Bug 934698 - Suppress nsISupports.{AddRef,Release} when called directly, r=bhackett

DONBUILD because NPOTB yet

js/src/devtools/rootAnalysis/analyzeRoots.js

@@ -236,7 +236,9 @@ function edgeCanGC(edge)
         var field = callee.Exp[0].Field;
         var csuName = field.FieldCSU.Type.Name;
         var fullFieldName = csuName + "." + field.Name[0];
-        return fieldCallCannotGC(csuName, fullFieldName) ? null : fullFieldName;
+        if (fieldCallCannotGC(csuName, fullFieldName))
+            return null;
+        return (fullFieldName in suppressedFunctions) ? null : fullFieldName;
     }
     assert(callee.Exp[0].Kind == "Var");
     var calleeName = callee.Exp[0].Variable.Name[0];

js/src/devtools/rootAnalysis/annotations.js

@@ -69,8 +69,6 @@ var ignoreCallees = {
     "js::Class.trace" : true,
     "js::Class.finalize" : true,
     "JSRuntime.destroyPrincipals" : true,
-    "nsISupports.AddRef" : true,
-    "nsISupports.Release" : true, // makes me a bit nervous; this is a bug but can happen
     "nsIGlobalObject.GetGlobalJSObject" : true, // virtual but no implementation can GC
     "nsAXPCNativeCallContext.GetJSContext" : true,
     "js::jit::MDefinition.op" : true, // macro generated virtuals just return a constant

js/src/devtools/rootAnalysis/computeCallgraph.js

@@ -49,7 +49,7 @@ function processCSU(csuName, csu)
     }
 }
 
-function findVirtualFunctions(csu, field)
+function findVirtualFunctions(csu, field, suppressed)
 {
     var worklist = [csu];
 
@@ -60,8 +60,10 @@ function findVirtualFunctions(csu, field)
     while (worklist.length) {
         var csu = worklist.pop();
         if (csu == "nsISupports") {
-            if (field == "AddRef" || field == "Release")
+            if (field == "AddRef" || field == "Release") {
+                suppressed[0] = true;
                 return [];
+            }
             return null;
         }
         if (csu in superclasses) {
@@ -132,8 +134,16 @@ function getCallees(edge)
             var fieldName = field.Name[0];
             var csuName = field.FieldCSU.Type.Name;
             var functions = null;
-            if ("FieldInstanceFunction" in field)
-                functions = findVirtualFunctions(csuName, fieldName);
+            if ("FieldInstanceFunction" in field) {
+                var suppressed = [ false ];
+                functions = findVirtualFunctions(csuName, fieldName, suppressed);
+                if (suppressed[0]) {
+                    // Field call known to not GC; mark it as suppressed so
+                    // direct invocations will be ignored
+                    callees.push({'kind': "field", 'csu': csuName, 'field': fieldName,
+                                  'suppressed': true});
+                }
+            }
             if (functions) {
                 // Known set of virtual call targets.
                 for (var name of functions)
@@ -173,14 +183,15 @@ function processBody(caller, body)
     for (var edge of body.PEdge) {
         if (edge.Kind != "Call")
             continue;
-        var suppressText = "";
+        var edgeSuppressed = false;
         var seen = seenCallees;
         if (edge.Index[0] in body.suppressed) {
-            suppressText = "SUPPRESS_GC ";
+            edgeSuppressed = true;
             seen = seenSuppressedCallees;
         }
-        var prologue = suppressText + memo(caller) + " ";
         for (var callee of getCallees(edge)) {
+            var prologue = (edgeSuppressed || callee.suppressed) ? "SUPPRESS_GC " : "";
+            prologue += memo(caller) + " ";
             if (callee.kind == 'direct') {
                 if (!(callee.name in seen)) {
                     seen[name] = true;

js/src/devtools/rootAnalysis/explain.py

@@ -48,9 +48,11 @@ try:
                 print >>refs, line
                 continue
 
-            m = re.match(r"^Function.*has unrooted.*of type.*live across GC call '(.*?)'", line)
+            m = re.match(r"^Function.*has unrooted.*of type.*live across GC call ('?)(.*?)('?) at \S+:\d+$", line)
             if m:
-                current_gcFunction = m.group(1)
+                # Function names are surrounded by single quotes. Field calls
+                # are unquoted.
+                current_gcFunction = m.group(2)
                 hazardousGCFunctions.setdefault(current_gcFunction, []).append(line)
                 hazardOrder.append((current_gcFunction, len(hazardousGCFunctions[current_gcFunction]) - 1))
                 num_hazards += 1
@@ -84,7 +86,10 @@ try:
 
             for gcFunction, index in hazardOrder:
                 gcHazards = hazardousGCFunctions[gcFunction]
-                print >>hazards, (gcHazards[index] + gcExplanations[gcFunction])
+                if gcFunction in gcExplanations:
+                    print >>hazards, (gcHazards[index] + gcExplanations[gcFunction])
+                else:
+                    print >>hazards, gcHazards[index]
 
 except IOError as e:
     print 'Failed: %s' % str(e)

js/src/devtools/rootAnalysis/loadCallgraph.js

@@ -39,6 +39,8 @@ var functionNames = [""];
 
 function loadCallgraph(file)
 {
+    var suppressedFieldCalls = {};
+
     var textLines = snarf(file).split('\n');
     for (var line of textLines) {
         var match;
@@ -62,7 +64,9 @@ function loadCallgraph(file)
             var caller = functionNames[match[1]];
             var csu = match[2];
             var fullfield = csu + "." + match[3];
-            if (!fieldCallCannotGC(csu, fullfield) && !suppressed)
+            if (suppressed)
+                suppressedFieldCalls[fullfield] = true;
+            else if (!fieldCallCannotGC(csu, fullfield))
                 addGCFunction(caller, "FieldCall: " + fullfield);
         } else if (match = /^D (\d+) (\d+)/.exec(line)) {
             var caller = functionNames[match[1]];
@@ -100,6 +104,10 @@ function loadCallgraph(file)
             delete gcFunctions[name];
     }
 
+    for (var name in suppressedFieldCalls) {
+        suppressedFunctions[name] = true;
+    }
+
     for (var gcName of [ 'jsgc.cpp:void Collect(JSRuntime*, uint8, int64, uint32, uint32)',
                          'void js::MinorGC(JSRuntime*, uint32)' ])
     {