Add dex file intermediate representation

Add an intermediate representation, constructed from the DexFile
utilities, that can be used to optimize the layout and re-emit dex
files.

BUG: 29921113
TEST: TODO: Add dex files to compare output with dexdump

(cherry-picked from commit af14d9f551e6169c201dc7981d9cfbcb53c7d2c7)

Change-Id: I3dacb78fad5228e43d77f20b110bd40e0e116cdb
diff --git a/dexlayout/dexlayout_main.cc b/dexlayout/dexlayout_main.cc
new file mode 100644
index 0000000..286a0c6
--- /dev/null
+++ b/dexlayout/dexlayout_main.cc
@@ -0,0 +1,157 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Main driver of the dexlayout utility.
+ *
+ * This is a tool to read dex files into an internal representation,
+ * reorganize the representation, and emit dex files with a better
+ * file layout.
+ */
+
+#include "dexlayout.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "mem_map.h"
+#include "runtime.h"
+
+namespace art {
+
+static const char* kProgramName = "dexlayout";
+
+/*
+ * Shows usage.
+ */
+static void Usage(void) {
+  fprintf(stderr, "Copyright (C) 2007 The Android Open Source Project\n\n");
+  fprintf(stderr, "%s: [-a] [-c] [-d] [-e] [-f] [-h] [-i] [-l layout] [-o outfile]"
+                  " dexfile...\n\n", kProgramName);
+  fprintf(stderr, " -a : display annotations\n");
+  fprintf(stderr, " -b : build dex_ir\n");
+  fprintf(stderr, " -c : verify checksum and exit\n");
+  fprintf(stderr, " -d : disassemble code sections\n");
+  fprintf(stderr, " -e : display exported items only\n");
+  fprintf(stderr, " -f : display summary information from file header\n");
+  fprintf(stderr, " -g : display CFG for dex\n");
+  fprintf(stderr, " -h : display file header details\n");
+  fprintf(stderr, " -i : ignore checksum failures\n");
+  fprintf(stderr, " -l : output layout, either 'plain' or 'xml'\n");
+  fprintf(stderr, " -o : output file name (defaults to stdout)\n");
+}
+
+/*
+ * Main driver of the dexlayout utility.
+ */
+int DexlayoutDriver(int argc, char** argv) {
+  // Art specific set up.
+  InitLogging(argv);
+  MemMap::Init();
+
+  // Reset options.
+  bool want_usage = false;
+  memset(&options_, 0, sizeof(options_));
+  options_.verbose_ = true;
+
+  // Parse all arguments.
+  while (1) {
+    const int ic = getopt(argc, argv, "abcdefghil:o:");
+    if (ic < 0) {
+      break;  // done
+    }
+    switch (ic) {
+      case 'a':  // display annotations
+        options_.show_annotations_ = true;
+        break;
+      case 'b':  // build dex_ir
+        options_.build_dex_ir_ = true;
+        break;
+      case 'c':  // verify the checksum then exit
+        options_.checksum_only_ = true;
+        break;
+      case 'd':  // disassemble Dalvik instructions
+        options_.disassemble_ = true;
+        break;
+      case 'e':  // exported items only
+        options_.exports_only_ = true;
+        break;
+      case 'f':  // display outer file header
+        options_.show_file_headers_ = true;
+        break;
+      case 'g':  // display cfg
+        options_.show_cfg_ = true;
+        break;
+      case 'h':  // display section headers, i.e. all meta-data
+        options_.show_section_headers_ = true;
+        break;
+      case 'i':  // continue even if checksum is bad
+        options_.ignore_bad_checksum_ = true;
+        break;
+      case 'l':  // layout
+        if (strcmp(optarg, "plain") == 0) {
+          options_.output_format_ = kOutputPlain;
+        } else if (strcmp(optarg, "xml") == 0) {
+          options_.output_format_ = kOutputXml;
+          options_.verbose_ = false;
+        } else {
+          want_usage = true;
+        }
+        break;
+      case 'o':  // output file
+        options_.output_file_name_ = optarg;
+        break;
+      default:
+        want_usage = true;
+        break;
+    }  // switch
+  }  // while
+
+  // Detect early problems.
+  if (optind == argc) {
+    fprintf(stderr, "%s: no file specified\n", kProgramName);
+    want_usage = true;
+  }
+  if (options_.checksum_only_ && options_.ignore_bad_checksum_) {
+    fprintf(stderr, "Can't specify both -c and -i\n");
+    want_usage = true;
+  }
+  if (want_usage) {
+    Usage();
+    return 2;
+  }
+
+  // Open alternative output file.
+  if (options_.output_file_name_) {
+    out_file_ = fopen(options_.output_file_name_, "w");
+    if (!out_file_) {
+      fprintf(stderr, "Can't open %s\n", options_.output_file_name_);
+      return 1;
+    }
+  }
+
+  // Process all files supplied on command line.
+  int result = 0;
+  while (optind < argc) {
+    result |= ProcessFile(argv[optind++]);
+  }  // while
+  return result != 0;
+}
+
+}  // namespace art
+
+int main(int argc, char** argv) {
+  return art::DexlayoutDriver(argc, argv);
+}