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[6.0] [LLD] [COFF] Add a separate option for allowing duplicate weak symbols #8959

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Merged
merged 1 commit into from
Jul 9, 2024
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[6.0] [LLD] [COFF] Add a separate option for allowing duplicate weak symbols #8959

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1 change: 1 addition & 0 deletions lld/COFF/Config.h
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Original file line number Diff line number Diff line change
Expand Up @@ -313,6 +313,7 @@ struct Configuration {
bool pseudoRelocs = false;
bool stdcallFixup = false;
bool writeCheckSum = false;
bool allowDuplicateWeak = false;
};

} // namespace lld::coff
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3 changes: 3 additions & 0 deletions lld/COFF/Driver.cpp
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Expand Up @@ -1980,6 +1980,9 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
config->stdcallFixup =
args.hasFlag(OPT_stdcall_fixup, OPT_stdcall_fixup_no, config->mingw);
config->warnStdcallFixup = !args.hasArg(OPT_stdcall_fixup);
config->allowDuplicateWeak =
args.hasFlag(OPT_lld_allow_duplicate_weak,
OPT_lld_allow_duplicate_weak_no, config->mingw);

if (args.hasFlag(OPT_inferasanlibs, OPT_inferasanlibs_no, false))
warn("ignoring '/inferasanlibs', this flag is not supported");
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2 changes: 1 addition & 1 deletion lld/COFF/InputFiles.cpp
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Expand Up @@ -81,7 +81,7 @@ static void checkAndSetWeakAlias(COFFLinkerContext &ctx, InputFile *f,
// of another symbol emitted near the weak symbol.
// Just use the definition from the first object file that defined
// this weak symbol.
if (ctx.config.mingw)
if (ctx.config.allowDuplicateWeak)
return;
ctx.symtab.reportDuplicate(source, f);
}
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1 change: 1 addition & 0 deletions lld/COFF/Options.td
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Expand Up @@ -232,6 +232,7 @@ defm demangle : B<"demangle",
def include_optional : Joined<["/", "-", "/?", "-?"], "includeoptional:">,
HelpText<"Add symbol as undefined, but allow it to remain undefined">;
def kill_at : F<"kill-at">;
defm lld_allow_duplicate_weak : B_priv<"lld-allow-duplicate-weak">;
def lldmingw : F<"lldmingw">;
def noseh : F<"noseh">;
def osversion : P_priv<"osversion">;
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5 changes: 5 additions & 0 deletions lld/test/COFF/gnu-weak.test
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@@ -1,4 +1,9 @@
RUN: lld-link -lldmingw %S/Inputs/gnu-weak.o %S/Inputs/gnu-weak2.o -out:%t.exe
RUN: lld-link -lld-allow-duplicate-weak %S/Inputs/gnu-weak.o %S/Inputs/gnu-weak2.o -out:%t.exe
RUN: not lld-link %S/Inputs/gnu-weak.o %S/Inputs/gnu-weak2.o -out:%t.exe 2>&1 | FileCheck %s --check-prefix=DEFAULT-ERROR

DEFAULT-ERROR: error: duplicate symbol: weakfunc


GNU ld can handle several definitions of the same weak symbol, and
unless there is a strong definition of it, it just picks the first
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