MolecularMatters
commented
3 years ago In case it should matter, here are the command line arguments used for invoking clang-cl:
-c -Zi -JMC -nologo -W0 -WX- -diagnostics:column -Od -Oy- -D_DEBUG -D_WINDOWS -D_UNICODE -DUNICODE -EHs -EHc -RTC1 -MDd -GS -Zc:wchar_t -Zc:forScope -Zc:inline -Zc:rvalueCast -GR- -openmp- -Gd -TP -FC -I"C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\VC\Tools\MSVC\14.16.27023\include" -I"C:\Program Files (x86)\Windows Kits\10\Include\10.0.19041.0\ucrt" -I"C:\Program Files (x86)\Windows Kits\10\Include\10.0.19041.0\um" -I"C:\Program Files (x86)\Windows Kits\10\Include\10.0.19041.0\shared" -I"C:\Program Files (x86)\Windows Kits\10\Include\10.0.19041.0\winrt" -I"C:\Program Files (x86)\Windows Kits\10\Include\10.0.19041.0\cppwinrt" -I"C:\Program Files (x86)\Windows Kits\NETFXSDK\4.8\Include\um" -X
And here they are for lld-link: /ERRORREPORT:PROMPT /OUT:%outDir%\Repro.exe /INCREMENTAL:NO /NOLOGO /FUNCTIONPADMIN /MANIFEST "/MANIFESTUAC:level='asInvoker' uiAccess='false'" /manifest:embed /DEBUG:FULL /PDB:%outDir%\Repro.pdb /SUBSYSTEM:CONSOLE /OPT:NOREF /OPT:NOICF /TLBID:1 /DYNAMICBASE /NXCOMPAT /MACHINE:X64 /LIBPATH:"C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.29.30037\lib\x64" /LIBPATH:"C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.29.30037\atlmfc\lib\x64" /LIBPATH:"C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Auxiliary\VS\lib\x64" /LIBPATH:"C:\Program Files (x86)\Windows Kits\10\lib\10.0.19041.0\ucrt\x64" /LIBPATH:"C:\Program Files (x86)\Windows Kits\10\lib\10.0.19041.0\um\x64" /LIBPATH:"C:\Program Files (x86)\Windows Kits\NETFXSDK\4.8\lib\um\x64"
llvmbot
Extended Description
I recently noticed that in certain cases, the PDB file produced by lld will contain symbols twice in the public symbol stream.
Here's a short repro case:
include
void Func(void) {}
int main(void) { std::thread t(&Func); return 0; }
Compile and link the above with clang-cl and lld-link, respectively. Note that the PDB file will contain the symbol ??_Gbad_array_new_length@std@@UEAAPEAXI@Z twice in the public symbol stream.
I've noticed this with other symbols as well, but the above repro should be the easiest to reproduce.
I have never seen any duplicate symbol in PDBs produced by MSVC, and the public symbol stream is meant to contain only unique, external symbols with their RVA and mangled name, so I don't think this is intentional. It might trip up some tools working with PDB files, as it did Live++.