Changeset 253015 in webkit

Timestamp:

Dec 2, 2019 4:20:49 PM (4 years ago)

Author:

mark.lam@apple.com

Message:

Only check each use...FuzzerAgent() option in VM constructor if any of the options are enabled.
​https://bugs.webkit.org/show_bug.cgi?id=204763

Reviewed by Keith Miller.

We know that we'll never use fuzzer agents in deployment. Hence, we shouldn't
spend time checking for them in the normal use case. This probably doesn't matter
much for Web processes, but for clients of JSC that repeatedly spawn and kill VMs,
it might matter more. We might want to eventually widen this idiom to include
other debugging / development options, but for now, I'm only covering the fuzzer
agent options.

• runtime/Options.cpp:

(JSC::computeIfUsingFuzzerAgent):
(JSC::Options::initialize):

• runtime/Options.h:

(JSC::Options::isUsingFuzzerAgent):

• runtime/OptionsList.h:

(JSC::OptionRange::operator bool const):

• runtime/VM.cpp:

(JSC::VM::VM):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• runtime/Options.cpp (modified) (2 diffs)
• runtime/Options.h (modified) (1 diff)
• runtime/OptionsList.h (modified) (2 diffs)
• runtime/VM.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2019-12-02  Mark Lam  <mark.lam@apple.com>
+
+        Only check each use...FuzzerAgent() option in VM constructor if any of the options are enabled.
+        https://bugs.webkit.org/show_bug.cgi?id=204763
+
+        Reviewed by Keith Miller.
+
+        We know that we'll never use fuzzer agents in deployment.  Hence, we shouldn't
+        spend time checking for them in the normal use case.  This probably doesn't matter
+        much for Web processes, but for clients of JSC that repeatedly spawn and kill VMs,
+        it might matter more.  We might want to eventually widen this idiom to include
+        other debugging / development options, but for now, I'm only covering the fuzzer
+        agent options.
+
+        * runtime/Options.cpp:
+        (JSC::computeIfUsingFuzzerAgent):
+        (JSC::Options::initialize):
+        * runtime/Options.h:
+        (JSC::Options::isUsingFuzzerAgent):
+        * runtime/OptionsList.h:
+        (JSC::OptionRange::operator bool const):
+        * runtime/VM.cpp:
+        (JSC::VM::VM):
+
 2019-12-02  Tadeu Zagallo  <tzagallo@apple.com>
 

trunk/Source/JavaScriptCore/runtime/Options.cpp

@@ -537 +537 @@
 }
 
+static void computeIfUsingFuzzerAgent()
+{
+    g_jscConfig.options.isUsingFuzzerAgent = false;
+#define CHECK_IF_USING_FUZZER_AGENT(type_, name_, defaultValue_, availability_, description_) { \
+        const char name[] = #name_; \
+        unsigned nameLength = strlen(name); \
+        if (nameLength > 14 && !strncmp(name, "use", 3) && !strncmp(&name[nameLength -11], "FuzzerAgent", 11)) { \
+            if (Options::name_()) \
+                g_jscConfig.options.isUsingFuzzerAgent = true; \
+        } \
+    }
+    FOR_EACH_JSC_OPTION(CHECK_IF_USING_FUZZER_AGENT)
+#undef CHECK_IF_USING_FUZZER_AGENT
+}
+
 void Options::initialize()
 {
@@ -610 +625 @@
             dumpOptionsIfNeeded();
             ensureOptionsAreCoherent();
+            computeIfUsingFuzzerAgent();
 
 #if HAVE(MACH_EXCEPTIONS)

trunk/Source/JavaScriptCore/runtime/Options.h

@@ -98 +98 @@
     static bool isAvailable(ID, Availability);
 
+    static bool isUsingFuzzerAgent() { return g_jscConfig.options.isUsingFuzzerAgent; }
+
 private:
     struct ConstMetaData {

trunk/Source/JavaScriptCore/runtime/OptionsList.h

@@ -573 +573 @@
     const char* rangeString() const { return (m_state > InitError) ? m_rangeString : s_nullRangeStr; }
     
+    operator bool() const { return m_state != Uninitialized; }
+
     void dump(PrintStream& out) const;
 
@@ -599 +601 @@
 FOR_EACH_JSC_OPTION(DECLARE_OPTION)
 #undef DECLARE_OPTION
+
+    bool isUsingFuzzerAgent; // This value is computed in Options::initialize().
 };
 

trunk/Source/JavaScriptCore/runtime/VM.cpp

@@ -463 +463 @@
 #endif // ENABLE(SAMPLING_PROFILER)
 
-    if (Options::useRandomizingFuzzerAgent())
-        setFuzzerAgent(makeUnique<RandomizingFuzzerAgent>(*this));
-    if (Options::useDoublePredictionFuzzerAgent())
-        setFuzzerAgent(makeUnique<DoublePredictionFuzzerAgent>(*this));
-    if (Options::useFileBasedFuzzerAgent())
-        setFuzzerAgent(makeUnique<FileBasedFuzzerAgent>(*this));
-    if (Options::usePredictionFileCreatingFuzzerAgent())
-        setFuzzerAgent(makeUnique<PredictionFileCreatingFuzzerAgent>(*this));
+    if (UNLIKELY(Options::isUsingFuzzerAgent())) {
+        if (Options::useRandomizingFuzzerAgent())
+            setFuzzerAgent(makeUnique<RandomizingFuzzerAgent>(*this));
+        if (Options::useDoublePredictionFuzzerAgent())
+            setFuzzerAgent(makeUnique<DoublePredictionFuzzerAgent>(*this));
+        if (Options::useFileBasedFuzzerAgent())
+            setFuzzerAgent(makeUnique<FileBasedFuzzerAgent>(*this));
+        if (Options::usePredictionFileCreatingFuzzerAgent())
+            setFuzzerAgent(makeUnique<PredictionFileCreatingFuzzerAgent>(*this));
+    }
 
     if (Options::alwaysGeneratePCToCodeOriginMap())