Second step towards loading the core library scripts directly from the sources

runtime/vm/bootstrap.cc

Index: runtime/vm/bootstrap.cc
===================================================================
--- runtime/vm/bootstrap.cc	(revision 22375)
+++ runtime/vm/bootstrap.cc	(working copy)
@@ -25,7 +25,7 @@
 typedef struct {
   intptr_t index_;
   const char* uri_;
-  const char* source_;
+  const char** source_paths_;
   const char* patch_uri_;
   const char* patch_source_;
 } bootstrap_lib_props;
@@ -34,73 +34,171 @@
 static bootstrap_lib_props bootstrap_libraries[] = {
   INIT_LIBRARY(ObjectStore::kCore,
                core,
-               Bootstrap::corelib_source_,
+               Bootstrap::corelib_source_paths_,
                Bootstrap::corelib_patch_),
   INIT_LIBRARY(ObjectStore::kAsync,
                async,
-               Bootstrap::async_source_,
+               Bootstrap::async_source_paths_,
                Bootstrap::async_patch_),
   INIT_LIBRARY(ObjectStore::kCollection,
                collection,
-               Bootstrap::collection_source_,
+               Bootstrap::collection_source_paths_,
                Bootstrap::collection_patch_),
   INIT_LIBRARY(ObjectStore::kCollectionDev,
                _collection-dev,
-               Bootstrap::collection_dev_source_,
+               Bootstrap::collection_dev_source_paths_,
                Bootstrap::collection_dev_patch_),
   INIT_LIBRARY(ObjectStore::kCrypto,
                crypto,
-               Bootstrap::crypto_source_,
+               Bootstrap::crypto_source_paths_,
                NULL),
   INIT_LIBRARY(ObjectStore::kIsolate,
                isolate,
-               Bootstrap::isolate_source_,
+               Bootstrap::isolate_source_paths_,
                Bootstrap::isolate_patch_),
   INIT_LIBRARY(ObjectStore::kJson,
                json,
-               Bootstrap::json_source_,
+               Bootstrap::json_source_paths_,
                Bootstrap::json_patch_),
   INIT_LIBRARY(ObjectStore::kMath,
                math,
-               Bootstrap::math_source_,
+               Bootstrap::math_source_paths_,
                Bootstrap::math_patch_),
   INIT_LIBRARY(ObjectStore::kMirrors,
                mirrors,
-               Bootstrap::mirrors_source_,
+               Bootstrap::mirrors_source_paths_,
                Bootstrap::mirrors_patch_),
   INIT_LIBRARY(ObjectStore::kTypedData,
                typed_data,
-               Bootstrap::typed_data_source_,
+               Bootstrap::typed_data_source_paths_,
                Bootstrap::typed_data_patch_),
   INIT_LIBRARY(ObjectStore::kUtf,
                utf,
-               Bootstrap::utf_source_,
+               Bootstrap::utf_source_paths_,
                NULL),
   INIT_LIBRARY(ObjectStore::kUri,
                uri,
-               Bootstrap::uri_source_,
+               Bootstrap::uri_source_paths_,
                NULL),
 
   { ObjectStore::kNone, NULL, NULL, NULL, NULL }
 };
 
 
-static RawString* GetLibrarySource(intptr_t index, bool patch) {
-  // TODO(asiva): Replace with actual read of the source file.
-  const char* source = patch ? bootstrap_libraries[index].patch_source_ :
-                               bootstrap_libraries[index].source_;
-  ASSERT(source != NULL);
-  return String::New(source, Heap::kOld);
+static RawString* GetLibrarySource(const Library& lib,
+                                   const String& uri,
+                                   bool patch) {
+  // First check if this is a valid boot strap library and find it's index
+  // in the 'bootstrap_libraries' table above.
+  intptr_t index = 0;
+  const String& lib_uri = String::Handle(lib.url());
+  while (bootstrap_libraries[index].index_ != ObjectStore::kNone) {
+    if (lib_uri.Equals(bootstrap_libraries[index].uri_)) {
+      break;
+    }
+    index += 1;
+  }
+  if (bootstrap_libraries[index].index_ == ObjectStore::kNone) {
+    return String::null();  // Library is not a boot strap library.
+  }
+
+  if (patch) {
+    // TODO(asiva): Replace with actual read of the source file.
+    const char* source = bootstrap_libraries[index].patch_source_;
+    ASSERT(source != NULL);
+    return String::New(source, Heap::kOld);
+  }
+
+  // Try to read the source using the path specified for the uri.
+  const char** source_paths = bootstrap_libraries[index].source_paths_;
+  if (source_paths == NULL) {
+    return String::null();  // No path mapping information exists for library.
+  }
+  intptr_t i = 0;
+  const char* source_path = NULL;
+  while (source_paths[i] != NULL) {
+    if (uri.Equals(source_paths[i])) {
+      source_path = source_paths[i + 1];
+      break;
+    }
+    i += 2;
+  }
+  if (source_path == NULL) {
+    return String::null();  // Uri does not exist in path mapping information.
+  }
+
+  Dart_FileOpenCallback file_open = Isolate::file_open_callback();
+  Dart_FileReadCallback file_read = Isolate::file_read_callback();
+  Dart_FileCloseCallback file_close = Isolate::file_close_callback();
+  if (file_open == NULL || file_read == NULL || file_close == NULL) {
+    return String::null();  // File operations are not supported.
+  }
+
+  void* stream = (*file_open)(source_path, false);
+  if (stream == NULL) {
+    return String::null();
+  }
+
+  const uint8_t* utf8_array = NULL;
+  intptr_t file_length = -1;
+  (*file_read)(&utf8_array, &file_length, stream);
+  if (file_length == -1) {
+    return String::null();
+  }
+  ASSERT(utf8_array != NULL);
+
+  (*file_close)(stream);
+
+  return String::FromUTF8(utf8_array, file_length);
 }
 
 
+static RawError* Compile(const Library& library, const Script& script) {
+  if (FLAG_print_bootstrap) {
+    OS::Print("Bootstrap source '%s':\n%s\n",
+              String::Handle(script.url()).ToCString(),
+              String::Handle(script.Source()).ToCString());
+  }
+  bool update_lib_status = (script.kind() == RawScript::kScriptTag ||
+                            script.kind() == RawScript::kLibraryTag);
+  if (update_lib_status) {
+    library.SetLoadInProgress();
+  }
+  const Error& error = Error::Handle(Compiler::Compile(library, script));
+  if (update_lib_status) {
+    if (error.IsNull()) {
+      library.SetLoaded();
+    } else {
+      library.SetLoadError();
+    }
+  }
+  return error.raw();
+}
+
+
 static Dart_Handle LoadPartSource(Isolate* isolate,
                                   const Library& lib,
                                   const String& uri) {
-  // TODO(asiva): For now we return an error here, once we start
-  // loading libraries from the real source this would have to call the
-  // file read callback here and invoke Compiler::Compile on it.
-  return Dart_NewApiError("Unable to load source '%s' ", uri.ToCString());
+  const String& part_source = String::Handle(
+      isolate, GetLibrarySource(lib, uri, false));
+  const String& lib_uri = String::Handle(isolate, lib.url());
+  if (part_source.IsNull()) {
+    return Dart_NewApiError("Unable to read part file '%s' of library '%s'",
+                            uri.ToCString(), lib_uri.ToCString());
+  }
+
+  // Prepend the library URI to form a unique script URI for the part.
+  const Array& strings = Array::Handle(isolate, Array::New(3));
+  strings.SetAt(0, lib_uri);
+  strings.SetAt(1, Symbols::Slash());
+  strings.SetAt(2, uri);
+  const String& part_uri = String::Handle(isolate, String::ConcatAll(strings));
+
+  // Create a script object and compile the part.
+  const Script& part_script = Script::Handle(
+      isolate, Script::New(part_uri, part_source, RawScript::kSourceTag));
+  const Error& error = Error::Handle(isolate, Compile(lib, part_script));
+  return Api::NewHandle(isolate, error.raw());
 }
 
 
@@ -114,18 +212,12 @@
   if (!Dart_IsString(uri)) {
     return Dart_NewApiError("uri is not a string");
   }
-  const String& uri_str = Api::UnwrapStringHandle(isolate, uri);
-  ASSERT(!uri_str.IsNull());
-  bool is_dart_scheme_uri = uri_str.StartsWith(Symbols::DartScheme());
-  if (!is_dart_scheme_uri) {
-    // The bootstrap tag handler can only handle dart scheme uris.
-    return Dart_NewApiError("Do not know how to load '%s' ",
-                            uri_str.ToCString());
-  }
   if (tag == kCanonicalizeUrl) {
-    // Dart Scheme URIs do not need any canonicalization.
+    // In the boot strap loader we do not try and do any canonicalization.
     return uri;
   }
+  const String& uri_str = Api::UnwrapStringHandle(isolate, uri);
+  ASSERT(!uri_str.IsNull());
   if (tag == kImportTag) {
     // We expect the core bootstrap libraries to only import other
     // core bootstrap libraries.
@@ -142,23 +234,6 @@
 }
 
 
-static RawError* Compile(const Library& library, const Script& script) {
-  if (FLAG_print_bootstrap) {
-    OS::Print("Bootstrap source '%s':\n%s\n",
-              String::Handle(script.url()).ToCString(),
-              String::Handle(script.Source()).ToCString());
-  }
-  library.SetLoadInProgress();
-  const Error& error = Error::Handle(Compiler::Compile(library, script));
-  if (error.IsNull()) {
-    library.SetLoaded();
-  } else {
-    library.SetLoadError();
-  }
-  return error.raw();
-}
-
-
 RawError* Bootstrap::LoadandCompileScripts() {
   Isolate* isolate = Isolate::Current();
   String& uri = String::Handle();
@@ -197,7 +272,13 @@
     uri = Symbols::New(bootstrap_libraries[i].uri_);
     lib = Library::LookupLibrary(uri);
     ASSERT(!lib.IsNull());
-    source = GetLibrarySource(i, false);
+    source = GetLibrarySource(lib, uri, false);
+    if (source.IsNull()) {
+      error ^= Api::UnwrapErrorHandle(
+          isolate, Api::NewError("Unable to find dart source for %s",
+                                 uri.ToCString())).raw();
+      break;
+    }
     script = Script::New(uri, source, RawScript::kLibraryTag);
     error = Compile(lib, script);
     if (!error.IsNull()) {
@@ -207,7 +288,13 @@
     if (bootstrap_libraries[i].patch_source_ != NULL) {
       patch_uri = String::New(bootstrap_libraries[i].patch_uri_,
                               Heap::kOld);
-      source = GetLibrarySource(i, true);
+      source = GetLibrarySource(lib, uri, true);
+      if (source.IsNull()) {
+        error ^= Api::UnwrapErrorHandle(
+            isolate, Api::NewError("Unable to find dart patch source for %s",
+                                   uri.ToCString())).raw();
+        break;
+      }
       script = Script::New(patch_uri, source, RawScript::kPatchTag);
       error = lib.Patch(script);
       if (!error.IsNull()) {