Bug report

Bug description:

GDB stack trace is incomplete when enabling Perf support under specific optimization options on x86_64. It seems that through various changes the stack trace was broken and/or fixed. I've bisected the relevant commits.

Perf 6.13.4, GDB 16.2, GCC 14.2.1 on x86_64, Fedora 41.

With frame pointers using -X perf:

./configure --enable-shared --without-static-libpython && CFLAGS="-fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -<optmization>" make

Run LD_LIBRARY_PATH=$PWD gdb -args ./python -X perf -m test -vv test_sys and within the GDB shell run.

Press ctrl+c during execution and run bt. On specific configurations the stack trace is trimmed, usually right after the unknown frames.

python3.12:

• -O3, -O1, -O0, -Og:
  Complete gdb stack trace.
• -O2:
  Incomplete gdb stack trace (stops at the unknown frames). (Didn't work from the beginning, resolved in 3.13)

python3.13:

• -O3, -O2, -O0, -Og:
  Complete gdb stack trace.

• -O1:
  Incomplete gdb stack trace (stops at the unknown frames). (regressed on 3.13 here and fixed again in 3.14 here)

python3.14:

• -O3, -O2, -Og:
  Incomplete gdb stack trace (stops at the unknown frames). (-O3, -O2 regressed here, -Og regressed here)

• -O1, -O0:
  Complete gdb stack trace.

Without frame pointers using -X perf_jit

./configure --enable-shared --without-static-libpython && CFLAGS="-<optmization>" make

Run LD_LIBRARY_PATH=$PWD gdb -args ./python -X perf_jit -m test -vv test_sys and within the GDB shell run.

Press ctrl+c during execution and run bt. On specific configurations the stack trace is trimmed, usually right after the unknown frames.

python3.12:

• Not supported

python3.13:

• -O3:
  Incomplete gdb stack trace (stops at the unknown frames). (Worked initially, regressed here, fixed in 3.14)

• -O2, -O1, -Og:
  Complete gdb stack trace.

• -O0:
  Complete gdb stack trace.
  Python functions are not visible in Perf output.

python3.14:

• -O3, -O2, -O1:
  Complete gdb stack trace.

• -Og:
  Incomplete gdb stack trace (stops at the unknown frames). (Regressed here, same as with frame pointers)

• -O0:
  Complete gdb stack trace.
  Python functions are not visible in Perf output.

CPython versions tested on:

CPython main branch, 3.14, 3.13, 3.12

Operating systems tested on:

Linux