[PATCH] D111750: [llvm-profgen] Allow unsymbolized profile as perf input

[Lei Wang via Phabricator via llvm-commits]

wlei added inline comments.


================
Comment at: llvm/tools/llvm-profgen/PerfReader.cpp:788-789
+  while (!TraceIt.isAtEoF()) {
+    std::shared_ptr<StringBasedCtxKey> Key =
+        std::make_shared<StringBasedCtxKey>();
+    StringRef Line = TraceIt.getCurrentLine();
----------------
wenlei wrote:
> The underlying object created by make_shared stays on heap, but SampleCounters.emplace creates another copy of the object? is that intentional or did I miss anything? 
(Seems phabricator lost my comments..)

`SampleCounters` key is a  `Hashable<ContextKey>` type.

My understanding is `emplace` will call the ctor of `Hashable`, it's like:

```
template <class T> class Hashable {
public:
  std::shared_ptr<T> Data;
  Hashable(const std::shared_ptr<T> &D) : Data(D) {}
...
```
`Hashable` only own the shared_ptr, do not own the underlying object, so it should only copy the shared_ptr.



Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D111750/new/

https://reviews.llvm.org/D111750