llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-llvm-binary-utilities Author: Fangrui Song (MaskRay) <details> <summary>Changes</summary> Make it easier to add custom section [de]compression. In GNU ld, --compress-debug-sections doesn't compress SHF_ALLOC sections. Match its behavior. --- Full diff: https://github.com/llvm/llvm-project/pull/84885.diff 4 Files Affected: - (modified) llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp (+25-40) - (modified) llvm/lib/ObjCopy/ELF/ELFObject.h (+1) - (modified) llvm/test/tools/llvm-objcopy/ELF/Inputs/compress-debug-sections.yaml (+4) - (modified) llvm/test/tools/llvm-objcopy/ELF/compress-debug-sections-zlib.test (+2) ``````````diff diff --git a/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp b/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp index f52bcb74938d15..36826e02a62712 100644 --- a/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp +++ b/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp @@ -214,33 +214,34 @@ static Error dumpSectionToFile(StringRef SecName, StringRef Filename, SecName.str().c_str()); } -static bool isCompressable(const SectionBase &Sec) { - return !(Sec.Flags & ELF::SHF_COMPRESSED) && - StringRef(Sec.Name).starts_with(".debug"); -} - -static Error replaceDebugSections( - Object &Obj, function_ref<bool(const SectionBase &)> ShouldReplace, - function_ref<Expected<SectionBase *>(const SectionBase *)> AddSection) { +Error Object::compressOrDecompressSections(const CommonConfig &Config) { // Build a list of the debug sections we are going to replace. // We can't call `AddSection` while iterating over sections, // because it would mutate the sections array. - SmallVector<SectionBase *, 13> ToReplace; - for (auto &Sec : Obj.sections()) - if (ShouldReplace(Sec)) - ToReplace.push_back(&Sec); - - // Build a mapping from original section to a new one. - DenseMap<SectionBase *, SectionBase *> FromTo; - for (SectionBase *S : ToReplace) { - Expected<SectionBase *> NewSection = AddSection(S); - if (!NewSection) - return NewSection.takeError(); - - FromTo[S] = *NewSection; + SmallVector<std::pair<SectionBase *, std::function<SectionBase *()>>, 0> + ToReplace; + for (SectionBase &Sec : sections()) { + if (!StringRef(Sec.Name).starts_with(".debug")) + continue; + if (auto *CS = dyn_cast<CompressedSection>(&Sec)) { + if (Config.DecompressDebugSections) { + ToReplace.emplace_back( + &Sec, [=] { return &addSection<DecompressedSection>(*CS); }); + } + } else if (!(Sec.Flags & SHF_ALLOC) && + Config.CompressionType != DebugCompressionType::None) { + auto *S = &Sec; + ToReplace.emplace_back(S, [=] { + return &addSection<CompressedSection>( + CompressedSection(*S, Config.CompressionType, Is64Bits)); + }); + } } - return Obj.replaceSections(FromTo); + DenseMap<SectionBase *, SectionBase *> FromTo; + for (auto [S, Func] : ToReplace) + FromTo[S] = Func(); + return replaceSections(FromTo); } static bool isAArch64MappingSymbol(const Symbol &Sym) { @@ -534,24 +535,8 @@ static Error replaceAndRemoveSections(const CommonConfig &Config, if (Error E = Obj.removeSections(ELFConfig.AllowBrokenLinks, RemovePred)) return E; - if (Config.CompressionType != DebugCompressionType::None) { - if (Error Err = replaceDebugSections( - Obj, isCompressable, - [&Config, &Obj](const SectionBase *S) -> Expected<SectionBase *> { - return &Obj.addSection<CompressedSection>( - CompressedSection(*S, Config.CompressionType, Obj.Is64Bits)); - })) - return Err; - } else if (Config.DecompressDebugSections) { - if (Error Err = replaceDebugSections( - Obj, - [](const SectionBase &S) { return isa<CompressedSection>(&S); }, - [&Obj](const SectionBase *S) { - const CompressedSection *CS = cast<CompressedSection>(S); - return &Obj.addSection<DecompressedSection>(*CS); - })) - return Err; - } + if (Error E = Obj.compressOrDecompressSections(Config)) + return E; return Error::success(); } diff --git a/llvm/lib/ObjCopy/ELF/ELFObject.h b/llvm/lib/ObjCopy/ELF/ELFObject.h index 7a2e20d82d1150..f72c109b6009e8 100644 --- a/llvm/lib/ObjCopy/ELF/ELFObject.h +++ b/llvm/lib/ObjCopy/ELF/ELFObject.h @@ -1210,6 +1210,7 @@ class Object { Error removeSections(bool AllowBrokenLinks, std::function<bool(const SectionBase &)> ToRemove); + Error compressOrDecompressSections(const CommonConfig &Config); Error replaceSections(const DenseMap<SectionBase *, SectionBase *> &FromTo); Error removeSymbols(function_ref<bool(const Symbol &)> ToRemove); template <class T, class... Ts> T &addSection(Ts &&...Args) { diff --git a/llvm/test/tools/llvm-objcopy/ELF/Inputs/compress-debug-sections.yaml b/llvm/test/tools/llvm-objcopy/ELF/Inputs/compress-debug-sections.yaml index 67d8435fa486c1..e2dfee9163a2b8 100644 --- a/llvm/test/tools/llvm-objcopy/ELF/Inputs/compress-debug-sections.yaml +++ b/llvm/test/tools/llvm-objcopy/ELF/Inputs/compress-debug-sections.yaml @@ -43,6 +43,10 @@ Sections: Type: SHT_PROGBITS Flags: [ SHF_GROUP ] Content: '00' + - Name: .debug_alloc + Type: SHT_PROGBITS + Flags: [ SHF_ALLOC ] + Content: 000102030405060708090a0b0c0d0e0f000102030405060708090a0b0c0d0e0f000102030405060708090a0b0c0d0e0f000102030405060708090a0b0c0d0e0f Symbols: - Type: STT_SECTION Section: .debug_foo diff --git a/llvm/test/tools/llvm-objcopy/ELF/compress-debug-sections-zlib.test b/llvm/test/tools/llvm-objcopy/ELF/compress-debug-sections-zlib.test index e1ebeed8d4fcb0..056ae84ce4915f 100644 --- a/llvm/test/tools/llvm-objcopy/ELF/compress-debug-sections-zlib.test +++ b/llvm/test/tools/llvm-objcopy/ELF/compress-debug-sections-zlib.test @@ -12,8 +12,10 @@ # CHECK: Name Type Address Off Size ES Flg Lk Inf Al # COMPRESSED: .debug_foo PROGBITS 0000000000000000 000040 {{.*}} 00 C 0 0 8 # COMPRESSED-NEXT: .notdebug_foo PROGBITS 0000000000000000 {{.*}} 000008 00 0 0 0 +# COMPRESSED: .debug_alloc PROGBITS 0000000000000000 {{.*}} 000040 00 A 0 0 0 # UNCOMPRESSED: .debug_foo PROGBITS 0000000000000000 000040 000008 00 0 0 0 # UNCOMPRESSED-NEXT: .notdebug_foo PROGBITS 0000000000000000 {{.*}} 000008 00 0 0 0 +# UNCOMPRESSED: .debug_alloc PROGBITS 0000000000000000 {{.*}} 000040 00 A 0 0 0 ## Relocations do not change. # CHECK: Relocation section '.rela.debug_foo' at offset {{.*}} contains 2 entries: `````````` </details> https://github.com/llvm/llvm-project/pull/84885 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
