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DEFINITIONS
This source file includes following definitions.
- InitTraceEnv
- DoTrace
- DoTraceHideCEntryFPAddress
- GetNativeFunction
- GetFP
- JSTrace
- GetJsEntrySp
- JSEntrySP
- JSEntrySPLevel2
- InitializeVM
- IsAddressWithinFuncCode
- IsAddressWithinFuncCode
- construct_call
- CreateFramePointerGrabberConstructor
- CreateTraceCallerFunction
- TEST
- TEST
- CFuncDoTrace
- CFunc
- TEST
- TEST
// Copyright 2011 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Tests of profiler-related functions from log.h
#include <stdlib.h>
#include "v8.h"
#include "api.h"
#include "codegen.h"
#include "log.h"
#include "isolate.h"
#include "cctest.h"
#include "disassembler.h"
#include "vm-state-inl.h"
using v8::Function;
using v8::Local;
using v8::Object;
using v8::Script;
using v8::String;
using v8::Value;
using v8::internal::byte;
using v8::internal::Address;
using v8::internal::Handle;
using v8::internal::Isolate;
using v8::internal::JSFunction;
using v8::internal::StackTracer;
using v8::internal::TickSample;
static v8::Persistent<v8::Context> env;
static struct {
TickSample* sample;
} trace_env = { NULL };
static void InitTraceEnv(TickSample* sample) {
trace_env.sample = sample;
}
static void DoTrace(Address fp) {
trace_env.sample->fp = fp;
// sp is only used to define stack high bound
trace_env.sample->sp =
reinterpret_cast<Address>(trace_env.sample) - 10240;
StackTracer::Trace(Isolate::Current(), trace_env.sample);
}
// Hide c_entry_fp to emulate situation when sampling is done while
// pure JS code is being executed
static void DoTraceHideCEntryFPAddress(Address fp) {
v8::internal::Address saved_c_frame_fp =
*(Isolate::Current()->c_entry_fp_address());
CHECK(saved_c_frame_fp);
*(Isolate::Current()->c_entry_fp_address()) = 0;
DoTrace(fp);
*(Isolate::Current()->c_entry_fp_address()) = saved_c_frame_fp;
}
// --- T r a c e E x t e n s i o n ---
class TraceExtension : public v8::Extension {
public:
TraceExtension() : v8::Extension("v8/trace", kSource) { }
virtual v8::Handle<v8::FunctionTemplate> GetNativeFunction(
v8::Handle<String> name);
static v8::Handle<v8::Value> Trace(const v8::Arguments& args);
static v8::Handle<v8::Value> JSTrace(const v8::Arguments& args);
static v8::Handle<v8::Value> JSEntrySP(const v8::Arguments& args);
static v8::Handle<v8::Value> JSEntrySPLevel2(const v8::Arguments& args);
private:
static Address GetFP(const v8::Arguments& args);
static const char* kSource;
};
const char* TraceExtension::kSource =
"native function trace();"
"native function js_trace();"
"native function js_entry_sp();"
"native function js_entry_sp_level2();";
v8::Handle<v8::FunctionTemplate> TraceExtension::GetNativeFunction(
v8::Handle<String> name) {
if (name->Equals(String::New("trace"))) {
return v8::FunctionTemplate::New(TraceExtension::Trace);
} else if (name->Equals(String::New("js_trace"))) {
return v8::FunctionTemplate::New(TraceExtension::JSTrace);
} else if (name->Equals(String::New("js_entry_sp"))) {
return v8::FunctionTemplate::New(TraceExtension::JSEntrySP);
} else if (name->Equals(String::New("js_entry_sp_level2"))) {
return v8::FunctionTemplate::New(TraceExtension::JSEntrySPLevel2);
} else {
CHECK(false);
return v8::Handle<v8::FunctionTemplate>();
}
}
Address TraceExtension::GetFP(const v8::Arguments& args) {
// Convert frame pointer from encoding as smis in the arguments to a pointer.
CHECK_EQ(2, args.Length()); // Ignore second argument on 32-bit platform.
#if defined(V8_HOST_ARCH_32_BIT)
Address fp = *reinterpret_cast<Address*>(*args[0]);
#elif defined(V8_HOST_ARCH_64_BIT)
int64_t low_bits = *reinterpret_cast<uint64_t*>(*args[0]) >> 32;
int64_t high_bits = *reinterpret_cast<uint64_t*>(*args[1]);
Address fp = reinterpret_cast<Address>(high_bits | low_bits);
#else
#error Host architecture is neither 32-bit nor 64-bit.
#endif
printf("Trace: %p\n", fp);
return fp;
}
v8::Handle<v8::Value> TraceExtension::Trace(const v8::Arguments& args) {
DoTrace(GetFP(args));
return v8::Undefined();
}
v8::Handle<v8::Value> TraceExtension::JSTrace(const v8::Arguments& args) {
DoTraceHideCEntryFPAddress(GetFP(args));
return v8::Undefined();
}
static Address GetJsEntrySp() {
CHECK_NE(NULL, i::Isolate::Current()->thread_local_top());
return Isolate::js_entry_sp(i::Isolate::Current()->thread_local_top());
}
v8::Handle<v8::Value> TraceExtension::JSEntrySP(const v8::Arguments& args) {
CHECK_NE(0, GetJsEntrySp());
return v8::Undefined();
}
v8::Handle<v8::Value> TraceExtension::JSEntrySPLevel2(
const v8::Arguments& args) {
v8::HandleScope scope;
const Address js_entry_sp = GetJsEntrySp();
CHECK_NE(0, js_entry_sp);
CompileRun("js_entry_sp();");
CHECK_EQ(js_entry_sp, GetJsEntrySp());
return v8::Undefined();
}
static TraceExtension kTraceExtension;
v8::DeclareExtension kTraceExtensionDeclaration(&kTraceExtension);
static void InitializeVM() {
if (env.IsEmpty()) {
v8::HandleScope scope;
const char* extensions[] = { "v8/trace" };
v8::ExtensionConfiguration config(1, extensions);
env = v8::Context::New(&config);
}
v8::HandleScope scope;
env->Enter();
}
static bool IsAddressWithinFuncCode(JSFunction* function, Address addr) {
i::Code* code = function->code();
return code->contains(addr);
}
static bool IsAddressWithinFuncCode(const char* func_name, Address addr) {
v8::Local<v8::Value> func = env->Global()->Get(v8_str(func_name));
CHECK(func->IsFunction());
JSFunction* js_func = JSFunction::cast(*v8::Utils::OpenHandle(*func));
return IsAddressWithinFuncCode(js_func, addr);
}
// This C++ function is called as a constructor, to grab the frame pointer
// from the calling function. When this function runs, the stack contains
// a C_Entry frame and a Construct frame above the calling function's frame.
static v8::Handle<Value> construct_call(const v8::Arguments& args) {
i::StackFrameIterator frame_iterator;
CHECK(frame_iterator.frame()->is_exit());
frame_iterator.Advance();
CHECK(frame_iterator.frame()->is_construct());
frame_iterator.Advance();
i::StackFrame* calling_frame = frame_iterator.frame();
CHECK(calling_frame->is_java_script());
#if defined(V8_HOST_ARCH_32_BIT)
int32_t low_bits = reinterpret_cast<int32_t>(calling_frame->fp());
args.This()->Set(v8_str("low_bits"), v8_num(low_bits >> 1));
#elif defined(V8_HOST_ARCH_64_BIT)
uint64_t fp = reinterpret_cast<uint64_t>(calling_frame->fp());
int32_t low_bits = static_cast<int32_t>(fp & 0xffffffff);
int32_t high_bits = static_cast<int32_t>(fp >> 32);
args.This()->Set(v8_str("low_bits"), v8_num(low_bits));
args.This()->Set(v8_str("high_bits"), v8_num(high_bits));
#else
#error Host architecture is neither 32-bit nor 64-bit.
#endif
return args.This();
}
// Use the API to create a JSFunction object that calls the above C++ function.
void CreateFramePointerGrabberConstructor(const char* constructor_name) {
Local<v8::FunctionTemplate> constructor_template =
v8::FunctionTemplate::New(construct_call);
constructor_template->SetClassName(v8_str("FPGrabber"));
Local<Function> fun = constructor_template->GetFunction();
env->Global()->Set(v8_str(constructor_name), fun);
}
// Creates a global function named 'func_name' that calls the tracing
// function 'trace_func_name' with an actual EBP register value,
// encoded as one or two Smis.
static void CreateTraceCallerFunction(const char* func_name,
const char* trace_func_name) {
i::EmbeddedVector<char, 256> trace_call_buf;
i::OS::SNPrintF(trace_call_buf,
"function %s() {"
" fp = new FPGrabber();"
" %s(fp.low_bits, fp.high_bits);"
"}",
func_name, trace_func_name);
// Create the FPGrabber function, which grabs the caller's frame pointer
// when called as a constructor.
CreateFramePointerGrabberConstructor("FPGrabber");
// Compile the script.
CompileRun(trace_call_buf.start());
}
// This test verifies that stack tracing works when called during
// execution of a native function called from JS code. In this case,
// StackTracer uses Isolate::c_entry_fp as a starting point for stack
// walking.
TEST(CFromJSStackTrace) {
// BUG(1303) Inlining of JSFuncDoTrace() in JSTrace below breaks this test.
i::FLAG_use_inlining = false;
TickSample sample;
InitTraceEnv(&sample);
InitializeVM();
v8::HandleScope scope;
// Create global function JSFuncDoTrace which calls
// extension function trace() with the current frame pointer value.
CreateTraceCallerFunction("JSFuncDoTrace", "trace");
Local<Value> result = CompileRun(
"function JSTrace() {"
" JSFuncDoTrace();"
"};\n"
"JSTrace();\n"
"true;");
CHECK(!result.IsEmpty());
// When stack tracer is invoked, the stack should look as follows:
// script [JS]
// JSTrace() [JS]
// JSFuncDoTrace() [JS] [captures EBP value and encodes it as Smi]
// trace(EBP) [native (extension)]
// DoTrace(EBP) [native]
// StackTracer::Trace
CHECK(sample.has_external_callback);
CHECK_EQ(FUNCTION_ADDR(TraceExtension::Trace), sample.external_callback);
// Stack tracing will start from the first JS function, i.e. "JSFuncDoTrace"
int base = 0;
CHECK_GT(sample.frames_count, base + 1);
CHECK(IsAddressWithinFuncCode("JSFuncDoTrace", sample.stack[base + 0]));
CHECK(IsAddressWithinFuncCode("JSTrace", sample.stack[base + 1]));
}
// This test verifies that stack tracing works when called during
// execution of JS code. However, as calling StackTracer requires
// entering native code, we can only emulate pure JS by erasing
// Isolate::c_entry_fp value. In this case, StackTracer uses passed frame
// pointer value as a starting point for stack walking.
TEST(PureJSStackTrace) {
// This test does not pass with inlining enabled since inlined functions
// don't appear in the stack trace.
i::FLAG_use_inlining = false;
TickSample sample;
InitTraceEnv(&sample);
InitializeVM();
v8::HandleScope scope;
// Create global function JSFuncDoTrace which calls
// extension function js_trace() with the current frame pointer value.
CreateTraceCallerFunction("JSFuncDoTrace", "js_trace");
Local<Value> result = CompileRun(
"function JSTrace() {"
" JSFuncDoTrace();"
"};\n"
"function OuterJSTrace() {"
" JSTrace();"
"};\n"
"OuterJSTrace();\n"
"true;");
CHECK(!result.IsEmpty());
// When stack tracer is invoked, the stack should look as follows:
// script [JS]
// OuterJSTrace() [JS]
// JSTrace() [JS]
// JSFuncDoTrace() [JS]
// js_trace(EBP) [native (extension)]
// DoTraceHideCEntryFPAddress(EBP) [native]
// StackTracer::Trace
//
CHECK(sample.has_external_callback);
CHECK_EQ(FUNCTION_ADDR(TraceExtension::JSTrace), sample.external_callback);
// Stack sampling will start from the caller of JSFuncDoTrace, i.e. "JSTrace"
int base = 0;
CHECK_GT(sample.frames_count, base + 1);
CHECK(IsAddressWithinFuncCode("JSTrace", sample.stack[base + 0]));
CHECK(IsAddressWithinFuncCode("OuterJSTrace", sample.stack[base + 1]));
}
static void CFuncDoTrace(byte dummy_parameter) {
Address fp;
#ifdef __GNUC__
fp = reinterpret_cast<Address>(__builtin_frame_address(0));
#elif defined _MSC_VER
// Approximate a frame pointer address. We compile without base pointers,
// so we can't trust ebp/rbp.
fp = &dummy_parameter - 2 * sizeof(void*); // NOLINT
#else
#error Unexpected platform.
#endif
DoTrace(fp);
}
static int CFunc(int depth) {
if (depth <= 0) {
CFuncDoTrace(0);
return 0;
} else {
return CFunc(depth - 1) + 1;
}
}
// This test verifies that stack tracing doesn't crash when called on
// pure native code. StackTracer only unrolls JS code, so we can't
// get any meaningful info here.
TEST(PureCStackTrace) {
TickSample sample;
InitTraceEnv(&sample);
InitializeVM();
// Check that sampler doesn't crash
CHECK_EQ(10, CFunc(10));
}
TEST(JsEntrySp) {
InitializeVM();
v8::HandleScope scope;
CHECK_EQ(0, GetJsEntrySp());
CompileRun("a = 1; b = a + 1;");
CHECK_EQ(0, GetJsEntrySp());
CompileRun("js_entry_sp();");
CHECK_EQ(0, GetJsEntrySp());
CompileRun("js_entry_sp_level2();");
CHECK_EQ(0, GetJsEntrySp());
}