From e71c12efcddc1076d5367461a5b416092267aa77 Mon Sep 17 00:00:00 2001
From: Pablo Galindo Salgado <Pablogsal@gmail.com>
Date: Sat, 27 Nov 2021 18:04:06 +0000
Subject: [PATCH] bpo-42268: Fail the configure step if the selected compiler
 doesn't support memory sanitizer (GH-29806)

---
 .../2021-11-26-22-31-22.bpo-42268.3wl-09.rst  |  2 ++
 configure                                     | 36 +++++++++++++++++++
 configure.ac                                  |  2 ++
 3 files changed, 40 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2021-11-26-22-31-22.bpo-42268.3wl-09.rst

diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-11-26-22-31-22.bpo-42268.3wl-09.rst b/Misc/NEWS.d/next/Core and Builtins/2021-11-26-22-31-22.bpo-42268.3wl-09.rst
new file mode 100644
index 00000000000..615bbb22ae2
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2021-11-26-22-31-22.bpo-42268.3wl-09.rst	
@@ -0,0 +1,2 @@
+Fail the configure step if the selected compiler doesn't support memory
+sanitizer. Patch by Pablo Galindo
diff --git a/configure b/configure
index 1c398929c96..958007288a1 100755
--- a/configure
+++ b/configure
@@ -9920,8 +9920,44 @@ if test "${with_memory_sanitizer+set}" = set; then :
   withval=$with_memory_sanitizer;
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $withval" >&5
 $as_echo "$withval" >&6; }
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C compiler accepts -fsanitize=memory" >&5
+$as_echo_n "checking whether C compiler accepts -fsanitize=memory... " >&6; }
+if ${ax_cv_check_cflags___fsanitize_memory+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CFLAGS
+  CFLAGS="$CFLAGS  -fsanitize=memory"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ax_cv_check_cflags___fsanitize_memory=yes
+else
+  ax_cv_check_cflags___fsanitize_memory=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CFLAGS=$ax_check_save_flags
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_check_cflags___fsanitize_memory" >&5
+$as_echo "$ax_cv_check_cflags___fsanitize_memory" >&6; }
+if test "x$ax_cv_check_cflags___fsanitize_memory" = xyes; then :
+
 BASECFLAGS="-fsanitize=memory -fsanitize-memory-track-origins=2 -fno-omit-frame-pointer $BASECFLAGS"
 LDFLAGS="-fsanitize=memory -fsanitize-memory-track-origins=2 $LDFLAGS"
+
+else
+  as_fn_error $? "The selected compiler doesn't support memory sanitizer" "$LINENO" 5
+fi
+
 # MSan works by controlling memory allocation, our own malloc interferes.
 with_pymalloc="no"
 
diff --git a/configure.ac b/configure.ac
index e96d88fb8c8..0fce3f61f5a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2565,8 +2565,10 @@ AC_ARG_WITH(memory_sanitizer,
                            [enable MemorySanitizer allocation error detector, 'msan' (default is no)]),
 [
 AC_MSG_RESULT($withval)
+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"
 ],