[CMake] Do not require GNU Gold usage to enable DEBUG_FISSION

• Component: CMake
• Status: RESOLVED FIXED

[Adrian Perez]

As per my comment at https://bugs.webkit.org/show_bug.cgi?id=235476#c4
all of ld.bfd, lld, and mold support split-debug builds, and there is
not reason whatsoever to make the DEBUG_FISSION option depend on the
value of the USE_LD_GOLD one.

   % cat hello.cc         
   #include <cstdio>
   extern const char* whom();
   int main() { std::printf("Hello, %s!\n", whom()); }
   % cat other.cc         
   const char* whom() { return "Pete"; }
   % g++ -gsplit-dwarf -ggdb -c hello.cc                  
   % g++ -gsplit-dwarf -ggdb -c other.cc  
   % g++ -gsplit-dwarf -ggdb -fuse-ld=bfd -o hello hello.o other.o        
   % dwarfdump hello | grep DW_AT_dwo_name | sort -u 
                    DW_AT_dwo_name              hello.dwo
                    DW_AT_dwo_name              other.dwo

(Replacing g++ with clang++ above also works, plus the Clang compiler
driver will happily accept any -fuse-ld=whatever as long as there is
a “ld.whatever” binary in the $PATH.)

[Adrian Perez]

Created attachment 450187 [details]
Patch

[EWS]

Committed r288718 (246511@main): <https://commits.webkit.org/246511@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 450187 [details].

[Adrian Perez]

For the record: I did some tests, and debug builds now take about the
same time with ld.bfd after applying this patch, and ld.lld is faster
than both ld.gold and ld.bfd (no surprises there!). I have not tried
with ld.mold because we do not yet have it in the Flatpak SDK.