately following it strips the location wrapper, and suddenly we don't know whether we have an lvalue anymore. And that's sad because then decltype produces the wrong type, causing nonsense errors. * fold-const.c (maybe_lvalue_p): Handle VIEW_CONVERT_EXPR. * g++.dg/cpp0x/decltype73.C: New test. Added: trunk/gcc/testsuite/g++.dg/cpp0x/decltype73.C Modified: trunk/gcc/ChangeLog trunk/gcc/fold-const.c trunk/gcc/testsuite/ChangeLog
[Bug c++/91678] [9/10 Regression] decltype returns wrong type under certain conditions
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91678 --- Comment #5 from Marek Polacek --- Sorry, I'll try to respond to https://gcc.gnu.org/ml/gcc-patches/2019-09/msg01042.html soon. It doesn't seem to fix Comment 4 though, will have to look why :/.
[Bug c++/91678] [9/10 Regression] decltype returns wrong type under certain conditions
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91678
--- Comment #4 from Jonathan Wakely ---
Marek, are you still working on the patch?
Does it also fix the testcase from PR 92766?
template
void foo(T&& begin, T&& end);
void test()
{
unsigned char buffer[16];
const unsigned char* ptr = buffer;
foo(ptr+0, ptr+8);
}
[Bug c++/91678] [9/10 Regression] decltype returns wrong type under certain conditions
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91678 Jonathan Wakely changed: What|Removed |Added CC||bisqwit at iki dot fi --- Comment #3 from Jonathan Wakely --- *** Bug 92766 has been marked as a duplicate of this bug. ***
[Bug c++/91678] [9/10 Regression] decltype returns wrong type under certain conditions
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91678 Marek Polacek changed: What|Removed |Added Keywords||patch --- Comment #2 from Marek Polacek --- Patch posted Sep 5: https://gcc.gnu.org/ml/gcc-patches/2019-09/msg00330.html
[Bug c++/91678] [9/10 Regression] decltype returns wrong type under certain conditions
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91678 Marek Polacek changed: What|Removed |Added Target Milestone|--- |9.3
[Bug c++/91678] [9/10 Regression] decltype returns wrong type under certain conditions
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91678 Marek Polacek changed: What|Removed |Added Status|NEW |ASSIGNED CC||mpolacek at gcc dot gnu.org Assignee|unassigned at gcc dot gnu.org |mpolacek at gcc dot gnu.org
[Bug c++/91678] [9/10 Regression] decltype returns wrong type under certain conditions
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91678 Jonathan Wakely changed: What|Removed |Added Status|UNCONFIRMED |NEW Known to work||8.3.0 Version|unknown |9.2.0 Keywords||rejects-valid Last reconfirmed||2019-09-05 CC||dmalcolm at gcc dot gnu.org Ever confirmed|0 |1 Summary|decltype returns wrong type |[9/10 Regression] decltype |under certain conditions|returns wrong type under ||certain conditions Known to fail||10.0, 9.2.0 --- Comment #1 from Jonathan Wakely --- Confirmed. This is a regression that started with r267272: C++: more location wrapper nodes (PR c++/43064, PR c++/43486)
