Bug 763848 - Expose the path to libxul at OS.Constants.Sys. r=khuey

dom/system/Makefile.in

@@ -29,6 +29,9 @@ ifdef MOZ_B2G_RIL
 DIRS += gonk
 endif
 
+DEFINES += -DDLL_PREFIX=\"$(DLL_PREFIX)\" -DDLL_SUFFIX=\"$(DLL_SUFFIX)\"
+
+
 CPPSRCS     = \
   nsDeviceSensors.cpp \
   OSFileConstants.cpp \

dom/system/OSFileConstants.cpp

@@ -5,6 +5,8 @@
 #include "fcntl.h"
 #include "errno.h"
 
+#include "prsystem.h"
+
 #if defined(XP_UNIX)
 #include "unistd.h"
 #endif // defined(XP_UNIX)
@@ -23,6 +25,8 @@
 
 // Used to provide information on the OS
 
+#include "nsThreadUtils.h"
+#include "nsDirectoryServiceUtils.h"
 #include "nsIXULRuntime.h"
 #include "nsXPCOMCIDInternal.h"
 #include "nsServiceManagerUtils.h"
@@ -35,8 +39,65 @@
  * etc.) used by OS.File and possibly other OS-bound JavaScript libraries.
  */
 
+
 namespace mozilla {
 
+// Use an anonymous namespace to hide the symbols and avoid any collision
+// with, for instance, |extern bool gInitialized;|
+namespace {
+/**
+ * |true| if this module has been initialized, |false| otherwise
+ */
+bool gInitialized = false;
+
+/**
+ * The name of the directory holding all the libraries (libxpcom, libnss, etc.)
+ */
+nsString* gLibDirectory;
+}
+
+/**
+ * Perform the part of initialization that can only be
+ * executed on the main thread.
+ */
+nsresult InitOSFileConstants()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (gInitialized) {
+    return NS_ERROR_ALREADY_INITIALIZED;
+  }
+
+  gInitialized = true;
+
+  // Initialize gLibDirectory
+  nsCOMPtr<nsIFile> xpcomLib;
+  nsresult rv = NS_GetSpecialDirectory("XpcomLib", getter_AddRefs(xpcomLib));
+  if (NS_FAILED(rv) || !xpcomLib) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIFile> libDir;
+  rv = xpcomLib->GetParent(getter_AddRefs(libDir));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  gLibDirectory = new nsString();
+  return libDir->GetPath(*gLibDirectory);
+}
+
+nsresult CleanupOSFileConstants()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (!gInitialized) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  delete gLibDirectory;
+  return NS_OK;
+}
+
+
 /**
  * Define a simple read-only property holding an integer.
  *
@@ -321,6 +382,8 @@ JSObject *GetOrCreateObjectProperty(JSContext *cx, JSObject *aObject,
  */
 bool DefineOSFileConstants(JSContext *cx, JSObject *global)
 {
+  MOZ_ASSERT(gInitialized);
+
   JSObject *objOS;
   if (!(objOS = GetOrCreateObjectProperty(cx, global, "OS"))) {
     return false;
@@ -329,6 +392,9 @@ bool DefineOSFileConstants(JSContext *cx, JSObject *global)
   if (!(objConstants = GetOrCreateObjectProperty(cx, objOS, "Constants"))) {
     return false;
   }
+
+  // Build OS.Constants.libc
+
   JSObject *objLibc;
   if (!(objLibc = GetOrCreateObjectProperty(cx, objConstants, "libc"))) {
     return false;
@@ -336,7 +402,10 @@ bool DefineOSFileConstants(JSContext *cx, JSObject *global)
   if (!dom::DefineConstants(cx, objLibc, gLibcProperties)) {
     return false;
   }
+
 #if defined(XP_WIN)
+  // Build OS.Constants.Win
+
   JSObject *objWin;
   if (!(objWin = GetOrCreateObjectProperty(cx, objConstants, "Win"))) {
     return false;
@@ -345,6 +414,9 @@ bool DefineOSFileConstants(JSContext *cx, JSObject *global)
     return false;
   }
 #endif // defined(XP_WIN)
+
+  // Build OS.Constants.Sys
+
   JSObject *objSys;
   if (!(objSys = GetOrCreateObjectProperty(cx, objConstants, "Sys"))) {
     return false;
@@ -353,7 +425,7 @@ bool DefineOSFileConstants(JSContext *cx, JSObject *global)
   nsCOMPtr<nsIXULRuntime> runtime = do_GetService(XULRUNTIME_SERVICE_CONTRACTID);
   if (runtime) {
     nsCAutoString os;
-    nsresult rv = runtime->GetOS(os);
+    DebugOnly<nsresult> rv = runtime->GetOS(os);
     MOZ_ASSERT(NS_SUCCEEDED(rv));
 
     JSString* strVersion = JS_NewStringCopyZ(cx, os.get());
@@ -367,6 +439,30 @@ bool DefineOSFileConstants(JSContext *cx, JSObject *global)
     }
   }
 
+  // Locate libxul
+  {
+    nsAutoString xulPath(*gLibDirectory);
+
+    xulPath.Append(PR_GetDirectorySeparator());
+
+#if defined(XP_MACOSX)
+    // Under MacOS X, for some reason, libxul is called simply "XUL"
+    xulPath.Append(NS_LITERAL_STRING("XUL"));
+#else
+    // On other platforms, libxul is a library "xul" with regular
+    // library prefix/suffix
+    xulPath.Append(NS_LITERAL_STRING(DLL_PREFIX));
+    xulPath.Append(NS_LITERAL_STRING("xul"));
+    xulPath.Append(NS_LITERAL_STRING(DLL_SUFFIX));
+#endif // defined(XP_MACOSX)
+
+    JSString* strPathToLibXUL = JS_NewUCStringCopyZ(cx, xulPath.get());
+    jsval valXul = STRING_TO_JSVAL(strPathToLibXUL);
+    if (!JS_SetProperty(cx, objSys, "libxulpath", &valXul)) {
+      return false;
+    }
+  }
+
   return true;
 }
 

dom/system/OSFileConstants.h

@@ -9,6 +9,26 @@
 
 namespace mozilla {
 
+/**
+ * Perform initialization of this module.
+ *
+ * This function _must_ be called:
+ * - from the main thread;
+ * - only once;
+ * - before any Chrome Worker is created.
+ */
+nsresult InitOSFileConstants();
+
+/**
+ * Perform cleanup of this module.
+ *
+ * This function _must_ be called:
+ * - from the main thread;
+ * - only once;
+ * - after all Chrome Workers are dead.
+ */
+nsresult CleanupOSFileConstants();
+
 /**
  * Define OS-specific constants.
  *

dom/workers/RuntimeService.cpp

@@ -36,6 +36,8 @@
 #include "Worker.h"
 #include "WorkerPrivate.h"
 
+#include "OSFileConstants.h"
+
 using namespace mozilla;
 using namespace mozilla::dom;
 
@@ -929,6 +931,11 @@ RuntimeService::Init()
                                      mSystemCharset);
   }
 
+  rv = InitOSFileConstants();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
   return NS_OK;
 }
 
@@ -1043,6 +1050,11 @@ RuntimeService::Cleanup()
       mObserved = NS_FAILED(rv);
     }
   }
+
+  nsresult rv = CleanupOSFileConstants();
+  if (NS_FAILED(rv)) {
+    MOZ_NOT_REACHED("Could not cleanup OSFileConstants");
+  }
 }
 
 // static