From d4228eb0774a94536c1b47ee4e331586f23b2a8a Mon Sep 17 00:00:00 2001 From: Paul Kirth Date: Mon, 20 May 2024 14:45:11 -0700 Subject: [PATCH 1/2] =?UTF-8?q?[=F0=9D=98=80=F0=9D=97=BD=F0=9D=97=BF]=20ch?= =?UTF-8?q?anges=20to=20main=20this=20commit=20is=20based=20on?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Created using spr 1.3.4 [skip ci] --- lld/test/ELF/fatlto/fatlto.test | 41 +++++++++++++++++++ .../CodeGen/TargetLoweringObjectFileImpl.cpp | 3 ++ llvm/test/CodeGen/X86/fat-lto-section.ll | 2 +- 3 files changed, 45 insertions(+), 1 deletion(-) diff --git a/lld/test/ELF/fatlto/fatlto.test b/lld/test/ELF/fatlto/fatlto.test index edf4ef2da2b88..e250325dc54f4 100644 --- a/lld/test/ELF/fatlto/fatlto.test +++ b/lld/test/ELF/fatlto/fatlto.test @@ -49,6 +49,25 @@ ; RUN: ld.lld -o %t/foo-fatLTO.archive %t/a.a %t/main-LTO.bc --fat-lto-objects ; RUN: cmp %t/foo-fatLTO.archive %t/foo-LTO +;; Test FatLTO works with relocatable links using PIC objects +;; Currently, with PIC relocatable links, FatLTO sections are treated as +;; orphan sections and incorrectly concatenated together. This test verifies +;; the current behavior, but should be fixed to either merge those sections +;; correctly, or to drop them altogether. +; RUN: opt < %t/a-LTO.ll -passes="embed-bitcode" | llc --relocation-model=pic --filetype=obj -o %t/a-fat-pic.o +; RUN: llvm-readobj -S %t/a-fat-pic.o | FileCheck --check-prefix=HAS_LLVM_LTO %s + +; RUN: opt < %t/b-LTO.ll -passes="embed-bitcode" | llc --relocation-model=pic --filetype=obj -o %t/b-fat-pic.o +; RUN: llvm-readobj -S %t/b-fat-pic.o | FileCheck --check-prefix=HAS_LLVM_LTO %s + +; RUN: llvm-ar rcs %t/fat.pic.archive %t/a-fat-pic.o %t/b-fat-pic.o +; RUN: llvm-readobj -S %t/fat.pic.archive | FileCheck --check-prefix=HAS_LLVM_LTO %s + +; RUN: ld.lld --whole-archive %t/fat.pic.archive -r -o %t/fat-pic-relocatable.o +; RUN: llvm-readobj -S %t/fat-pic-relocatable.o | FileCheck --check-prefix=HAS_LLVM_LTO %s + +; HAS_LLVM_LTO: Name: .llvm.lto + ;--- a-LTO.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" @@ -71,6 +90,28 @@ attributes #0 = { noinline nounwind uwtable } !5 = !{i32 1, !"ThinLTO", i32 0} !6 = !{i32 1, !"EnableSplitLTOUnit", i32 1} +;--- b-LTO.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" + +; Function Attrs: noinline nounwind uwtable +define dso_local i32 @foo() #0 { +entry: + ret i32 0 +} + +attributes #0 = { noinline nounwind uwtable } + +!llvm.module.flags = !{!0, !1, !2, !3, !4, !5, !6} + +!0 = !{i32 1, !"wchar_size", i32 4} +!1 = !{i32 7, !"PIC Level", i32 2} +!2 = !{i32 7, !"PIE Level", i32 2} +!3 = !{i32 7, !"uwtable", i32 2} +!4 = !{i32 7, !"frame-pointer", i32 2} +!5 = !{i32 1, !"ThinLTO", i32 0} +!6 = !{i32 1, !"EnableSplitLTOUnit", i32 1} + ;--- main-LTO.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" diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp index 3e1897ce670a6..567e9443759f1 100644 --- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp +++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp @@ -527,6 +527,9 @@ static unsigned getELFSectionType(StringRef Name, SectionKind K) { if (K.isBSS() || K.isThreadBSS()) return ELF::SHT_NOBITS; + if(hasPrefix(Name, ".llvm.lto")) + return ELF::SHT_LLVM_LTO; + return ELF::SHT_PROGBITS; } diff --git a/llvm/test/CodeGen/X86/fat-lto-section.ll b/llvm/test/CodeGen/X86/fat-lto-section.ll index 30c56229a0e2a..f3ca8436affb4 100644 --- a/llvm/test/CodeGen/X86/fat-lto-section.ll +++ b/llvm/test/CodeGen/X86/fat-lto-section.ll @@ -5,6 +5,6 @@ ; RUN: | FileCheck %s --check-prefix=EXCLUDE ; EXCLUDE: Name Type {{.*}} ES Flg Lk Inf Al -; EXCLUDE: .llvm.lto PROGBITS {{.*}} 00 E 0 0 1 +; EXCLUDE: .llvm.lto LLVM_LTO {{.*}} 00 E 0 0 1 @a = global i32 1 From 0b9155faf2dc063f81091c8e78d14dd4446c2db5 Mon Sep 17 00:00:00 2001 From: Paul Kirth Date: Tue, 21 May 2024 09:58:46 -0700 Subject: [PATCH 2/2] Fix fallthrough and update comment Created using spr 1.3.4 --- lld/ELF/InputFiles.cpp | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp index 0ac49761601c4..33fd86b269f81 100644 --- a/lld/ELF/InputFiles.cpp +++ b/lld/ELF/InputFiles.cpp @@ -833,14 +833,15 @@ void ObjFile::initializeSections(bool ignoreComdats, createInputSection(i, sec, check(obj.getSectionName(sec, shstrtab))); break; case SHT_LLVM_LTO: - // When doing a relocatable link with FatLTO objects, if we're not using - // the bitcode, discard it, since it will be concatenated together when - // handling orphan sections, and which will be an invalid bitcode object. + // Discard .llvm.lto in a relocatable link that does not use the bitcode. + // The concatenated output does not properly reflect the linking + // semantics. In addition, since we do not use the bitcode wrapper format, + // the concatenated raw bitcode would be invalid. if (config->relocatable && !config->fatLTOObjects) { sections[i] = &InputSection::discarded; break; } - LLVM_FALLTHROUGH; + [[fallthrough]]; default: this->sections[i] = createInputSection(i, sec, check(obj.getSectionName(sec, shstrtab)));