[llvm] d2ef8c1 - [ThinLTO] Drop dso_local if a GlobalVariable satisfies isDeclarationForLinker()
Fangrui Song via llvm-commits
llvm-commits at lists.llvm.org
Tue Apr 7 15:47:39 PDT 2020
Author: Fangrui Song
Date: 2020-04-07T15:46:01-07:00
New Revision: d2ef8c1f2ca33457247be26374852573098553c7
URL: https://github.com/llvm/llvm-project/commit/d2ef8c1f2ca33457247be26374852573098553c7
DIFF: https://github.com/llvm/llvm-project/commit/d2ef8c1f2ca33457247be26374852573098553c7.diff
LOG: [ThinLTO] Drop dso_local if a GlobalVariable satisfies isDeclarationForLinker()
dso_local leads to direct access even if the definition is not within this compilation unit (it is
still in the same linkage unit). On ELF, such a relocation (e.g. R_X86_64_PC32) referencing a
STB_GLOBAL STV_DEFAULT object can cause a linker error in a -shared link.
If the linkage is changed to available_externally, the dso_local flag should be dropped, so that no
direct access will be generated.
The current behavior is benign, because -fpic does not assume dso_local
(clang/lib/CodeGen/CodeGenModule.cpp:shouldAssumeDSOLocal).
If we do that for -fno-semantic-interposition (D73865), there will be an
R_X86_64_PC32 linker error without this patch.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D74751
Added:
llvm/test/ThinLTO/X86/index-const-prop-gvref-pie.ll
Modified:
llvm/include/llvm/Transforms/IPO/FunctionImport.h
llvm/include/llvm/Transforms/Utils/FunctionImportUtils.h
llvm/lib/LTO/LTOBackend.cpp
llvm/lib/LTO/ThinLTOCodeGenerator.cpp
llvm/lib/Transforms/IPO/FunctionImport.cpp
llvm/lib/Transforms/Utils/FunctionImportUtils.cpp
llvm/test/LTO/Resolution/X86/local-def-dllimport.ll
llvm/test/ThinLTO/X86/Inputs/index-const-prop-gvref.ll
llvm/test/ThinLTO/X86/funcimport_alwaysinline.ll
llvm/test/ThinLTO/X86/index-const-prop-alias.ll
llvm/test/ThinLTO/X86/index-const-prop-comdat.ll
llvm/test/ThinLTO/X86/index-const-prop-dead.ll
llvm/test/ThinLTO/X86/index-const-prop-full-lto.ll
llvm/test/ThinLTO/X86/index-const-prop-gvref.ll
llvm/test/ThinLTO/X86/index-const-prop-ldst.ll
llvm/test/ThinLTO/X86/index-const-prop-linkage.ll
llvm/test/ThinLTO/X86/index-const-prop2.ll
llvm/tools/llvm-link/llvm-link.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/Transforms/IPO/FunctionImport.h b/llvm/include/llvm/Transforms/IPO/FunctionImport.h
index b4dde7b199ff..6eaf82a6bfec 100644
--- a/llvm/include/llvm/Transforms/IPO/FunctionImport.h
+++ b/llvm/include/llvm/Transforms/IPO/FunctionImport.h
@@ -105,8 +105,10 @@ class FunctionImporter {
std::function<Expected<std::unique_ptr<Module>>(StringRef Identifier)>;
/// Create a Function Importer.
- FunctionImporter(const ModuleSummaryIndex &Index, ModuleLoaderTy ModuleLoader)
- : Index(Index), ModuleLoader(std::move(ModuleLoader)) {}
+ FunctionImporter(const ModuleSummaryIndex &Index, ModuleLoaderTy ModuleLoader,
+ bool ClearDSOLocalOnDeclarations)
+ : Index(Index), ModuleLoader(std::move(ModuleLoader)),
+ ClearDSOLocalOnDeclarations(ClearDSOLocalOnDeclarations) {}
/// Import functions in Module \p M based on the supplied import list.
Expected<bool> importFunctions(Module &M, const ImportMapTy &ImportList);
@@ -117,6 +119,10 @@ class FunctionImporter {
/// Factory function to load a Module for a given identifier
ModuleLoaderTy ModuleLoader;
+
+ /// See the comment of ClearDSOLocalOnDeclarations in
+ /// Utils/FunctionImportUtils.h.
+ bool ClearDSOLocalOnDeclarations;
};
/// The function importing pass
diff --git a/llvm/include/llvm/Transforms/Utils/FunctionImportUtils.h b/llvm/include/llvm/Transforms/Utils/FunctionImportUtils.h
index 2c6c3adc8dad..acdd8fffa1c1 100644
--- a/llvm/include/llvm/Transforms/Utils/FunctionImportUtils.h
+++ b/llvm/include/llvm/Transforms/Utils/FunctionImportUtils.h
@@ -39,6 +39,19 @@ class FunctionImportGlobalProcessing {
/// as part of a
diff erent backend compilation process.
bool HasExportedFunctions = false;
+ /// Set to true (only applicatable to ELF -fpic) if dso_local should be
+ /// dropped for a declaration.
+ ///
+ /// On ELF, the assembler is conservative and assumes a global default
+ /// visibility symbol can be interposable. No direct access relocation is
+ /// allowed, if the definition is not in the translation unit, even if the
+ /// definition is available in the linkage unit. Thus we need to clear
+ /// dso_local to disable direct access.
+ ///
+ /// This flag should not be set for -fno-pic or -fpie, which would
+ /// unnecessarily disable direct access.
+ bool ClearDSOLocalOnDeclarations;
+
/// Set of llvm.*used values, in order to validate that we don't try
/// to promote any non-renamable values.
SmallPtrSet<GlobalValue *, 8> Used;
@@ -85,10 +98,11 @@ class FunctionImportGlobalProcessing {
GlobalValue::LinkageTypes getLinkage(const GlobalValue *SGV, bool DoPromote);
public:
- FunctionImportGlobalProcessing(
- Module &M, const ModuleSummaryIndex &Index,
- SetVector<GlobalValue *> *GlobalsToImport = nullptr)
- : M(M), ImportIndex(Index), GlobalsToImport(GlobalsToImport) {
+ FunctionImportGlobalProcessing(Module &M, const ModuleSummaryIndex &Index,
+ SetVector<GlobalValue *> *GlobalsToImport,
+ bool ClearDSOLocalOnDeclarations)
+ : M(M), ImportIndex(Index), GlobalsToImport(GlobalsToImport),
+ ClearDSOLocalOnDeclarations(ClearDSOLocalOnDeclarations) {
// If we have a ModuleSummaryIndex but no function to import,
// then this is the primary module being compiled in a ThinLTO
// backend compilation, and we need to see if it has functions that
@@ -111,6 +125,7 @@ class FunctionImportGlobalProcessing {
/// exported local functions renamed and promoted for ThinLTO.
bool renameModuleForThinLTO(
Module &M, const ModuleSummaryIndex &Index,
+ bool ClearDSOLocalOnDeclarations,
SetVector<GlobalValue *> *GlobalsToImport = nullptr);
/// Compute synthetic function entry counts.
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index b749909d7871..dbd6f8c67557 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -521,7 +521,13 @@ Error lto::thinBackend(const Config &Conf, unsigned Task, AddStreamFn AddStream,
if (Conf.PreOptModuleHook && !Conf.PreOptModuleHook(Task, Mod))
return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile));
- renameModuleForThinLTO(Mod, CombinedIndex);
+ // When linking an ELF shared object, dso_local should be dropped. We
+ // conservatively do this for -fpic.
+ bool ClearDSOLocalOnDeclarations =
+ TM->getTargetTriple().isOSBinFormatELF() &&
+ TM->getRelocationModel() != Reloc::Static &&
+ Mod.getPIELevel() == PIELevel::Default;
+ renameModuleForThinLTO(Mod, CombinedIndex, ClearDSOLocalOnDeclarations);
dropDeadSymbols(Mod, DefinedGlobals, CombinedIndex);
@@ -547,7 +553,8 @@ Error lto::thinBackend(const Config &Conf, unsigned Task, AddStreamFn AddStream,
/*IsImporting*/ true);
};
- FunctionImporter Importer(CombinedIndex, ModuleLoader);
+ FunctionImporter Importer(CombinedIndex, ModuleLoader,
+ ClearDSOLocalOnDeclarations);
if (Error Err = Importer.importFunctions(Mod, ImportList).takeError())
return Err;
diff --git a/llvm/lib/LTO/ThinLTOCodeGenerator.cpp b/llvm/lib/LTO/ThinLTOCodeGenerator.cpp
index 0346954c7a0a..3d8d48d7d73f 100644
--- a/llvm/lib/LTO/ThinLTOCodeGenerator.cpp
+++ b/llvm/lib/LTO/ThinLTOCodeGenerator.cpp
@@ -152,8 +152,9 @@ generateModuleMap(std::vector<std::unique_ptr<lto::InputFile>> &Modules) {
return ModuleMap;
}
-static void promoteModule(Module &TheModule, const ModuleSummaryIndex &Index) {
- if (renameModuleForThinLTO(TheModule, Index))
+static void promoteModule(Module &TheModule, const ModuleSummaryIndex &Index,
+ bool ClearDSOLocalOnDeclarations) {
+ if (renameModuleForThinLTO(TheModule, Index, ClearDSOLocalOnDeclarations))
report_fatal_error("renameModuleForThinLTO failed");
}
@@ -205,15 +206,16 @@ static std::unique_ptr<Module> loadModuleFromInput(lto::InputFile *Input,
static void
crossImportIntoModule(Module &TheModule, const ModuleSummaryIndex &Index,
- StringMap<lto::InputFile*> &ModuleMap,
- const FunctionImporter::ImportMapTy &ImportList) {
+ StringMap<lto::InputFile *> &ModuleMap,
+ const FunctionImporter::ImportMapTy &ImportList,
+ bool ClearDSOLocalOnDeclarations) {
auto Loader = [&](StringRef Identifier) {
auto &Input = ModuleMap[Identifier];
return loadModuleFromInput(Input, TheModule.getContext(),
/*Lazy=*/true, /*IsImporting*/ true);
};
- FunctionImporter Importer(Index, Loader);
+ FunctionImporter Importer(Index, Loader, ClearDSOLocalOnDeclarations);
Expected<bool> Result = Importer.importFunctions(TheModule, ImportList);
if (!Result) {
handleAllErrors(Result.takeError(), [&](ErrorInfoBase &EIB) {
@@ -411,8 +413,15 @@ ProcessThinLTOModule(Module &TheModule, ModuleSummaryIndex &Index,
// "Benchmark"-like optimization: single-source case
bool SingleModule = (ModuleMap.size() == 1);
+ // When linking an ELF shared object, dso_local should be dropped. We
+ // conservatively do this for -fpic.
+ bool ClearDSOLocalOnDeclarations =
+ TM.getTargetTriple().isOSBinFormatELF() &&
+ TM.getRelocationModel() != Reloc::Static &&
+ TheModule.getPIELevel() == PIELevel::Default;
+
if (!SingleModule) {
- promoteModule(TheModule, Index);
+ promoteModule(TheModule, Index, ClearDSOLocalOnDeclarations);
// Apply summary-based prevailing-symbol resolution decisions.
thinLTOResolvePrevailingInModule(TheModule, DefinedGlobals);
@@ -432,7 +441,8 @@ ProcessThinLTOModule(Module &TheModule, ModuleSummaryIndex &Index,
saveTempBitcode(TheModule, SaveTempsDir, count, ".2.internalized.bc");
if (!SingleModule) {
- crossImportIntoModule(TheModule, Index, ModuleMap, ImportList);
+ crossImportIntoModule(TheModule, Index, ModuleMap, ImportList,
+ ClearDSOLocalOnDeclarations);
// Save temps: after cross-module import.
saveTempBitcode(TheModule, SaveTempsDir, count, ".3.imported.bc");
@@ -673,7 +683,8 @@ void ThinLTOCodeGenerator::promote(Module &TheModule, ModuleSummaryIndex &Index,
Index, IsExported(ExportLists, GUIDPreservedSymbols),
IsPrevailing(PrevailingCopy));
- promoteModule(TheModule, Index);
+ // FIXME Set ClearDSOLocalOnDeclarations.
+ promoteModule(TheModule, Index, /*ClearDSOLocalOnDeclarations=*/false);
}
/**
@@ -705,7 +716,9 @@ void ThinLTOCodeGenerator::crossModuleImport(Module &TheModule,
ExportLists);
auto &ImportList = ImportLists[TheModule.getModuleIdentifier()];
- crossImportIntoModule(TheModule, Index, ModuleMap, ImportList);
+ // FIXME Set ClearDSOLocalOnDeclarations.
+ crossImportIntoModule(TheModule, Index, ModuleMap, ImportList,
+ /*ClearDSOLocalOnDeclarations=*/false);
}
/**
@@ -832,7 +845,8 @@ void ThinLTOCodeGenerator::internalize(Module &TheModule,
Index, IsExported(ExportLists, GUIDPreservedSymbols),
IsPrevailing(PrevailingCopy));
- promoteModule(TheModule, Index);
+ // FIXME Set ClearDSOLocalOnDeclarations.
+ promoteModule(TheModule, Index, /*ClearDSOLocalOnDeclarations=*/false);
// Internalization
thinLTOResolvePrevailingInModule(
diff --git a/llvm/lib/Transforms/IPO/FunctionImport.cpp b/llvm/lib/Transforms/IPO/FunctionImport.cpp
index 792c14d49b7c..2ebd5cbd124a 100644
--- a/llvm/lib/Transforms/IPO/FunctionImport.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionImport.cpp
@@ -1233,7 +1233,8 @@ Expected<bool> FunctionImporter::importFunctions(
UpgradeDebugInfo(*SrcModule);
// Link in the specified functions.
- if (renameModuleForThinLTO(*SrcModule, Index, &GlobalsToImport))
+ if (renameModuleForThinLTO(*SrcModule, Index, ClearDSOLocalOnDeclarations,
+ &GlobalsToImport))
return true;
if (PrintImports) {
@@ -1302,7 +1303,8 @@ static bool doImportingForModule(Module &M) {
// Next we need to promote to global scope and rename any local values that
// are potentially exported to other modules.
- if (renameModuleForThinLTO(M, *Index, nullptr)) {
+ if (renameModuleForThinLTO(M, *Index, /*clearDSOOnDeclarations=*/false,
+ /*GlobalsToImport=*/nullptr)) {
errs() << "Error renaming module\n";
return false;
}
@@ -1311,7 +1313,8 @@ static bool doImportingForModule(Module &M) {
auto ModuleLoader = [&M](StringRef Identifier) {
return loadFile(std::string(Identifier), M.getContext());
};
- FunctionImporter Importer(*Index, ModuleLoader);
+ FunctionImporter Importer(*Index, ModuleLoader,
+ /*ClearDSOLocalOnDeclarations=*/false);
Expected<bool> Result = Importer.importFunctions(M, ImportList);
// FIXME: Probably need to propagate Errors through the pass manager.
diff --git a/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp b/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp
index 26d48ee0d23f..8df7ae9563d8 100644
--- a/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp
+++ b/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp
@@ -212,13 +212,6 @@ void FunctionImportGlobalProcessing::processGlobalForThinLTO(GlobalValue &GV) {
}
}
}
- // Check the summaries to see if the symbol gets resolved to a known local
- // definition.
- if (VI && VI.isDSOLocal()) {
- GV.setDSOLocal(true);
- if (GV.hasDLLImportStorageClass())
- GV.setDLLStorageClass(GlobalValue::DefaultStorageClass);
- }
}
// We should always have a ValueInfo (i.e. GV in index) for definitions when
@@ -280,6 +273,20 @@ void FunctionImportGlobalProcessing::processGlobalForThinLTO(GlobalValue &GV) {
} else
GV.setLinkage(getLinkage(&GV, /* DoPromote */ false));
+ // When ClearDSOLocalOnDeclarations is true, clear dso_local if GV is
+ // converted to a declaration, to disable direct access. Don't do this if GV
+ // is implicitly dso_local due to a non-default visibility.
+ if (ClearDSOLocalOnDeclarations && GV.isDeclarationForLinker() &&
+ !GV.isImplicitDSOLocal()) {
+ GV.setDSOLocal(false);
+ } else if (VI && VI.isDSOLocal()) {
+ // If all summaries are dso_local, symbol gets resolved to a known local
+ // definition.
+ GV.setDSOLocal(true);
+ if (GV.hasDLLImportStorageClass())
+ GV.setDLLStorageClass(GlobalValue::DefaultStorageClass);
+ }
+
// Remove functions imported as available externally defs from comdats,
// as this is a declaration for the linker, and will be dropped eventually.
// It is illegal for comdats to contain declarations.
@@ -319,7 +326,9 @@ bool FunctionImportGlobalProcessing::run() {
}
bool llvm::renameModuleForThinLTO(Module &M, const ModuleSummaryIndex &Index,
+ bool ClearDSOLocalOnDeclarations,
SetVector<GlobalValue *> *GlobalsToImport) {
- FunctionImportGlobalProcessing ThinLTOProcessing(M, Index, GlobalsToImport);
+ FunctionImportGlobalProcessing ThinLTOProcessing(M, Index, GlobalsToImport,
+ ClearDSOLocalOnDeclarations);
return ThinLTOProcessing.run();
}
diff --git a/llvm/test/LTO/Resolution/X86/local-def-dllimport.ll b/llvm/test/LTO/Resolution/X86/local-def-dllimport.ll
index 4c70e72803e6..25b69b737362 100644
--- a/llvm/test/LTO/Resolution/X86/local-def-dllimport.ll
+++ b/llvm/test/LTO/Resolution/X86/local-def-dllimport.ll
@@ -13,9 +13,7 @@ target triple = "x86_64-unknown-linux-gnu"
$g = comdat any
@g = global i8 42, comdat, !type !0
-; CHECK: define
-; CHECK-NOT: dllimport
-; CHECK-SAME: @f
+; CHECK: define available_externally dllimport i8* @f()
define available_externally dllimport i8* @f() {
ret i8* @g
}
diff --git a/llvm/test/ThinLTO/X86/Inputs/index-const-prop-gvref.ll b/llvm/test/ThinLTO/X86/Inputs/index-const-prop-gvref.ll
index 53020763dffc..28a58b306af5 100644
--- a/llvm/test/ThinLTO/X86/Inputs/index-const-prop-gvref.ll
+++ b/llvm/test/ThinLTO/X86/Inputs/index-const-prop-gvref.ll
@@ -1,5 +1,5 @@
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
- at b = global i32* @a, align 8
- at a = global i32 42, align 4
+ at b = dso_local global i32* @a, align 8
+ at a = dso_local global i32 42, align 4
diff --git a/llvm/test/ThinLTO/X86/funcimport_alwaysinline.ll b/llvm/test/ThinLTO/X86/funcimport_alwaysinline.ll
index aa4947602f78..c43c1d5df300 100644
--- a/llvm/test/ThinLTO/X86/funcimport_alwaysinline.ll
+++ b/llvm/test/ThinLTO/X86/funcimport_alwaysinline.ll
@@ -11,7 +11,7 @@
; foo() being always_inline should be imported irrespective of the
; instruction limit
-; CHECK1: define available_externally dso_local void @foo()
+; CHECK1: define available_externally void @foo()
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
diff --git a/llvm/test/ThinLTO/X86/index-const-prop-alias.ll b/llvm/test/ThinLTO/X86/index-const-prop-alias.ll
index bd15b5a6204c..4a1e68f46f05 100644
--- a/llvm/test/ThinLTO/X86/index-const-prop-alias.ll
+++ b/llvm/test/ThinLTO/X86/index-const-prop-alias.ll
@@ -16,15 +16,15 @@
; RUN: llvm-dis %t5.1.3.import.bc -o - | FileCheck %s --check-prefix=PRESERVED
; We currently don't support importing aliases
-; IMPORT: @g.alias = external dso_local global i32
+; IMPORT: @g.alias = external global i32
; IMPORT-NEXT: @g = internal global i32 42, align 4 #0
; IMPORT: attributes #0 = { "thinlto-internalize" }
; CODEGEN: define dso_local i32 @main
; CODEGEN-NEXT: ret i32 42
-; PRESERVED: @g.alias = external dso_local global i32
-; PRESERVED-NEXT: @g = available_externally dso_local global i32 42, align 4
+; PRESERVED: @g.alias = external global i32
+; PRESERVED-NEXT: @g = available_externally global i32 42, align 4
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
diff --git a/llvm/test/ThinLTO/X86/index-const-prop-comdat.ll b/llvm/test/ThinLTO/X86/index-const-prop-comdat.ll
index 2fdc793b3c2d..d90bcbacba96 100644
--- a/llvm/test/ThinLTO/X86/index-const-prop-comdat.ll
+++ b/llvm/test/ThinLTO/X86/index-const-prop-comdat.ll
@@ -4,7 +4,7 @@
; RUN: llvm-dis %t3.2.3.import.bc -o - | FileCheck %s
; Comdats are not internalized even if they are read only.
-; CHECK: @g = available_externally dso_local global i32 42
+; CHECK: @g = available_externally global i32 42
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
diff --git a/llvm/test/ThinLTO/X86/index-const-prop-dead.ll b/llvm/test/ThinLTO/X86/index-const-prop-dead.ll
index 44fc350e909d..6766a5ee7104 100644
--- a/llvm/test/ThinLTO/X86/index-const-prop-dead.ll
+++ b/llvm/test/ThinLTO/X86/index-const-prop-dead.ll
@@ -6,7 +6,7 @@
; Dead globals are converted to declarations by ThinLTO in dropDeadSymbols
; If we try to internalize such we'll get a broken module.
-; CHECK: @g = external dso_local global i32
+; CHECK: @g = external global i32
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
diff --git a/llvm/test/ThinLTO/X86/index-const-prop-full-lto.ll b/llvm/test/ThinLTO/X86/index-const-prop-full-lto.ll
index f6260c535ed5..0b9412a576f6 100644
--- a/llvm/test/ThinLTO/X86/index-const-prop-full-lto.ll
+++ b/llvm/test/ThinLTO/X86/index-const-prop-full-lto.ll
@@ -8,7 +8,7 @@
; All references from functions in full LTO module are not constant.
; We cannot internalize @g
-; CHECK: @g = available_externally dso_local global i32 42
+; CHECK: @g = available_externally global i32 42
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
diff --git a/llvm/test/ThinLTO/X86/index-const-prop-gvref-pie.ll b/llvm/test/ThinLTO/X86/index-const-prop-gvref-pie.ll
new file mode 100644
index 000000000000..62c4164594c3
--- /dev/null
+++ b/llvm/test/ThinLTO/X86/index-const-prop-gvref-pie.ll
@@ -0,0 +1,28 @@
+;; The same as index-const-prop-gvref.ll, except for PIE.
+; RUN: opt -module-summary %s -o %t1.bc
+; RUN: opt -module-summary %p/Inputs/index-const-prop-gvref.ll -o %t2.bc
+; RUN: llvm-lto2 run -save-temps %t2.bc -r=%t2.bc,b,pl -r=%t2.bc,a,pl \
+; RUN: %t1.bc -r=%t1.bc,main,plx -r=%t1.bc,a, -r=%t1.bc,b, -o %t3
+; RUN: llvm-dis %t3.2.3.import.bc -o - | FileCheck %s --check-prefix=DEST
+
+;; For PIE, keep dso_local for declarations to enable direct access.
+; DEST: @b = external dso_local global i32*
+; DEST-NEXT: @a = available_externally dso_local global i32 42, align 4
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+ at a = external global i32
+ at b = external global i32*
+
+define i32 @main() {
+ %p = load i32*, i32** @b, align 8
+ store i32 33, i32* %p, align 4
+ %v = load i32, i32* @a, align 4
+ ret i32 %v
+}
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 7, !"PIE Level", i32 2}
+!1 = !{i32 7, !"PIC Level", i32 2}
diff --git a/llvm/test/ThinLTO/X86/index-const-prop-gvref.ll b/llvm/test/ThinLTO/X86/index-const-prop-gvref.ll
index 972283774b8c..293eb1dc33a6 100644
--- a/llvm/test/ThinLTO/X86/index-const-prop-gvref.ll
+++ b/llvm/test/ThinLTO/X86/index-const-prop-gvref.ll
@@ -1,17 +1,41 @@
; RUN: opt -module-summary %s -o %t1.bc
; RUN: opt -module-summary %p/Inputs/index-const-prop-gvref.ll -o %t2.bc
-; RUN: llvm-lto2 run -save-temps %t2.bc -r=%t2.bc,b,pl -r=%t2.bc,a,pl \
-; RUN: %t1.bc -r=%t1.bc,main,plx -r=%t1.bc,a, -r=%t1.bc,b, -o %t3
+; RUN: llvm-lto2 run -relocation-model=static -save-temps %t2.bc -r=%t2.bc,b,pl -r=%t2.bc,a,pl \
+; RUN: %t1.bc -r=%t1.bc,main,plx -r=%t1.bc,a, -r=%t1.bc,b, -o %t3
; RUN: llvm-dis %t3.1.3.import.bc -o - | FileCheck %s --check-prefix=SRC
; RUN: llvm-dis %t3.2.3.import.bc -o - | FileCheck %s --check-prefix=DEST
+;; When producing an ELF DSO, clear dso_local for declarations to avoid direct access.
+; RUN: llvm-lto2 run -relocation-model=pic -save-temps %t2.bc -r=%t2.bc,b,pl -r=%t2.bc,a,pl \
+; RUN: %t1.bc -r=%t1.bc,main,plx -r=%t1.bc,a, -r=%t1.bc,b, -o %t4
+; RUN: llvm-dis %t4.1.3.import.bc -o - | FileCheck %s --check-prefix=SRC
+; RUN: llvm-dis %t4.2.3.import.bc -o - | FileCheck %s --check-prefix=DEST_DSO
+
; No variable in the source module should have been internalized
; SRC: @b = dso_local global i32* @a
; SRC-NEXT: @a = dso_local global i32 42
; We can't internalize globals referenced by other live globals
-; DEST: @b = external dso_local global i32*
-; DEST-NEXT: @a = available_externally dso_local global i32 42, align 4
+; DEST: @b = external dso_local global i32*
+; DEST-NEXT: @a = available_externally dso_local global i32 42, align 4
+; DEST_DSO: @b = external global i32*
+; DEST_DSO-NEXT: @a = available_externally global i32 42, align 4
+
+;; Test old API.
+;; When producing an ELF DSO, clear dso_local for declarations to avoid direct access.
+; RUN: llvm-lto -thinlto-action=run %t2.bc %t1.bc -relocation-model=static -thinlto-save-temps=%t5.
+; RUN: llvm-dis < %t5.0.3.imported.bc | FileCheck %s --check-prefix=OLDAPI_SRC
+; RUN: llvm-dis < %t5.1.3.imported.bc | FileCheck %s --check-prefix=OLDAPI_DST
+; RUN: llvm-lto -thinlto-action=run %t2.bc %t1.bc -relocation-model=pic -thinlto-save-temps=%t6.
+; RUN: llvm-dis < %t6.0.3.imported.bc | FileCheck %s --check-prefix=OLDAPI_SRC
+; RUN: llvm-dis < %t6.1.3.imported.bc | FileCheck %s --check-prefix=OLDAPI_DST_DSO
+
+; OLDAPI_SRC: @b = internal global i32* @a, align 8
+; OLDAPI_SRC-NEXT: @a = dso_local global i32 42, align 4
+; OLDAPI_DST: @b = external dso_local global i32*
+; OLDAPI_DST-NEXT: @a = available_externally dso_local global i32 42, align 4
+; OLDAPI_DST_DSO: @b = external global i32*
+; OLDAPI_DST_DSO-NEXT: @a = available_externally global i32 42, align 4
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
diff --git a/llvm/test/ThinLTO/X86/index-const-prop-ldst.ll b/llvm/test/ThinLTO/X86/index-const-prop-ldst.ll
index 3c6d03cb75da..7c0f8229a7d0 100644
--- a/llvm/test/ThinLTO/X86/index-const-prop-ldst.ll
+++ b/llvm/test/ThinLTO/X86/index-const-prop-ldst.ll
@@ -5,7 +5,7 @@
; The 'store' instruction in @main should prevent internalization
; even when there is 'load' instruction before it.
-; CHECK: @g = available_externally dso_local global i32 42
+; CHECK: @g = available_externally global i32 42
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
diff --git a/llvm/test/ThinLTO/X86/index-const-prop-linkage.ll b/llvm/test/ThinLTO/X86/index-const-prop-linkage.ll
index 2c7c794379fa..9eb85da92698 100644
--- a/llvm/test/ThinLTO/X86/index-const-prop-linkage.ll
+++ b/llvm/test/ThinLTO/X86/index-const-prop-linkage.ll
@@ -11,7 +11,7 @@
; - reference from @llvm.used
; CHECK: @llvm.used = appending global [1 x i32*] [i32* @g2]
; CHECK-NEXT: @g1 = external dso_local global i32, align 4
-; CHECK-NEXT: @g2 = available_externally dso_local global i32 42, align 4
+; CHECK-NEXT: @g2 = available_externally global i32 42, align 4
; CHECK-NEXT: @g3 = available_externally global i32 42, align 4
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
diff --git a/llvm/test/ThinLTO/X86/index-const-prop2.ll b/llvm/test/ThinLTO/X86/index-const-prop2.ll
index 928d00adc9a2..5bf40fc688d5 100644
--- a/llvm/test/ThinLTO/X86/index-const-prop2.ll
+++ b/llvm/test/ThinLTO/X86/index-const-prop2.ll
@@ -68,7 +68,7 @@
; CODEGEN: i32 @main()
; CODEGEN-NEXT: ret i32 3
-; IMPORT2: @gBar = available_externally dso_local local_unnamed_addr global i32 2, align 4
+; IMPORT2: @gBar = available_externally local_unnamed_addr global i32 2, align 4
; CODEGEN2: i32 @main2
; CODEGEN2-NEXT: %1 = tail call i32 @rand()
diff --git a/llvm/tools/llvm-link/llvm-link.cpp b/llvm/tools/llvm-link/llvm-link.cpp
index d0c2b4555b92..d99659f3d50a 100644
--- a/llvm/tools/llvm-link/llvm-link.cpp
+++ b/llvm/tools/llvm-link/llvm-link.cpp
@@ -266,7 +266,8 @@ static bool importFunctions(const char *argv0, Module &DestModule) {
auto CachedModuleLoader = [&](StringRef Identifier) {
return ModuleLoaderCache.takeModule(std::string(Identifier));
};
- FunctionImporter Importer(*Index, CachedModuleLoader);
+ FunctionImporter Importer(*Index, CachedModuleLoader,
+ /*ClearDSOLocalOnDeclarations=*/false);
ExitOnErr(Importer.importFunctions(DestModule, ImportList));
return true;
@@ -313,7 +314,8 @@ static bool linkFiles(const char *argv0, LLVMContext &Context, Linker &L,
}
// Promotion
- if (renameModuleForThinLTO(*M, *Index))
+ if (renameModuleForThinLTO(*M, *Index,
+ /*ClearDSOLocalOnDeclarations=*/false))
return true;
}
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