Add new dependency generation option to aidl.

The SDK build system does not provide an output file
and instead uses the -o<FOLDER> option and lets aidl figure
out the intermediary folders that represents the packages,
and the filename based on the input file (and its package).

Because of this the -d<FILE> option to generate a dependency
file is not convenient.

Instead the new option, -a (no parameters), automatically generate
a dependency files next to the output file.

Also, when compiling parcelable aidl files, without the -b option,
a dependency file is still generated. This is used by the SDK build
system since it cannot parse the file separately and instead tries
to compile every .aidl file.
The generation of this dependency file (which shows no output) allows
to know when any type of aidl file has been compiled.

Change-Id: If81dc7e1e0a780592c94d1850a1d1b094d6e7908
diff --git a/tools/aidl/aidl.cpp b/tools/aidl/aidl.cpp
index 92f5b64..fb4067a 100644
--- a/tools/aidl/aidl.cpp
+++ b/tools/aidl/aidl.cpp
@@ -575,12 +575,19 @@
 
 // ==========================================================
 void
-generate_dep_file(const Options& options)
+generate_dep_file(const Options& options, const document_item_type* items)
 {
-   /* we open the file in binary mode to ensure that the same output is
-    * generated on all platforms !!
-    */
-    FILE* to = fopen(options.depFileName.c_str(), "wb");
+    /* we open the file in binary mode to ensure that the same output is
+     * generated on all platforms !!
+     */
+    FILE* to = NULL;
+    if (options.autoDepFile) {
+        string fileName = options.outputFileName + ".d";
+        to = fopen(fileName.c_str(), "wb");
+    } else {
+        to = fopen(options.depFileName.c_str(), "wb");
+    }
+
     if (to == NULL) {
         return;
     }
@@ -591,7 +598,12 @@
         slash = "";
     }
 
-    fprintf(to, "%s: \\\n", options.outputFileName.c_str());
+    if (items->item_type == INTERFACE_TYPE) {
+        fprintf(to, "%s: \\\n", options.outputFileName.c_str());
+    } else {
+        // parcelable: there's no output file.
+        fprintf(to, " : \\\n");
+    }
     fprintf(to, "  %s %s\n", options.inputFileName.c_str(), slash);
 
     while (import) {
@@ -611,44 +623,60 @@
 
 // ==========================================================
 static string
-generate_outputFileName(const Options& options, const document_item_type* items)
+generate_outputFileName2(const Options& options, const buffer_type& name, const char* package)
 {
     string result;
 
-    // items has already been checked to have only one interface.
-    if (items->item_type == INTERFACE_TYPE) {
-        interface_type* type = (interface_type*)items;
+    // create the path to the destination folder based on the
+    // interface package name
+    result = options.outputBaseFolder;
+    result += OS_PATH_SEPARATOR;
 
-        // create the path to the destination folder based on the
-        // interface package name
-        result = options.outputBaseFolder;
-        result += OS_PATH_SEPARATOR;
-
-        string package = type->package;
-        size_t len = package.length();
-        for (size_t i=0; i<len; i++) {
-            if (package[i] == '.') {
-                package[i] = OS_PATH_SEPARATOR;
-            }
+    string packageStr = package;
+    size_t len = packageStr.length();
+    for (size_t i=0; i<len; i++) {
+        if (packageStr[i] == '.') {
+            packageStr[i] = OS_PATH_SEPARATOR;
         }
-
-        result += package;
-        
-        // add the filename by replacing the .aidl extension to .java
-        const char* p = strchr(type->name.data, '.');
-        len = p ? p-type->name.data : strlen(type->name.data);
-
-        result += OS_PATH_SEPARATOR;
-        result.append(type->name.data, len);
-        result += ".java";
     }
 
+    result += packageStr;
+
+    // add the filename by replacing the .aidl extension to .java
+    const char* p = strchr(name.data, '.');
+    len = p ? p-name.data : strlen(name.data);
+
+    result += OS_PATH_SEPARATOR;
+    result.append(name.data, len);
+    result += ".java";
+
     return result;
 }
 
 // ==========================================================
+static string
+generate_outputFileName(const Options& options, const document_item_type* items)
+{
+    // items has already been checked to have only one interface.
+    if (items->item_type == INTERFACE_TYPE) {
+        interface_type* type = (interface_type*)items;
+
+        return generate_outputFileName2(options, type->name, type->package);
+    } else if (items->item_type == PARCELABLE_TYPE) {
+        parcelable_type* type = (parcelable_type*)items;
+        return generate_outputFileName2(options, type->name, type->package);
+    }
+
+    // I don't think we can come here, but safer than returning NULL.
+    string result;
+    return result;
+}
+
+
+
+// ==========================================================
 static void
-check_outputFileName(const string& path) {
+check_outputFilePath(const string& path) {
     size_t len = path.length();
     for (size_t i=0; i<len ; i++) {
         if (path[i] == OS_PATH_SEPARATOR) {
@@ -756,7 +784,7 @@
 
 // ==========================================================
 static int
-compile_aidl(const Options& options)
+compile_aidl(Options& options)
 {
     int err = 0, N;
 
@@ -850,27 +878,30 @@
         return 1;
     }
 
+    // if needed, generate the outputFileName from the outputBaseFolder
+    if (options.outputFileName.length() == 0 &&
+            options.outputBaseFolder.length() > 0) {
+        options.outputFileName = generate_outputFileName(options, mainDoc);
+    }
+
+    // if we were asked to, generate a make dependency file
+    // unless it's a parcelable *and* it's supposed to fail on parcelable
+    if ((options.autoDepFile || options.depFileName != "") &&
+            !(onlyParcelable && options.failOnParcelable)) {
+        // make sure the folders of the output file all exists
+        check_outputFilePath(options.outputFileName);
+        generate_dep_file(options, mainDoc);
+    }
+
     // they didn't ask to fail on parcelables, so just exit quietly.
     if (onlyParcelable && !options.failOnParcelable) {
         return 0;
     }
 
-    // if we were asked to, generate a make dependency file
-    if (options.depFileName != "") {
-        generate_dep_file(options);
-    }
-
-    // if needed, generate the outputFileName from the outputBaseFolder
-    string outputFileName = options.outputFileName;
-    if (outputFileName.length() == 0 &&
-            options.outputBaseFolder.length() > 0) {
-        outputFileName = generate_outputFileName(options, mainDoc);
-    }
-    
     // make sure the folders of the output file all exists
-    check_outputFileName(outputFileName);
+    check_outputFilePath(options.outputFileName);
 
-    err = generate_java(outputFileName, options.inputFileName.c_str(),
+    err = generate_java(options.outputFileName, options.inputFileName.c_str(),
                         (interface_type*)mainDoc);
 
     return err;
diff --git a/tools/aidl/options.cpp b/tools/aidl/options.cpp
index 0aa7db2..7b2daeb 100644
--- a/tools/aidl/options.cpp
+++ b/tools/aidl/options.cpp
@@ -15,6 +15,7 @@
             "OPTIONS:\n"
             "   -I<DIR>    search path for import statements.\n"
             "   -d<FILE>   generate dependency file.\n"
+            "   -a         generate dependency file next to the output file with the name based on the input file.\n"
             "   -p<FILE>   file created by --preprocess to import.\n"
             "   -o<FOLDER> base output folder for generated files.\n"
             "   -b         fail when trying to compile a parcelable.\n"
@@ -49,6 +50,7 @@
 
     options->task = COMPILE_AIDL;
     options->failOnParcelable = false;
+    options->autoDepFile = false;
 
     // OPTIONS
     while (i < argc) {
@@ -73,6 +75,9 @@
                         return usage();
                     }
                 }
+                else if (s[1] == 'a') {
+                    options->autoDepFile = true;
+                }
                 else if (s[1] == 'p') {
                     if (len > 2) {
                         options->preprocessedFiles.push_back(s+2);
diff --git a/tools/aidl/options.h b/tools/aidl/options.h
index d88d988..387e37d 100644
--- a/tools/aidl/options.h
+++ b/tools/aidl/options.h
@@ -23,6 +23,7 @@
     string outputFileName;
     string outputBaseFolder;
     string depFileName;
+    bool autoDepFile;
 
     vector<string> filesToPreprocess;
 };