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Debugger: speed up setting break points in nested SFI.

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If the shared function info is newly compiled when looking for
it in the script (Debug::FindSharedFunctionInfoInScript), then
we can bypass iterating the heap to find JSFunctions referencing
it (Debug::PrepareFunctionForBreakpoints).

BUG=v8:4553
LOG=N

Review URL: https://codereview.chromium.org/1454673002

Cr-Commit-Position: refs/heads/master@{#32107}
This commit is contained in:
yangguo 2015-11-19 02:38:27 -08:00 committed by Commit bot
parent eb25b8c54b
commit de884f201a
2 changed files with 22 additions and 4 deletions
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25
src/debug/debug.cc
View File

@ -1377,6 +1377,7 @@ class SharedFunctionInfoFinder {
target_position_(target_position) {}
void NewCandidate(SharedFunctionInfo* shared, JSFunction* closure = NULL) {
if (!shared->IsSubjectToDebugging()) return;
int start_position = shared->function_token_position();
if (start_position == RelocInfo::kNoPosition) {
start_position = shared->start_position();
@ -1426,7 +1427,7 @@ class SharedFunctionInfoFinder {
// cannot be compiled without context (need to find outer compilable SFI etc.)
Handle<Object> Debug::FindSharedFunctionInfoInScript(Handle<Script> script,
int position) {
while (true) {
for (int iteration = 0;; iteration++) {
// Go through all shared function infos associated with this script to
// find the inner most function containing this position.
// If there is no shared function info for this script at all, there is
@ -1444,7 +1445,18 @@ Handle<Object> Debug::FindSharedFunctionInfoInScript(Handle<Script> script,
shared = finder.Result();
if (shared == NULL) break;
// We found it if it's already compiled and has debug code.
if (shared->HasDebugCode()) return handle(shared);
if (shared->HasDebugCode()) {
Handle<SharedFunctionInfo> shared_handle(shared);
// If the iteration count is larger than 1, we had to compile the outer
// function in order to create this shared function info. So there can
// be no JSFunction referencing it. We can anticipate creating a debug
// info while bypassing PrepareFunctionForBreakpoints.
if (iteration > 1) {
AllowHeapAllocation allow_before_return;
CreateDebugInfo(shared_handle);
}
return shared_handle;
}
}
// If not, compile to reveal inner functions, if possible.
if (shared->allows_lazy_compilation_without_context()) {
@ -1509,6 +1521,13 @@ bool Debug::EnsureDebugInfo(Handle<SharedFunctionInfo> shared,
shared->code()->ClearInlineCaches();
shared->ClearTypeFeedbackInfo();
CreateDebugInfo(shared);
return true;
}
void Debug::CreateDebugInfo(Handle<SharedFunctionInfo> shared) {
// Create the debug info object.
DCHECK(shared->HasDebugCode());
Handle<DebugInfo> debug_info = isolate_->factory()->NewDebugInfo(shared);
@ -1517,8 +1536,6 @@ bool Debug::EnsureDebugInfo(Handle<SharedFunctionInfo> shared,
DebugInfoListNode* node = new DebugInfoListNode(*debug_info);
node->set_next(debug_info_list_);
debug_info_list_ = node;
return true;
}

1
src/debug/debug.h
View File

@ -424,6 +424,7 @@ class Debug {
// function needs to be compiled already.
bool EnsureDebugInfo(Handle<SharedFunctionInfo> shared,
Handle<JSFunction> function);
void CreateDebugInfo(Handle<SharedFunctionInfo> shared);
static Handle<DebugInfo> GetDebugInfo(Handle<SharedFunctionInfo> shared);
template <typename C>