Add volatile to temporary variable.
FuseBuffer::HandleNotImpl save the value of |request.header.unique| to the
temporary variable, clear the buffer which is a union of |request| and
|response|, then write back the unique value to response.header.unique.
Before the CL, the temporary variable was wrongly removed by the compiler
optimization, and response.header.unique was always 0. The CL adds
volatile modifier as workaround to prevent the compiler optimization
from removing the temporary value.
Bug: 62429763
Test: libappfuse_tests
Change-Id: Ia853f805633f646f316f585a35c7b018000b6eb3
(cherry picked from commit a6dee5e279de56751238f750d12f8a6237992043)
diff --git a/libappfuse/FuseBuffer.cc b/libappfuse/FuseBuffer.cc
index 1b47e0a..1eab46c 100644
--- a/libappfuse/FuseBuffer.cc
+++ b/libappfuse/FuseBuffer.cc
@@ -251,7 +251,9 @@
void FuseBuffer::HandleNotImpl() {
LOG(VERBOSE) << "NOTIMPL op=" << request.header.opcode << " uniq="
<< request.header.unique << " nid=" << request.header.nodeid;
- const uint64_t unique = request.header.unique;
+ // Add volatile as a workaround for compiler issue which removes the temporary
+ // variable.
+ const volatile uint64_t unique = request.header.unique;
response.Reset(0, -ENOSYS, unique);
}