Segfault in SROA while using the overload deduction guide pattern and copy capture

[llvmbot]

Bugzilla Link	40771
Resolution	FIXED
Resolved on	Jul 29, 2019 01:56
Version	trunk
OS	Linux
Blocks	#41819
Reporter	LLVM Bugzilla Contributor
CC	@adrian-prantl,@dexonsmith,@zmodem,@joker-eph,@LebedevRI,@oystedal,@zygoloid

Extended Description

Godbolt demonstrating the issue: https://godbolt.org/z/Vs3QZe

Clang options: -std=c++17 -O1

#include

template <class... Ts> struct ctad : Ts... {};
template <class... Ts> ctad(Ts...)->ctad<Ts...>;

void crash()
{
std::string s;
ctad c {s{}, s{}};
}

[oystedal]

This is still an issue in latest trunk. Works with -O0, crashes with -O1 and above.

[oystedal]

Minimal source required to reproduce the crash.

[oystedal]

Preprocessed source

[oystedal]

Run script

[oystedal]

See https://reviews.llvm.org/D64656 for a proposed fix.

[LebedevRI]

See https://reviews.llvm.org/D64656 for a proposed fix.

To be noted, these may or may not be two separate issues.
The pass will assert on that IR regardless of whether or not that
is the IR that clang produces; so clang fix, likely, only makes sense
if the clang is currently miscompiling that code C++17.

[oystedal]

The patch that fixes this issue has now been committed.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@367042 91177308-0d34-0410-b5e6-96231b3b80d8

[oystedal]

https://godbolt.org/z/Vs3QZe now compiles using latest trunk.

[oystedal]

The proper commit for this fix is:

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@367055 91177308-0d34-0410-b5e6-96231b3b80d8

This commit added a triple to the test case. Without it, the test would break on some platforms.

[zmodem]

The proper commit for this fix is:

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@367055
91177308-0d34-0410-b5e6-96231b3b80d8

This commit added a triple to the test case. Without it, the test would
break on some platforms.

Merged to release_90 in r367209.

[tstellar]

mentioned in issue #41819