Add JSC option to trigger a hardware breakpoint when debugger expressions are reached.

kmiller68 · kmiller68 · commit 10892bd63f5b · 2020-10-05T21:35:19.000Z
https://bugs.webkit.org/show_bug.cgi?id=217334 Reviewed by Yusuke Suzuki. * interpreter/Interpreter.cpp: (JSC::Interpreter::debug): * runtime/JSGlobalObject.h: (JSC::JSGlobalObject::defaultCodeGenerationMode const): * runtime/OptionsList.h: Canonical link: https://commits.webkit.org/230107@main git-svn-id: https://svn.webkit.org/repository/webkit/trunk@268004 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
@@ -1,3 +1,16 @@
+2020-10-05  Keith Miller  <keith_miller@apple.com>
+
+        Add JSC option to trigger a hardware breakpoint when debugger expressions are reached.
+        https://bugs.webkit.org/show_bug.cgi?id=217334
+
+        Reviewed by Yusuke Suzuki.
+
+        * interpreter/Interpreter.cpp:
+        (JSC::Interpreter::debug):
+        * runtime/JSGlobalObject.h:
+        (JSC::JSGlobalObject::defaultCodeGenerationMode const):
+        * runtime/OptionsList.h:
+
 2020-10-05  David Kilzer  <ddkilzer@apple.com>
 
         Build fix: Use JSC_DEFINE_HOST_FUNCTION_WITH_ATTRIBUTES() with SUPPRESS_ASAN
diff --git a/Source/JavaScriptCore/interpreter/Interpreter.cpp b/Source/JavaScriptCore/interpreter/Interpreter.cpp
@@ -1265,6 +1265,10 @@ NEVER_INLINE void Interpreter::debug(CallFrame* callFrame, DebugHookType debugHo
 {
     VM& vm = callFrame->deprecatedVM();
     auto scope = DECLARE_CATCH_SCOPE(vm);
+
+    if (UNLIKELY(Options::debuggerTriggersBreakpointException()) && debugHookType == DidReachDebuggerStatement)
+        WTFBreakpointTrap();
+
     Debugger* debugger = callFrame->lexicalGlobalObject(vm)->debugger();
     if (!debugger)
         return;
diff --git a/Source/JavaScriptCore/runtime/JSGlobalObject.h b/Source/JavaScriptCore/runtime/JSGlobalObject.h
@@ -1164,7 +1164,7 @@ inline JSObject* JSGlobalObject::globalThis() const
 inline OptionSet<CodeGenerationMode> JSGlobalObject::defaultCodeGenerationMode() const
 {
     OptionSet<CodeGenerationMode> codeGenerationMode;
-    if (hasInteractiveDebugger() || Options::forceDebuggerBytecodeGeneration())
+    if (hasInteractiveDebugger() || Options::forceDebuggerBytecodeGeneration() || Options::debuggerTriggersBreakpointException())
         codeGenerationMode.add(CodeGenerationMode::Debugger);
     if (vm().typeProfiler())
         codeGenerationMode.add(CodeGenerationMode::TypeProfiler);
diff --git a/Source/JavaScriptCore/runtime/OptionsList.h b/Source/JavaScriptCore/runtime/OptionsList.h
@@ -110,6 +110,7 @@ constexpr bool enableWebAssemblyStreamingApi = false;
     v(Bool, dumpBytecodeLivenessResults, false, Normal, nullptr) \
     v(Bool, validateBytecode, false, Normal, nullptr) \
     v(Bool, forceDebuggerBytecodeGeneration, false, Normal, nullptr) \
+    v(Bool, debuggerTriggersBreakpointException, false, Normal, "Using the debugger statement will trigger an breakpoint exception (Useful when lldbing)") \
     v(Bool, dumpBytecodesBeforeGeneratorification, false, Normal, nullptr) \
     \
     v(Bool, useFunctionDotArguments, true, Normal, nullptr) \

Original file line number	Diff line number	Diff line change
`@@ -1164,7 +1164,7 @@ inline JSObject* JSGlobalObject::globalThis() const`
`1164`	`1164`	`inline OptionSet<CodeGenerationMode> JSGlobalObject::defaultCodeGenerationMode() const`
`1165`	`1165`	`{`
`1166`	`1166`	`OptionSet<CodeGenerationMode> codeGenerationMode;`
`1167`		`- if (hasInteractiveDebugger() \|\| Options::forceDebuggerBytecodeGeneration())`
	`1167`	`+ if (hasInteractiveDebugger() \|\| Options::forceDebuggerBytecodeGeneration() \|\| Options::debuggerTriggersBreakpointException())`
`1168`	`1168`	`codeGenerationMode.add(CodeGenerationMode::Debugger);`
`1169`	`1169`	`if (vm().typeProfiler())`
`1170`	`1170`	`codeGenerationMode.add(CodeGenerationMode::TypeProfiler);`
Original file line number	Diff line number	Diff line change
`@@ -110,6 +110,7 @@ constexpr bool enableWebAssemblyStreamingApi = false;`
`110`	`110`	`v(Bool, dumpBytecodeLivenessResults, false, Normal, nullptr) \`
`111`	`111`	`v(Bool, validateBytecode, false, Normal, nullptr) \`
`112`	`112`	`v(Bool, forceDebuggerBytecodeGeneration, false, Normal, nullptr) \`
	`113`	`+ v(Bool, debuggerTriggersBreakpointException, false, Normal, "Using the debugger statement will trigger an breakpoint exception (Useful when lldbing)") \`
`113`	`114`	`v(Bool, dumpBytecodesBeforeGeneratorification, false, Normal, nullptr) \`
`114`	`115`	`\`
`115`	`116`	`v(Bool, useFunctionDotArguments, true, Normal, nullptr) \`