Add native extensions for the Dart shell to the Windows platform and the Mac OS X platform.

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com//9465004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@5235 260f80e4-7a28-3924-810f-c04153c831b5

runtime/bin/bin.gypi

@@ -346,7 +346,15 @@
           'link_settings': {
             'libraries': [ '-lws2_32.lib', '-lRpcrt4.lib' ],
           },
-       }]],
+          # Generate an import library on Windows, by exporting a function.
+          # Extensions use this import library to link to the API in dart.exe.
+          'msvs_settings': {
+            'VCLinkerTool': {
+              'AdditionalOptions': [ '/EXPORT:Dart_True' ],
+            },
+          },
+        }],
+       ],
     },
     {
       # dart binary without any snapshot built in.
@@ -421,27 +429,38 @@
         }],
       ],
     },
-  ],
-  'conditions': [
-    ['OS=="linux"', {
-      'targets': [
-        {
-          'target_name': 'test_extension',
-          'type': 'shared_library',
-          'dependencies': [
-          ],
-          'include_dirs': [
-            '.',
-          ],
-          'sources': [
-            'test_extension_linux.cc',
-          ],
-          'defines': [
-            'DART_SHARED_LIB',
-          ],
-        },
+    {
+      'target_name': 'test_extension',
+      'type': 'shared_library',
+      'dependencies': [
+        'dart',
       ],
-    }],
+      'include_dirs': [
+        '..',
+      ],
+      'sources': [
+        'test_extension.cc',
+        'test_extension_dllmain_win.cc',
+      ],
+      'defines': [
+        'DART_SHARED_LIB',
+      ],
+      'conditions': [
+        ['OS=="win"', {
+          'msvs_settings': {
+            'VCLinkerTool': {
+              'AdditionalDependencies': [ 'dart.lib' ],
+              'AdditionalLibraryDirectories': [ '<(PRODUCT_DIR)' ],
+            },
+          },
+        }],
+        ['OS=="mac"', {
+          'xcode_settings': {
+            'OTHER_LDFLAGS': [ '-undefined', 'dynamic_lookup' ],
+          },
+        }],
+      ],
+    },
   ],
 }
 

runtime/bin/builtin_impl_sources.gypi

@@ -21,6 +21,7 @@
     'eventhandler_win.cc',
     'eventhandler_win.h',
     'extensions.h',
+    'extensions.cc',
     'extensions_linux.cc',
     'extensions_macos.cc',
     'extensions_win.cc',

runtime/bin/extensions.cc

@@ -0,0 +1,57 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "bin/extensions.h"
+
+#include <stdio.h>
+
+#include "include/dart_api.h"
+#include "platform/assert.h"
+#include "platform/globals.h"
+#include "bin/dartutils.h"
+
+Dart_Handle Extensions::LoadExtension(const char* extension_url,
+                                      Dart_Handle parent_library) {
+  ASSERT(DartUtils::IsDartExtensionSchemeURL(extension_url));
+  const char* library_name =
+      extension_url + strlen(DartUtils::kDartExtensionScheme);
+  if (strchr(library_name, '/') != NULL ||
+      strchr(library_name, '\\') != NULL) {
+    return Dart_Error("path components not allowed in extension library name");
+  }
+  void* library_handle = LoadExtensionLibrary(library_name);
+  if (!library_handle) {
+    return Dart_Error("cannot find extension library");
+  }
+
+  const char* strings[3] = { library_name, "_Init", NULL };
+  char* init_function_name = Concatenate(strings);
+  typedef Dart_Handle (*InitFunctionType)(Dart_Handle import_map);
+  InitFunctionType fn = reinterpret_cast<InitFunctionType>(
+      ResolveSymbol(library_handle, init_function_name));
+  free(init_function_name);
+
+  if (fn == NULL) {
+    return Dart_Error("cannot find initialization function in extension");
+  }
+  return (*fn)(parent_library);
+}
+
+
+// Concatenates a NULL terminated array of strings.
+// The returned string must be freed.
+char* Extensions::Concatenate(const char** strings) {
+  int size = 1;  // null termination.
+  for (int i = 0; strings[i] != NULL; i++) {
+    size += strlen(strings[i]);
+  }
+  char* result = reinterpret_cast<char*>(malloc(size));
+  int index = 0;
+  for (int i = 0; strings[i] != NULL; i++) {
+    index += snprintf(result + index, size - index, "%s", strings[i]);
+  }
+  ASSERT(index == size - 1);
+  ASSERT(result[size - 1] == '\0');
+  return result;
+}

runtime/bin/extensions.h

@@ -10,13 +10,19 @@
 
 class Extensions {
  public:
-  // TODO(whesse): Make loading extensions lazy, so dynamic library is loaded
-  // only when first native function is called.
   // TODO(whesse): Make extension load from a relative path relative to
   // the library it is in.  Currently loads from current working directory.
   static Dart_Handle LoadExtension(const char* extension_url,
-                                   Dart_Handle library);
+                                   Dart_Handle parent_library);
+
  private:
+  // The returned string must be freed.
+  static char* Concatenate(const char** strings);
+
+  // Platform-specific implementations.
+  static void* LoadExtensionLibrary(const char* library_name);
+  static void* ResolveSymbol(void* lib_handle, const char* symbol);
+
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(Extensions);
 };

runtime/bin/extensions_linux.cc

@@ -2,44 +2,19 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-#include <stdio.h>
+#include "bin/extensions.h"
 #include <dlfcn.h>
 
-#include "include/dart_api.h"
-#include "platform/assert.h"
-#include "platform/globals.h"
-#include "bin/extensions.h"
-#include "bin/dartutils.h"
-
-Dart_Handle Extensions::LoadExtension(const char* extension_url,
-                                      Dart_Handle parent_library) {
-  // TODO(whesse): Consider making loading extensions lazy, so the
-  // dynamic library is loaded only when first native function is called.
-  ASSERT(DartUtils::IsDartExtensionSchemeURL(extension_url));
-  const char* library_name =
-      extension_url + strlen(DartUtils::kDartExtensionScheme);
-  if (strchr(library_name, '/') != NULL) {
-    return Dart_Error("path components not allowed in extension library name");
-  }
-  const int buffer_length = strlen(library_name) + strlen("./lib.so") + 1;
-  char* library_path = new char[buffer_length];
-  snprintf(library_path, buffer_length, "./lib%s.so", library_name);
-
+void* Extensions::LoadExtensionLibrary(const char* library_name) {
+  const char* strings[4] = { "./lib", library_name, ".so", NULL };
+  char* library_path = Concatenate(strings);
   void* lib_handle = dlopen(library_path, RTLD_LAZY);
-  if (!lib_handle) {
-    delete[] library_path;
-    return Dart_Error("cannot find extension library");
-  }
-  // Reuse library_path buffer for intialization function name.
-  char* library_init_function = library_path;
-  snprintf(library_init_function, buffer_length, "%s_Init", library_name);
-  typedef Dart_Handle (*InitFunctionType)(Dart_Handle import_map);
-  InitFunctionType fn = reinterpret_cast<InitFunctionType>(
-      dlsym(lib_handle, library_init_function));
-  delete[] library_path;
-  char *error = dlerror();
-  if (error != NULL) {
-    return Dart_Error(error);
-  }
-  return (*fn)(parent_library);
+  free(library_path);
+  return lib_handle;
+}
+
+void* Extensions::ResolveSymbol(void* lib_handle, const char* symbol) {
+  void* result = dlsym(lib_handle, symbol);
+  if (dlerror() != NULL) return NULL;
+  return result;
 }

runtime/bin/extensions_macos.cc

@@ -3,12 +3,18 @@
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/extensions.h"
+#include <dlfcn.h>
 
-#include "include/dart_api.h"
-#include "platform/assert.h"
-
-Dart_Handle Extensions::LoadExtension(const char* extension_url,
-                                      Dart_Handle parent_library) {
-  UNIMPLEMENTED();
-  return NULL;
+void* Extensions::LoadExtensionLibrary(const char* library_name) {
+  const char* strings[4] = { "./lib", library_name, ".dylib", NULL };
+  char* library_path = Concatenate(strings);
+  void* lib_handle = dlopen(library_path, RTLD_LAZY);
+  free(library_path);
+  return lib_handle;
+}
+
+void* Extensions::ResolveSymbol(void* lib_handle, const char* symbol) {
+  void* result = dlsym(lib_handle, symbol);
+  if (dlerror() != NULL) return NULL;
+  return result;
 }

runtime/bin/extensions_win.cc

@@ -4,11 +4,14 @@
 
 #include "bin/extensions.h"
 
-#include "include/dart_api.h"
-#include "platform/assert.h"
-
-Dart_Handle Extensions::LoadExtension(const char* extension_url,
-                                      Dart_Handle parent_library) {
-  UNIMPLEMENTED();
-  return NULL;
+void* Extensions::LoadExtensionLibrary(const char* library_name) {
+  const char* strings[3] = { library_name, ".dll", NULL };
+  char* library_path = Concatenate(strings);
+  void* lib_handle = LoadLibrary(library_path);
+  free(library_path);
+  return lib_handle;
+}
+
+void* Extensions::ResolveSymbol(void* lib_handle, const char* symbol) {
+  return GetProcAddress(reinterpret_cast<HMODULE>(lib_handle), symbol);
 }

runtime/bin/test_extension.cc

@@ -1,23 +1,22 @@
 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
 #include <string.h>
 
-#include "../include/dart_api.h"
+#include "include/dart_api.h"
 
-#define EXPORT_SYMBOL __attribute__ ((visibility ("default")))
+Dart_NativeFunction ResolveName(Dart_Handle name, int argc);
 
-extern "C" Dart_NativeFunction ResolveName(Dart_Handle name, int argc);
+DART_EXPORT Dart_Handle test_extension_Init(Dart_Handle parent_library) {
+  if (Dart_IsError(parent_library)) { return parent_library; }
 
-extern "C" EXPORT_SYMBOL Dart_Handle test_extension_Init(Dart_Handle library) {
-  if (Dart_IsError(library)) return library;
-  Dart_Handle check_return = Dart_SetNativeResolver(library, ResolveName);
-  if (Dart_IsError(check_return)) return check_return;
-  return Dart_Null();
+  Dart_Handle result_code = Dart_SetNativeResolver(parent_library, ResolveName);
+  if (Dart_IsError(result_code)) return result_code;
+
+  return parent_library;
 }
 
-extern "C" void IfNull(Dart_NativeArguments arguments) {
+void IfNull(Dart_NativeArguments arguments) {
   Dart_Handle object = Dart_GetNativeArgument(arguments, 0);
   if (Dart_IsNull(object)) {
     Dart_SetReturnValue(arguments, Dart_GetNativeArgument(arguments, 1));
@@ -26,7 +25,7 @@ extern "C" void IfNull(Dart_NativeArguments arguments) {
   }
 }
 
-extern "C" Dart_NativeFunction ResolveName(Dart_Handle name, int argc) {
+Dart_NativeFunction ResolveName(Dart_Handle name, int argc) {
   assert(Dart_IsString8(name));
   const char* cname;
   Dart_Handle check_error;
@@ -35,7 +34,7 @@ extern "C" Dart_NativeFunction ResolveName(Dart_Handle name, int argc) {
   if (Dart_IsError(check_error)) {
     Dart_PropagateError(check_error);
   }
-  if (!strcmp("Cat_IfNull", cname) && argc == 2) {
+  if (!strcmp("TestExtension_IfNull", cname) && argc == 2) {
     return IfNull;
   }
   return NULL;

runtime/bin/test_extension_dllmain_win.cc

@@ -0,0 +1,12 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+BOOL APIENTRY DllMain(HMODULE module,
+                      DWORD  reason,
+                      LPVOID reserved) {
+  return true;
+}

tests/standalone/src/io/test_extension.dart

@@ -14,5 +14,5 @@ class Cat {
   String toString() => 'cat $x';
 
   // Implements (a != null) ? a : b using a native C++ function and the API.
-  static int ifNull(a, b) native 'Cat_IfNull';
+  static int ifNull(a, b) native 'TestExtension_IfNull';
 }