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[lld-macho] Fix duplicate GOT entries for personality functions #95054

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Merged
merged 1 commit into from
Jun 11, 2024
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[lld-macho] Fix duplicate GOT entries for personality functions #95054

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34 changes: 23 additions & 11 deletions lld/MachO/UnwindInfoSection.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -298,19 +298,31 @@ void UnwindInfoSectionImpl::prepareRelocations(ConcatInputSection *isec) {
assert(!isCoalescedWeak(referentIsec));
// Personality functions can be referenced via section relocations
// if they live in the same object file. Create placeholder synthetic
// symbols for them in the GOT.
// symbols for them in the GOT. If the corresponding symbol is already
// in the GOT, use that to avoid creating a duplicate entry. All GOT
// entries needed by non-unwind sections will have already been added
// by this point.
Symbol *&s = personalityTable[{referentIsec, r.addend}];
if (s == nullptr) {
// This runs after dead stripping, so the noDeadStrip argument does not
// matter.
s = make<Defined>("<internal>", /*file=*/nullptr, referentIsec,
r.addend, /*size=*/0, /*isWeakDef=*/false,
/*isExternal=*/false, /*isPrivateExtern=*/false,
/*includeInSymtab=*/true,
/*isReferencedDynamically=*/false,
/*noDeadStrip=*/false);
s->used = true;
in.got->addEntry(s);
Defined *const *gotEntry =
llvm::find_if(referentIsec->symbols, [&](Defined const *d) {
return d->value == static_cast<uint64_t>(r.addend) &&
d->isInGot();
});
if (gotEntry != referentIsec->symbols.end()) {
s = *gotEntry;
} else {
// This runs after dead stripping, so the noDeadStrip argument does
// not matter.
s = make<Defined>("<internal>", /*file=*/nullptr, referentIsec,
r.addend, /*size=*/0, /*isWeakDef=*/false,
/*isExternal=*/false, /*isPrivateExtern=*/false,
/*includeInSymtab=*/true,
/*isReferencedDynamically=*/false,
/*noDeadStrip=*/false);
s->used = true;
in.got->addEntry(s);
}
}
r.referent = s;
r.addend = 0;
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15 changes: 8 additions & 7 deletions lld/test/MachO/compact-unwind-both-local-and-dylib-personality.s
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Expand Up @@ -42,19 +42,20 @@

# RUN: llvm-objdump --macho --indirect-symbols --unwind-info --bind %t/d.out | FileCheck %s --check-prefixes=D -D#%x,OFF=0x100000000

# A: Indirect symbols for (__DATA_CONST,__got)
# A: Indirect symbols for (__DATA_CONST,__got) 4 entries
# A-NEXT: address index name
# A: 0x[[#%x,GXX_PERSONALITY_LO:]] [[#]] ___gxx_personality_v0
# A: 0x[[#%x,PERSONALITY_1:]] [[#]] _personality_1
# A: 0x[[#%x,PERSONALITY_2:]] [[#]] _personality_2
# A: 0x[[#%x,GXX_PERSONALITY_HI:]] [[#]] ___gxx_personality_v0
# A: 0x[[#%x,PERSONALITY_1:]] LOCAL
# A: 0x[[#%x,PERSONALITY_2:]] LOCAL

# BC: Indirect symbols for (__DATA_CONST,__got)
# BC-NEXT: address index name
# C: 0x[[#%x,GXX_PERSONALITY_HI:]] LOCAL
# BC: 0x[[#%x,GXX_PERSONALITY_LO:]] LOCAL
# BC: 0x[[#%x,PERSONALITY_1:]] LOCAL
# BC: 0x[[#%x,PERSONALITY_2:]] LOCAL
# C: 0x[[#%x,GXX_PERSONALITY_HI:]] [[#]] ___gxx_personality_v0
# BC: 0x[[#%x,PERSONALITY_1:]] [[#]] _personality_1
# BC: 0x[[#%x,PERSONALITY_2:]] [[#]] _personality_2
# BC-EMPTY:

# CHECK: Personality functions: (count = 3)
# CHECK-DAG: personality[{{[0-9]+}}]: 0x{{0*}}[[#GXX_PERSONALITY_LO-OFF]]
Expand All @@ -66,7 +67,7 @@
# A-NEXT: __DATA_CONST __got 0x[[#GXX_PERSONALITY_LO-0]] pointer 0 libc++abi ___gxx_personality_v0


# D: Indirect symbols for (__DATA_CONST,__got)
# D: Indirect symbols for (__DATA_CONST,__got) 6 entries
# D-NEXT: address index name
# D: 0x[[#%x,GXX_PERSONALITY_HI:]] [[#]] ___gxx_personality_v0
# D: 0x[[#%x,PERSONALITY_1:]] [[#]] _personality_1
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2 changes: 1 addition & 1 deletion lld/test/MachO/compact-unwind.s
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Expand Up @@ -29,7 +29,7 @@
# FIRST: Indirect symbols for (__DATA_CONST,__got)
# FIRST-NEXT: address index name
# FIRST-DAG: 0x[[#%x,GXX_PERSONALITY:]] [[#]] ___gxx_personality_v0
# FIRST-DAG: 0x[[#%x,MY_PERSONALITY:]] LOCAL
# FIRST-DAG: 0x[[#%x,MY_PERSONALITY:]]

# SECOND: Indirect symbols for (__DATA_CONST,__got)
# SECOND-NEXT: address index name
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