From dcd2094389d607cac1c2de1dd417bcd87298596f Mon Sep 17 00:00:00 2001
From: Jonathan Roelofs <jonathan@codesourcery.com>
Date: Fri, 27 Feb 2015 23:35:47 +0000
Subject: [PATCH] Discourage in-source autoconf builds (as we already do for
 the cmake build)

http://reviews.llvm.org/D7961


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230812 91177308-0d34-0410-b5e6-96231b3b80d8
---
 autoconf/configure.ac | 5 +++++
 configure             | 6 ++++++
 2 files changed, 11 insertions(+)

diff --git a/autoconf/configure.ac b/autoconf/configure.ac
index e0bc78310c9..807de559036 100644
--- a/autoconf/configure.ac
+++ b/autoconf/configure.ac
@@ -73,6 +73,11 @@ if test ${srcdir} != "." ; then
   fi
 fi
 
+dnl Quit if it is an in-source build
+if test ${srcdir} == "." ; then
+  AC_MSG_ERROR([In-source builds are discouraged. Configure from a separate build directory.])
+fi
+
 dnl Default to empty (i.e. assigning the null string to) CFLAGS and CXXFLAGS,
 dnl instead of the autoconf default (for example, '-g -O2' for CC=gcc).
 : ${CFLAGS=}
diff --git a/configure b/configure
index cac9bf6533a..29437550f0d 100755
--- a/configure
+++ b/configure
@@ -1999,6 +1999,12 @@ echo "$as_me: error: Already configured in ${srcdir}" >&2;}
   fi
 fi
 
+if test ${srcdir} == "." ; then
+  { { echo "$as_me:$LINENO: error: In-source builds are discouraged. Configure from a separate build directory." >&5
+echo "$as_me: error: In-source builds are discouraged. Configure from a separate build directory." >&2;}
+   { (exit 1); exit 1; }; }
+fi
+
 : ${CFLAGS=}
 : ${CXXFLAGS=}
 
-- 
2.34.1