Implement fromEnvironment on bool, int and String

runtime/bin/main.cc

Index: runtime/bin/main.cc
diff --git a/runtime/bin/main.cc b/runtime/bin/main.cc
index 59501a952700fcd561ef120d1c5238f5a4682651..8ec815cf978db263d26a0ee70e2ee4dbe60e3d62 100644
--- a/runtime/bin/main.cc
+++ b/runtime/bin/main.cc
@@ -72,6 +72,8 @@ static bool start_vm_service = false;
 static int vm_service_server_port = -1;
 static const int DEFAULT_VM_SERVICE_SERVER_PORT = 8181;
 
+// The configuration provided through the command line using -D options.
+static HashMap* environment = NULL;
 
 static bool IsValidFlag(const char* name,
                         const char* prefix,
@@ -132,6 +134,48 @@ static bool ProcessPackageRootOption(const char* arg) {
 }
 
 
+static void* GetHashmapKeyFromString(char* key) {
+  return reinterpret_cast<void*>(key);
+}
+
+static bool ProcessDefineOption(const char* arg) {
+  ASSERT(arg != NULL);
+  if (*arg == '\0') {
+    // Ignore empty -D option.
+    Log::PrintErr("No arguments given to -D option\n");
+    return true;
+  }
+  if (environment == NULL) {
+    environment = new HashMap(&HashMap::SameStringValue, 4);
+  }
+  // Split the name=value part of the -Dname=value argument.
+  char* name;
+  char* value = NULL;
+  const char* equals_pos = strchr(arg, '=');
+  if (equals_pos == NULL) {
+    // No equal sign (name without value) currently not supported.
+    Log::PrintErr("No value given to -D option\n");
+    return false;
+  } else {
+    int name_len = equals_pos - arg;
+    if (name_len == 0) {
+      Log::PrintErr("No name given to -D option\n");
+      return false;
+    }
+    // Split name=value into name and value.
+    name = reinterpret_cast<char*>(malloc(name_len + 1));
+    strncpy(name, arg, name_len);
+    name[name_len] = '\0';
+    value = strdup(equals_pos + 1);
+  }
+  HashMap::Entry* entry = environment->Lookup(
+      GetHashmapKeyFromString(name), HashMap::StringHash(name), true);
+  ASSERT(entry != NULL);  // Lookup adds an entry if key not found.
+  entry->value = value;
+  return true;
+}
+
+
 static bool ProcessCompileAllOption(const char* arg) {
   ASSERT(arg != NULL);
   if (*arg != '\0') {
@@ -246,6 +290,7 @@ static struct {
   { "--verbose", ProcessVerboseOption },
   { "-v", ProcessVerboseOption },
   { "--package-root=", ProcessPackageRootOption },
+  { "-D", ProcessDefineOption },
   // VM specific options to the standalone dart program.
   { "--break-at=", ProcessBreakpointOption },
   { "--compile_all", ProcessCompileAllOption },
@@ -433,6 +478,37 @@ static Dart_Handle SetupRuntimeOptions(CommandLineOptions* options) {
   }                                                                            \
 
 
+static Dart_Handle ConfigCallback(Dart_Handle name) {
+  uint8_t* utf8_array;
+  intptr_t utf8_len;
+  Dart_Handle result = Dart_Null();
+  Dart_Handle handle = Dart_StringToUTF8(name, &utf8_array, &utf8_len);
+  if (Dart_IsError(handle)) {
+    handle = Dart_ThrowException(
+        DartUtils::NewDartArgumentError(Dart_GetError(handle)));
+  } else {
+    char* name_chars = reinterpret_cast<char*>(malloc(utf8_len + 1));
+    memmove(name_chars, utf8_array, utf8_len);
+    name_chars[utf8_len] = '\0';
+    const char* value = NULL;
+    if (environment != NULL) {
+      HashMap::Entry* entry = environment->Lookup(
+          GetHashmapKeyFromString(name_chars),
+          HashMap::StringHash(name_chars),
+          false);
+      if (entry != NULL) {
+        value = reinterpret_cast<char*>(entry->value);
+      }
+    }
+    if (value != NULL) {
+      result = Dart_NewStringFromUTF8(reinterpret_cast<const uint8_t*>(value),
+                                      strlen(value));
+    }
+  }
+  return result;
+}
+
+
 // Returns true on success, false on failure.
 static Dart_Isolate CreateIsolateAndSetupHelper(const char* script_uri,
                                                 const char* main,
@@ -457,6 +533,9 @@ static Dart_Isolate CreateIsolateAndSetupHelper(const char* script_uri,
   Dart_Handle result = Dart_SetLibraryTagHandler(DartUtils::LibraryTagHandler);
   CHECK_RESULT(result);
 
+  result = Dart_SetConfigCallback(ConfigCallback);
+  CHECK_RESULT(result);
+
   // Load the specified application script into the newly created isolate.
 
   // Prepare builtin and its dependent libraries for use to resolve URIs.