From 4f87c917c8c48840fd67cb2b3050fcf78c4e3745 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend@python.org>
Date: Mon, 6 May 2024 00:21:46 +0200
Subject: [PATCH] Address review: warn if system library was not found

---
 configure    | 20 +++++++++++++-------
 configure.ac | 26 ++++++++++++++------------
 2 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/configure b/configure
index c96c89bafee29f..2405938af71c82 100755
--- a/configure
+++ b/configure
@@ -14708,9 +14708,10 @@ save_CPPFLAGS=$CPPFLAGS
 save_LDFLAGS=$LDFLAGS
 save_LIBS=$LIBS
 
-CPPFLAGS="$LIBMPDEC_CFLAGS $CPPFLAGS"
-     LDFLAGS="$LIBMPDEC_LIBS $LDFLAGS"
-     { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing mpd_version" >&5
+
+    CPPFLAGS="$LIBMPDEC_CFLAGS $CPPFLAGS"
+    LDFLAGS="$LIBMPDEC_LIBS $LDFLAGS"
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing mpd_version" >&5
 printf %s "checking for library containing mpd_version... " >&6; }
 if test ${ac_cv_search_mpd_version+y}
 then :
@@ -14778,11 +14779,16 @@ LIBS=$save_LIBS
 
 
 else $as_nop
-  have_mpdec=yes
-   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: the bundled copy of libmpdecimal is scheduled for removal in Python 3.15; consider using a system installed mpdecimal library." >&5
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: the bundled copy of libmpdecimal is scheduled for removal in Python 3.15; consider using a system installed mpdecimal library." >&5
 printf "%s\n" "$as_me: WARNING: the bundled copy of libmpdecimal is scheduled for removal in Python 3.15; consider using a system installed mpdecimal library." >&2;}
 fi
 
+if test "$with_system_libmpdec" = "yes" && test "$have_mpdec" = "no"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: no system libmpdecimal found; unable to build _decimal" >&5
+printf "%s\n" "$as_me: WARNING: no system libmpdecimal found; unable to build _decimal" >&2;}
+fi
+
 # Disable forced inlining in debug builds, see GH-94847
 if test "x$with_pydebug" = xyes
 then :
@@ -30507,9 +30513,9 @@ printf %s "checking for stdlib extension module _decimal... " >&6; }
         if test "$py_cv_module__decimal" != "n/a"
 then :
 
-    if test "$have_mpdec" = "yes"
+    if true
 then :
-  if true
+  if test "$have_mpdec" = "yes"
 then :
   py_cv_module__decimal=yes
 else $as_nop
diff --git a/configure.ac b/configure.ac
index e298d1daf0c220..102d4ffb75615f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3991,17 +3991,19 @@ AS_VAR_IF(
    LIBMPDEC_LIBS="-lm \$(LIBMPDEC_A)"
    LIBMPDEC_INTERNAL="\$(LIBMPDEC_HEADERS) \$(LIBMPDEC_A)"])
 
-AS_VAR_IF(
-  [with_system_libmpdec], [yes],
-  [WITH_SAVE_ENV(
-    [CPPFLAGS="$LIBMPDEC_CFLAGS $CPPFLAGS"
-     LDFLAGS="$LIBMPDEC_LIBS $LDFLAGS"
-     AC_SEARCH_LIBS([mpd_version], [mpdec],
-                    [have_mpdec=yes], [have_mpdec=no])])],
-  [AS_VAR_SET([have_mpdec], [yes])
-   AC_MSG_WARN([m4_normalize([the bundled copy of libmpdecimal is scheduled for
-                              removal in Python 3.15; consider using a system
-                              installed mpdecimal library.])])])
+AS_VAR_IF([with_system_libmpdec], [yes],
+  [WITH_SAVE_ENV([
+    CPPFLAGS="$LIBMPDEC_CFLAGS $CPPFLAGS"
+    LDFLAGS="$LIBMPDEC_LIBS $LDFLAGS"
+    AC_SEARCH_LIBS(
+      [mpd_version], [mpdec],
+      [have_mpdec=yes], [have_mpdec=no])])],
+  [AC_MSG_WARN([m4_normalize([
+     the bundled copy of libmpdecimal is scheduled for removal in Python 3.15;
+     consider using a system installed mpdecimal library.])])])
+
+AS_IF([test "$with_system_libmpdec" = "yes" && test "$have_mpdec" = "no"],
+      [AC_MSG_WARN([no system libmpdecimal found; unable to build _decimal])])
 
 # Disable forced inlining in debug builds, see GH-94847
 AS_VAR_IF(
@@ -7681,7 +7683,7 @@ PY_STDLIB_MOD([_curses_panel],
   [$PANEL_CFLAGS $CURSES_CFLAGS], [$PANEL_LIBS $CURSES_LIBS]
 )
 PY_STDLIB_MOD([_decimal],
-  [test "$have_mpdec" = "yes"], [],
+  [], [test "$have_mpdec" = "yes"],
   [$LIBMPDEC_CFLAGS], [$LIBMPDEC_LIBS])
 PY_STDLIB_MOD([_dbm],
   [test -n "$with_dbmliborder"], [test "$have_dbm" != "no"],