When URL mapping was specified, library loads where not being called for the URLs that were mapped.

bin/gen_snapshot.cc

 // Copyright (c) 2011, 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.
 
 // Generate a snapshot file after loading all the scripts specified on the
 // command line.
 
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
@@ skipping 90 matching lines @@
   const bool kWritable = true;
   File* file = File::Open(snapshot_filename, kWritable);
   ASSERT(file != NULL);
   for (intptr_t i = 0; i < size; i++) {
     file->WriteByte(buffer[i]);
   }
   delete file;
 }
 
 
-static const char* MapLibraryUrl(const char* library_url_chars) {
-  const char* mapped_url_chars = NULL;
+static bool MapLibraryUrl(const char* url_chars,

[Anton Muhin, 2011/11/17 18:15:36]

maybe consider passing only const char** url_chars to be overwritten by mapped
path if present.

[siva, 2011/11/17 19:09:46]

I prefer keeping the input read only and not overwriting it in case there is a
need later to print it in some error or diagnostics.

On 2011/11/17 18:15:36, antonmuhin wrote:

+                          const char** mapped_url_chars) {
+  *mapped_url_chars = url_chars;
   if (url_mapping != NULL) {
     // We need to check if the passed in url is found in the url_mapping array,
     // in that case use the mapped entry.
-    int len = strlen(library_url_chars);
+    int len = strlen(url_chars);
     for (int idx = 0; idx < url_mapping->count(); idx++) {
       const char* url_name = url_mapping->GetArgument(idx);
-      if (!strncmp(library_url_chars, url_name, len) &&
+      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_chars = url_mapped_name;
+          *mapped_url_chars = url_mapped_name;
+          return true;  // Found a mapping for this URL.
         }
-        break;
       }
     }
   }
-  return mapped_url_chars;
+  return false;  // Did not find any mapping for this URL.
 }
 
 
-static Dart_Handle CanonicalizeUrl(const char* library_url_chars,
-                                   const char* url_chars) {
-  // Calculate the canonical path based on the importing library and the url.
-  const char* canonical_filename = GetCanonicalPath(library_url_chars,
-                                                    url_chars);
-  Dart_Handle canon_url = Dart_NewString(canonical_filename);
-  free(const_cast<char*>(canonical_filename));
-  return canon_url;
+static Dart_Handle LoadSourceFile(const char* name,
+                                  Dart_LibraryTag tag,
+                                  Dart_Handle library,
+                                  Dart_Handle url) {
+  // The tag is either an import or a source tag. Read the file based on the
+  // url chars.
+  Dart_Handle source = ReadStringFromFile(name);
+  if (Dart_IsError(source)) {
+    return source;  // source contains the error string.
+  }
+  if (tag == kImportTag) {
+    return Dart_LoadLibrary(url, source);
+  } else if (tag == kSourceTag) {
+    return Dart_LoadSource(library, url, source);
+  }
+  return Dart_Error("wrong tag");
 }
 
 
 static Dart_Handle CreateSnapshotLibraryTagHandler(Dart_LibraryTag tag,
                                                    Dart_Handle library,
                                                    Dart_Handle url) {
   if (!Dart_IsLibrary(library)) {
     return Dart_Error("not a library");
   }
   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);
   if (Dart_IsError(result)) {
     return Dart_Error("accessing url characters failed");
   }
 
   // If the URL starts with "dart:" then it is handled specially.
   static const char* kDartScheme = "dart:";
   static const intptr_t kDartSchemeLen = strlen(kDartScheme);
   if (strncmp(url_chars, kDartScheme, kDartSchemeLen) == 0) {
     if (tag == kCanonicalizeUrl) {

[Anton Muhin, 2011/11/17 18:15:36]

just a suggestion (feel free ignore).  Control flow might grow too complicated
what about something along those lines:

bool is_dart_scheme_url = strncmp(url_chars, kDartScheme,...)

if (tag == kCanonicalizeUrl) {
  if (is_dart_scheme_url) {
    return url;
  }
  // ln. 185--205 go here
} else {
  bool mapped = MapLibraryUrl(url_chars, &url_chars);
  if (dart_scheme_url && !mapped) {
     Dart_Error(...);
  }
  // Code of LoadSourceFile goes here.
}

Another benefit is we got rid of LoadSoureFile helper.
}

[siva, 2011/11/17 19:09:46]

Redid the loop per your suggestion.

On 2011/11/17 18:15:36, antonmuhin wrote:

-      return Dart_NewString(url_chars);
+      return url;
     }
-    const char* mapped_url_chars = MapLibraryUrl(url_chars);
-    if (mapped_url_chars != NULL) {
-      // We have a URL mapping specified, just return the mapped version.
-      return Dart_NewString(mapped_url_chars);
+    const char* mapped_url_chars;
+    bool url_is_mapped = MapLibraryUrl(url_chars, &mapped_url_chars);
+    if (url_is_mapped) {
+      // We have a URL mapping specified, just read the file that the
+      // URL mapping specifies and load it.
+      return LoadSourceFile(mapped_url_chars, tag, library, url);
     }
-  }
-  // Get the url of the calling library.
-  Dart_Handle library_url = Dart_LibraryUrl(library);
-  if (Dart_IsError(library_url)) {
-    return Dart_Error("accessing library url failed");
-  }
-  if (!Dart_IsString8(library_url)) {
-    return Dart_Error("library url is not a string");
-  }
-  const char* library_url_chars = NULL;
-  result = Dart_StringToCString(library_url, &library_url_chars);
-  if (Dart_IsError(result)) {
-    return Dart_Error("accessing library url characters failed");
-  }
-  library_url_chars = MapLibraryUrl(library_url_chars);
-  Dart_Handle canon_url = CanonicalizeUrl(library_url_chars, url_chars);
-  if (Dart_IsError(canon_url)) {
-    return canon_url;  // canon_url contains the error string.
+    return Dart_Error("Do not know how to load %s", url_chars);
   }
   if (tag == kCanonicalizeUrl) {
-    return canon_url;
-  }
-  result = Dart_StringToCString(canon_url, &url_chars);
-  if (Dart_IsError(result)) {
-    return Dart_Error("accessing canon url characters failed");
+    // Get the url of the calling library.
+    Dart_Handle library_url = Dart_LibraryUrl(library);
+    if (Dart_IsError(library_url)) {
+      return Dart_Error("accessing library url failed");
+    }
+    if (!Dart_IsString8(library_url)) {
+      return Dart_Error("library url is not a string");
+    }
+    const char* library_url_chars = NULL;
+    result = Dart_StringToCString(library_url, &library_url_chars);
+    if (Dart_IsError(result)) {
+      return Dart_Error("accessing library url characters failed");
+    }
+    const char* mapped_library_url_chars;
+    MapLibraryUrl(library_url_chars, &mapped_library_url_chars);
+    const char* canon_url_chars = GetCanonicalPath(library_url_chars,
+                                                   url_chars);
+    Dart_Handle canon_url = Dart_NewString(canon_url_chars);
+    free(const_cast<char*>(canon_url_chars));
+
+    return canon_url;  // canon_url has error string in case of errors.
   }
   // The tag is either an import or a source tag. Read the file based on the
-  // url chars.
-  Dart_Handle source = ReadStringFromFile(url_chars);
-  if (Dart_IsError(source)) {
-    return source;  // source contains the error string.
-  }
-  if (tag == kImportTag) {
-    return Dart_LoadLibrary(url, source);
-  } else if (tag == kSourceTag) {
-    return Dart_LoadSource(library, url, source);
-  }
-  return Dart_Error("wrong tag");
+  // url chars and load it.
+  return LoadSourceFile(url_chars, tag, library, url);
 }
 
 
 static Dart_Handle LoadSnapshotCreationScript(const char* script_name) {
   Dart_Handle source = ReadStringFromFile(script_name);
   if (Dart_IsError(source)) {
     return source;  // source contains the error string.
   }
   Dart_Handle url = Dart_NewString(script_name);
 
@@ skipping 91 matching lines @@
   // and writes out a snapshot.
   Dart_Isolate isolate = Dart_CreateIsolate(NULL, script_name);
   if (isolate == NULL) {
     return 255;
   }
 
   // Shutdown the isolate.
   Dart_ShutdownIsolate();
   return 0;
 }