[C++] extractor gets catastrophic error

[hello123leo]

clang++ version: 17.0.6 or 21.1.5
codeql version: 2.24.0

main.cpp

#include <stdint.h>
#include <iostream>
#include <string>

struct TestStruct {
public:
  operator uint32_t() const;

  TestStruct& operator=(const uint32_t v) __attribute__((enable_if(v == v, "test..."))) {
    return *this;
  }
};

int main(int argc, char* argv[]){
    std::cout<<std::is_copy_assignable<TestStruct>::value<<std::endl;
    return 0;
}

create database command:

codeql database create --language=cpp --threads=0 --command='clang++-17 main.cpp -stdlib=libc++ -lc++abi' -- /root/codeqltest/db

build-tracer.log:

CodeQL C++ extractor: Current location: main.cpp:19280,113
CodeQL C++ extractor: Current physical location: /usr/lib/llvm-17/bin/../include/c++/v1/__type_traits/is_copy_assignable.h:27,113
"/usr/lib/llvm-17/bin/../include/c++/v1/__type_traits/is_copy_assignable.h", line 27: internal error: assertion failed at: "overload.c", line 18641 in prep_special_selector_operand

            __is_assignable(__add_lvalue_reference_t<_Tp>, __add_lvalue_reference_t<typename add_const<_Tp>::type>)> {};
                                                                                                                  ^

[E 06:42:45 471327] Warning[extractor-c++]: In construct_text_message: "/usr/lib/llvm-17/bin/../include/c++/v1/__type_traits/is_copy_assignable.h", line 27: internal error: assertion failed at: "overload.c", line 18641 in prep_special_selector_operand

            __is_assignable(__add_lvalue_reference_t<_Tp>, __add_lvalue_reference_t<typename add_const<_Tp>::type>)> {};
                                                                                                                  ^


1 catastrophic error detected in the compilation of "main.cpp".
Compilation aborted.

I tried compiling with clang++ 21.1.5, but I’m still seeing the same error.

[redsun82]

👋 @hello123leo thanks for reporting this. I can confirm this is a bug affecting the frontend we use for C/C++ extraction. I'm reporting this to the internal team working on this area. Stay tuned 🙌