Fix reading of uninitialized bool (cancelled_) upon moving NextResult. (#39709)
Hello,
This should hopefully fix #35381, or at least eliminate one possible cause.
This is a classical uninitialized variable:
- Not all constructors initialize `cancelled_`.
- We rely on the compiler-provided move operations, which unconditionally copy all non-static data members.
- As a result, a move operation reads from an uninitialized `cancelled_`.
It is probably innocuous in that context, but it is still undefined behavior.
I see two possible ways to fix it:
1. Always initizalize `cancelled_`.
2. Don't rely on the compiler-provided move operations, and implement it manually so it skips the `cancelled_` field when not relevant.
This fix takes path 1, filling in semantically correct values (even though they should not be used). Happy to change it if needed.
Closes #39709
COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/39709 from juliencamille-hartmann-simplisafe:fix-35381 717e477ed55a0260b73746390db0dec7c1841a9e
PiperOrigin-RevId: 800643444
diff --git a/src/core/lib/promise/pipe.h b/src/core/lib/promise/pipe.h
index 95799f3..75123ce 100644
--- a/src/core/lib/promise/pipe.h
+++ b/src/core/lib/promise/pipe.h
@@ -58,9 +58,9 @@
template <typename T>
class NextResult final {
public:
- NextResult() : center_(nullptr) {}
+ NextResult() : center_(nullptr), cancelled_(true) {}
explicit NextResult(RefCountedPtr<pipe_detail::Center<T>> center)
- : center_(std::move(center)) {
+ : center_(std::move(center)), cancelled_(false) {
CHECK(center_ != nullptr);
}
explicit NextResult(bool cancelled)
