[llvm] LTO: Redesign the CFI !aliases metadata. (PR #150690)
Peter Collingbourne via llvm-commits
llvm-commits at lists.llvm.org
Fri Jul 25 13:50:39 PDT 2025
https://github.com/pcc updated https://github.com/llvm/llvm-project/pull/150690
>From 10ee161f16842946cfc768a2d489a5627b0e483f Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <peter at pcc.me.uk>
Date: Fri, 25 Jul 2025 13:04:55 -0700
Subject: [PATCH 1/2] =?UTF-8?q?[=F0=9D=98=80=F0=9D=97=BD=F0=9D=97=BF]=20in?=
=?UTF-8?q?itial=20version?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Created using spr 1.3.6-beta.1
---
llvm/include/llvm/LTO/LTO.h | 17 +--
llvm/lib/LTO/LTO.cpp | 50 +++++---
llvm/lib/Transforms/IPO/LowerTypeTests.cpp | 119 +++++++++++-------
.../Transforms/IPO/ThinLTOBitcodeWriter.cpp | 31 +++--
.../LowerTypeTests/Inputs/exported-funcs.yaml | 8 ++
.../Transforms/LowerTypeTests/export-alias.ll | 20 ++-
.../ThinLTOBitcodeWriter/function-alias.ll | 13 +-
7 files changed, 156 insertions(+), 102 deletions(-)
diff --git a/llvm/include/llvm/LTO/LTO.h b/llvm/include/llvm/LTO/LTO.h
index d8e632b5a49d5..290b0ef4e2aa4 100644
--- a/llvm/include/llvm/LTO/LTO.h
+++ b/llvm/include/llvm/LTO/LTO.h
@@ -541,20 +541,21 @@ class LTO {
void addModuleToGlobalRes(ArrayRef<InputFile::Symbol> Syms,
ArrayRef<SymbolResolution> Res, unsigned Partition,
bool InSummary);
-
- // These functions take a range of symbol resolutions [ResI, ResE) and consume
- // the resolutions used by a single input module by incrementing ResI. After
- // these functions return, [ResI, ResE) will refer to the resolution range for
- // the remaining modules in the InputFile.
Error addModule(InputFile &Input, unsigned ModI,
- const SymbolResolution *&ResI, const SymbolResolution *ResE);
+ const SymbolResolution *&ResI,
+ ArrayRef<SymbolResolution> Res);
Expected<RegularLTOState::AddedModule>
- addRegularLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms,
- const SymbolResolution *&ResI, const SymbolResolution *ResE);
+ addRegularLTO(InputFile &Input, BitcodeModule BM,
+ ArrayRef<InputFile::Symbol> Syms, const SymbolResolution *&ResI,
+ ArrayRef<SymbolResolution> Res);
Error linkRegularLTO(RegularLTOState::AddedModule Mod,
bool LivenessFromIndex);
+ // This function takes a range of symbol resolutions [ResI, ResE) and consume
+ // the resolutions used by a single input module by incrementing ResI. After
+ // these functions return, [ResI, ResE) will refer to the resolution range for
+ // the remaining modules in the InputFile.
Error addThinLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms,
const SymbolResolution *&ResI, const SymbolResolution *ResE);
diff --git a/llvm/lib/LTO/LTO.cpp b/llvm/lib/LTO/LTO.cpp
index 73e79c08a56ca..459b6e8b2c803 100644
--- a/llvm/lib/LTO/LTO.cpp
+++ b/llvm/lib/LTO/LTO.cpp
@@ -744,7 +744,7 @@ Error LTO::add(std::unique_ptr<InputFile> Input,
const SymbolResolution *ResI = Res.begin();
for (unsigned I = 0; I != Input->Mods.size(); ++I)
- if (Error Err = addModule(*Input, I, ResI, Res.end()))
+ if (Error Err = addModule(*Input, I, ResI, Res))
return Err;
assert(ResI == Res.end());
@@ -753,7 +753,7 @@ Error LTO::add(std::unique_ptr<InputFile> Input,
Error LTO::addModule(InputFile &Input, unsigned ModI,
const SymbolResolution *&ResI,
- const SymbolResolution *ResE) {
+ ArrayRef<SymbolResolution> Res) {
Expected<BitcodeLTOInfo> LTOInfo = Input.Mods[ModI].getLTOInfo();
if (!LTOInfo)
return LTOInfo.takeError();
@@ -782,16 +782,16 @@ Error LTO::addModule(InputFile &Input, unsigned ModI,
bool IsThinLTO = LTOInfo->IsThinLTO && (LTOMode != LTOK_UnifiedRegular);
auto ModSyms = Input.module_symbols(ModI);
- addModuleToGlobalRes(ModSyms, {ResI, ResE},
+ addModuleToGlobalRes(ModSyms, {ResI, Res.end()},
IsThinLTO ? ThinLTO.ModuleMap.size() + 1 : 0,
LTOInfo->HasSummary);
if (IsThinLTO)
- return addThinLTO(BM, ModSyms, ResI, ResE);
+ return addThinLTO(BM, ModSyms, ResI, Res.end());
RegularLTO.EmptyCombinedModule = false;
Expected<RegularLTOState::AddedModule> ModOrErr =
- addRegularLTO(BM, ModSyms, ResI, ResE);
+ addRegularLTO(Input, BM, ModSyms, ResI, Res);
if (!ModOrErr)
return ModOrErr.takeError();
@@ -839,10 +839,9 @@ handleNonPrevailingComdat(GlobalValue &GV,
// Add a regular LTO object to the link.
// The resulting module needs to be linked into the combined LTO module with
// linkRegularLTO.
-Expected<LTO::RegularLTOState::AddedModule>
-LTO::addRegularLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms,
- const SymbolResolution *&ResI,
- const SymbolResolution *ResE) {
+Expected<LTO::RegularLTOState::AddedModule> LTO::addRegularLTO(
+ InputFile &Input, BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms,
+ const SymbolResolution *&ResI, ArrayRef<SymbolResolution> Res) {
RegularLTOState::AddedModule Mod;
Expected<std::unique_ptr<Module>> MOrErr =
BM.getLazyModule(RegularLTO.Ctx, /*ShouldLazyLoadMetadata*/ true,
@@ -855,13 +854,34 @@ LTO::addRegularLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms,
if (Error Err = M.materializeMetadata())
return std::move(Err);
- // If cfi.functions is present and we are in regular LTO mode, LowerTypeTests
- // will rename local functions in the merged module as "<function name>.1".
- // This causes linking errors, since other parts of the module expect the
- // original function name.
- if (LTOMode == LTOK_UnifiedRegular)
+ if (LTOMode == LTOK_UnifiedRegular) {
+ // cfi.functions metadata is intended to be used with ThinLTO and may
+ // trigger invalid IR transformations if they are present when doing regular
+ // LTO, so delete it.
if (NamedMDNode *CfiFunctionsMD = M.getNamedMetadata("cfi.functions"))
M.eraseNamedMetadata(CfiFunctionsMD);
+ } else if (NamedMDNode *AliasesMD = M.getNamedMetadata("aliases")) {
+ // Delete aliases entries for non-prevailing symbols on the ThinLTO side of
+ // this input file.
+ std::set<StringRef> Prevailing;
+ for (auto P : zip(Input.symbols(), Res))
+ if (std::get<1>(P).Prevailing && !std::get<0>(P).getIRName().empty())
+ Prevailing.insert(std::get<0>(P).getIRName());
+ std::vector<MDNode *> AliasGroups;
+ for (MDNode *AliasGroup : AliasesMD->operands()) {
+ std::vector<Metadata *> Aliases;
+ for (Metadata *Alias : AliasGroup->operands()) {
+ if (isa<MDString>(Alias) &&
+ Prevailing.count(cast<MDString>(Alias)->getString()))
+ Aliases.push_back(Alias);
+ }
+ if (Aliases.size() > 1)
+ AliasGroups.push_back(MDTuple::get(RegularLTO.Ctx, Aliases));
+ }
+ AliasesMD->clearOperands();
+ for (MDNode *G : AliasGroups)
+ AliasesMD->addOperand(G);
+ }
UpgradeDebugInfo(M);
@@ -899,7 +919,7 @@ LTO::addRegularLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms,
std::set<const Comdat *> NonPrevailingComdats;
SmallSet<StringRef, 2> NonPrevailingAsmSymbols;
for (const InputFile::Symbol &Sym : Syms) {
- assert(ResI != ResE);
+ assert(ResI != Res.end());
SymbolResolution Res = *ResI++;
assert(MsymI != MsymE);
diff --git a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
index 486205c8a3848..392f3240c0ae8 100644
--- a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
+++ b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
@@ -349,6 +349,7 @@ struct ICallBranchFunnel final
struct ScopedSaveAliaseesAndUsed {
Module &M;
+ std::set<GlobalAlias *> *ExcludedAliases;
SmallVector<GlobalValue *, 4> Used, CompilerUsed;
std::vector<std::pair<GlobalAlias *, Function *>> FunctionAliases;
std::vector<std::pair<GlobalIFunc *, Function *>> ResolverIFuncs;
@@ -377,7 +378,9 @@ struct ScopedSaveAliaseesAndUsed {
Vec.resize(NonFuncBegin - Vec.begin());
}
- ScopedSaveAliaseesAndUsed(Module &M) : M(M) {
+ ScopedSaveAliaseesAndUsed(Module &M,
+ std::set<GlobalAlias *> *ExcludedAliases = nullptr)
+ : M(M), ExcludedAliases(ExcludedAliases) {
// The users of this class want to replace all function references except
// for aliases and llvm.used/llvm.compiler.used with references to a jump
// table. We avoid replacing aliases in order to avoid introducing a double
@@ -396,8 +399,9 @@ struct ScopedSaveAliaseesAndUsed {
for (auto &GA : M.aliases()) {
// FIXME: This should look past all aliases not just interposable ones,
// see discussion on D65118.
- if (auto *F = dyn_cast<Function>(GA.getAliasee()->stripPointerCasts()))
- FunctionAliases.push_back({&GA, F});
+ if (!ExcludedAliases || !ExcludedAliases->count(&GA))
+ if (auto *F = dyn_cast<Function>(GA.getAliasee()->stripPointerCasts()))
+ FunctionAliases.push_back({&GA, F});
}
for (auto &GI : M.ifuncs())
@@ -2137,6 +2141,18 @@ bool LowerTypeTestsModule::lower() {
if (auto Alias = dyn_cast<AliasSummary>(RefGVS.get()))
AddressTaken.insert(Alias->getAliaseeGUID());
}
+ auto IsAddressTaken = [&](GlobalValue::GUID GUID) {
+ if (AddressTaken.count(GUID))
+ return true;
+ auto VI = ExportSummary->getValueInfo(GUID);
+ if (!VI)
+ return false;
+ for (auto &I : VI.getSummaryList())
+ if (auto Alias = dyn_cast<AliasSummary>(I.get()))
+ if (AddressTaken.count(Alias->getAliaseeGUID()))
+ return true;
+ return false;
+ };
for (auto *FuncMD : CfiFunctionsMD->operands()) {
assert(FuncMD->getNumOperands() >= 2);
StringRef FunctionName =
@@ -2153,7 +2169,7 @@ bool LowerTypeTestsModule::lower() {
// have no live references (and are not exported with cross-DSO CFI.)
if (!ExportSummary->isGUIDLive(GUID))
continue;
- if (!AddressTaken.count(GUID)) {
+ if (!IsAddressTaken(GUID)) {
if (!CrossDsoCfi || Linkage != CFL_Definition)
continue;
@@ -2227,6 +2243,44 @@ bool LowerTypeTestsModule::lower() {
}
}
+ struct AliasToCreate {
+ Function *Alias;
+ std::string TargetName;
+ };
+ std::vector<AliasToCreate> AliasesToCreate;
+
+ // Parse alias data to replace stand-in function declarations for aliases
+ // with an alias to the intended target.
+ std::set<GlobalAlias *> ExcludedAliases;
+ if (ExportSummary) {
+ if (NamedMDNode *AliasesMD = M.getNamedMetadata("aliases")) {
+ for (auto *AliasMD : AliasesMD->operands()) {
+ std::vector<Function *> Aliases;
+ for (Metadata *MD : AliasMD->operands()) {
+ auto *MDS = dyn_cast<MDString>(MD);
+ if (!MDS)
+ continue;
+ StringRef AliasName = MDS->getString();
+ if (!ExportedFunctions.count(AliasName))
+ continue;
+ auto *AliasF = M.getFunction(AliasName);
+ if (AliasF)
+ Aliases.push_back(AliasF);
+ }
+
+ if (Aliases.empty())
+ continue;
+
+ for (unsigned I = 1; I != Aliases.size(); ++I) {
+ auto *AliasF = Aliases[I];
+ ExportedFunctions.erase(AliasF->getName());
+ AliasesToCreate.push_back(
+ {AliasF, std::string(Aliases[0]->getName())});
+ }
+ }
+ }
+ }
+
DenseMap<GlobalObject *, GlobalTypeMember *> GlobalTypeMembers;
for (GlobalObject &GO : M.global_objects()) {
if (isa<GlobalVariable>(GO) && GO.isDeclarationForLinker())
@@ -2374,7 +2428,7 @@ bool LowerTypeTestsModule::lower() {
return false;
{
- ScopedSaveAliaseesAndUsed S(M);
+ ScopedSaveAliaseesAndUsed S(M, &ExcludedAliases);
// For each disjoint set we found...
for (const auto &C : GlobalClasses) {
if (!C->isLeader())
@@ -2414,49 +2468,18 @@ bool LowerTypeTestsModule::lower() {
allocateByteArrays();
- // Parse alias data to replace stand-in function declarations for aliases
- // with an alias to the intended target.
- if (ExportSummary) {
- if (NamedMDNode *AliasesMD = M.getNamedMetadata("aliases")) {
- for (auto *AliasMD : AliasesMD->operands()) {
- assert(AliasMD->getNumOperands() >= 4);
- StringRef AliasName =
- cast<MDString>(AliasMD->getOperand(0))->getString();
- StringRef Aliasee = cast<MDString>(AliasMD->getOperand(1))->getString();
-
- if (auto It = ExportedFunctions.find(Aliasee);
- It == ExportedFunctions.end() ||
- It->second.Linkage != CFL_Definition || !M.getNamedAlias(Aliasee))
- continue;
-
- GlobalValue::VisibilityTypes Visibility =
- static_cast<GlobalValue::VisibilityTypes>(
- cast<ConstantAsMetadata>(AliasMD->getOperand(2))
- ->getValue()
- ->getUniqueInteger()
- .getZExtValue());
- bool Weak =
- static_cast<bool>(cast<ConstantAsMetadata>(AliasMD->getOperand(3))
- ->getValue()
- ->getUniqueInteger()
- .getZExtValue());
-
- auto *Alias = GlobalAlias::create("", M.getNamedAlias(Aliasee));
- Alias->setVisibility(Visibility);
- if (Weak)
- Alias->setLinkage(GlobalValue::WeakAnyLinkage);
-
- if (auto *F = M.getFunction(AliasName)) {
- Alias->takeName(F);
- F->replaceAllUsesWith(Alias);
- F->eraseFromParent();
- } else {
- Alias->setName(AliasName);
- }
- }
- }
- }
-
+ for (auto A : AliasesToCreate) {
+ auto *Target = M.getNamedValue(A.TargetName);
+ if (!isa<GlobalAlias>(Target))
+ continue;
+ auto *AliasGA = GlobalAlias::create("", Target);
+ AliasGA->setVisibility(A.Alias->getVisibility());
+ AliasGA->setLinkage(A.Alias->getLinkage());
+ AliasGA->takeName(A.Alias);
+ A.Alias->replaceAllUsesWith(AliasGA);
+ A.Alias->eraseFromParent();
+ }
+
// Emit .symver directives for exported functions, if they exist.
if (ExportSummary) {
if (NamedMDNode *SymversMD = M.getNamedMetadata("symvers")) {
diff --git a/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp b/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
index e276376f21583..019831f550cbd 100644
--- a/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
+++ b/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
@@ -384,6 +384,10 @@ void splitAndWriteThinLTOBitcode(
for (auto &F : M)
if ((!F.hasLocalLinkage() || F.hasAddressTaken()) && HasTypeMetadata(&F))
CfiFunctions.insert(&F);
+ for (auto &A : M.aliases())
+ if (auto *F = dyn_cast<Function>(A.getAliasee()))
+ if (HasTypeMetadata(F))
+ CfiFunctions.insert(&A);
// Remove all globals with type metadata, globals with comdats that live in
// MergedM, and aliases pointing to such globals from the thin LTO module.
@@ -403,12 +407,12 @@ void splitAndWriteThinLTOBitcode(
auto &Ctx = MergedM->getContext();
SmallVector<MDNode *, 8> CfiFunctionMDs;
for (auto *V : CfiFunctions) {
- Function &F = *cast<Function>(V);
+ Function &F = *cast<Function>(V->getAliaseeObject());
SmallVector<MDNode *, 2> Types;
F.getMetadata(LLVMContext::MD_type, Types);
SmallVector<Metadata *, 4> Elts;
- Elts.push_back(MDString::get(Ctx, F.getName()));
+ Elts.push_back(MDString::get(Ctx, V->getName()));
CfiFunctionLinkage Linkage;
if (lowertypetests::isJumpTableCanonical(&F))
Linkage = CFL_Definition;
@@ -428,29 +432,24 @@ void splitAndWriteThinLTOBitcode(
NMD->addOperand(MD);
}
- SmallVector<MDNode *, 8> FunctionAliases;
+ MapVector<Function *, std::vector<GlobalAlias *>> FunctionAliases;
for (auto &A : M.aliases()) {
if (!isa<Function>(A.getAliasee()))
continue;
auto *F = cast<Function>(A.getAliasee());
-
- Metadata *Elts[] = {
- MDString::get(Ctx, A.getName()),
- MDString::get(Ctx, F->getName()),
- ConstantAsMetadata::get(
- ConstantInt::get(Type::getInt8Ty(Ctx), A.getVisibility())),
- ConstantAsMetadata::get(
- ConstantInt::get(Type::getInt8Ty(Ctx), A.isWeakForLinker())),
- };
-
- FunctionAliases.push_back(MDTuple::get(Ctx, Elts));
+ FunctionAliases[F].push_back(&A);
}
if (!FunctionAliases.empty()) {
NamedMDNode *NMD = MergedM->getOrInsertNamedMetadata("aliases");
- for (auto *MD : FunctionAliases)
- NMD->addOperand(MD);
+ for (auto &Alias : FunctionAliases) {
+ std::vector<Metadata *> Elts;
+ Elts.push_back(MDString::get(Ctx, Alias.first->getName()));
+ for (auto *A : Alias.second)
+ Elts.push_back(MDString::get(Ctx, A->getName()));
+ NMD->addOperand(MDTuple::get(Ctx, Elts));
+ }
}
SmallVector<MDNode *, 8> Symvers;
diff --git a/llvm/test/Transforms/LowerTypeTests/Inputs/exported-funcs.yaml b/llvm/test/Transforms/LowerTypeTests/Inputs/exported-funcs.yaml
index 5457e36573bb7..81df2f198f91b 100644
--- a/llvm/test/Transforms/LowerTypeTests/Inputs/exported-funcs.yaml
+++ b/llvm/test/Transforms/LowerTypeTests/Inputs/exported-funcs.yaml
@@ -19,4 +19,12 @@ GlobalValueMap:
15859245615183425489: # guid("internal")
- Linkage: 7 # internal
Live: true
+ 1062103744896965210: # guid("alias1")
+ - Linkage: 4 # weak
+ Live: true
+ Aliasee: 16594175687743574550 # guid("external_addrtaken")
+ 2510616090736846890: # guid("alias2")
+ - Linkage: 0 # weak
+ Live: true
+ Aliasee: 16594175687743574550 # guid("external_addrtaken")
...
diff --git a/llvm/test/Transforms/LowerTypeTests/export-alias.ll b/llvm/test/Transforms/LowerTypeTests/export-alias.ll
index 45b4db63def18..25d34833c82c3 100644
--- a/llvm/test/Transforms/LowerTypeTests/export-alias.ll
+++ b/llvm/test/Transforms/LowerTypeTests/export-alias.ll
@@ -1,21 +1,19 @@
; RUN: opt -S %s -passes=lowertypetests -lowertypetests-summary-action=export -lowertypetests-read-summary=%S/Inputs/exported-funcs.yaml | FileCheck %s
;
-; CHECK: @alias1 = weak alias [8 x i8], ptr @external_addrtaken
-; CHECK: @alias2 = hidden alias [8 x i8], ptr @external_addrtaken
+; CHECK: @alias1 = alias [8 x i8], ptr @external_addrtaken
+; CHECK: @alias2 = alias [8 x i8], ptr @external_addrtaken
; CHECK-NOT: @alias3 = alias
; CHECK-NOT: @not_present
target triple = "x86_64-unknown-linux"
-!cfi.functions = !{!0, !2, !3}
-!aliases = !{!4, !5, !6}
+!cfi.functions = !{!0, !2, !3, !4}
+!aliases = !{!5, !6}
!0 = !{!"external_addrtaken", i8 0, !1}
!1 = !{i64 0, !"typeid1"}
-!2 = !{!"alias1", i8 1, !1}
-; alias2 not included here, this could happen if the only reference to alias2
-; is in a module compiled without cfi-icall
-!3 = !{!"alias3", i8 1, !1}
-!4 = !{!"alias1", !"external_addrtaken", i8 0, i8 1}
-!5 = !{!"alias2", !"external_addrtaken", i8 1, i8 0}
-!6 = !{!"alias3", !"not_present", i8 0, i8 0}
+!2 = !{!"alias1", i8 0, !1}
+!3 = !{!"alias2", i8 0, !1}
+!4 = !{!"alias3", i8 0, !1}
+!5 = !{!"external_addrtaken", !"alias1", !"alias2"}
+!6 = !{!"not_present", !"alias3"}
diff --git a/llvm/test/Transforms/ThinLTOBitcodeWriter/function-alias.ll b/llvm/test/Transforms/ThinLTOBitcodeWriter/function-alias.ll
index efc04e99f0459..74693c1312b01 100644
--- a/llvm/test/Transforms/ThinLTOBitcodeWriter/function-alias.ll
+++ b/llvm/test/Transforms/ThinLTOBitcodeWriter/function-alias.ll
@@ -7,11 +7,16 @@ define hidden void @Func() !type !0 {
ret void
}
-; CHECK1: !aliases = !{![[A1:[0-9]+]], ![[A2:[0-9]+]], ![[A3:[0-9]+]]}
+; CHECK1: !cfi.functions = !{![[F1:[0-9]+]], ![[F2:[0-9]+]], ![[F3:[0-9]+]], ![[F4:[0-9]+]]}
+; CHECK1: !aliases = !{![[A:[0-9]+]]}
-; CHECK1: ![[A1]] = !{!"Alias", !"Func", i8 1, i8 0}
-; CHECK1: ![[A2]] = !{!"Hidden_Alias", !"Func", i8 1, i8 0}
-; CHECK1: ![[A3]] = !{!"Weak_Alias", !"Func", i8 0, i8 1}
+; CHECK1: ![[F1]] = !{!"Func", i8 0, ![[T:[0-9]+]]}
+; CHECK1: ![[T]] = !{i64 0, !"_ZTSFvvE"}
+; CHECK1: ![[F2]] = !{!"Alias", i8 0, ![[T]]}
+; CHECK1: ![[F3]] = !{!"Hidden_Alias", i8 0, ![[T]]}
+; CHECK1: ![[F4]] = !{!"Weak_Alias", i8 0, ![[T]]}
+;
+; CHECK1: ![[A]] = !{!"Func", !"Alias", !"Hidden_Alias", !"Weak_Alias"}
@Alias = hidden alias void (), ptr @Func
@Hidden_Alias = hidden alias void (), ptr @Func
@Weak_Alias = weak alias void (), ptr @Func
>From 709e43bbd73f9707abed0f3030b790cb741b95bb Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <peter at pcc.me.uk>
Date: Fri, 25 Jul 2025 13:50:25 -0700
Subject: [PATCH 2/2] Remove unused code
Created using spr 1.3.6-beta.1
---
llvm/lib/Transforms/IPO/LowerTypeTests.cpp | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
index 392f3240c0ae8..883b94ead9f9f 100644
--- a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
+++ b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
@@ -349,7 +349,6 @@ struct ICallBranchFunnel final
struct ScopedSaveAliaseesAndUsed {
Module &M;
- std::set<GlobalAlias *> *ExcludedAliases;
SmallVector<GlobalValue *, 4> Used, CompilerUsed;
std::vector<std::pair<GlobalAlias *, Function *>> FunctionAliases;
std::vector<std::pair<GlobalIFunc *, Function *>> ResolverIFuncs;
@@ -378,9 +377,7 @@ struct ScopedSaveAliaseesAndUsed {
Vec.resize(NonFuncBegin - Vec.begin());
}
- ScopedSaveAliaseesAndUsed(Module &M,
- std::set<GlobalAlias *> *ExcludedAliases = nullptr)
- : M(M), ExcludedAliases(ExcludedAliases) {
+ ScopedSaveAliaseesAndUsed(Module &M) : M(M) {
// The users of this class want to replace all function references except
// for aliases and llvm.used/llvm.compiler.used with references to a jump
// table. We avoid replacing aliases in order to avoid introducing a double
@@ -399,9 +396,8 @@ struct ScopedSaveAliaseesAndUsed {
for (auto &GA : M.aliases()) {
// FIXME: This should look past all aliases not just interposable ones,
// see discussion on D65118.
- if (!ExcludedAliases || !ExcludedAliases->count(&GA))
- if (auto *F = dyn_cast<Function>(GA.getAliasee()->stripPointerCasts()))
- FunctionAliases.push_back({&GA, F});
+ if (auto *F = dyn_cast<Function>(GA.getAliasee()->stripPointerCasts()))
+ FunctionAliases.push_back({&GA, F});
}
for (auto &GI : M.ifuncs())
@@ -2251,7 +2247,6 @@ bool LowerTypeTestsModule::lower() {
// Parse alias data to replace stand-in function declarations for aliases
// with an alias to the intended target.
- std::set<GlobalAlias *> ExcludedAliases;
if (ExportSummary) {
if (NamedMDNode *AliasesMD = M.getNamedMetadata("aliases")) {
for (auto *AliasMD : AliasesMD->operands()) {
@@ -2428,7 +2423,7 @@ bool LowerTypeTestsModule::lower() {
return false;
{
- ScopedSaveAliaseesAndUsed S(M, &ExcludedAliases);
+ ScopedSaveAliaseesAndUsed S(M);
// For each disjoint set we found...
for (const auto &C : GlobalClasses) {
if (!C->isLeader())
More information about the llvm-commits
mailing list