Support command line parameters to specify a url to file name mapping. This is used during snapsh...

bin/gen_snapshot.cc

Index: bin/gen_snapshot.cc
===================================================================
--- bin/gen_snapshot.cc	(revision 1106)
+++ bin/gen_snapshot.cc	(working copy)
@@ -20,6 +20,9 @@
 // if so which file to write the snapshot into.
 static const char* snapshot_filename = NULL;
 
+// Global state that captures the URL mappings specified on the command line.
+static CommandLineOptions* url_mapping = NULL;
+
 static bool IsValidFlag(const char* name,
                         const char* prefix,
                         intptr_t prefix_length) {
@@ -40,11 +43,26 @@
 
 static bool ProcessSnapshotOption(const char* option) {
   const char* kSnapshotOption = "--snapshot=";
-  snapshot_filename = ProcessOption(option, kSnapshotOption);
-  return snapshot_filename != NULL;
+  const char* name = ProcessOption(option, kSnapshotOption);
+  if (name != NULL) {
+    snapshot_filename = name;
+    return true;
+  }
+  return false;
 }
 
 
+static bool ProcessURLmappingOption(const char* option) {
+  const char* kURLmappingOption = "--url_mapping=";
+  const char* mapping = ProcessOption(option, kURLmappingOption);
+  if (mapping != NULL) {
+    url_mapping->AddArgument(mapping);
+    return true;
+  }
+  return false;
+}
+
+
 // Parse out the command line arguments. Returns -1 if the arguments
 // are incorrect, 0 otherwise.
 static int ParseArguments(int argc,
@@ -59,7 +77,7 @@
 
   // Parse out the vm options.
   while ((i < argc) && IsValidFlag(argv[i], kPrefix, kPrefixLen)) {
-    if (ProcessSnapshotOption(argv[i])) {
+    if (ProcessSnapshotOption(argv[i]) || ProcessURLmappingOption(argv[i])) {
       i += 1;
       continue;
     }
@@ -90,6 +108,49 @@
 }
 
 
+static Dart_Handle CreateSnapshotLibraryTagHandler(Dart_LibraryTag tag,
+                                                   Dart_Handle library,
+                                                   Dart_Handle url) {
+  const bool kDontImportBuiltinLib = false;  // Do not import builtin lib.
+  Dart_Handle mapped_url = url;
+  if ((tag == kCanonicalizeUrl) && (url_mapping != NULL)) {
+    // We need to check if the passed in url is found in the url_mapping array,
+    // in that case return the mapped entry as the cannonical form.
+    if (!Dart_IsString8(url)) {
+      return Dart_Error("url is not a string");
+    }
+    const char* url_chars = NULL;
+    Dart_Handle result = Dart_StringToCString(url, &url_chars);

[Anton Muhin, 2011/11/14 14:02:13]

nit: maybe TODO to switch to API like Dart_StringGet8 later on.

+    if (!Dart_IsValid(result)) {
+      return Dart_Error("accessing url characters failed");
+    }
+    for (int idx = 0; idx < url_mapping->count(); idx++) {
+      const char* url_name = url_mapping->GetArgument(idx);
+      int len = strlen(url_chars);
+      if (!strncmp(url_chars, url_name, len) && (url_name[len] == ',')) {
+        const char* url_mapped_name = url_name + len + 1;
+        if (strlen(url_mapped_name) != 0) {
+          mapped_url = Dart_NewString(url_mapped_name);
+        }
+        break;
+      }
+    }
+  }
+  return LibraryTagHandler(tag, library, mapped_url, kDontImportBuiltinLib);
+}
+
+
+static Dart_Handle LoadSnapshotCreationScript(const char* script_name) {
+  Dart_Handle source = ReadStringFromFile(script_name);
+  if (!Dart_IsValid(source)) {
+    return source;
+  }
+  Dart_Handle url = Dart_NewString(script_name);
+
+  return Dart_LoadScript(url, source, CreateSnapshotLibraryTagHandler);
+}
+
+
 static void* SnapshotCreateCallback(void* data) {
   const char* script_name = reinterpret_cast<const char*>(data);
   Dart_Handle result;
@@ -151,6 +212,10 @@
   CommandLineOptions vm_options(argc);
   char* script_name;
 
+  // Initialize the URL mapping array.
+  CommandLineOptions url_mapping_array(argc);
+  url_mapping = &url_mapping_array;
+
   // Parse command line arguments.
   if (ParseArguments(argc,
                      argv,