From 59acfd4a09df1c141dac7845eed008af8970fce7 Mon Sep 17 00:00:00 2001
From: Ned Deily <nad@python.org>
Date: Mon, 24 May 2021 23:00:04 -0400
Subject: [PATCH] bpo-43109: Fix --with-lto configure option on macOS
 (GH-26341)

Allow --with-lto configure option to work with Apple-supplied Xcode or
Command Line Tools which do not provide llvm-ar.
---
 .../next/macOS/2021-05-24-21-15-41.bpo-43109.npKJ9c.rst  | 2 ++
 configure                                                | 9 ++++++---
 configure.ac                                             | 9 ++++++---
 3 files changed, 14 insertions(+), 6 deletions(-)
 create mode 100644 Misc/NEWS.d/next/macOS/2021-05-24-21-15-41.bpo-43109.npKJ9c.rst

diff --git a/Misc/NEWS.d/next/macOS/2021-05-24-21-15-41.bpo-43109.npKJ9c.rst b/Misc/NEWS.d/next/macOS/2021-05-24-21-15-41.bpo-43109.npKJ9c.rst
new file mode 100644
index 00000000000..bb4d24fa955
--- /dev/null
+++ b/Misc/NEWS.d/next/macOS/2021-05-24-21-15-41.bpo-43109.npKJ9c.rst
@@ -0,0 +1,2 @@
+Allow --with-lto configure option to work with Apple-supplied Xcode or
+Command Line Tools.
diff --git a/configure b/configure
index e1d450131fe..1756d25d16f 100755
--- a/configure
+++ b/configure
@@ -6711,10 +6711,11 @@ fi
       fi
       if test "$ac_sys_system" = "Darwin" -a "${LLVM_AR_FOUND}" = "not-found"
       then
-        found_llvm_ar=`/usr/bin/xcrun -find llvm-ar 2>/dev/null`
+        # The Apple-supplied ar in Xcode or the Command Line Tools is apparently sufficient
+        found_llvm_ar=`/usr/bin/xcrun -find ar 2>/dev/null`
         if test -n "${found_llvm_ar}"
         then
-          LLVM_AR='/usr/bin/xcrun llvm-ar'
+          LLVM_AR='/usr/bin/xcrun ar'
           LLVM_AR_FOUND=found
           { $as_echo "$as_me:${as_lineno-$LINENO}: llvm-ar found via xcrun: ${LLVM_AR}" >&5
 $as_echo "$as_me: llvm-ar found via xcrun: ${LLVM_AR}" >&6;}
@@ -6732,6 +6733,7 @@ $as_echo "$as_me: llvm-ar found via xcrun: ${LLVM_AR}" >&6;}
         Darwin*)
           # Any changes made here should be reflected in the GCC+Darwin case below
           LTOFLAGS="-flto -Wl,-export_dynamic"
+          LTOCFLAGS="-flto"
           ;;
         *)
           LTOFLAGS="-flto"
@@ -6742,6 +6744,7 @@ $as_echo "$as_me: llvm-ar found via xcrun: ${LLVM_AR}" >&6;}
       case $ac_sys_system in
         Darwin*)
           LTOFLAGS="-flto -Wl,-export_dynamic"
+          LTOCFLAGS="-flto"
           ;;
         *)
           LTOFLAGS="-flto -fuse-linker-plugin -ffat-lto-objects -flto-partition=none"
@@ -6757,7 +6760,7 @@ $as_echo "$as_me: llvm-ar found via xcrun: ${LLVM_AR}" >&6;}
       LTOFLAGS="$LTOFLAGS -g"
   fi
 
-  CFLAGS_NODIST="$CFLAGS_NODIST $LTOFLAGS"
+  CFLAGS_NODIST="$CFLAGS_NODIST ${LTOCFLAGS-$LTOFLAGS}"
   LDFLAGS_NODIST="$LDFLAGS_NODIST $LTOFLAGS"
 fi
 
diff --git a/configure.ac b/configure.ac
index 553f8ad3b52..2f792aa60ee 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1385,10 +1385,11 @@ if test "$Py_LTO" = 'true' ; then
       fi
       if test "$ac_sys_system" = "Darwin" -a "${LLVM_AR_FOUND}" = "not-found"
       then
-        found_llvm_ar=`/usr/bin/xcrun -find llvm-ar 2>/dev/null`
+        # The Apple-supplied ar in Xcode or the Command Line Tools is apparently sufficient
+        found_llvm_ar=`/usr/bin/xcrun -find ar 2>/dev/null`
         if test -n "${found_llvm_ar}"
         then
-          LLVM_AR='/usr/bin/xcrun llvm-ar'
+          LLVM_AR='/usr/bin/xcrun ar'
           LLVM_AR_FOUND=found
           AC_MSG_NOTICE([llvm-ar found via xcrun: ${LLVM_AR}])
         fi
@@ -1405,6 +1406,7 @@ if test "$Py_LTO" = 'true' ; then
         Darwin*)
           # Any changes made here should be reflected in the GCC+Darwin case below
           LTOFLAGS="-flto -Wl,-export_dynamic"
+          LTOCFLAGS="-flto"
           ;;
         *)
           LTOFLAGS="-flto"
@@ -1415,6 +1417,7 @@ if test "$Py_LTO" = 'true' ; then
       case $ac_sys_system in
         Darwin*)
           LTOFLAGS="-flto -Wl,-export_dynamic"
+          LTOCFLAGS="-flto"
           ;;
         *)
           LTOFLAGS="-flto -fuse-linker-plugin -ffat-lto-objects -flto-partition=none"
@@ -1430,7 +1433,7 @@ if test "$Py_LTO" = 'true' ; then
       LTOFLAGS="$LTOFLAGS -g"
   fi
 
-  CFLAGS_NODIST="$CFLAGS_NODIST $LTOFLAGS"
+  CFLAGS_NODIST="$CFLAGS_NODIST ${LTOCFLAGS-$LTOFLAGS}"
   LDFLAGS_NODIST="$LDFLAGS_NODIST $LTOFLAGS"
 fi