[3.15] gh-157354: Honor --with-<name>-sanitizer=no and --without-<name>-sanitizer in configure (GH-157355)

Lib/test/support/__init__.py

@@ -11,6 +11,7 @@
 import _opcode
 import os
 import re
+import shlex
 import stat
 import sys
 import sysconfig
@@ -444,22 +445,34 @@ def check_sanitizer(*, address=False, memory=False, ub=False, thread=False,
 
 
     cflags = sysconfig.get_config_var('CFLAGS') or ''
-    config_args = sysconfig.get_config_var('CONFIG_ARGS') or ''
+    config_args = shlex.split(sysconfig.get_config_var('CONFIG_ARGS') or '')
+
+    def configured_with_sanitizer(name):
+        with_option = f'--with-{name}-sanitizer'
+        without_option = f'--without-{name}-sanitizer'
+        enabled = False
+        for arg in config_args:
+            if arg == without_option or arg == f'{with_option}=no':
+                enabled = False
+            elif arg == with_option or arg.startswith(f'{with_option}='):
+                enabled = True
+        return enabled
+
     memory_sanitizer = (
         '-fsanitize=memory' in cflags or
-        '--with-memory-sanitizer' in config_args
+        configured_with_sanitizer('memory')
     )
     address_sanitizer = (
         '-fsanitize=address' in cflags or
-        '--with-address-sanitizer' in config_args
+        configured_with_sanitizer('address')
     )
     ub_sanitizer = (
         '-fsanitize=undefined' in cflags or
-        '--with-undefined-behavior-sanitizer' in config_args
+        configured_with_sanitizer('undefined-behavior')
     )
     thread_sanitizer = (
         '-fsanitize=thread' in cflags or
-        '--with-thread-sanitizer' in config_args
+        configured_with_sanitizer('thread')
     )
     function_sanitizer = (
         '-fsanitize=function' in cflags

Misc/NEWS.d/next/Build/2026-09-12-15-33-26.gh-issue-157354.2hw6fe.rst

@@ -0,0 +1,2 @@
+Fix the :samp:`--with-{name}-sanitizer=no` and :samp:`--without-{name}-sanitizer`
+:program:`configure` options enabling the sanitizer instead of disabling it.

configure.ac

@@ -3496,14 +3496,14 @@ AC_MSG_CHECKING([for --with-address-sanitizer])
 AC_ARG_WITH([address_sanitizer],
             AS_HELP_STRING([--with-address-sanitizer],
                            [enable AddressSanitizer memory error detector, 'asan' (default is no)]),
-[
-AC_MSG_RESULT([$withval])
+[], [with_address_sanitizer=no])
+AC_MSG_RESULT([$with_address_sanitizer])
+AS_VAR_IF([with_address_sanitizer], [no], [], [
 BASECFLAGS="-fsanitize=address -fno-omit-frame-pointer $BASECFLAGS"
 LDFLAGS="-fsanitize=address $LDFLAGS"
 # ASan works by controlling memory allocation, our own malloc interferes.
 with_pymalloc="no"
-],
-[AC_MSG_RESULT([no])])
+])
 
 AC_MSG_CHECKING([for --with-memory-sanitizer])
 AC_ARG_WITH(
@@ -3512,16 +3512,16 @@ AC_ARG_WITH(
     [--with-memory-sanitizer],
     [enable MemorySanitizer allocation error detector, 'msan' (default is no)]
   )],
-[
-AC_MSG_RESULT([$withval])
+[], [with_memory_sanitizer=no])
+AC_MSG_RESULT([$with_memory_sanitizer])
+AS_VAR_IF([with_memory_sanitizer], [no], [], [
 AX_CHECK_COMPILE_FLAG([-fsanitize=memory],[
 BASECFLAGS="-fsanitize=memory -fsanitize-memory-track-origins=2 -fno-omit-frame-pointer $BASECFLAGS"
 LDFLAGS="-fsanitize=memory -fsanitize-memory-track-origins=2 $LDFLAGS"
 ],[AC_MSG_ERROR([The selected compiler doesn't support memory sanitizer])])
 # MSan works by controlling memory allocation, our own malloc interferes.
 with_pymalloc="no"
-],
-[AC_MSG_RESULT([no])])
+])
 
 AC_MSG_CHECKING([for --with-undefined-behavior-sanitizer])
 AC_ARG_WITH(
@@ -3530,15 +3530,14 @@ AC_ARG_WITH(
     [--with-undefined-behavior-sanitizer],
     [enable UndefinedBehaviorSanitizer undefined behaviour detector, 'ubsan' (default is no)]
   )],
-[
-AC_MSG_RESULT([$withval])
+[], [with_undefined_behavior_sanitizer=no])
+AC_MSG_RESULT([$with_undefined_behavior_sanitizer])
+AS_VAR_IF([with_undefined_behavior_sanitizer], [no], [
+with_ubsan="no"
+], [
 BASECFLAGS="-fsanitize=undefined $BASECFLAGS"
 LDFLAGS="-fsanitize=undefined $LDFLAGS"
 with_ubsan="yes"
-],
-[
-AC_MSG_RESULT([no])
-with_ubsan="no"
 ])
 
 AC_MSG_CHECKING([for --with-thread-sanitizer])
@@ -3548,15 +3547,14 @@ AC_ARG_WITH(
     [--with-thread-sanitizer],
     [enable ThreadSanitizer data race detector, 'tsan' (default is no)]
   )],
-[
-AC_MSG_RESULT([$withval])
+[], [with_thread_sanitizer=no])
+AC_MSG_RESULT([$with_thread_sanitizer])
+AS_VAR_IF([with_thread_sanitizer], [no], [
+with_tsan="no"
+], [
 BASECFLAGS="-fsanitize=thread $BASECFLAGS"
 LDFLAGS="-fsanitize=thread $LDFLAGS"
 with_tsan="yes"
-],
-[
-AC_MSG_RESULT([no])
-with_tsan="no"
 ])
 
 # Set info about shared libraries.