LTO: introduce object file-based on-disk module format.
This format is simply a regular object file with the bitcode stored in a
section named ".llvmbc", plus any number of other (non-allocated) sections.
One immediate use case for this is to accommodate compilation processes
which expect the object file to contain metadata in non-allocated sections,
such as the ".go_export" section used by some Go compilers [1], although I
imagine that in the future we could consider compiling parts of the module
(such as large non-inlinable functions) directly into the object file to
improve LTO efficiency.
[1] http://golang.org/doc/install/gccgo#Imports
Differential Revision: http://reviews.llvm.org/D4371
llvm-svn: 218078
diff --git a/llvm/lib/LTO/LTOModule.cpp b/llvm/lib/LTO/LTOModule.cpp
index 88f82f0..b9320d2 100644
--- a/llvm/lib/LTO/LTOModule.cpp
+++ b/llvm/lib/LTO/LTOModule.cpp
@@ -29,6 +29,8 @@
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCTargetAsmParser.h"
#include "llvm/MC/SubtargetFeature.h"
+#include "llvm/Object/IRObjectFile.h"
+#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Host.h"
@@ -44,6 +46,7 @@
#include "llvm/Transforms/Utils/GlobalStatus.h"
#include <system_error>
using namespace llvm;
+using namespace llvm::object;
LTOModule::LTOModule(std::unique_ptr<object::IRObjectFile> Obj,
llvm::TargetMachine *TM)
@@ -51,23 +54,31 @@
/// isBitcodeFile - Returns 'true' if the file (or memory contents) is LLVM
/// bitcode.
-bool LTOModule::isBitcodeFile(const void *mem, size_t length) {
- return sys::fs::identify_magic(StringRef((const char *)mem, length)) ==
- sys::fs::file_magic::bitcode;
+bool LTOModule::isBitcodeFile(const void *Mem, size_t Length) {
+ ErrorOr<MemoryBufferRef> BCData = IRObjectFile::findBitcodeInMemBuffer(
+ MemoryBufferRef(StringRef((const char *)Mem, Length), "<mem>"));
+ return bool(BCData);
}
-bool LTOModule::isBitcodeFile(const char *path) {
- sys::fs::file_magic type;
- if (sys::fs::identify_magic(path, type))
+bool LTOModule::isBitcodeFile(const char *Path) {
+ ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
+ MemoryBuffer::getFile(Path);
+ if (!BufferOrErr)
return false;
- return type == sys::fs::file_magic::bitcode;
+
+ ErrorOr<MemoryBufferRef> BCData = IRObjectFile::findBitcodeInMemBuffer(
+ BufferOrErr.get()->getMemBufferRef());
+ return bool(BCData);
}
-bool LTOModule::isBitcodeForTarget(MemoryBuffer *buffer,
- StringRef triplePrefix) {
- std::string Triple =
- getBitcodeTargetTriple(buffer->getMemBufferRef(), getGlobalContext());
- return StringRef(Triple).startswith(triplePrefix);
+bool LTOModule::isBitcodeForTarget(MemoryBuffer *Buffer,
+ StringRef TriplePrefix) {
+ ErrorOr<MemoryBufferRef> BCOrErr =
+ IRObjectFile::findBitcodeInMemBuffer(Buffer->getMemBufferRef());
+ if (!BCOrErr)
+ return false;
+ std::string Triple = getBitcodeTargetTriple(*BCOrErr, getGlobalContext());
+ return StringRef(Triple).startswith(TriplePrefix);
}
LTOModule *LTOModule::createFromFile(const char *path, TargetOptions options,
@@ -113,7 +124,13 @@
LTOModule *LTOModule::makeLTOModule(MemoryBufferRef Buffer,
TargetOptions options,
std::string &errMsg) {
- ErrorOr<Module *> MOrErr = parseBitcodeFile(Buffer, getGlobalContext());
+ ErrorOr<MemoryBufferRef> MBOrErr =
+ IRObjectFile::findBitcodeInMemBuffer(Buffer);
+ if (std::error_code EC = MBOrErr.getError()) {
+ errMsg = EC.message();
+ return nullptr;
+ }
+ ErrorOr<Module *> MOrErr = parseBitcodeFile(*MBOrErr, getGlobalContext());
if (std::error_code EC = MOrErr.getError()) {
errMsg = EC.message();
return nullptr;