The empty husk of a JSFunction is useful to us.

We hollow out the rotting core and with evil intent repurpose its dry carcass to empower ourselves; with such a shell we can test.

R=mstarzinger@chromium.org

BUG=

Review URL: https://codereview.chromium.org/637873002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24459 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/cctest/compiler/function-tester.h

@@ -9,6 +9,7 @@
 #include "test/cctest/cctest.h"
 
 #include "src/compiler.h"
+#include "src/compiler/linkage.h"
 #include "src/compiler/pipeline.h"
 #include "src/execution.h"
 #include "src/full-codegen.h"
@@ -37,51 +38,15 @@ class FunctionTester : public InitializedHandleScope {
     CHECK_EQ(0, flags_ & ~supported_flags);
   }
 
-  Isolate* isolate;
-  Handle<JSFunction> function;
-
-  Handle<JSFunction> Compile(Handle<JSFunction> function) {
-#if V8_TURBOFAN_TARGET
-    CompilationInfoWithZone info(function);
-
-    CHECK(Parser::Parse(&info));
-    info.SetOptimizing(BailoutId::None(), Handle<Code>(function->code()));
-    if (flags_ & CompilationInfo::kContextSpecializing) {
-      info.MarkAsContextSpecializing();
-    }
-    if (flags_ & CompilationInfo::kInliningEnabled) {
-      info.MarkAsInliningEnabled();
-    }
-    if (flags_ & CompilationInfo::kTypingEnabled) {
-      info.MarkAsTypingEnabled();
-    }
-    CHECK(Rewriter::Rewrite(&info));
-    CHECK(Scope::Analyze(&info));
-    CHECK(Compiler::EnsureDeoptimizationSupport(&info));
-
-    Pipeline pipeline(&info);
-    Handle<Code> code = pipeline.GenerateCode();
-    if (FLAG_turbo_deoptimization) {
-      info.context()->native_context()->AddOptimizedCode(*code);
+  explicit FunctionTester(Graph* graph)
+      : isolate(main_isolate()),
+        function(NewFunction("(function(a,b){})")),
+        flags_(0) {
+    CompileGraph(graph);
   }
 
-    CHECK(!code.is_null());
-    function->ReplaceCode(*code);
-#elif USE_CRANKSHAFT
-    Handle<Code> unoptimized = Handle<Code>(function->code());
-    Handle<Code> code = Compiler::GetOptimizedCode(function, unoptimized,
-                                                   Compiler::NOT_CONCURRENT);
-    CHECK(!code.is_null());
-#if ENABLE_DISASSEMBLER
-    if (FLAG_print_opt_code) {
-      CodeTracer::Scope tracing_scope(isolate->GetCodeTracer());
-      code->Disassemble("test code", tracing_scope.file());
-    }
-#endif
-    function->ReplaceCode(*code);
-#endif
-    return function;
-  }
+  Isolate* isolate;
+  Handle<JSFunction> function;
 
   MaybeHandle<Object> Call(Handle<Object> a, Handle<Object> b) {
     Handle<Object> args[] = {a, b};
@@ -183,8 +148,82 @@ class FunctionTester : public InitializedHandleScope {
 
   Handle<Object> false_value() { return isolate->factory()->false_value(); }
 
+  Handle<JSFunction> Compile(Handle<JSFunction> function) {
+// TODO(titzer): make this method private.
+#if V8_TURBOFAN_TARGET
+    CompilationInfoWithZone info(function);
+
+    CHECK(Parser::Parse(&info));
+    info.SetOptimizing(BailoutId::None(), Handle<Code>(function->code()));
+    if (flags_ & CompilationInfo::kContextSpecializing) {
+      info.MarkAsContextSpecializing();
+    }
+    if (flags_ & CompilationInfo::kInliningEnabled) {
+      info.MarkAsInliningEnabled();
+    }
+    if (flags_ & CompilationInfo::kTypingEnabled) {
+      info.MarkAsTypingEnabled();
+    }
+    CHECK(Rewriter::Rewrite(&info));
+    CHECK(Scope::Analyze(&info));
+    CHECK(Compiler::EnsureDeoptimizationSupport(&info));
+
+    Pipeline pipeline(&info);
+    Handle<Code> code = pipeline.GenerateCode();
+    if (FLAG_turbo_deoptimization) {
+      info.context()->native_context()->AddOptimizedCode(*code);
+    }
+
+    CHECK(!code.is_null());
+    function->ReplaceCode(*code);
+#elif USE_CRANKSHAFT
+    Handle<Code> unoptimized = Handle<Code>(function->code());
+    Handle<Code> code = Compiler::GetOptimizedCode(function, unoptimized,
+                                                   Compiler::NOT_CONCURRENT);
+    CHECK(!code.is_null());
+#if ENABLE_DISASSEMBLER
+    if (FLAG_print_opt_code) {
+      CodeTracer::Scope tracing_scope(isolate->GetCodeTracer());
+      code->Disassemble("test code", tracing_scope.file());
+    }
+#endif
+    function->ReplaceCode(*code);
+#endif
+    return function;
+  }
+
+  static Handle<JSFunction> ForMachineGraph(Graph* graph) {
+    JSFunction* p = NULL;
+    {  // because of the implicit handle scope of FunctionTester.
+      FunctionTester f(graph);
+      p = *f.function;
+    }
+    return Handle<JSFunction>(p);  // allocated in outer handle scope.
+  }
+
  private:
   uint32_t flags_;
+
+  // Compile the given machine graph instead of the source of the function
+  // and replace the JSFunction's code with the result.
+  Handle<JSFunction> CompileGraph(Graph* graph) {
+    CHECK(Pipeline::SupportedTarget());
+    CompilationInfoWithZone info(function);
+
+    CHECK(Parser::Parse(&info));
+    info.SetOptimizing(BailoutId::None(),
+                       Handle<Code>(function->shared()->code()));
+    CHECK(Rewriter::Rewrite(&info));
+    CHECK(Scope::Analyze(&info));
+    CHECK(Compiler::EnsureDeoptimizationSupport(&info));
+
+    Pipeline pipeline(&info);
+    Linkage linkage(&info);
+    Handle<Code> code = pipeline.GenerateCodeForMachineGraph(&linkage, graph);
+    CHECK(!code.is_null());
+    function->ReplaceCode(*code);
+    return function;
+  }
 };
 }
 }

test/cctest/compiler/test-changes-lowering.cc

@@ -19,6 +19,7 @@
 #include "src/scopes.h"
 #include "test/cctest/cctest.h"
 #include "test/cctest/compiler/codegen-tester.h"
+#include "test/cctest/compiler/function-tester.h"
 #include "test/cctest/compiler/graph-builder-tester.h"
 #include "test/cctest/compiler/value-helper.h"
 
@@ -45,29 +46,10 @@ class ChangesLoweringTester : public GraphBuilderTester<ReturnType> {
 
   template <typename T>
   T* CallWithPotentialGC() {
-    // TODO(titzer): we need to wrap the code in a JSFunction and call it via
-    // Execution::Call() so that the GC knows about the frame, can walk it,
-    // relocate the code object if necessary, etc.
-    // This is pretty ugly and at the least should be moved up to helpers.
+    // TODO(titzer): we wrap the code in a JSFunction here to reuse the
+    // JSEntryStub; that could be done with a special prologue or other stub.
     if (function.is_null()) {
-      function =
-          v8::Utils::OpenHandle(*v8::Handle<v8::Function>::Cast(CompileRun(
-              "(function() { 'use strict'; return 2.7123; })")));
-      CompilationInfoWithZone info(function);
-      CHECK(Parser::Parse(&info));
-      info.SetOptimizing(BailoutId::None(), Handle<Code>(function->code()));
-      CHECK(Rewriter::Rewrite(&info));
-      CHECK(Scope::Analyze(&info));
-      CHECK_NE(NULL, info.scope());
-      Handle<ScopeInfo> scope_info =
-          ScopeInfo::Create(info.scope(), info.zone());
-      info.shared_info()->set_scope_info(*scope_info);
-      Pipeline pipeline(&info);
-      Linkage linkage(&info);
-      Handle<Code> code =
-          pipeline.GenerateCodeForMachineGraph(&linkage, this->graph());
-      CHECK(!code.is_null());
-      function->ReplaceCode(*code);
+      function = FunctionTester::ForMachineGraph(this->graph());
     }
     Handle<Object>* args = NULL;
     MaybeHandle<Object> result =