Bug 929120 - Add a way to get compartment locations ignoring non-addon locations. r=njn

Use that new way to map compartments to add-ons. As an added bonus, fix a currently unproblematic off-by-one error in the location parser.

js/xpconnect/src/XPCJSRuntime.cpp

@@ -289,12 +289,46 @@ CompartmentPrivate::~CompartmentPrivate()
         --kLivingAdopters;
 }
 
-bool CompartmentPrivate::TryParseLocationURI()
+static bool
+TryParseLocationURICandidate(const nsACString& uristr,
+                             CompartmentPrivate::LocationHint aLocationHint,
+                             nsIURI** aURI)
 {
-    // Already tried parsing the location before
-    if (locationWasParsed)
+    static NS_NAMED_LITERAL_CSTRING(kGRE, "resource://gre/");
+    static NS_NAMED_LITERAL_CSTRING(kToolkit, "chrome://global/");
+    static NS_NAMED_LITERAL_CSTRING(kBrowser, "chrome://browser/");
+
+    if (aLocationHint == CompartmentPrivate::LocationHintAddon) {
+        // Blacklist some known locations which are clearly not add-on related.
+        if (StringBeginsWith(uristr, kGRE) ||
+            StringBeginsWith(uristr, kToolkit) ||
+            StringBeginsWith(uristr, kBrowser))
+            return false;
+    }
+
+    nsCOMPtr<nsIURI> uri;
+    if (NS_FAILED(NS_NewURI(getter_AddRefs(uri), uristr)))
+        return false;
+
+    nsAutoCString scheme;
+    if (NS_FAILED(uri->GetScheme(scheme)))
+        return false;
+
+    // Cannot really map data: and blob:.
+    // Also, data: URIs are pretty memory hungry, which is kinda bad
+    // for memory reporter use.
+    if (scheme.EqualsLiteral("data") || scheme.EqualsLiteral("blob"))
+        return false;
+
+    uri.forget(aURI);
+    return true;
+}
+
+bool CompartmentPrivate::TryParseLocationURI(CompartmentPrivate::LocationHint aLocationHint,
+                                             nsIURI **aURI)
+{
+    if (!aURI)
         return false;
-    locationWasParsed = true;
 
     // Need to parse the URI.
     if (location.IsEmpty())
@@ -320,12 +354,13 @@ bool CompartmentPrivate::TryParseLocationURI()
     // See: XPCComponents.cpp#AssembleSandboxMemoryReporterName
     int32_t idx = location.Find(from);
     if (idx < 0)
-        return TryParseLocationURICandidate(location);
+        return TryParseLocationURICandidate(location, aLocationHint, aURI);
 
 
     // When parsing we're looking for the right-most URI. This URI may be in
     // <sandboxName>, so we try this first.
-    if (TryParseLocationURICandidate(Substring(location, 0, idx)))
+    if (TryParseLocationURICandidate(Substring(location, 0, idx), aLocationHint,
+                                     aURI))
         return true;
 
     // Not in <sandboxName> so we need to inspect <js-stack-frame-filename> and
@@ -343,42 +378,21 @@ bool CompartmentPrivate::TryParseLocationURI()
         idx = chain.RFind(arrow);
         if (idx < 0) {
             // This is the last chain item. Try to parse what is left.
-            return TryParseLocationURICandidate(chain);
+            return TryParseLocationURICandidate(chain, aLocationHint, aURI);
         }
 
         // Try to parse current chain item
-        if (TryParseLocationURICandidate(Substring(chain, idx + arrowLength)))
+        if (TryParseLocationURICandidate(Substring(chain, idx + arrowLength),
+                                         aLocationHint, aURI))
             return true;
 
         // Current chain item couldn't be parsed.
-        // Don't forget whitespace in " -> "
-        idx -= 1;
-        // Strip current item and continue
+        // Strip current item and continue.
         chain = Substring(chain, 0, idx);
     }
     MOZ_ASSUME_UNREACHABLE("Chain parser loop does not terminate");
 }
 
-bool CompartmentPrivate::TryParseLocationURICandidate(const nsACString& uristr)
-{
-    nsCOMPtr<nsIURI> uri;
-    if (NS_FAILED(NS_NewURI(getter_AddRefs(uri), uristr)))
-        return false;
-
-    nsAutoCString scheme;
-    if (NS_FAILED(uri->GetScheme(scheme)))
-        return false;
-
-    // Cannot really map data: and blob:.
-    // Also, data: URIs are pretty memory hungry, which is kinda bad
-    // for memory reporter use.
-    if (scheme.EqualsLiteral("data") || scheme.EqualsLiteral("blob"))
-        return false;
-
-    locationURI = uri.forget();
-    return true;
-}
-
 CompartmentPrivate*
 EnsureCompartmentPrivate(JSObject *obj)
 {
@@ -2534,7 +2548,8 @@ class XPCJSRuntimeStats : public JS::RuntimeStats
         if (mGetLocations) {
             CompartmentPrivate *cp = GetCompartmentPrivate(c);
             if (cp)
-              cp->GetLocationURI(getter_AddRefs(extras->location));
+              cp->GetLocationURI(CompartmentPrivate::LocationHintAddon,
+                                 getter_AddRefs(extras->location));
             // Note: cannot use amIAddonManager implementation at this point,
             // as it is a JS service and the JS heap is currently not idle.
             // Otherwise, we could have computed the add-on id at this point.

js/xpconnect/src/xpcprivate.h

@@ -3741,13 +3741,17 @@ namespace xpc {
 class CompartmentPrivate
 {
 public:
+    enum LocationHint {
+        LocationHintRegular,
+        LocationHintAddon
+    };
+
     CompartmentPrivate()
         : wantXrays(false)
         , universalXPConnectEnabled(false)
         , adoptedNode(false)
         , donatedNode(false)
         , scope(nullptr)
-        , locationWasParsed(false)
     {
         MOZ_COUNT_CTOR(xpc::CompartmentPrivate);
     }
@@ -3778,11 +3782,15 @@ public:
         return location;
     }
     bool GetLocationURI(nsIURI **aURI) {
-        if (!locationURI && !TryParseLocationURI())
-            return false;
+        return GetLocationURI(LocationHintRegular, aURI);
+    }
+    bool GetLocationURI(LocationHint aLocationHint, nsIURI **aURI) {
+        if (locationURI) {
             NS_IF_ADDREF(*aURI = locationURI);
             return true;
         }
+        return TryParseLocationURI(aLocationHint, aURI);
+    }
     void SetLocation(const nsACString& aLocation) {
         if (aLocation.IsEmpty())
             return;
@@ -3801,10 +3809,8 @@ public:
 private:
     nsCString location;
     nsCOMPtr<nsIURI> locationURI;
-    bool locationWasParsed;
 
-    bool TryParseLocationURI();
-    bool TryParseLocationURICandidate(const nsACString& uristr);
+    bool TryParseLocationURI(LocationHint aType, nsIURI** aURI);
 };
 
 CompartmentPrivate*