https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109719
Bug ID: 109719
Summary: Truncated frame-pointer unwinding via Linux perf with
g++
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: chergert at redhat dot com
Target Milestone: ---
On Fedora 38, frame-pointers are enabled by default. Caveats of course.
However, I noticed that clang++ is generating code that can unwind with
frame-pointers just fine where as g++ is generating code that fails to unwind
past a single frame for some projects.
Where I've noticed this is when profiling GTK/GNOME applications. Harfbuzz,
which is C++ (no-rtti, no-exceptions, no-threadsafe-statics, and no stdlibc++),
regularly results in stacktraces from Linux perf containing 2 frames. One of
them looks corrupted, and the second to a Harfbuzz function.
When I recompile the project with clang++ instead (leaving the rest of the
system still compiled with gcc) I get proper stacktraces from Linux perf
showing how the Harfbuzz API was called (via GLib/GTK/Pango/etc).
Happy to provide more information and/or be remote hands/eyes.
Thanks!
