From 689ff9c00f4f3dcf3491778bcdbda79e19e2285d Mon Sep 17 00:00:00 2001 From: Preston Gurd Date: Mon, 16 Apr 2012 22:12:58 +0000 Subject: Implement GDB integration for source level debugging of code JITed using the MCJIT execution engine. The GDB JIT debugging integration support works by registering a loaded object image with a pre-defined function that GDB will monitor if GDB is attached. GDB integration support is implemented for ELF only at this time. This integration requires GDB version 7.0 or newer. Patch by Andy Kaylor! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154868 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp | 169 ++++++++++++++++++++- 1 file changed, 167 insertions(+), 2 deletions(-) (limited to 'lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp') diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp index 57fefee5de..e2ebc342ad 100644 --- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp +++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp @@ -20,11 +20,176 @@ #include "llvm/Object/ObjectFile.h" #include "llvm/Support/ELF.h" #include "llvm/ADT/Triple.h" +#include "llvm/Object/ELF.h" +#include "JITRegistrar.h" using namespace llvm; using namespace llvm::object; +namespace { + +template +class DyldELFObject : public ELFObjectFile { + LLVM_ELF_IMPORT_TYPES(target_endianness, is64Bits) + + typedef Elf_Shdr_Impl Elf_Shdr; + typedef Elf_Sym_Impl Elf_Sym; + typedef Elf_Rel_Impl Elf_Rel; + typedef Elf_Rel_Impl Elf_Rela; + + typedef typename ELFObjectFile:: + Elf_Ehdr Elf_Ehdr; + + typedef typename ELFDataTypeTypedefHelper< + target_endianness, is64Bits>::value_type addr_type; + +protected: + // This duplicates the 'Data' member in the 'Binary' base class + // but it is necessary to workaround a bug in gcc 4.2 + MemoryBuffer *InputData; + +public: + DyldELFObject(MemoryBuffer *Object, error_code &ec); + + void updateSectionAddress(const SectionRef &Sec, uint64_t Addr); + void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr); + + const MemoryBuffer& getBuffer() const { return *InputData; } + + // Methods for type inquiry through isa, cast, and dyn_cast + static inline bool classof(const Binary *v) { + return (isa >(v) + && classof(cast >(v))); + } + static inline bool classof( + const ELFObjectFile *v) { + return v->isDyldType(); + } + static inline bool classof(const DyldELFObject *v) { + return true; + } +}; + +template +class ELFObjectImage : public ObjectImage { + protected: + DyldELFObject *DyldObj; + bool Registered; + + public: + ELFObjectImage(DyldELFObject *Obj) + : ObjectImage(Obj), + DyldObj(Obj), + Registered(false) {} + + virtual ~ELFObjectImage() { + if (Registered) + deregisterWithDebugger(); + } + + // Subclasses can override these methods to update the image with loaded + // addresses for sections and common symbols + virtual void updateSectionAddress(const SectionRef &Sec, uint64_t Addr) + { + DyldObj->updateSectionAddress(Sec, Addr); + } + + virtual void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr) + { + DyldObj->updateSymbolAddress(Sym, Addr); + } + + virtual void registerWithDebugger() + { + JITRegistrar::getGDBRegistrar().registerObject(DyldObj->getBuffer()); + Registered = true; + } + virtual void deregisterWithDebugger() + { + JITRegistrar::getGDBRegistrar().deregisterObject(DyldObj->getBuffer()); + } +}; + +template +DyldELFObject::DyldELFObject(MemoryBuffer *Object, + error_code &ec) + : ELFObjectFile(Object, ec), + InputData(Object) { + this->isDyldELFObject = true; +} + +template +void DyldELFObject::updateSectionAddress( + const SectionRef &Sec, + uint64_t Addr) { + DataRefImpl ShdrRef = Sec.getRawDataRefImpl(); + Elf_Shdr *shdr = const_cast( + reinterpret_cast(ShdrRef.p)); + + // This assumes the address passed in matches the target address bitness + // The template-based type cast handles everything else. + shdr->sh_addr = static_cast(Addr); +} + +template +void DyldELFObject::updateSymbolAddress( + const SymbolRef &SymRef, + uint64_t Addr) { + + Elf_Sym *sym = const_cast( + ELFObjectFile:: + getSymbol(SymRef.getRawDataRefImpl())); + + // This assumes the address passed in matches the target address bitness + // The template-based type cast handles everything else. + sym->st_value = static_cast(Addr); +} + +} // namespace + + namespace llvm { +ObjectImage *RuntimeDyldELF::createObjectImage( + const MemoryBuffer *ConstInputBuffer) { + MemoryBuffer *InputBuffer = const_cast(ConstInputBuffer); + std::pair Ident = getElfArchType(InputBuffer); + error_code ec; + + if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) { + DyldELFObject *Obj = + new DyldELFObject(InputBuffer, ec); + return new ELFObjectImage(Obj); + } + else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) { + DyldELFObject *Obj = + new DyldELFObject(InputBuffer, ec); + return new ELFObjectImage(Obj); + } + else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) { + DyldELFObject *Obj = + new DyldELFObject(InputBuffer, ec); + return new ELFObjectImage(Obj); + } + else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) { + DyldELFObject *Obj = + new DyldELFObject(InputBuffer, ec); + return new ELFObjectImage(Obj); + } + else + llvm_unreachable("Unexpected ELF format"); +} + +void RuntimeDyldELF::handleObjectLoaded(ObjectImage *Obj) +{ + Obj->registerWithDebugger(); + // Save the loaded object. It will deregister itself when deleted + LoadedObject = Obj; +} + +RuntimeDyldELF::~RuntimeDyldELF() { + if (LoadedObject) + delete LoadedObject; +} void RuntimeDyldELF::resolveX86_64Relocation(uint8_t *LocalAddress, uint64_t FinalAddress, @@ -167,7 +332,7 @@ void RuntimeDyldELF::resolveRelocation(uint8_t *LocalAddress, } void RuntimeDyldELF::processRelocationRef(const ObjRelocationInfo &Rel, - const ObjectFile &Obj, + ObjectImage &Obj, ObjSectionToIDMap &ObjSectionToID, LocalSymbolMap &Symbols, StubMap &Stubs) { @@ -206,7 +371,7 @@ void RuntimeDyldELF::processRelocationRef(const ObjRelocationInfo &Rel, if (si == Obj.end_sections()) llvm_unreachable("Symbol section not found, bad object file format!"); DEBUG(dbgs() << "\t\tThis is section symbol\n"); - Value.SectionID = findOrEmitSection((*si), true, ObjSectionToID); + Value.SectionID = findOrEmitSection(Obj, (*si), true, ObjSectionToID); Value.Addend = Addend; break; } -- cgit v1.2.3-18-g5258