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ReflectionContext: Remove platform #ifs for image format checks. #27237

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merged 1 commit into from
Sep 18, 2019
Merged

ReflectionContext: Remove platform #ifs for image format checks. #27237

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67 changes: 42 additions & 25 deletions include/swift/Reflection/ReflectionContext.h
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Original file line number Diff line number Diff line change
Expand Up @@ -123,7 +123,6 @@ class ReflectionContext
return sizeof(StoredPointer) * 2;
}

#if defined(__APPLE__) && defined(__MACH__)
template <typename T> bool readMachOSections(RemoteAddress ImageStart) {
auto Buf =
this->getReader().readBytes(ImageStart, sizeof(typename T::Header));
Expand Down Expand Up @@ -277,22 +276,6 @@ class ReflectionContext
return true;
}

bool addImage(RemoteAddress ImageStart) {
// We start reading 4 bytes. The first 4 bytes are supposed to be
// the magic, so we understand whether this is a 32-bit executable or
// a 64-bit one.
auto Buf = this->getReader().readBytes(ImageStart, sizeof(uint32_t));
if (!Buf)
return false;
auto HeaderMagic = reinterpret_cast<const uint32_t *>(Buf.get());
if (*HeaderMagic == llvm::MachO::MH_MAGIC)
return readMachOSections<MachOTraits<4>>(ImageStart);
if (*HeaderMagic == llvm::MachO::MH_MAGIC_64)
return readMachOSections<MachOTraits<8>>(ImageStart);
return false;
}

#elif defined(_WIN32)
bool readPECOFFSections(RemoteAddress ImageStart) {
auto DOSHdrBuf = this->getReader().readBytes(
ImageStart, sizeof(llvm::object::dos_header));
Expand Down Expand Up @@ -384,15 +367,13 @@ class ReflectionContext
return true;
}

bool addImage(RemoteAddress ImageStart) {
bool readPECOFF(RemoteAddress ImageStart) {
auto Buf = this->getReader().readBytes(ImageStart,
sizeof(llvm::object::dos_header));
if (!Buf)
return false;

auto DOSHdr = reinterpret_cast<const llvm::object::dos_header *>(Buf.get());
if (!(DOSHdr->Magic[0] == 'M' && DOSHdr->Magic[1] == 'Z'))
return false;

auto PEHeaderAddress =
ImageStart.getAddressData() + DOSHdr->AddressOfNewExeHeader;
Expand All @@ -407,7 +388,7 @@ class ReflectionContext

return readPECOFFSections(ImageStart);
}
#else // ELF platforms.

template <typename T> bool readELFSections(RemoteAddress ImageStart) {
auto Buf =
this->getReader().readBytes(ImageStart, sizeof(typename T::Header));
Expand Down Expand Up @@ -506,8 +487,8 @@ class ReflectionContext
savedBuffers.push_back(std::move(Buf));
return true;
}

bool addImage(RemoteAddress ImageStart) {
bool readELF(RemoteAddress ImageStart) {
auto Buf =
this->getReader().readBytes(ImageStart, sizeof(llvm::ELF::Elf64_Ehdr));

Expand All @@ -527,12 +508,48 @@ class ReflectionContext
return false;
}
}
#endif

bool addImage(RemoteAddress ImageStart) {
// Read the first few bytes to look for a magic header.
auto Magic = this->getReader().readBytes(ImageStart, sizeof(uint32_t));
if (!Magic)
return false;

uint32_t MagicWord;
memcpy(&MagicWord, Magic.get(), sizeof(MagicWord));

// 32- and 64-bit Mach-O.
if (MagicWord == llvm::MachO::MH_MAGIC) {
return readMachOSections<MachOTraits<4>>(ImageStart);
}

if (MagicWord == llvm::MachO::MH_MAGIC_64) {
return readMachOSections<MachOTraits<8>>(ImageStart);
}

// PE. (This just checks for the DOS header; `readPECOFF` will further
// validate the existence of the PE header.)
auto MagicBytes = (const char*)Magic.get();
if (MagicBytes[0] == 'M' && MagicBytes[1] == 'Z') {
return readPECOFF(ImageStart);
}

// ELF.
if (MagicBytes[0] == llvm::ELF::ElfMagic[0]
&& MagicBytes[1] == llvm::ELF::ElfMagic[1]
&& MagicBytes[2] == llvm::ELF::ElfMagic[2]
&& MagicBytes[3] == llvm::ELF::ElfMagic[3]) {
return readELF(ImageStart);
}

// We don't recognize the format.
return false;
}

void addReflectionInfo(ReflectionInfo I) {
getBuilder().addReflectionInfo(I);
}

bool ownsObject(RemoteAddress ObjectAddress) {
auto MetadataAddress = readMetadataFromInstance(ObjectAddress.getAddressData());
if (!MetadataAddress)
Expand Down