1 files changed, 165 insertions, 0 deletions
diff --git a/tools/llvm-mc/Disassembler.cpp b/tools/llvm-mc/Disassembler.cpp
new file mode 100644
index 0000000000000..5fde71238dc93
--- /dev/null
+++ b/tools/llvm-mc/Disassembler.cpp
@@ -0,0 +1,165 @@
+//===- Disassembler.cpp - Disassembler for hex strings --------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This class implements the disassembler of strings of bytes written in
+// hexadecimal, from standard input or from a file.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Disassembler.h"
+
+#include "llvm/ADT/OwningPtr.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCDisassembler.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstPrinter.h"
+#include "llvm/Target/TargetRegistry.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/MemoryObject.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/SourceMgr.h"
+using namespace llvm;
+
+typedef std::vector<std::pair<unsigned char, const char*> > ByteArrayTy;
+
+namespace {
+class VectorMemoryObject : public MemoryObject {
+private:
+  const ByteArrayTy &Bytes;
+public:
+  VectorMemoryObject(const ByteArrayTy &bytes) : Bytes(bytes) {}
+  
+  uint64_t getBase() const { return 0; }
+  uint64_t getExtent() const { return Bytes.size(); }
+
+  int readByte(uint64_t Addr, uint8_t *Byte) const {
+    if (Addr > getExtent())
+      return -1;
+    *Byte = Bytes[Addr].first;
+    return 0;
+  }
+};
+}
+
+static bool PrintInst(const llvm::MCDisassembler &DisAsm,
+                      llvm::MCInstPrinter &Printer, const ByteArrayTy &Bytes,
+                      SourceMgr &SM) {
+  // Wrap the vector in a MemoryObject.
+  VectorMemoryObject memoryObject(Bytes);
+  
+  // Disassemble it to a string and get the size of the instruction.
+  MCInst Inst;
+  uint64_t Size;
+  
+  if (!DisAsm.getInstruction(Inst, Size, memoryObject, 0, 
+                             /*REMOVE*/ nulls())) {
+    SM.PrintMessage(SMLoc::getFromPointer(Bytes[0].second),
+                    "invalid instruction encoding", "error");
+    return true;
+  }
+  
+  Printer.printInst(&Inst);
+  outs() << "\n";
+  
+  // If the disassembled instruction was smaller than the number of bytes we
+  // read, reject the excess bytes.
+  if (Bytes.size() != Size) {
+    SM.PrintMessage(SMLoc::getFromPointer(Bytes[Size].second),
+                    "excess data detected in input", "error");
+    return true;
+  }
+  
+  return false;
+}
+
+int Disassembler::disassemble(const Target &T, const std::string &Triple,
+                                 MemoryBuffer &Buffer) {
+  // Set up disassembler.
+  llvm::OwningPtr<const llvm::MCAsmInfo> AsmInfo(T.createAsmInfo(Triple));
+  
+  if (!AsmInfo) {
+    errs() << "error: no assembly info for target " << Triple << "\n";
+    return -1;
+  }
+  
+  llvm::OwningPtr<const llvm::MCDisassembler> DisAsm(T.createMCDisassembler());
+  if (!DisAsm) {
+    errs() << "error: no disassembler for target " << Triple << "\n";
+    return -1;
+  }
+  
+  llvm::MCInstPrinter *InstPrinter = T.createMCInstPrinter(0, *AsmInfo, outs());
+  
+  if (!InstPrinter) {
+    errs() << "error: no instruction printer for target " << Triple << '\n';
+    return -1;
+  }
+  
+  bool ErrorOccurred = false;
+  
+  SourceMgr SM;
+  SM.AddNewSourceBuffer(&Buffer, SMLoc());
+  
+  // Convert the input to a vector for disassembly.
+  ByteArrayTy ByteArray;
+  
+  StringRef Str = Buffer.getBuffer();
+  while (!Str.empty()) {
+    // Strip horizontal whitespace.
+    if (size_t Pos = Str.find_first_not_of(" \t\r")) {
+      Str = Str.substr(Pos);
+      continue;
+    }
+    
+    // If this is the end of a line or start of a comment, process the
+    // instruction we have so far.
+    if (Str[0] == '\n' || Str[0] == '#') {
+      // If we have bytes to process, do so.
+      if (!ByteArray.empty()) {
+        ErrorOccurred |= PrintInst(*DisAsm, *InstPrinter, ByteArray, SM);
+        ByteArray.clear();
+      }
+      
+      // Strip to the end of line if we already processed any bytes on this
+      // line.  This strips the comment and/or the \n.
+      if (Str[0] == '\n')
+        Str = Str.substr(1);
+      else {
+        Str = Str.substr(Str.find_first_of('\n'));
+        if (!Str.empty())
+          Str = Str.substr(1);
+      }
+      continue;
+    }
+    
+    // Get the current token.
+    size_t Next = Str.find_first_of(" \t\n\r#");
+    StringRef Value = Str.substr(0, Next);
+    
+    // Convert to a byte and add to the byte vector.
+    unsigned ByteVal;
+    if (Value.getAsInteger(0, ByteVal) || ByteVal > 255) {
+      // If we have an error, print it and skip to the end of line.
+      SM.PrintMessage(SMLoc::getFromPointer(Value.data()),
+                                 "invalid input token", "error");
+      ErrorOccurred = true;
+      Str = Str.substr(Str.find('\n'));
+      ByteArray.clear();
+      continue;
+    }
+    
+    ByteArray.push_back(std::make_pair((unsigned char)ByteVal, Value.data()));
+    Str = Str.substr(Next);
+  }
+  
+  if (!ByteArray.empty())
+    ErrorOccurred |= PrintInst(*DisAsm, *InstPrinter, ByteArray, SM);
+    
+  return ErrorOccurred;
+}