Index: test/tools/llvm-objcopy/COFF/add-gnu-debuglink.test =================================================================== --- /dev/null +++ test/tools/llvm-objcopy/COFF/add-gnu-debuglink.test @@ -0,0 +1,42 @@ +RUN: yaml2obj %p/Inputs/x86_64-exe.yaml > %t.in123.exe + +Using a debuglink filename with a length that is a multiple of 4, to +showcase padding in CONTENTS below. + +RUN: llvm-objcopy --add-gnu-debuglink=%t.in123.exe %t.in123.exe %t.out.exe +RUN: llvm-readobj -sections %t.out.exe | FileCheck %s --check-prefix=SECTIONS +RUN: llvm-objdump -s %t.out.exe | FileCheck %s --check-prefix=CONTENTS + +Show the last of the preexisting sections, which is used for choosing +a virtual address for the generated one. + +SECTIONS: Section { +SECTIONS: Number: 4 +SECTIONS-NEXT: Name: .pdata +SECTIONS-NEXT: VirtualSize: 0x18 +SECTIONS-NEXT: VirtualAddress: 0x4000 +SECTIONS-NEXT: RawDataSize: 512 +SECTIONS: Section { +SECTIONS-NEXT: Number: 5 +SECTIONS-NEXT: Name: .gnu_debuglink +SECTIONS-NEXT: VirtualSize: 0x2C +SECTIONS-NEXT: VirtualAddress: 0x5000 +SECTIONS-NEXT: RawDataSize: 512 +SECTIONS-NEXT: PointerToRawData: +SECTIONS-NEXT: PointerToRelocations: +SECTIONS-NEXT: PointerToLineNumbers: +SECTIONS-NEXT: RelocationCount: +SECTIONS-NEXT: LineNumberCount: +SECTIONS-NEXT: Characteristics [ (0x42000040) +SECTIONS-NEXT: IMAGE_SCN_CNT_INITIALIZED_DATA (0x40) +SECTIONS-NEXT: IMAGE_SCN_MEM_DISCARDABLE (0x2000000) +SECTIONS-NEXT: IMAGE_SCN_MEM_READ (0x40000000) +SECTIONS-NEXT: ] + +Note: The last 4 bytes here are the crc of the referenced file - if the +yaml2obj generated file changes, this crc changes. + +CONTENTS: Contents of section .gnu_debuglink: +CONTENTS: 40005000 6164642d 676e752d 64656275 676c696e add-gnu-debuglin +CONTENTS: 40005010 6b2e7465 73742e74 6d702e69 6e313233 k.test.tmp.in123 +CONTENTS: 40005020 2e657865 00000000 7929adc3 .exe Index: tools/llvm-objcopy/COFF/COFFObjcopy.cpp =================================================================== --- tools/llvm-objcopy/COFF/COFFObjcopy.cpp +++ tools/llvm-objcopy/COFF/COFFObjcopy.cpp @@ -17,6 +17,8 @@ #include "llvm/Object/Binary.h" #include "llvm/Object/COFF.h" #include "llvm/Support/Errc.h" +#include "llvm/Support/JamCRC.h" +#include "llvm/Support/Path.h" #include namespace llvm { @@ -30,6 +32,60 @@ return Sec.Name.startswith(".debug"); } +static uint64_t getNextRVA(const Object &Obj) { + if (Obj.getSections().empty()) + return 0; + const Section &Last = Obj.getSections().back(); + return alignTo(Last.Header.VirtualAddress + Last.Header.VirtualSize, + Obj.PeHeader.SectionAlignment); +} + +static uint32_t getCRC32(StringRef Data) { + JamCRC CRC; + CRC.update(ArrayRef(Data.data(), Data.size())); + // The CRC32 value needs to be complemented because the JamCRC dosn't + // finalize the CRC32 value. It also dosn't negate the initial CRC32 value + // but it starts by default at 0xFFFFFFFF which is the complement of zero. + return ~CRC.getCRC(); +} + +static void createGnuDebugLinkSectionContents(std::vector &Data, + StringRef File) { + auto LinkTargetOrErr = MemoryBuffer::getFile(File); + if (!LinkTargetOrErr) + error("'" + File + "': " + LinkTargetOrErr.getError().message()); + auto LinkTarget = std::move(*LinkTargetOrErr); + uint32_t CRC32 = getCRC32(LinkTarget->getBuffer()); + + StringRef FileName = sys::path::filename(File); + size_t CRCPos = alignTo(FileName.size() + 1, 4); + Data.resize(CRCPos + 4, 0); + memcpy(Data.data(), FileName.data(), FileName.size()); + support::endian::write32le(Data.data() + CRCPos, CRC32); +} + +static void addGnuDebugLink(Object &Obj, StringRef DebugLinkFile) { + uint32_t StartRVA = getNextRVA(Obj); + + std::vector
Sections; + Section Sec; + createGnuDebugLinkSectionContents(Sec.LocalContents, DebugLinkFile); + Sec.Name = ".gnu_debuglink"; + Sec.Header.VirtualSize = Sec.LocalContents.size(); + Sec.Header.VirtualAddress = StartRVA; + Sec.Header.SizeOfRawData = + alignTo(Sec.Header.VirtualSize, Obj.PeHeader.FileAlignment); + // Sec.Header.PointerToRawData is filled in by the writer. + Sec.Header.PointerToRelocations = 0; + Sec.Header.PointerToLinenumbers = 0; + // Sec.Header.NumberOfRelocations is filled in by the writer. + Sec.Header.NumberOfLinenumbers = 0; + Sec.Header.Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA | + IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_DISCARDABLE; + Sections.push_back(Sec); + Obj.addSections(Sections); +} + static Error handleArgs(const CopyConfig &Config, Object &Obj) { // Perform the actual section removals. Obj.removeSections([&Config](const Section &Sec) { @@ -109,6 +165,10 @@ return false; }); + + if (!Config.AddGnuDebugLink.empty() && Obj.IsPE) + addGnuDebugLink(Obj, Config.AddGnuDebugLink); + return Error::success(); } Index: tools/llvm-objcopy/COFF/Object.h =================================================================== --- tools/llvm-objcopy/COFF/Object.h +++ tools/llvm-objcopy/COFF/Object.h @@ -40,6 +40,10 @@ StringRef Name; ssize_t UniqueId; size_t Index; + + // A container which actually owns the Contents data. If non-empty, this + // is used instead of Contents above. + std::vector LocalContents; }; struct Symbol { Index: tools/llvm-objcopy/COFF/Object.cpp =================================================================== --- tools/llvm-objcopy/COFF/Object.cpp +++ tools/llvm-objcopy/COFF/Object.cpp @@ -133,6 +133,7 @@ Sec.Contents = ArrayRef(); Sec.Relocs.clear(); Sec.Header.SizeOfRawData = 0; + Sec.LocalContents.clear(); } } } Index: tools/llvm-objcopy/COFF/Writer.cpp =================================================================== --- tools/llvm-objcopy/COFF/Writer.cpp +++ tools/llvm-objcopy/COFF/Writer.cpp @@ -284,14 +284,17 @@ void COFFWriter::writeSections() { for (const auto &S : Obj.getSections()) { uint8_t *Ptr = Buf.getBufferStart() + S.Header.PointerToRawData; - std::copy(S.Contents.begin(), S.Contents.end(), Ptr); + ArrayRef Contents = S.Contents; + if (!S.LocalContents.empty()) + Contents = S.LocalContents; + std::copy(Contents.begin(), Contents.end(), Ptr); // For executable sections, pad the remainder of the raw data size with // 0xcc, which is int3 on x86. if ((S.Header.Characteristics & IMAGE_SCN_CNT_CODE) && - S.Header.SizeOfRawData > S.Contents.size()) - memset(Ptr + S.Contents.size(), 0xcc, - S.Header.SizeOfRawData - S.Contents.size()); + S.Header.SizeOfRawData > Contents.size()) + memset(Ptr + Contents.size(), 0xcc, + S.Header.SizeOfRawData - Contents.size()); Ptr += S.Header.SizeOfRawData; for (const auto &R : S.Relocs) {