Propagate compilation errors to our caller to make syntax errors easier to debug. bug 408412, r=shaver sr=brendan

js/src/xpconnect/loader/mozJSComponentLoader.cpp

@@ -637,7 +637,8 @@ mozJSComponentLoader::LoadModule(nsILocalFile* aComponentFile,
     if (!entry)
         return NS_ERROR_OUT_OF_MEMORY;
 
-    rv = GlobalForLocation(aComponentFile, &entry->global, &entry->location);
+    rv = GlobalForLocation(aComponentFile, &entry->global, &entry->location,
+                           nsnull);
     if (NS_FAILED(rv)) {
 #ifdef DEBUG_shaver
         fprintf(stderr, "GlobalForLocation failed!\n");
@@ -1060,7 +1061,8 @@ mozJSComponentLoader::WriteScript(nsIFastLoadService *flSvc, JSScript *script,
 nsresult
 mozJSComponentLoader::GlobalForLocation(nsILocalFile *aComponent,
                                         JSObject **aGlobal,
-                                        char **aLocation)
+                                        char **aLocation,
+                                        jsval *exception)
 {
     nsresult rv;
 
@@ -1190,22 +1192,37 @@ mozJSComponentLoader::GlobalForLocation(nsILocalFile *aComponent,
         // The script wasn't in the fastload cache, so compile it now.
         LOG(("Slow loading %s\n", nativePath.get()));
 
+        // If |exception| is non-null, then our caller wants to propagate any
+        // exceptions out to our caller. Ensure that the engine doesn't
+        // eagerly report the exception.
+        uint32 oldopts = 0;
+        if (exception) {
+            oldopts = JS_GetOptions(cx);
+            JS_SetOptions(cx, oldopts | JSOPTION_DONT_REPORT_UNCAUGHT);
+        }
+
 #ifdef HAVE_PR_MEMMAP
         PRInt64 fileSize;
         rv = aComponent->GetFileSize(&fileSize);
-        if (NS_FAILED(rv))
+        if (NS_FAILED(rv)) {
+            JS_SetOptions(cx, oldopts);
             return rv;
+        }
 
         PRInt64 maxSize;
         LL_UI2L(maxSize, PR_UINT32_MAX);
         if (LL_CMP(fileSize, >, maxSize)) {
             NS_ERROR("file too large");
+            JS_SetOptions(cx, oldopts);
             return NS_ERROR_FAILURE;
         }
 
         PRFileDesc *fileHandle;
         rv = aComponent->OpenNSPRFileDesc(PR_RDONLY, 0, &fileHandle);
-        NS_ENSURE_SUCCESS(rv, rv);
+        if (NS_FAILED(rv)) {
+            JS_SetOptions(cx, oldopts);
+            return NS_ERROR_FILE_NOT_FOUND;
+        }
 
         // Make sure the file is closed, no matter how we return.
         FileAutoCloser fileCloser(fileHandle);
@@ -1214,6 +1231,7 @@ mozJSComponentLoader::GlobalForLocation(nsILocalFile *aComponent,
                                           PR_PROT_READONLY);
         if (!map) {
             NS_ERROR("Failed to create file map");
+            JS_SetOptions(cx, oldopts);
             return NS_ERROR_FAILURE;
         }
 
@@ -1226,6 +1244,7 @@ mozJSComponentLoader::GlobalForLocation(nsILocalFile *aComponent,
         char *buf = static_cast<char*>(PR_MemMap(map, 0, fileSize32));
         if (!buf) {
             NS_WARNING("Failed to map file");
+            JS_SetOptions(cx, oldopts);
             return NS_ERROR_FAILURE;
         }
 
@@ -1244,15 +1263,29 @@ mozJSComponentLoader::GlobalForLocation(nsILocalFile *aComponent,
 
         FILE *fileHandle;
         rv = aComponent->OpenANSIFileDesc("r", &fileHandle);
-        NS_ENSURE_SUCCESS(rv, rv);
+        if (NS_FAILED(rv)) {
+            JS_SetOptions(cx, oldopts);
+            return NS_ERROR_FILE_NOT_FOUND;
+        }
 
         script = JS_CompileFileHandleForPrincipals(cx, global,
                                                    nativePath.get(),
                                                    fileHandle, jsPrincipals);
 
         /* JS will close the filehandle after compilation is complete. */
-
 #endif /* HAVE_PR_MEMMAP */
+
+        // Propagate the exception, if one exists. Also, don't leave the stale
+        // exception on this context.
+        // NB: The caller must stick exception into a rooted slot (probably on
+        // its context) as soon as possible to avoid GC hazards.
+        if (exception) {
+            JS_SetOptions(cx, oldopts);
+            if (!script) {
+                JS_GetPendingException(cx, exception);
+                JS_ClearPendingException(cx);
+            }
+        }
     }
 
     if (!script) {
@@ -1474,14 +1507,27 @@ mozJSComponentLoader::ImportInto(const nsACString & aLocation,
         if (!newEntry || !mInProgressImports.Put(lfhash, newEntry))
             return NS_ERROR_OUT_OF_MEMORY;
 
+        jsval exception = JSVAL_VOID;
         rv = GlobalForLocation(componentFile, &newEntry->global,
-                               &newEntry->location);
+                               &newEntry->location, &exception);
 
         mInProgressImports.Remove(lfhash);
 
         if (NS_FAILED(rv)) {
             *_retval = nsnull;
-            return NS_ERROR_FILE_NOT_FOUND;
+
+            if (!JSVAL_IS_VOID(exception)) {
+                // An exception was thrown during compilation. Propagate it
+                // out to our caller so they can report it.
+                JSContext *callercx;
+                cc->GetJSContext(&callercx);
+                JS_SetPendingException(callercx, exception);
+                cc->SetExceptionWasThrown(PR_TRUE);
+                return NS_OK;
+            }
+
+            // Something failed, but we don't know what it is, guess.
+            return rv;
         }
 
         mod = newEntry;

js/src/xpconnect/loader/mozJSComponentLoader.h

@@ -110,7 +110,8 @@ class mozJSComponentLoader : public nsIModuleLoader,
 
     nsresult GlobalForLocation(nsILocalFile *aComponent,
                                JSObject **aGlobal,
-                               char **location);
+                               char **location,
+                               jsval *exception);
 
     nsresult StartFastLoad(nsIFastLoadService *flSvc);
     nsresult ReadScript(nsIFastLoadService *flSvc, const char *nativePath,

js/src/xpconnect/tests/unit/syntax_error.jsm

@@ -0,0 +1 @@
+bogusjs)(

js/src/xpconnect/tests/unit/test_bug408412.js

@@ -0,0 +1,51 @@
+/*
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Mozilla code.
+ *
+ * The Initial Developer of the Original Code is
+ * Mozilla Foundation.
+ * Portions created by the Initial Developer are Copyright (C) 2007
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *    Dave Townsend <dtownsend@oxymoronical.com> (original author)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+ 
+function run_test() {
+  var file = do_get_file("js/src/xpconnect/tests/unit/syntax_error.jsm");
+  var ios = Components.classes["@mozilla.org/network/io-service;1"]
+                      .getService(Components.interfaces.nsIIOService);
+  var uri = ios.newFileURI(file);
+
+  try {
+    Components.utils.import(uri.spec);
+    do_throw("Failed to report any error at all");
+  } catch (e) {
+    do_check_neq(/^SyntaxError:/(e + ''), null);
+  }
+}