diff options
4 files changed, 209 insertions, 8 deletions
diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryUtils.h b/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryUtils.h index 613c1b2f251..1226860b021 100644 --- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryUtils.h +++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryUtils.h @@ -168,7 +168,8 @@ void relocatableSectionInfoForContentType(DefinedAtom::ContentType atomType, StringRef &segmentName, StringRef §ionName, SectionType §ionType, - SectionAttr §ionAttrs); + SectionAttr §ionAttrs, + bool &relocsToDefinedCanBeImplicit); } // namespace normalized } // namespace mach_o diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp index e830db9fcc7..575bc1a2b3a 100644 --- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp +++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp @@ -50,7 +50,8 @@ struct AtomInfo { struct SectionInfo { SectionInfo(StringRef seg, StringRef sect, SectionType type, - const MachOLinkingContext &ctxt, uint32_t attr=0); + const MachOLinkingContext &ctxt, uint32_t attr, + bool relocsToDefinedCanBeImplicit); StringRef segmentName; StringRef sectionName; @@ -59,15 +60,25 @@ struct SectionInfo { uint64_t address; uint64_t size; uint16_t alignment; + + /// If this is set, the any relocs in this section which point to defined + /// addresses can be implicitly generated. This is the case for the + /// __eh_frame section where references to the function can be implicit if the + /// function is defined. + bool relocsToDefinedCanBeImplicit; + + std::vector<AtomInfo> atomsAndOffsets; uint32_t normalizedSectionIndex; uint32_t finalSectionIndex; }; SectionInfo::SectionInfo(StringRef sg, StringRef sct, SectionType t, - const MachOLinkingContext &ctxt, uint32_t attrs) + const MachOLinkingContext &ctxt, uint32_t attrs, + bool relocsToDefinedCanBeImplicit) : segmentName(sg), sectionName(sct), type(t), attributes(attrs), address(0), size(0), alignment(1), + relocsToDefinedCanBeImplicit(relocsToDefinedCanBeImplicit), normalizedSectionIndex(0), finalSectionIndex(0) { uint16_t align = 1; if (ctxt.sectionAligned(segmentName, sectionName, align)) { @@ -193,10 +204,12 @@ SectionInfo *Util::getRelocatableSection(DefinedAtom::ContentType type) { StringRef sectionName; SectionType sectionType; SectionAttr sectionAttrs; + bool relocsToDefinedCanBeImplicit; // Use same table used by when parsing .o files. relocatableSectionInfoForContentType(type, segmentName, sectionName, - sectionType, sectionAttrs); + sectionType, sectionAttrs, + relocsToDefinedCanBeImplicit); // If we already have a SectionInfo with this name, re-use it. // This can happen if two ContentType map to the same mach-o section. for (auto sect : _sectionMap) { @@ -207,7 +220,8 @@ SectionInfo *Util::getRelocatableSection(DefinedAtom::ContentType type) { } // Otherwise allocate new SectionInfo object. auto *sect = new (_allocator) - SectionInfo(segmentName, sectionName, sectionType, _ctx, sectionAttrs); + SectionInfo(segmentName, sectionName, sectionType, _ctx, sectionAttrs, + relocsToDefinedCanBeImplicit); _sectionInfos.push_back(sect); _sectionMap[type] = sect; return sect; @@ -287,7 +301,8 @@ SectionInfo *Util::getFinalSection(DefinedAtom::ContentType atomType) { } // Otherwise allocate new SectionInfo object. auto *sect = new (_allocator) SectionInfo( - p.segmentName, p.sectionName, p.sectionType, _ctx, sectionAttrs); + p.segmentName, p.sectionName, p.sectionType, _ctx, sectionAttrs, + /* relocsToDefinedCanBeImplicit */ false); _sectionInfos.push_back(sect); _sectionMap[atomType] = sect; return sect; @@ -320,7 +335,8 @@ SectionInfo *Util::sectionForAtom(const DefinedAtom *atom) { StringRef segName = customName.slice(0, seperatorIndex); StringRef sectName = customName.drop_front(seperatorIndex + 1); auto *sect = - new (_allocator) SectionInfo(segName, sectName, S_REGULAR, _ctx); + new (_allocator) SectionInfo(segName, sectName, S_REGULAR, _ctx, + 0, /* relocsToDefinedCanBeImplicit */ false); _customSections.push_back(sect); _sectionInfos.push_back(sect); return sect; @@ -1024,6 +1040,11 @@ void Util::addSectionRelocs(const lld::File &, NormalizedFile &file) { for (const AtomInfo &info : si->atomsAndOffsets) { const DefinedAtom *atom = info.atom; for (const Reference *ref : *atom) { + // Skip emitting relocs for sections which are always able to be + // implicitly regenerated and where the relocation targets an address + // which is defined. + if (si->relocsToDefinedCanBeImplicit && isa<DefinedAtom>(ref->target())) + continue; _archHandler.appendSectionRelocations(*atom, info.offsetInSection, *ref, symIndexForAtom, sectIndexForAtom, diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp index 1c4bb1d4f6a..f9499b60321 100644 --- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp +++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp @@ -1034,7 +1034,8 @@ void relocatableSectionInfoForContentType(DefinedAtom::ContentType atomType, StringRef &segmentName, StringRef §ionName, SectionType §ionType, - SectionAttr §ionAttrs) { + SectionAttr §ionAttrs, + bool &relocsToDefinedCanBeImplicit) { for (const MachORelocatableSectionToAtomType *p = sectsToAtomType ; p->atomType != DefinedAtom::typeUnknown; ++p) { @@ -1047,8 +1048,11 @@ void relocatableSectionInfoForContentType(DefinedAtom::ContentType atomType, sectionName = p->sectionName; sectionType = p->sectionType; sectionAttrs = 0; + relocsToDefinedCanBeImplicit = false; if (atomType == DefinedAtom::typeCode) sectionAttrs = S_ATTR_PURE_INSTRUCTIONS; + if (atomType == DefinedAtom::typeCFI) + relocsToDefinedCanBeImplicit = true; return; } llvm_unreachable("content type not yet supported"); diff --git a/lld/test/mach-o/do-not-emit-unwind-fde-arm64.yaml b/lld/test/mach-o/do-not-emit-unwind-fde-arm64.yaml new file mode 100644 index 00000000000..4a121252fc6 --- /dev/null +++ b/lld/test/mach-o/do-not-emit-unwind-fde-arm64.yaml @@ -0,0 +1,175 @@ +# RUN: lld -flavor darwin -arch arm64 -r -print_atoms %s -o %t | FileCheck %s +# RUN: lld -flavor darwin -arch arm64 -r -print_atoms %t -o %t2 | FileCheck %s +# RUN: llvm-objdump -r -macho %t | FileCheck -check-prefix=CODE %s +# RUN: llvm-objdump -r -macho %t2 | FileCheck -check-prefix=CODE %s + + +--- !mach-o +arch: arm64 +file-type: MH_OBJECT +flags: [ MH_SUBSECTIONS_VIA_SYMBOLS ] +compat-version: 0.0 +current-version: 0.0 +has-UUID: false +OS: unknown +sections: + - segment: __TEXT + section: __text + type: S_REGULAR + attributes: [ S_ATTR_PURE_INSTRUCTIONS, S_ATTR_SOME_INSTRUCTIONS ] + alignment: 4 + address: 0x0000000000000000 + content: [ 0xFD, 0x7B, 0xBF, 0xA9, 0xFD, 0x03, 0x00, 0x91, + 0x00, 0x00, 0x00, 0x90, 0x00, 0x00, 0x00, 0x91, + 0x00, 0x00, 0x00, 0x94, 0x00, 0x00, 0x80, 0x52, + 0xFD, 0x7B, 0xC1, 0xA8, 0xC0, 0x03, 0x5F, 0xD6 ] + relocations: + - offset: 0x00000010 + type: ARM64_RELOC_BRANCH26 + length: 2 + pc-rel: true + extern: true + symbol: 9 + - offset: 0x0000000C + type: ARM64_RELOC_PAGEOFF12 + length: 2 + pc-rel: false + extern: true + symbol: 1 + - offset: 0x00000008 + type: ARM64_RELOC_PAGE21 + length: 2 + pc-rel: true + extern: true + symbol: 1 + - segment: __TEXT + section: __cstring + type: S_CSTRING_LITERALS + attributes: [ ] + address: 0x0000000000000020 + content: [ 0x48, 0x65, 0x6C, 0x6C, 0x6F, 0x20, 0x77, 0x6F, + 0x72, 0x6C, 0x64, 0x00 ] + - segment: __LD + section: __compact_unwind + type: S_REGULAR + attributes: [ ] + alignment: 8 + address: 0x0000000000000030 + content: [ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 ] + relocations: + - offset: 0x00000000 + type: ARM64_RELOC_UNSIGNED + length: 3 + pc-rel: false + extern: false + symbol: 1 + - segment: __TEXT + section: __eh_frame + type: S_COALESCED + attributes: [ ] + alignment: 8 + address: 0x0000000000000050 + content: [ 0x1C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x01, 0x7A, 0x50, 0x4C, 0x52, 0x00, 0x01, 0x78, + 0x1E, 0x0B, 0x00, 0xED, 0xFF, 0xFF, 0xFF, 0xFF, + 0xFF, 0xFF, 0xFF, 0x00, 0x10, 0x0C, 0x1F, 0x00, + 0x24, 0x00, 0x00, 0x00, 0x24, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x48, 0x0E, 0x10, 0x9E, 0x01, 0x9D, 0x02 ] +local-symbols: + - name: ltmp0 + type: N_SECT + sect: 1 + value: 0x0000000000000000 + - name: L_str + type: N_SECT + sect: 2 + value: 0x0000000000000020 + - name: ltmp1 + type: N_SECT + sect: 2 + value: 0x0000000000000020 + - name: ltmp2 + type: N_SECT + sect: 3 + value: 0x0000000000000030 + - name: ltmp3 + type: N_SECT + sect: 4 + value: 0x0000000000000050 + - name: ltmp4 + type: N_SECT + sect: 4 + value: 0x0000000000000070 +global-symbols: + - name: __Z3fooi + type: N_SECT + scope: [ N_EXT ] + sect: 1 + value: 0x0000000000000000 +undefined-symbols: + - name: __gxx_personality_v0 + type: N_UNDF + scope: [ N_EXT ] + value: 0x0000000000000000 + - name: _bar + type: N_UNDF + scope: [ N_EXT ] + value: 0x0000000000000000 + - name: _puts + type: N_UNDF + scope: [ N_EXT ] + value: 0x0000000000000000 +page-size: 0x00000000 + +# CHECK: defined-atoms: +# CHECK: - ref-name: L{{[0-9]*}} +# CHECK: scope: hidden +# CHECK: type: c-string +# CHECK: content: [ 48, 65, 6C, 6C, 6F, 20, 77, 6F, 72, 6C, 64, 00 ] +# CHECK: merge: by-content +# CHECK: type: unwind-cfi +# CHECK: content: [ 1C, 00, 00, 00, 00, 00, 00, 00, 01, 7A, 50, 4C, +# CHECK: 52, 00, 01, 78, 1E, 0B, 00, ED, FF, FF, FF, FF, +# CHECK: FF, FF, FF, 00, 10, 0C, 1F, 00 ] +# CHECK: alignment: 8 +# CHECK: - ref-name: L{{[0-9]*}} +# CHECK: type: unwind-cfi +# CHECK: content: [ 24, 00, 00, 00, 24, 00, 00, 00, 00, 00, 00, 00, +# CHECK: 00, 00, 00, 00, 20, 00, 00, 00, 00, 00, 00, 00, +# CHECK: 08, 00, 00, 00, 00, 00, 00, 00, 00, 48, 0E, 10, +# CHECK: 9E, 01, 9D, 02 ] +# CHECK: alignment: 8 +# CHECK: - type: compact-unwind +# CHECK: content: [ 00, 00, 00, 00, 00, 00, 00, 00, 20, 00, 00, 00, +# CHECK: 00, 00, 00, 03, 00, 00, 00, 00, 00, 00, 00, 00, +# CHECK: 00, 00, 00, 00, 00, 00, 00, 00 ] +# CHECK: alignment: 8 +# CHECK: references: +# CHECK: - kind: pointer64 +# CHECK: offset: 0 +# CHECK: target: __Z3fooi +# CHECK: - name: __Z3fooi +# CHECK: scope: global +# CHECK: content: [ FD, 7B, BF, A9, FD, 03, 00, 91, 00, 00, 00, 90, +# CHECK: 00, 00, 00, 91, 00, 00, 00, 94, 00, 00, 80, 52, +# CHECK: FD, 7B, C1, A8, C0, 03, 5F, D6 ] +# CHECK: alignment: 4 +# CHECK: references: +# CHECK: - kind: page21 +# CHECK: offset: 8 +# CHECK: target: L{{[0-9]*}} +# CHECK: - kind: offset12 +# CHECK: offset: 12 +# CHECK: target: L{{[0-9]*}} +# CHECK: - kind: branch26 +# CHECK: offset: 16 +# CHECK: target: _puts + +# Make sure we don't have any relocations in the __eh_frame section +# CODE-NOT: __eh_frame
\ No newline at end of file |
