llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-lld-elf Author: Paul Kirth (ilovepi) <details> <summary>Changes</summary> So long as ld -r links using bitcode always result in an ELF object, and not a merged bitcode object, the output form a relocatable link using FatLTO objects should not have a .llvm.lto section. Prior to this, using the object code sections would cause the bitcode section in the output of a relocatable link to be corrupted, by concatenating all the .llvm.lto sections together. This patch discards SHT_LLVM_LTO sections when not using --fat-lto-objects, so that the relocatable ELF output won't contain inalid bitcode. --- Full diff: https://github.com/llvm/llvm-project/pull/92825.diff 2 Files Affected: - (modified) lld/ELF/InputFiles.cpp (+9) - (modified) lld/test/ELF/fatlto/fatlto.test (+2-5) ``````````diff diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp index 1f496026d3ae2..0ac49761601c4 100644 --- a/lld/ELF/InputFiles.cpp +++ b/lld/ELF/InputFiles.cpp @@ -832,6 +832,15 @@ void ObjFile<ELFT>::initializeSections(bool ignoreComdats, this->sections[i] = 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. + if (config->relocatable && !config->fatLTOObjects) { + sections[i] = &InputSection::discarded; + break; + } + LLVM_FALLTHROUGH; default: this->sections[i] = createInputSection(i, sec, check(obj.getSectionName(sec, shstrtab))); diff --git a/lld/test/ELF/fatlto/fatlto.test b/lld/test/ELF/fatlto/fatlto.test index e250325dc54f4..d2c96c3c51b98 100644 --- a/lld/test/ELF/fatlto/fatlto.test +++ b/lld/test/ELF/fatlto/fatlto.test @@ -50,10 +50,6 @@ ; 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<thinlto;emit-summary>" | 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 @@ -64,9 +60,10 @@ ; 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 +; RUN: llvm-readobj -S %t/fat-pic-relocatable.o | FileCheck --check-prefix=CHECK-NON-LTO-TARGET %s ; HAS_LLVM_LTO: Name: .llvm.lto +; HAS_LLVM_LTO: Type: SHT_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" `````````` </details> https://github.com/llvm/llvm-project/pull/92825 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
