From 12b094d5f470da9f4fb16145ec3d8a7b1512ea77 Mon Sep 17 00:00:00 2001 From: Pete Cooper Date: Sat, 16 Jan 2016 01:09:23 +0000 Subject: [PATCH] Only emit files with subsections_via_symbols if all inputs had that set. When generating a relocatable file, its only valid to set this flag if all of the inputs also had the flag. Otherwise we may atomize incorrectly when we link the relocatable file again. Reviewed by Lang Hames. Differential Revision: http://reviews.llvm.org/D16018 llvm-svn: 257976 --- lld/lib/ReaderWriter/MachO/File.h | 6 ++++ .../MachO/MachONormalizedFileFromAtoms.cpp | 34 ++++++++++++++----- .../MachO/MachONormalizedFileToAtoms.cpp | 1 + lld/test/mach-o/parse-data-relocs-x86_64.yaml | 1 + 4 files changed, 33 insertions(+), 9 deletions(-) diff --git a/lld/lib/ReaderWriter/MachO/File.h b/lld/lib/ReaderWriter/MachO/File.h index c95b2da989ac..7b28590d3cab 100644 --- a/lld/lib/ReaderWriter/MachO/File.h +++ b/lld/lib/ReaderWriter/MachO/File.h @@ -197,6 +197,11 @@ public: uint32_t swiftVersion() const { return _swiftVersion; } void setSwiftVersion(uint32_t v) { _swiftVersion = v; } + bool subsectionsViaSymbols() const { + return _flags & llvm::MachO::MH_SUBSECTIONS_VIA_SYMBOLS; + } + void setFlags(normalized::FileFlags v) { _flags = v; } + /// Methods for support type inquiry through isa, cast, and dyn_cast: static inline bool classof(const File *F) { return F->kind() == File::kindMachObject; @@ -238,6 +243,7 @@ private: MachOLinkingContext::Arch _arch = MachOLinkingContext::arch_unknown; MachOLinkingContext::OS _os = MachOLinkingContext::OS::unknown; uint32_t _swiftVersion = 0; + normalized::FileFlags _flags; }; class MachODylibFile : public SharedLibraryFile { diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp index b8e462631eef..122b5405b86a 100644 --- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp +++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp @@ -105,10 +105,12 @@ class Util { public: Util(const MachOLinkingContext &ctxt) : _ctx(ctxt), _archHandler(ctxt.archHandler()), _entryAtom(nullptr), - _hasTLVDescriptors(false) {} + _hasTLVDescriptors(false), _subsectionsViaSymbols(true) {} ~Util(); - void assignAtomsToSections(const lld::File &atomFile); + void processDefinedAtoms(const lld::File &atomFile); + void processAtomAttributes(const DefinedAtom *atom); + void assignAtomToSection(const DefinedAtom *atom); void organizeSections(); void assignAddressesToSections(const NormalizedFile &file); uint32_t fileFlags(); @@ -180,6 +182,7 @@ private: AtomToIndex _atomToSymbolIndex; std::vector _machHeaderAliasAtoms; bool _hasTLVDescriptors; + bool _subsectionsViaSymbols; }; Util::~Util() { @@ -366,15 +369,28 @@ void Util::appendAtom(SectionInfo *sect, const DefinedAtom *atom) { sect->size = offset + atom->size(); } -void Util::assignAtomsToSections(const lld::File &atomFile) { +void Util::processDefinedAtoms(const lld::File &atomFile) { for (const DefinedAtom *atom : atomFile.defined()) { - if (atom->contentType() == DefinedAtom::typeMachHeader) - _machHeaderAliasAtoms.push_back(atom); - else - appendAtom(sectionForAtom(atom), atom); + processAtomAttributes(atom); + assignAtomToSection(atom); } } +void Util::processAtomAttributes(const DefinedAtom *atom) { + auto *machoFile = static_cast(&atom->file()); + // If the file doesn't use subsections via symbols, then make sure we don't + // add that flag to the final output file if we have a relocatable file. + if (!machoFile->subsectionsViaSymbols()) + _subsectionsViaSymbols = false; +} + +void Util::assignAtomToSection(const DefinedAtom *atom) { + if (atom->contentType() == DefinedAtom::typeMachHeader) + _machHeaderAliasAtoms.push_back(atom); + else + appendAtom(sectionForAtom(atom), atom); +} + SegmentInfo *Util::segmentForName(StringRef segName) { for (SegmentInfo *si : _segmentInfos) { if ( si->name.equals(segName) ) @@ -1183,7 +1199,7 @@ void Util::addExportInfo(const lld::File &atomFile, NormalizedFile &nFile) { uint32_t Util::fileFlags() { // FIXME: these need to determined at runtime. if (_ctx.outputMachOType() == MH_OBJECT) { - return MH_SUBSECTIONS_VIA_SYMBOLS; + return _subsectionsViaSymbols ? MH_SUBSECTIONS_VIA_SYMBOLS : 0; } else { uint32_t flags = MH_DYLDLINK; if (!_ctx.useFlatNamespace()) @@ -1208,7 +1224,7 @@ normalizedFromAtoms(const lld::File &atomFile, const MachOLinkingContext &context) { // The util object buffers info until the normalized file can be made. Util util(context); - util.assignAtomsToSections(atomFile); + util.processDefinedAtoms(atomFile); util.organizeSections(); std::unique_ptr f(new NormalizedFile()); diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp index c99d6396cfa1..342cce4cbcf2 100644 --- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp +++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp @@ -1056,6 +1056,7 @@ normalizedObjectToAtoms(MachOFile *file, } // Cache some attributes on the file for use later. + file->setFlags(normalizedFile.flags); file->setArch(normalizedFile.arch); file->setOS(normalizedFile.os); diff --git a/lld/test/mach-o/parse-data-relocs-x86_64.yaml b/lld/test/mach-o/parse-data-relocs-x86_64.yaml index 6b05e26372b8..6aa36893367a 100644 --- a/lld/test/mach-o/parse-data-relocs-x86_64.yaml +++ b/lld/test/mach-o/parse-data-relocs-x86_64.yaml @@ -323,4 +323,5 @@ page-size: 0x00000000 # CHECK: content: [ 00, 00, 00, 00, 00, 00, 00, 00 ] # CHECK: section-choice: custom-required # CHECK: section-name: __DATA/__custom +# CHECK: dead-strip: never