From 4313a5b4c51e2093f1b45ef9845fc77d32b09330 Mon Sep 17 00:00:00 2001
From: Ryan Moeller <ryan@freqlabs.com>
Date: Wed, 16 Oct 2019 22:19:48 -0400
Subject: [PATCH] Detect if sed supports --in-place

Not all versions of sed have the --in-place flag. Detect support for
the flag during ./configure and provide a fallback mechanism for those
systems where sed's behavior differs. The autoconf variable
${ac_inplace} can be used to choose the correct flags for editing a
file in place with sed.

Replace violating usages in Makefile.am with ${ac_inplace}.

Reviewed-by: Chris Dunlop <chris@onthe.net.au>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@ixsystems.com>
Closes #9463
---
 cmd/arcstat/Makefile.am           |  2 +-
 cmd/dbufstat/Makefile.am          |  2 +-
 config/always-sed.m4              | 16 ++++++++++++++++
 config/zfs-build.m4               |  1 +
 tests/test-runner/bin/Makefile.am |  2 +-
 5 files changed, 20 insertions(+), 3 deletions(-)
 create mode 100644 config/always-sed.m4

diff --git a/cmd/arcstat/Makefile.am b/cmd/arcstat/Makefile.am
index 8166778a13..4b79f4bdd0 100644
--- a/cmd/arcstat/Makefile.am
+++ b/cmd/arcstat/Makefile.am
@@ -8,6 +8,6 @@ dist_bin_SCRIPTS = arcstat
 #
 if USING_PYTHON_2
 install-exec-hook:
-	sed --in-place 's|^#!/usr/bin/env python3|#!/usr/bin/env python2|' \
+	sed ${ac_inplace} -e 's|^#!/usr/bin/env python3|#!/usr/bin/env python2|' \
 	    $(DESTDIR)$(bindir)/arcstat
 endif
diff --git a/cmd/dbufstat/Makefile.am b/cmd/dbufstat/Makefile.am
index a3f0c6e50d..10c9fbabbf 100644
--- a/cmd/dbufstat/Makefile.am
+++ b/cmd/dbufstat/Makefile.am
@@ -8,6 +8,6 @@ dist_bin_SCRIPTS = dbufstat
 #
 if USING_PYTHON_2
 install-exec-hook:
-	sed --in-place 's|^#!/usr/bin/env python3|#!/usr/bin/env python2|' \
+	sed ${ac_inplace} -e 's|^#!/usr/bin/env python3|#!/usr/bin/env python2|' \
 	    $(DESTDIR)$(bindir)/dbufstat
 endif
diff --git a/config/always-sed.m4 b/config/always-sed.m4
new file mode 100644
index 0000000000..b9c7afd63d
--- /dev/null
+++ b/config/always-sed.m4
@@ -0,0 +1,16 @@
+dnl #
+dnl # Set the flags used for sed in-place edits.
+dnl #
+AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_SED], [
+	ac_inplace=""
+	AC_CACHE_CHECK([for sed --in-place], [ac_cv_path_SED],
+		[AC_PATH_PROGS_FEATURE_CHECK([SED], [sed],
+			[[tmpfile=$(mktemp)
+			  echo foo > $tmpfile
+			  $ac_path_SED --in-place 's#foo#bar#' $tmpfile \
+			  && ac_cv_path_SED=$ac_path_SED
+			  rm $tmpfile]],
+			[ac_inplace="-i ''"])])
+	AS_IF([test "x$ac_inplace" = "x"], [ac_inplace="--in-place"])
+	AC_SUBST([ac_inplace])
+])
diff --git a/config/zfs-build.m4 b/config/zfs-build.m4
index f0c2066af4..91fe048445 100644
--- a/config/zfs-build.m4
+++ b/config/zfs-build.m4
@@ -164,6 +164,7 @@ AC_DEFUN([ZFS_AC_CONFIG_ALWAYS], [
 	ZFS_AC_CONFIG_ALWAYS_ARCH
 	ZFS_AC_CONFIG_ALWAYS_PYTHON
 	ZFS_AC_CONFIG_ALWAYS_PYZFS
+	ZFS_AC_CONFIG_ALWAYS_SED
 ])
 
 AC_DEFUN([ZFS_AC_CONFIG], [
diff --git a/tests/test-runner/bin/Makefile.am b/tests/test-runner/bin/Makefile.am
index 2c031f7455..e7838e43d3 100644
--- a/tests/test-runner/bin/Makefile.am
+++ b/tests/test-runner/bin/Makefile.am
@@ -9,7 +9,7 @@ dist_pkgdata_SCRIPTS = \
 #
 if USING_PYTHON_2
 install-data-hook:
-	sed --in-place 's|^#!/usr/bin/env python3|#!/usr/bin/env python2|' \
+	sed ${ac_inplace} -e 's|^#!/usr/bin/env python3|#!/usr/bin/env python2|' \
 	    $(DESTDIR)$(pkgdatadir)/test-runner.py \
 	    $(DESTDIR)$(pkgdatadir)/zts-report.py
 endif