| commit 252a1eecc04080d852ba58c6727970c688eb1619 |
| Author: Fangrui Song <i@maskray.me> |
| Date: Fri Jul 2 17:08:25 2021 -0700 |
| |
| [ThinLTO] Respect ClearDSOLocalOnDeclarations for unimported functions |
| |
| D74751 added `ClearDSOLocalOnDeclarations` and dropped dso_local for |
| isDeclarationForLinker `GlobalValue`s. It missed a case for imported |
| declarations (`doImportAsDefinition` is false while `isPerformingImport` is |
| true). This can lead to a linker error for a default visibility symbol in |
| `ld.lld -shared`. |
| |
| When `ClearDSOLocalOnDeclarations` is true, we check |
| `isPerformingImport() && !doImportAsDefinition(&GV)` along with |
| `GV.isDeclarationForLinker()`. The new condition checks an imported declaration. |
| |
| This patch fixes a `LLVMPolly.so` link error using a trunk clang -DLLVM_ENABLE_LTO=Thin. |
| |
| Reviewed By: tejohnson |
| |
| Differential Revision: https://reviews.llvm.org/D104986 |
| |
| diff --git a/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp b/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp |
| index 94c97bb1264f..2946c0018c31 100644 |
| --- a/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp |
| +++ b/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp |
| @@ -276,7 +276,9 @@ void FunctionImportGlobalProcessing::processGlobalForThinLTO(GlobalValue &GV) { |
| // 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() && |
| + if (ClearDSOLocalOnDeclarations && |
| + (GV.isDeclarationForLinker() || |
| + (isPerformingImport() && !doImportAsDefinition(&GV))) && |
| !GV.isImplicitDSOLocal()) { |
| GV.setDSOLocal(false); |
| } else if (VI && VI.isDSOLocal(ImportIndex.withDSOLocalPropagation())) { |
| diff --git a/llvm/test/ThinLTO/X86/import-dsolocal.ll b/llvm/test/ThinLTO/X86/import-dsolocal.ll |
| new file mode 100644 |
| index 000000000000..11d41e70e19b |
| --- /dev/null |
| +++ b/llvm/test/ThinLTO/X86/import-dsolocal.ll |
| @@ -0,0 +1,124 @@ |
| +; RUN: split-file %s %t |
| +; RUN: opt -module-summary %t/a.ll -o %t/a.bc |
| +; RUN: opt -module-summary %t/b.ll -o %t/b.bc |
| + |
| +;; With a small limit, *_aux are either imported declarations (external/linkonce_odr/weak_odr) |
| +;; or unimported (linkonce/weak). Check we discard dso_local. |
| +; RUN: llvm-lto2 run %t/a.bc %t/b.bc -o %t1 -save-temps -import-instr-limit=3 \ |
| +; RUN: -r=%t/a.bc,main,plx -r=%t/a.bc,extern, -r=%t/a.bc,linkonce, -r=%t/a.bc,linkonceodr, -r=%t/a.bc,weak, -r=%t/a.bc,weakodr, \ |
| +; RUN: -r=%t/b.bc,a,pl -r=%t/b.bc,b,pl -r=%t/b.bc,extern,pl -r=%t/b.bc,extern_aux,pl \ |
| +; RUN: -r=%t/b.bc,linkonce,pl -r=%t/b.bc,linkonce_aux,pl -r=%t/b.bc,linkonceodr,pl -r=%t/b.bc,linkonceodr_aux,pl \ |
| +; RUN: -r=%t/b.bc,weak,pl -r=%t/b.bc,weak_aux,pl -r=%t/b.bc,weakodr,pl -r=%t/b.bc,weakodr_aux,pl |
| +; RUN: llvm-dis %t1.1.3.import.bc -o - | FileCheck %s --check-prefixes=DEST,DEST1 |
| + |
| +;; With a large limit, *_aux are either imported definitions (external/linkonce_odr/weak_odr) |
| +;; or unimported (linkonce/weak). Check we discard dso_local as well. |
| +; RUN: llvm-lto2 run %t/a.bc %t/b.bc -o %t2 -save-temps -import-instr-limit=10 \ |
| +; RUN: -r=%t/a.bc,main,plx -r=%t/a.bc,extern, -r=%t/a.bc,linkonce, -r=%t/a.bc,linkonceodr, -r=%t/a.bc,weak, -r=%t/a.bc,weakodr, \ |
| +; RUN: -r=%t/b.bc,a,pl -r=%t/b.bc,b,pl -r=%t/b.bc,extern,pl -r=%t/b.bc,extern_aux,pl \ |
| +; RUN: -r=%t/b.bc,linkonce,pl -r=%t/b.bc,linkonce_aux,pl -r=%t/b.bc,linkonceodr,pl -r=%t/b.bc,linkonceodr_aux,pl \ |
| +; RUN: -r=%t/b.bc,weak,pl -r=%t/b.bc,weak_aux,pl -r=%t/b.bc,weakodr,pl -r=%t/b.bc,weakodr_aux,pl |
| +; RUN: llvm-dis %t2.1.3.import.bc -o - | FileCheck %s --check-prefixes=DEST,DEST2 |
| + |
| +; DEST: @a = available_externally global i32 42, align 4 |
| +; DEST-NEXT: @b = external global i32*, align 8 |
| +; DEST: declare void @linkonce() |
| +; DEST: declare void @weak() |
| +; DEST: define dso_local i32 @main() |
| +; DEST: define available_externally void @extern() |
| + |
| +; DEST1: declare i32 @extern_aux(i32*, i32**) |
| +; DEST1: declare i32 @linkonceodr_aux(i32*, i32**) |
| +; DEST2: define available_externally i32 @extern_aux(i32* %a, i32** %b) |
| +; DEST2: define available_externally i32 @linkonceodr_aux(i32* %a, i32** %b) |
| + |
| +; DEST: define available_externally void @weakodr() |
| + |
| +; DEST1: declare i32 @weakodr_aux(i32*, i32**) |
| +; DEST2: define available_externally i32 @weakodr_aux(i32* %a, i32** %b) |
| + |
| +;--- a.ll |
| +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" |
| + |
| +declare void @extern() |
| +declare void @linkonce() |
| +declare void @linkonceodr() |
| +declare void @weak() |
| +declare void @weakodr() |
| + |
| +define i32 @main() { |
| + call void @extern() |
| + call void @linkonce() |
| + call void @linkonceodr() |
| + call void @weak() |
| + call void @weakodr() |
| + ret i32 0 |
| +} |
| + |
| +;--- b.ll |
| +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" |
| + |
| +@a = dso_local global i32 42, align 4 |
| +@b = dso_local global i32* @a, align 8 |
| + |
| +define dso_local void @extern() { |
| + call i32 @extern_aux(i32* @a, i32** @b) |
| + ret void |
| +} |
| + |
| +define dso_local i32 @extern_aux(i32* %a, i32** %b) { |
| + %p = load i32*, i32** %b, align 8 |
| + store i32 33, i32* %p, align 4 |
| + %v = load i32, i32* %a, align 4 |
| + ret i32 %v |
| +} |
| + |
| +define linkonce dso_local void @linkonce() { |
| + call i32 @linkonce_aux(i32* @a, i32** @b) |
| + ret void |
| +} |
| + |
| +define linkonce i32 @linkonce_aux(i32* %a, i32** %b) { |
| + %p = load i32*, i32** %b, align 8 |
| + store i32 33, i32* %p, align 4 |
| + %v = load i32, i32* %a, align 4 |
| + ret i32 %v |
| +} |
| + |
| +define linkonce_odr dso_local void @linkonceodr() { |
| + call i32 @linkonceodr_aux(i32* @a, i32** @b) |
| + ret void |
| +} |
| + |
| +define linkonce_odr i32 @linkonceodr_aux(i32* %a, i32** %b) { |
| + %p = load i32*, i32** %b, align 8 |
| + store i32 33, i32* %p, align 4 |
| + %v = load i32, i32* %a, align 4 |
| + ret i32 %v |
| +} |
| + |
| +define weak dso_local void @weak() { |
| + call i32 @weak_aux(i32* @a, i32** @b) |
| + ret void |
| +} |
| + |
| +define weak i32 @weak_aux(i32* %a, i32** %b) { |
| + %p = load i32*, i32** %b, align 8 |
| + store i32 33, i32* %p, align 4 |
| + %v = load i32, i32* %a, align 4 |
| + ret i32 %v |
| +} |
| + |
| +define weak_odr dso_local void @weakodr() { |
| + call i32 @weakodr_aux(i32* @a, i32** @b) |
| + ret void |
| +} |
| + |
| +define weak_odr i32 @weakodr_aux(i32* %a, i32** %b) { |
| + %p = load i32*, i32** %b, align 8 |
| + store i32 33, i32* %p, align 4 |
| + %v = load i32, i32* %a, align 4 |
| + ret i32 %v |
| +} |
| diff --git a/llvm/test/ThinLTO/X86/index-const-prop-linkage.ll b/llvm/test/ThinLTO/X86/index-const-prop-linkage.ll |
| index 9eb85da92698..80f3f11e2c54 100644 |
| --- a/llvm/test/ThinLTO/X86/index-const-prop-linkage.ll |
| +++ b/llvm/test/ThinLTO/X86/index-const-prop-linkage.ll |
| @@ -10,7 +10,7 @@ |
| ; - available_externally linkage |
| ; - 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: @g1 = external global i32, align 4 |
| ; CHECK-NEXT: @g2 = available_externally global i32 42, align 4 |
| ; CHECK-NEXT: @g3 = available_externally global i32 42, align 4 |
| |