Sketch out an CFG reconstruction mode for llvm-objdump.
- Not great yet, but it's a start.
- Requires an object file with a symbol table. (I really want to fix this, but it'll need a whole new algorithm)
- ELF and COFF won't work at the moment due to libObject shortcomings.
To try it out run
$ llvm-objdump -d --cfg foo.o
This will create a graphviz file for every symbol in the object file's text section containing a CFG.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135608 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-objdump/MCFunction.h b/tools/llvm-objdump/MCFunction.h
new file mode 100644
index 0000000..60f6429
--- /dev/null
+++ b/tools/llvm-objdump/MCFunction.h
@@ -0,0 +1,88 @@
+//===-- MCFunction.h ------------------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the data structures to hold a CFG reconstructed from
+// machine code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/MC/MCInst.h"
+#include <map>
+
+namespace llvm {
+
+class MCDisassembler;
+class MCInstrInfo;
+class MemoryObject;
+class raw_ostream;
+
+/// MCDecodedInst - Small container to hold an MCInst and associated info like
+/// address and size.
+struct MCDecodedInst {
+ uint64_t Address;
+ uint64_t Size;
+ MCInst Inst;
+
+ MCDecodedInst(uint64_t Address, uint64_t Size, MCInst Inst)
+ : Address(Address), Size(Size), Inst(Inst) {}
+};
+
+/// MCBasicBlock - Consists of multiple MCDecodedInsts and a list of successing
+/// MCBasicBlocks.
+class MCBasicBlock {
+ SmallVector<MCDecodedInst, 8> Insts;
+ typedef SmallPtrSet<MCBasicBlock*, 8> SetTy;
+ SetTy Succs;
+public:
+ ArrayRef<MCDecodedInst> getInsts() const { return Insts; }
+
+ typedef SetTy::const_iterator succ_iterator;
+ succ_iterator succ_begin() const { return Succs.begin(); }
+ succ_iterator succ_end() const { return Succs.end(); }
+
+ void addInst(const MCDecodedInst &Inst) { Insts.push_back(Inst); }
+ void addSucc(MCBasicBlock *BB) { Succs.insert(BB); }
+};
+
+/// MCFunction - Represents a named function in machine code, containing
+/// multiple MCBasicBlocks.
+class MCFunction {
+ const StringRef Name;
+ // Keep BBs sorted by address.
+ typedef std::map<uint64_t, MCBasicBlock> MapTy;
+ MapTy Blocks;
+public:
+ MCFunction(StringRef Name) : Name(Name) {}
+
+ // Create an MCFunction from a region of binary machine code.
+ static MCFunction
+ createFunctionFromMC(StringRef Name, const MCDisassembler *DisAsm,
+ const MemoryObject &Region, uint64_t Start, uint64_t End,
+ const MCInstrInfo *InstrInfo, raw_ostream &DebugOut);
+
+ typedef MapTy::iterator iterator;
+ iterator begin() { return Blocks.begin(); }
+ iterator end() { return Blocks.end(); }
+
+ StringRef getName() const { return Name; }
+
+ MCBasicBlock &addBlock(uint64_t Address, const MCBasicBlock &BB) {
+ assert(!Blocks.count(Address) && "Already a BB at address.");
+ return Blocks[Address] = BB;
+ }
+
+ MCBasicBlock &getBlockAtAddress(uint64_t Address) {
+ assert(Blocks.count(Address) && "No BB at address.");
+ return Blocks[Address];
+ }
+};
+
+}