Bug 941287 - Show optimized out and other missing variables in the debugger variables view with the appropriate message. r=victorporof

browser/devtools/debugger/test/browser_dbg_optimized-out-vars.js

@@ -27,10 +27,10 @@ function test() {
     outerScope.expand();
 
     let upvarVar = outerScope.get("upvar");
-    ok(!upvarVar, "upvar was optimized out.");
-    if (upvarVar) {
-      ok(false, "upvar = " + upvarVar.target.querySelector(".value").getAttribute("value"));
-    }
+    ok(upvarVar, "The variable `upvar` is shown.");
+    is(upvarVar.target.querySelector(".value").getAttribute("value"),
+       gDebugger.L10N.getStr('variablesViewOptimizedOut'),
+       "Should show the optimized out message for upvar.");
 
     let argVar = outerScope.get("arg");
     is(argVar.target.querySelector(".name").getAttribute("value"), "arg",

browser/devtools/shared/widgets/VariablesView.jsm

@@ -2426,10 +2426,27 @@ Variable.prototype = Heritage.extend(Scope.prototype, {
       this._valueLabel.classList.remove(VariablesView.getClass(prevGrip));
     }
     this._valueGrip = aGrip;
-    this._valueString = VariablesView.getString(aGrip, {
-      concise: true,
-      noEllipsis: true,
-    });
+
+    if(aGrip && (aGrip.optimizedOut || aGrip.uninitialized || aGrip.missingArguments)) {
+      if(aGrip.optimizedOut) {
+        this._valueString = STR.GetStringFromName("variablesViewOptimizedOut")
+      }
+      else if(aGrip.uninitialized) {
+        this._valueString = STR.GetStringFromName("variablesViewUninitialized")
+      }
+      else if(aGrip.missingArguments) {
+        this._valueString = STR.GetStringFromName("variablesViewMissingArgs")
+      }
+      this.eval = null;
+    }
+    else {
+      this._valueString = VariablesView.getString(aGrip, {
+        concise: true,
+        noEllipsis: true,
+      });
+      this.eval = this.ownerView.eval;
+    }
+
     this._valueClassName = VariablesView.getClass(aGrip);
 
     this._valueLabel.classList.add(this._valueClassName);

browser/locales/en-US/chrome/browser/devtools/debugger.properties

@@ -316,4 +316,8 @@ functionSearchSeparatorLabel=←
 # resumed first.
 resumptionOrderPanelTitle=There are one or more paused debuggers. Please resume the most-recently paused debugger first at: %S
 
+variablesViewOptimizedOut=(optimized away)
+variablesViewUninitialized=(uninitialized)
+variablesViewMissingArgs=(unavailable)
+
 evalGroupLabel=Evaluated Sources

toolkit/devtools/server/actors/script.js

@@ -1701,6 +1701,18 @@ ThreadActor.prototype = {
         if (aValue === null) {
           return { type: "null" };
         }
+      else if(aValue.optimizedOut ||
+              aValue.uninitialized ||
+              aValue.missingArguments) {
+          // The slot is optimized out, an uninitialized binding, or
+          // arguments on a dead scope
+          return {
+            type: "null",
+            optimizedOut: aValue.optimizedOut,
+            uninitialized: aValue.uninitialized,
+            missingArguments: aValue.missingArguments
+          };
+        }
         return this.objectGrip(aValue, aPool);
 
       case "symbol":
@@ -4864,20 +4876,14 @@ EnvironmentActor.prototype = {
     }
     for each (let name in parameterNames) {
       let arg = {};
-
       let value = this.obj.getVariable(name);
-      // The slot is optimized out.
-      // FIXME: Need actual UI, bug 941287.
-      if (value && value.optimizedOut) {
-        continue;
-      }
 
       // TODO: this part should be removed in favor of the commented-out part
       // below when getVariableDescriptor lands (bug 725815).
       let desc = {
         value: value,
         configurable: false,
-        writable: true,
+        writable: !(value && value.optimizedOut),
         enumerable: true
       };
 
@@ -4905,19 +4911,16 @@ EnvironmentActor.prototype = {
       }
 
       let value = this.obj.getVariable(name);
-      // The slot is optimized out, arguments on a dead scope, or an
-      // uninitialized binding.
-      // FIXME: Need actual UI, bug 941287.
-      if (value && (value.optimizedOut || value.missingArguments || value.uninitialized)) {
-        continue;
-      }
 
       // TODO: this part should be removed in favor of the commented-out part
       // below when getVariableDescriptor lands.
       let desc = {
         value: value,
         configurable: false,
-        writable: true,
+        writable: !(value &&
+                    (value.optimizedOut ||
+                     value.uninitialized ||
+                     value.missingArguments)),
         enumerable: true
       };