Bug 1351107 - Make the DeprecatedLanguageExtensions enum an enum class in a new header, to address a thorny cyclic dependency issue in subsequent patches. r=arai

js/src/frontend/LanguageExtensions.h

@@ -0,0 +1,45 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Code related to various SpiderMonkey-specific language syntax extensions. */
+
+#ifndef frontend_LanguageExtensions_h
+#define frontend_LanguageExtensions_h
+
+namespace js {
+
+/**
+ * Numeric identifiers for various deprecated language extensions.
+ *
+ * The initializer numbers are directly used in telemetry, so while it's okay
+ * to *remove* values as language extensions are removed from SpiderMonkey,
+ * it's *not* okay to compact or reorder them.  When an initializer falls into
+ * disuse, remove it without reassigning its value to a new or existing
+ * initializer.  The *only* initializer whose value should ever change is
+ * DeprecatedLanguageExtension::Count.
+ */
+enum class DeprecatedLanguageExtension
+{
+    ForEach = 0, // JS 1.6+
+    // NO LONGER USING 1
+    LegacyGenerator = 2, // JS 1.7+
+    ExpressionClosure = 3, // Added in JS 1.8
+    // NO LONGER USING 4
+    // NO LONGER USING 5
+    // NO LONGER USING 6
+    // NO LONGER USING 7
+    // NO LONGER USING 8
+    // NO LONGER USING 9
+    BlockScopeFunRedecl = 10,
+
+    // Sentinel value.  MAY change as extension initializers are added (only to
+    // the end) above.
+    Count
+};
+
+} // namespace js
+
+#endif /* frontend_LanguageExtensions_h */

js/src/frontend/Parser.cpp

@@ -3695,7 +3695,7 @@ Parser<ParseHandler, CharT>::functionFormalParametersAndBody(InHandling inHandli
             }
 
 #if JS_HAS_EXPR_CLOSURES
-            addTelemetry(JSCompartment::DeprecatedExpressionClosure);
+            addTelemetry(DeprecatedLanguageExtension::ExpressionClosure);
             if (!warnOnceAboutExprClosure())
                 return false;
 #else
@@ -6191,7 +6191,7 @@ Parser<ParseHandler, CharT>::forStatement(YieldHandling yieldHandling)
         if (matched) {
             iflags = JSITER_FOREACH;
             isForEach = true;
-            addTelemetry(JSCompartment::DeprecatedForEach);
+            addTelemetry(DeprecatedLanguageExtension::ForEach);
             if (!warnOnceAboutForEach())
                 return null();
         }
@@ -6702,7 +6702,7 @@ Parser<ParseHandler, CharT>::yieldExpression(InHandling inHandling)
         }
 
         pc->functionBox()->setGeneratorKind(LegacyGenerator);
-        addTelemetry(JSCompartment::DeprecatedLegacyGenerator);
+        addTelemetry(DeprecatedLanguageExtension::LegacyGenerator);
 
         MOZ_FALLTHROUGH;
 
@@ -10245,7 +10245,7 @@ Parser<ParseHandler, CharT>::exprInParens(InHandling inHandling, YieldHandling y
 }
 
 void
-ParserBase::addTelemetry(JSCompartment::DeprecatedLanguageExtension e)
+ParserBase::addTelemetry(DeprecatedLanguageExtension e)
 {
     if (context->helperThread())
         return;

js/src/frontend/Parser.h

@@ -13,13 +13,13 @@
 #include "mozilla/Maybe.h"
 #include "mozilla/TypeTraits.h"
 
-#include "jscompartment.h"
 #include "jsiter.h"
 #include "jspubtd.h"
 
 #include "ds/Nestable.h"
 #include "frontend/BytecodeCompiler.h"
 #include "frontend/FullParseHandler.h"
+#include "frontend/LanguageExtensions.h"
 #include "frontend/NameAnalysisTypes.h"
 #include "frontend/NameCollections.h"
 #include "frontend/SharedContext.h"
@@ -900,7 +900,7 @@ class ParserBase : public StrictModeGetter
 
     bool isValidStrictBinding(PropertyName* name);
 
-    void addTelemetry(JSCompartment::DeprecatedLanguageExtension e);
+    void addTelemetry(DeprecatedLanguageExtension e);
 
     bool warnOnceAboutExprClosure();
     bool warnOnceAboutForEach();

js/src/jscompartment.cpp

@@ -9,6 +9,8 @@
 #include "mozilla/DebugOnly.h"
 #include "mozilla/MemoryReporting.h"
 
+#include <stddef.h>
+
 #include "jscntxt.h"
 #include "jsfriendapi.h"
 #include "jsgc.h"
@@ -1380,7 +1382,7 @@ JSCompartment::reportTelemetry()
              : JS_TELEMETRY_DEPRECATED_LANGUAGE_EXTENSIONS_IN_CONTENT;
 
     // Call back into Firefox's Telemetry reporter.
-    for (size_t i = 0; i < DeprecatedLanguageExtensionCount; i++) {
+    for (size_t i = 0; i < size_t(DeprecatedLanguageExtension::Count); i++) {
         if (sawDeprecatedLanguageExtension[i])
             runtime_->addTelemetry(id, i);
     }
@@ -1395,7 +1397,7 @@ JSCompartment::addTelemetry(const char* filename, DeprecatedLanguageExtension e)
     if (!creationOptions_.addonIdOrNull() && (!filename || strncmp(filename, "http", 4) != 0))
         return;
 
-    sawDeprecatedLanguageExtension[e] = true;
+    sawDeprecatedLanguageExtension[size_t(e)] = true;
 }
 
 HashNumber

js/src/jscompartment.h

@@ -14,7 +14,10 @@
 #include "mozilla/Variant.h"
 #include "mozilla/XorShift128PlusRNG.h"
 
+#include <stddef.h>
+
 #include "builtin/RegExp.h"
+#include "frontend/LanguageExtensions.h"
 #include "gc/Barrier.h"
 #include "gc/NurseryAwareHashMap.h"
 #include "gc/Zone.h"
@@ -957,33 +960,18 @@ struct JSCompartment
         return jitCompartment_;
     }
 
-    enum DeprecatedLanguageExtension {
-        DeprecatedForEach = 0,              // JS 1.6+
-        // NO LONGER USING 1
-        DeprecatedLegacyGenerator = 2,      // JS 1.7+
-        DeprecatedExpressionClosure = 3,    // Added in JS 1.8
-        // NO LONGER USING 4
-        // NO LONGER USING 5
-        // NO LONGER USING 6
-        // NO LONGER USING 7
-        // NO LONGER USING 8
-        // NO LONGER USING 9
-        DeprecatedBlockScopeFunRedecl = 10,
-        DeprecatedLanguageExtensionCount
-    };
-
     js::ArgumentsObject* getOrCreateArgumentsTemplateObject(JSContext* cx, bool mapped);
 
     js::ArgumentsObject* maybeArgumentsTemplateObject(bool mapped) const;
 
   private:
     // Used for collecting telemetry on SpiderMonkey's deprecated language extensions.
-    bool sawDeprecatedLanguageExtension[DeprecatedLanguageExtensionCount];
+    bool sawDeprecatedLanguageExtension[size_t(js::DeprecatedLanguageExtension::Count)];
 
     void reportTelemetry();
 
   public:
-    void addTelemetry(const char* filename, DeprecatedLanguageExtension e);
+    void addTelemetry(const char* filename, js::DeprecatedLanguageExtension e);
 
   public:
     // Aggregated output used to collect JSScript hit counts when code coverage