From 2095d1616b2ba8e39daa6aac8004936b8a229354 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Tue, 21 Jun 2022 12:40:59 +0200
Subject: [PATCH] Add compiler option -ftabstop=4 if available

---
 configure    | 43 +++++++++++++++++++++++++++++++++++++++++++
 configure.ac |  5 +++++
 2 files changed, 48 insertions(+)

diff --git a/configure b/configure
index 7dec6b7bf9..b7420cceea 100755
--- a/configure
+++ b/configure
@@ -6303,6 +6303,49 @@ if test x"$pgac_cv_prog_CC_cflags__ftree_vectorize" = x"yes"; then
 fi
 
 
+  NOT_THE_CFLAGS=""
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -ftabstop=4, for NOT_THE_CFLAGS" >&5
+$as_echo_n "checking whether ${CC} supports -ftabstop=4, for NOT_THE_CFLAGS... " >&6; }
+if ${pgac_cv_prog_CC_cflags__ftabstop_4+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+pgac_save_CC=$CC
+CC=${CC}
+CFLAGS="${NOT_THE_CFLAGS} -ftabstop=4"
+ac_save_c_werror_flag=$ac_c_werror_flag
+ac_c_werror_flag=yes
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  pgac_cv_prog_CC_cflags__ftabstop_4=yes
+else
+  pgac_cv_prog_CC_cflags__ftabstop_4=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_c_werror_flag=$ac_save_c_werror_flag
+CFLAGS="$pgac_save_CFLAGS"
+CC="$pgac_save_CC"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__ftabstop_4" >&5
+$as_echo "$pgac_cv_prog_CC_cflags__ftabstop_4" >&6; }
+if test x"$pgac_cv_prog_CC_cflags__ftabstop_4" = x"yes"; then
+  NOT_THE_CFLAGS="${NOT_THE_CFLAGS} -ftabstop=4"
+fi
+
+
+  if test -n "$NOT_THE_CFLAGS"; then
+    CPPFLAGS="$CPPFLAGS -ftabstop=4"
+  fi
   #
   # The following tests want to suppress various unhelpful warnings by adding
   # -Wno-foo switches.  But gcc won't complain about unrecognized -Wno-foo
diff --git a/configure.ac b/configure.ac
index d093fb88dd..b1d7ac9fc2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -525,6 +525,11 @@ if test "$GCC" = yes -a "$ICC" = no; then
   PGAC_PROG_CC_VAR_OPT(CFLAGS_UNROLL_LOOPS, [-funroll-loops])
   # Optimization flags for specific files that benefit from vectorization
   PGAC_PROG_CC_VAR_OPT(CFLAGS_VECTORIZE, [-ftree-vectorize])
+  NOT_THE_CFLAGS=""
+  PGAC_PROG_CC_VAR_OPT(NOT_THE_CFLAGS, [-ftabstop=4])
+  if test -n "$NOT_THE_CFLAGS"; then
+    CPPFLAGS="$CPPFLAGS -ftabstop=4"
+  fi
   #
   # The following tests want to suppress various unhelpful warnings by adding
   # -Wno-foo switches.  But gcc won't complain about unrecognized -Wno-foo
-- 
2.36.1