MC CFG: Add MCObjectDisassembler Mach-O implementation.
Supports:
- entrypoint, using LC_MAIN.
- static ctors/dtors, using __mod_{init,exit}_func
- translation between effective and object load address, using
dyld's VM address slide.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188886 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCObjectDisassembler.cpp b/lib/MC/MCObjectDisassembler.cpp
index 4ce8e92..1969bcb 100644
--- a/lib/MC/MCObjectDisassembler.cpp
+++ b/lib/MC/MCObjectDisassembler.cpp
@@ -18,7 +18,10 @@
#include "llvm/MC/MCFunction.h"
#include "llvm/MC/MCInstrAnalysis.h"
#include "llvm/MC/MCModule.h"
+#include "llvm/Object/MachO.h"
#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/MachO.h"
#include "llvm/Support/MemoryObject.h"
#include "llvm/Support/StringRefMemoryObject.h"
#include "llvm/Support/raw_ostream.h"
@@ -285,3 +288,89 @@
}
}
}
+
+// MachO MCObjectDisassembler implementation.
+
+MCMachOObjectDisassembler::MCMachOObjectDisassembler(
+ const MachOObjectFile &MOOF, const MCDisassembler &Dis,
+ const MCInstrAnalysis &MIA, uint64_t VMAddrSlide,
+ uint64_t HeaderLoadAddress)
+ : MCObjectDisassembler(MOOF, Dis, MIA), MOOF(MOOF),
+ VMAddrSlide(VMAddrSlide), HeaderLoadAddress(HeaderLoadAddress) {
+
+ error_code ec;
+ for (section_iterator SI = MOOF.begin_sections(), SE = MOOF.end_sections();
+ SI != SE; SI.increment(ec)) {
+ if (ec)
+ break;
+ StringRef Name;
+ SI->getName(Name);
+ // FIXME: We should use the S_ section type instead of the name.
+ if (Name == "__mod_init_func") {
+ DEBUG(dbgs() << "Found __mod_init_func section!\n");
+ SI->getContents(ModInitContents);
+ } else if (Name == "__mod_exit_func") {
+ DEBUG(dbgs() << "Found __mod_exit_func section!\n");
+ SI->getContents(ModExitContents);
+ }
+ }
+}
+
+// FIXME: Only do the translations for addresses actually inside the object.
+uint64_t MCMachOObjectDisassembler::getEffectiveLoadAddr(uint64_t Addr) {
+ return Addr + VMAddrSlide;
+}
+
+uint64_t
+MCMachOObjectDisassembler::getOriginalLoadAddr(uint64_t EffectiveAddr) {
+ return EffectiveAddr - VMAddrSlide;
+}
+
+uint64_t MCMachOObjectDisassembler::getEntrypoint() {
+ uint64_t EntryFileOffset = 0;
+
+ // Look for LC_MAIN.
+ {
+ uint32_t LoadCommandCount = MOOF.getHeader().NumLoadCommands;
+ MachOObjectFile::LoadCommandInfo Load = MOOF.getFirstLoadCommandInfo();
+ for (unsigned I = 0;; ++I) {
+ if (Load.C.Type == MachO::LoadCommandMain) {
+ EntryFileOffset =
+ ((const MachO::entry_point_command *)Load.Ptr)->entryoff;
+ break;
+ }
+
+ if (I == LoadCommandCount - 1)
+ break;
+ else
+ Load = MOOF.getNextLoadCommandInfo(Load);
+ }
+ }
+
+ // If we didn't find anything, default to the common implementation.
+ // FIXME: Maybe we could also look at LC_UNIXTHREAD and friends?
+ if (EntryFileOffset)
+ return MCObjectDisassembler::getEntrypoint();
+
+ return EntryFileOffset + HeaderLoadAddress;
+}
+
+ArrayRef<uint64_t> MCMachOObjectDisassembler::getStaticInitFunctions() {
+ // FIXME: We only handle 64bit mach-o
+ assert(MOOF.is64Bit());
+
+ size_t EntrySize = 8;
+ size_t EntryCount = ModInitContents.size() / EntrySize;
+ return ArrayRef<uint64_t>(
+ reinterpret_cast<const uint64_t *>(ModInitContents.data()), EntryCount);
+}
+
+ArrayRef<uint64_t> MCMachOObjectDisassembler::getStaticExitFunctions() {
+ // FIXME: We only handle 64bit mach-o
+ assert(MOOF.is64Bit());
+
+ size_t EntrySize = 8;
+ size_t EntryCount = ModExitContents.size() / EntrySize;
+ return ArrayRef<uint64_t>(
+ reinterpret_cast<const uint64_t *>(ModExitContents.data()), EntryCount);
+}