Reland 'Classify llvm-cfi-verify.'

Summary: Move llvm-cfi-verify into a class in preparation for CFI analysis to come.

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Subscribers: mgorny, llvm-commits, pcc, kcc

Differential Revision: https://reviews.llvm.org/D38379

llvm-svn: 315504

1 files changed, 157 insertions, 0 deletions

diff --git a/llvm/tools/llvm-cfi-verify/lib/FileAnalysis.h b/llvm/tools/llvm-cfi-verify/lib/FileAnalysis.h
new file mode 100644
index 00000000000..80e3256da7b
--- /dev/null
+++ b/llvm/tools/llvm-cfi-verify/lib/FileAnalysis.h
@@ -0,0 +1,157 @@
+//===- FileAnalysis.h -------------------------------------------*- C++ -*-===//
+//
+//                      The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CFI_VERIFY_FILE_ANALYSIS_H
+#define LLVM_CFI_VERIFY_FILE_ANALYSIS_H
+
+#include "llvm/BinaryFormat/ELF.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDisassembler/MCDisassembler.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstPrinter.h"
+#include "llvm/MC/MCInstrAnalysis.h"
+#include "llvm/MC/MCInstrDesc.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCObjectFileInfo.h"
+#include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/Object/Binary.h"
+#include "llvm/Object/COFF.h"
+#include "llvm/Object/ELFObjectFile.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include <functional>
+#include <set>
+#include <string>
+#include <unordered_map>
+
+namespace llvm {
+namespace cfi_verify {
+
+// Disassembler and analysis tool for machine code files. Keeps track of non-
+// sequential control flows, including indirect control flow instructions.
+class FileAnalysis {
+public:
+  // A metadata struct for an instruction.
+  struct Instr {
+    uint64_t VMAddress;       // Virtual memory address of this instruction.
+    MCInst Instruction;       // Instruction.
+    uint64_t InstructionSize; // Size of this instruction.
+    bool Valid; // Is this a valid instruction? If false, Instr::Instruction is
+                // undefined.
+  };
+
+  // Construct a FileAnalysis from a file path.
+  static Expected<FileAnalysis> Create(StringRef Filename);
+
+  // Construct and take ownership of the supplied object. Do not use this
+  // constructor, prefer to use FileAnalysis::Create instead.
+  FileAnalysis(object::OwningBinary<object::Binary> Binary);
+  FileAnalysis() = delete;
+  FileAnalysis(const FileAnalysis &) = delete;
+  FileAnalysis(FileAnalysis &&Other) = default;
+
+  // Returns the instruction at the provided address. Returns nullptr if there
+  // is no instruction at the provided address.
+  const Instr *getInstruction(uint64_t Address) const;
+
+  // Returns the instruction at the provided adress, dying if the instruction is
+  // not found.
+  const Instr &getInstructionOrDie(uint64_t Address) const;
+
+  // Returns a pointer to the previous/next instruction in sequence,
+  // respectively. Returns nullptr if the next/prev instruction doesn't exist,
+  // or if the provided instruction doesn't exist.
+  const Instr *getPrevInstructionSequential(const Instr &InstrMeta) const;
+  const Instr *getNextInstructionSequential(const Instr &InstrMeta) const;
+
+  // Returns whether this instruction uses a register operand.
+  bool usesRegisterOperand(const Instr &InstrMeta) const;
+
+  // Returns the list of indirect instructions.
+  const std::set<uint64_t> &getIndirectInstructions() const;
+
+  const MCRegisterInfo *getRegisterInfo() const;
+  const MCInstrInfo *getMCInstrInfo() const;
+  const MCInstrAnalysis *getMCInstrAnalysis() const;
+
+protected:
+  // Construct a blank object with the provided triple and features. Used in
+  // testing, where a sub class will dependency inject protected methods to
+  // allow analysis of raw binary, without requiring a fully valid ELF file.
+  FileAnalysis(const Triple &ObjectTriple, const SubtargetFeatures &Features);
+
+  // Add an instruction to this object.
+  void addInstruction(const Instr &Instruction);
+
+  // Disassemble and parse the provided bytes into this object. Instruction
+  // address calculation is done relative to the provided SectionAddress.
+  void parseSectionContents(ArrayRef<uint8_t> SectionBytes,
+                            uint64_t SectionAddress);
+
+  // Constructs and initialises members required for disassembly.
+  Error initialiseDisassemblyMembers();
+
+  // Parses code sections from the internal object file. Saves them into the
+  // internal members. Should only be called once by Create().
+  Error parseCodeSections();
+
+private:
+  // Members that describe the input file.
+  object::OwningBinary<object::Binary> Binary;
+  const object::ObjectFile *Object = nullptr;
+  Triple ObjectTriple;
+  std::string ArchName;
+  std::string MCPU;
+  const Target *ObjectTarget = nullptr;
+  SubtargetFeatures Features;
+
+  // Members required for disassembly.
+  std::unique_ptr<const MCRegisterInfo> RegisterInfo;
+  std::unique_ptr<const MCAsmInfo> AsmInfo;
+  std::unique_ptr<MCSubtargetInfo> SubtargetInfo;
+  std::unique_ptr<const MCInstrInfo> MII;
+  MCObjectFileInfo MOFI;
+  std::unique_ptr<MCContext> Context;
+  std::unique_ptr<const MCDisassembler> Disassembler;
+  std::unique_ptr<const MCInstrAnalysis> MIA;
+  std::unique_ptr<MCInstPrinter> Printer;
+
+  // A mapping between the virtual memory address to the instruction metadata
+  // struct.
+  std::map<uint64_t, Instr> Instructions;
+
+  // Contains a mapping between a specific address, and a list of instructions
+  // that use this address as a branch target (including call instructions).
+  std::unordered_map<uint64_t, std::vector<uint64_t>> StaticBranchTargetings;
+
+  // A list of addresses of indirect control flow instructions.
+  std::set<uint64_t> IndirectInstructions;
+};
+
+class UnsupportedDisassembly : public ErrorInfo<UnsupportedDisassembly> {
+public:
+  static char ID;
+
+  void log(raw_ostream &OS) const override;
+  std::error_code convertToErrorCode() const override;
+};
+
+} // namespace cfi_verify
+} // namespace llvm
+
+#endif // LLVM_CFI_VERIFY_FILE_ANALYSIS_H