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[lld][ELF] Resolve Symbols with same comdat index as Defined Symbols #115140

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[lld][ELF] Resolve Symbols with same comdat index as Defined Symbols #115140

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1cde8af
[lld][ELF] Resolve Symbols with same comdat index as Defined Symbols
Nov 6, 2024
1ffb318
Used ltoCanOmit and modifed the InputFiles.cpp Accordingly,
Dec 9, 2024
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12 changes: 10 additions & 2 deletions lld/ELF/InputFiles.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1726,13 +1726,21 @@ static void createBitcodeSymbol(Ctx &ctx, Symbol *&sym,
sym = ctx.symtab->insert(objSym.getName());
}

int c = objSym.getComdatIndex();
if (objSym.isUndefined() || (c != -1 && !keptComdats[c])) {
if (objSym.isUndefined()) {
Undefined newSym(&f, StringRef(), binding, visibility, type);
sym->resolve(ctx, newSym);
sym->referenced = true;
return;
}
int c = objSym.getComdatIndex();
if (c != -1 && !keptComdats[c]) {
Defined newSym(ctx, &f, StringRef(), binding, visibility, type, 0, 0,
nullptr);
sym->ltoCanOmit = objSym.canBeOmittedFromSymbolTable() &&
(!sym->isDefined() || sym->ltoCanOmit);
sym->resolve(ctx, newSym);
return;
}

if (objSym.isCommon()) {
sym->resolve(ctx, CommonSymbol{ctx, &f, StringRef(), binding, visibility,
Expand Down
10 changes: 10 additions & 0 deletions lld/test/ELF/lto/Inputs/internalize-exportdyn.ll
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Original file line number Diff line number Diff line change
@@ -1,6 +1,16 @@
target triple = "x86_64-unknown-linux-gnu"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"

$f1 = comdat any
$f2 = comdat any

define weak_odr void @bah() {
ret void
}

define linkonce_odr void @f1() local_unnamed_addr comdat {
ret void
}
define weak_odr void @f2() local_unnamed_addr comdat {
ret void
}
15 changes: 15 additions & 0 deletions lld/test/ELF/lto/internalize-exportdyn.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,9 @@
target triple = "x86_64-unknown-linux-gnu"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"

$f1 = comdat any
$f2 = comdat any

@c = linkonce_odr constant i32 1
@g = linkonce_odr global i32 1
@u_c = linkonce_odr unnamed_addr constant i32 1
Expand Down Expand Up @@ -46,6 +49,14 @@ define linkonce_odr void @baz() {

@use_baz = global ptr @baz

define weak_odr void @f1() local_unnamed_addr comdat {
ret void
}

define linkonce_odr void @f2() local_unnamed_addr comdat {
ret void
}

; Check what gets internalized.
; CHECK: @c = weak_odr dso_local constant i32 1
; CHECK: @g = weak_odr dso_local global i32 1
Expand All @@ -60,6 +71,8 @@ define linkonce_odr void @baz() {
; CHECK: define internal void @zed2()
; CHECK: define weak_odr dso_local void @bah()
; CHECK: define weak_odr dso_local void @baz()
; CHECK: define weak_odr dso_local void @f1() comdat
; CHECK: define weak_odr dso_local void @f2() comdat

; DSO: @c = weak_odr constant i32 1
; DSO: @g = weak_odr global i32 1
Expand All @@ -74,3 +87,5 @@ define linkonce_odr void @baz() {
; DSO: define internal void @zed2()
; DSO: define weak_odr void @bah()
; DSO: define weak_odr void @baz()
; DSO: define weak_odr void @f1() comdat
; DSO: define weak_odr void @f2() comdat
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