On 2014/08/19 14:23:35, alph wrote:
https://codereview.chromium.org/424973004/diff/120001/test/cctest/test-cpu-profiler.cc
File test/cctest/test-cpu-profiler.cc (right):
https://codereview.chromium.org/424973004/diff/120001/test/cctest/test-cpu-profiler.cc#newcode1134
test/cctest/test-cpu-profiler.cc:1134: CHECK_NE(NULL, line_info);
On 2014/08/15 20:57:55, Denis Pravdin wrote:
> On 2014/08/15 12:10:47, alph wrote:
> > I've got the test failing at this line for ia32 target because
there's no
> > POSITION reloc infos for the code.
>
> Well, I found out what causes this test failure but I don't understand a
reason
> of this behavior and I am not sure what the best way to fix it is:
>
> In patch set 3, I iterate the heap to get a function object
> (GetFunctionInfoFromHeap). The test passes all the time.
>
> In patch set 4, I replace it with the lines below as you suggested (see
a
code
> snippet below) and test failed.
>
> i::Handle<i::JSFunction> func = v8::Utils::OpenHandle(
> *v8::Local<v8::Function>::Cast(
> (*env)->Global()->Get(v8_str(func_name))));
>
> Looking into it, I decided to check what the difference between these
two
ways:
> 1. I added heap iteration back in addition to v8::Utils::OpenHandle
> 2. Then checked that reloc info for both objects of Code type include
positions.
>
> The test looks like:
>
> CompileRun(script.start());
>
> i::SharedFunctionInfo* shared = GetFunctionInfoFromHeap(isolate,
func_name);
> int positions_ = 0;
> for (i::RelocIterator it(shared->code()); !it.done(); it.next()) {
> i::RelocInfo::Mode mode = it.rinfo()->rmode();
> if (i::RelocInfo::IsPosition(mode)) positions_++;
> }
> CHECK_GT(positions_, 0); // THIS CHECK PASSED
>
> i::Handle<i::JSFunction> func = v8::Utils::OpenHandle(
> *v8::Local<v8::Function>::Cast(
> (*env)->Global()->Get(v8_str(func_name))));
> CHECK_NE(NULL, func->shared());
> CHECK_NE(NULL, func->code());
> int positions = 0;
> for (i::RelocIterator it(func->code()); !it.done(); it.next()) {
> i::RelocInfo::Mode mode = it.rinfo()->rmode();
> if (i::RelocInfo::IsPosition(mode)) positions++;
> }
> CHECK_GT(positions, 0); // THIS CHECK DOES NOT PASS.
>
> Do you have idea why for the first case I have POSITION reloc info, and
never
> have it for the second case?
Could you please check the 'shared' and 'code' objects you get using
these two
approaches are the same.
I think there are several versions on the code for the function, e.g.
optimized
and non-optimized. One of them is missing relocations.
Yes, you're right.
I debugged the test and found out:
1. There are two ways to get 'code' using JSFunction object (jsf is type of
JSFunction):
(a) jsf->code()
(b) jsf->shared()->code()
2. When optimized code is compiled that both JSFunction::ReplaceCode(Code*
code)
and SharedFunctionInfo::ReplaceCode(Code* value) function are called. As the
result, the 'code' objects returned by (a) and (b) contains relocations.
3. Then, optimized version of code is generated and only
SFunction::ReplaceCode(Code* code) is called.
Note that I use func->code() instead of func->shared()->code():
for (i::RelocIterator it(func->code()); !it.done(); it.next()) {
i::RelocInfo::Mode mode = it.rinfo()->rmode();
if (i::RelocInfo::IsPosition(mode)) positions++;
}
That's why my previous approach (GetFunctionInfoFromHeap) always works but
new
one (OpenHandle) causes a test failure.
Possible solutions:
1) For testing purpose, always use unoptimized version of code (e.g.
func->shared()->code())
+ allows to make the test more deterministic
- optimized code is not tested
2) Set FLAG_hydrogen_track_positions flag as true by default before
CompileRun
for this test.
I checked on Windows and see that number of positions is increased from
9 to
19 for 'func' function from the test.
I think that the flag should be turned on always to achieve better
mapping to
source lines for generated optimized code. We can add a runtime switch to
turn
it on before profiling starts. It's a subject for a separate patch.
Can you suggest other ideas? If not that which of the above is the best?
>
> It seems it's Linux specific issue. At least I don't see it on Windows.
https://codereview.chromium.org/424973004/
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