| Issue |
127572
|
| Summary |
[clang-cl] access violation at runtime with clang-cl 20.1.0-rc2 using /std:c++latest
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
Mishura4
|
```c++
// test.hpp
#include <vector>
#include <string>
extern const std::vector<std::string>& my_vec;
void init();
```
```c++
// test.cpp
#include "test.hpp"
namespace
{
std::vector<std::string> impl;
}
const std::vector<std::string>& my_vec = impl;
void init() {
std::vector<std::string> vec_ref;
vec.push_back("hello");
vec.push_back("world!");
impl = std::move(vec);
}
```
```c++
// main.cpp
#include "test.hpp"
#include <iostream>
int main()
{
init();
for (auto& str : vec_ref)
{
std::cout << str << std::endl;
}
}
```
Compile with `clang-cl test.cpp main.cpp /std:c++latest`. For some reason either `vec_ref` or `impl` seems to become corrupted and the for loop seems to read garbage data. In the project I initially encountered this, the program crashed with an access violation.
The same code works without an issue with `/std:c++20`, the same code works without an issue on 19.1.0 even with `/std:c++latest`.
clang-cl was compiled with:
```bat
set CXX=clang-cl
set CC=clang-cl
set VECTORIZE="-march=native -mtune=native"
cmake llvm/ -B build ^
-DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra;lld;lldb" ^
-DLLVM_ENABLE_RUNTIMES="compiler-rt;libcxx" ^
-DLLVM_TARGETS_TO_BUILD=Native ^
-DLLVM_PARALLEL_COMPILE_JOBS=30 ^
-DLLVM_PARALLEL_LINK_JOBS=3 ^
-DLLVM_ENABLE_LLD=on ^
-DCLANG_DEFAULT_LINKER=lld ^
-DCMAKE_BUILD_TYPE=Release ^
-DCLANG_ENABLE_BOOTSTRAP=On ^
-DLLVM_HOST_TRIPLE=x86_64-pc-windows-msvc ^
-DLLVM_ENABLE_LTO=Thin ^
-DLLVM_ENABLE_EH=ON ^
-DLLVM_ENABLE_RTTI=ON ^
-DLLVM_ENABLE_LIBXML2=ON ^
-DCMAKE_CXX_STANDARD=20 ^
-DBOOTSTRAP_CMAKE_CXX_FLAGS=%VECTORIZE% ^
-DBOOTSTRAP_CMAKE_C_FLAGS=%VECTORIZE% ^
-DBOOTSTRAP_CMAKE_EXE_LINKER_FLAGS=%VECTORIZE% ^
-DRUNTIMES_x86_64-pc-windows-msvc_LLVM_ENABLE_EH=ON ^
-DRUNTIMES_x86_64-pc-windows-msvc_LLVM_ENABLE_RTTI=ON ^
-DRUNTIMES_x86_64-pc-windows-msvc_LLVM_ENABLE_LIBXML2=ON ^
-DCMAKE_MT=mt.exe ^
-G Ninja
ninja -C build
```
![]()
_______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
