Add --without-frame-pointers flag and docs

Author: savannahostrowski

Doc/using/configure.rst

@@ -780,6 +780,19 @@ also be used to improve performance.
 
    .. versionadded:: 3.14
 
+.. option:: --without-frame-pointers
+
+   Build without frame pointers (enabled by default, see :pep:`831`).
+
+   By default, the build appends ``-fno-omit-frame-pointer`` and
+   ``-mno-omit-leaf-frame-pointer`` to ``BASECFLAGS`` so profilers,
+   debuggers, and system tracing tools (``perf``, ``eBPF``, ``dtrace``,
+   ``gdb``) can walk the C call stack without DWARF metadata. The flags
+   propagate to third-party C extensions through :mod:`sysconfig`, and
+   are silently skipped on compilers that do not understand them.
+
+   .. versionadded:: 3.15
+
 .. option:: --without-mimalloc
 
    Disable the fast :ref:`mimalloc <mimalloc>` allocator

Doc/whatsnew/3.15.rst

@@ -1983,6 +1983,10 @@ Build changes
   and :option:`-X dev <-X>` is passed to the Python or Python is built in :ref:`debug mode <debug-build>`.
   (Contributed by Donghee Na in :gh:`141770`.)
 
+* CPython is now built with frame pointers enabled by default
+  (:pep:`831`). Pass :option:`--without-frame-pointers` to opt out.
+  (Contributed by Pablo Galindo Salgado and Savannah Ostrowski in :gh:`149202`.)
+
 .. _whatsnew315-windows-tail-calling-interpreter:
 
 * 64-bit builds using Visual Studio 2026 (MSVC 18) may now use the new

Misc/NEWS.d/next/Core_and_Builtins/2026-04-05-16-10-00.gh-issue-149202.W8sQeR.rst

@@ -1,3 +1,4 @@
 Enable frame pointers by default for GCC-compatible CPython builds, including
 ``-mno-omit-leaf-frame-pointer`` when the compiler supports it, so profilers
-and debuggers can unwind native interpreter frames more reliably.
+and debuggers can unwind native interpreter frames more reliably. Users can pass
+``--without-frame-pointers`` to opt out.

configure

@@ -2489,18 +2489,28 @@ then
   AX_CHECK_COMPILE_FLAG([-D_FORTIFY_SOURCE=3], [CFLAGS_NODIST="$CFLAGS_NODIST -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3"], [AC_MSG_WARN([-D_FORTIFY_SOURCE=3 not supported])], [-Werror])
 fi
 
+AC_MSG_CHECKING([whether to build with frame pointers])
+AC_ARG_WITH([frame-pointers],
+  [AS_HELP_STRING([--without-frame-pointers],
+                  [build without frame pointers (default is yes)])],
+  [],
+  [with_frame_pointers=yes])
+AC_MSG_RESULT([$with_frame_pointers])
+
 AS_VAR_IF([ac_cv_gcc_compat], [yes], [
-    dnl Keep frame pointers in CPython and stdlib objects so native profilers
-    dnl can unwind interpreter frames and generated trampolines without DWARF.
+    dnl Keep frame pointers in CPython, stdlib objects, and third-party
+    dnl extensions built against this Python (BASECFLAGS propagates via
+    dnl sysconfig) so native profilers can unwind interpreter frames and
+    dnl generated trampolines without DWARF.
     frame_pointer_cflags=
     AX_CHECK_COMPILE_FLAG([-fno-omit-frame-pointer], [
       frame_pointer_cflags="-fno-omit-frame-pointer"
       AX_CHECK_COMPILE_FLAG([-mno-omit-leaf-frame-pointer], [
         frame_pointer_cflags="$frame_pointer_cflags -mno-omit-leaf-frame-pointer"
       ], [], [-Werror])
     ], [], [-Werror])
-    if test -n "$frame_pointer_cflags"; then
-      CFLAGS_NODIST="$frame_pointer_cflags $CFLAGS_NODIST"
+    if test -n "$frame_pointer_cflags" && test "x$with_frame_pointers" != xno; then
+      BASECFLAGS="$frame_pointer_cflags $BASECFLAGS"
     fi
 
     CFLAGS_NODIST="$CFLAGS_NODIST -std=c11"