https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68080
Bug ID: 68080
Summary: gcov returns negative counts
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: Pidgeot18 at gmail dot com
Target Milestone: ---
Created attachment 36576
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36576&action=edit
File to run
(See also bug 67937 for bad things that happen when this occurs).
I finally minimized a test case that causes negative counts to happen. If you
name the attached file TestDeadlockDetector.cpp and run:
rm -rf *.gcda && c++ --coverage -std=c++11 -pthread -Os
TestDeadlockDetector.cpp && ./a.out && gcov -a -b -p TestDeadlockDetector.gcda
&& grep -- '-[0-9][0-9]*:' TestDeadlockDetector.cpp.gcov
you should usually see ContentionNoDeadlock_thread have negative counts. The
exact count changes from each run (and sometimes, it's not negative).
The -Os is in the c++ command line is definitely required.
