Unresolved external symbols from Absail

[dpservis]

What version of protobuf and what language are you using?
Version: v32.0 built from code
Language: C++

What operating system (Linux, Windows, ...) and version?
Windows
What runtime / compiler are you using (e.g., python version or gcc version)
Visual Studio 22
ISO C++ 20
Windows SDK 10.0
Unicode

What did you do?
Steps to reproduce the behavior:

1. Built protobuf from code
2. Tried to compile and link generated code
3. Got 5 unresolved externals

What did you expect to see
No linker errors
What did you see instead?
error LNK2001: unresolved external symbol "private: void __cdecl absl::lts_20250512::log_internal::LogMessage::CopyToEncodedBuffer<0>(class absl::lts_20250512::string_view)" (??$CopyToEncodedBuffer@$0A@@LogMessage@log_internal@lts_20250512@absl@@AEAAXVstring_view@23@@z)
error LNK2001: unresolved external symbol "private: unsigned char * __cdecl google::protobuf::io::EpsCopyOutputStream::WriteStringMaybeAliasedOutline(unsigned int,class absl::lts_20250512::string_view,unsigned char *)" (?WriteStringMaybeAliasedOutline@EpsCopyOutputStream@io@protobuf@google@@AEAAPEAEIVstring_view@lts_20250512@absl@@peae@Z)
error LNK2001: unresolved external symbol "public: void __cdecl google::protobuf::internal::ArenaStringPtr::Set(class absl::lts_20250512::string_view,class google::protobuf::Arena *)" (?Set@ArenaStringPtr@internal@protobuf@google@@QEAAXVstring_view@lts_20250512@absl@@PEAVArena@34@@z)
error LNK2001: unresolved external symbol "public: static bool __cdecl google::protobuf::internal::WireFormatLite::VerifyUtf8String(char const *,int,enum google::protobuf::internal::WireFormatLite::Operation,class absl::lts_20250512::string_view)" (?VerifyUtf8String@WireFormatLite@internal@protobuf@google@@SA_NPEBDHW4Operation@1234@Vstring_view@lts_20250512@absl@@@z)
error LNK2019: unresolved external symbol "private: unsigned char * __cdecl google::protobuf::io::EpsCopyOutputStream::WriteStringOutline(unsigned int,class absl::lts_20250512::string_view,unsigned char *)" (?WriteStringOutline@EpsCopyOutputStream@io@protobuf@google@@AEAAPEAEIVstring_view@lts_20250512@absl@@peae@Z) referenced in function "public: unsigned char * __cdecl google::protobuf::io::EpsCopyOutputStream::WriteString<class std::basic_string<char,struct std::char_traits,class std::allocator > >(unsigned int,class std::basic_string<char,struct std::char_traits,class std::allocator > const &,unsigned char *)" (??$WriteString@V?$basic_string@DU?$char_traits@D@std@@v?$allocator@D@2@@std@@@EpsCopyOutputStream@io@protobuf@google@@QEAAPEAEIAEBV?$basic_string@DU?$char_traits@D@std@@v?$allocator@D@2@@std@@peae@Z)

Make sure you include information that can help us debug (full error message, exception listing, stack trace, logs).

Anything else we should know about your project / environment

[dpservis]

I checked the template forward declarations, extern declatations of instantiations, instantiations in the code, they all look OK. But I cannot figure this one out... it looks as if absl::lts_20250512::string_view is not known at the time of compilation.

[dpservis]

I found out why this happens. When I compile the libraries, in absl-src/absl/base/options.h I see

#define ABSL_OPTION_USE_STD_STRING_VIEW 2

But when I install the libraries, for whatever reason, in include/absl/base/options.h I see

#define ABSL_OPTION_USE_STD_STRING_VIEW 0

If I change this to 1 then it links fine

[esrauchg]

The listed behavior would occur if you compile absl with a different /std setting than the code that uses the headers; the entire stack needs to be consistent flags for things to work.

Is it possible you have different set of flags set for the different libraries?

[dpservis]

No I have the same flags for /std, also the same SDK and Platform Toolset.

[SetoKaiba]

I encountered the same problem. The install generated include options.h is not matching the absl-src one.