auto import from //depot/cupcake/@135843
diff --git a/tools/aidl/options.cpp b/tools/aidl/options.cpp
new file mode 100644
index 0000000..57b10ae
--- /dev/null
+++ b/tools/aidl/options.cpp
@@ -0,0 +1,138 @@
+
+#include "options.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int
+usage()
+{
+    fprintf(stderr,
+            "usage: aidl OPTIONS INPUT [OUTPUT]\n"
+            "       aidl --preprocess OUTPUT INPUT...\n"
+            "\n"
+            "OPTIONS:\n"
+            "   -I<DIR>  search path for import statements.\n"
+            "   -d<FILE> generate dependency file.\n"
+            "   -p<FILE> file created by --preprocess to import.\n"
+            "   -b       fail when trying to compile a parcelable.\n"
+            "\n"
+            "INPUT:\n"
+            "   An aidl interface file.\n"
+            "\n"
+            "OUTPUT:\n"
+            "   The generated interface files. If omitted, the input filename is used, with the .aidl extension changed to a .java extension.\n"
+           );
+    return 1;
+}
+
+int
+parse_options(int argc, const char* const* argv, Options *options)
+{
+    int i = 1;
+
+    if (argc >= 2 && 0 == strcmp(argv[1], "--preprocess")) {
+        if (argc < 4) {
+            return usage();
+        }
+        options->outputFileName = argv[2];
+        for (int i=3; i<argc; i++) {
+            options->filesToPreprocess.push_back(argv[i]);
+        }
+        options->task = PREPROCESS_AIDL;
+        return 0;
+    }
+
+    options->task = COMPILE_AIDL;
+    options->failOnParcelable = false;
+
+    // OPTIONS
+    while (i < argc) {
+        const char* s = argv[i];
+        int len = strlen(s);
+        if (s[0] == '-') {
+            if (len > 1) {
+                // -I<system-import-path>
+                if (s[1] == 'I') {
+                    if (len > 2) {
+                        options->importPaths.push_back(s+2);
+                    } else {
+                        fprintf(stderr, "-I option (%d) requires a path.\n", i);
+                        return usage();
+                    }
+                }
+                else if (s[1] == 'd') {
+                    if (len > 2) {
+                        options->depFileName = s+2;
+                    } else {
+                        fprintf(stderr, "-d option (%d) requires a file.\n", i);
+                        return usage();
+                    }
+                }
+                else if (s[1] == 'p') {
+                    if (len > 2) {
+                        options->preprocessedFiles.push_back(s+2);
+                    } else {
+                        fprintf(stderr, "-p option (%d) requires a file.\n", i);
+                        return usage();
+                    }
+                }
+                else if (len == 2 && s[1] == 'b') {
+                    options->failOnParcelable = true;
+                }
+                else {
+                    // s[1] is not known
+                    fprintf(stderr, "unknown option (%d): %s\n", i, s);
+                    return usage();
+                }
+            } else {
+                // len <= 1
+                fprintf(stderr, "unknown option (%d): %s\n", i, s);
+                return usage();
+            }
+        } else {
+            // s[0] != '-'
+            break;
+        }
+        i++;
+    }
+
+    // INPUT
+    if (i < argc) {
+        options->inputFileName = argv[i];
+        i++;
+    } else {
+        fprintf(stderr, "INPUT required\n");
+        return usage();
+    }
+
+    // OUTPUT
+    if (i < argc) {
+        options->outputFileName = argv[i];
+        i++;
+    } else {
+        // copy input into output and change the extension from .aidl to .java
+        options->outputFileName = options->inputFileName;
+        string::size_type pos = options->outputFileName.size()-5;
+        if (options->outputFileName.compare(pos, 5, ".aidl") == 0) {  // 5 = strlen(".aidl")
+            options->outputFileName.replace(pos, 5, ".java"); // 5 = strlen(".aidl")
+        } else {
+            fprintf(stderr, "INPUT is not an .aidl file.\n");
+            return usage();
+        }
+     }
+
+    // anything remaining?
+    if (i != argc) {
+        fprintf(stderr, "unknown option%s:", (i==argc-1?(const char*)"":(const char*)"s"));
+        for (; i<argc-1; i++) {
+            fprintf(stderr, " %s", argv[i]);
+        }
+        fprintf(stderr, "\n");
+        return usage();
+    }
+
+    return 0;
+}
+