[PATCH v2] perf: accommodate for MacOSX

[Johannes Schindelin <johannes.schindelin@gmx.de>]

As this developer has no access to MacOSX developer setups anymore,
Travis becomes the best bet to run performance tests on that OS.

However, on MacOSX /usr/bin/time is that good old BSD executable that
no Linux user cares about, as demonstrated by the perf-lib.sh's use
of GNU-ish extensions. And by the hard-coded path.

Let's just work around this issue by using gtime on MacOSX, the
Homebrew-provided GNU implementation onto which pretty much every
MacOSX power user falls back anyway.

To help other developers use Travis to run performance tests on
MacOSX, the .travis.yml file now sports a commented-out line that
installs GNU time via Homebrew.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
Published-As: https://github.com/dscho/git/releases/tag/perf-macosx-v2
 .travis.yml        | 2 ++
 t/perf/perf-lib.sh | 6 +++++-
 2 files changed, 7 insertions(+), 1 deletion(-)
Interdiff vs v1:

 diff --git a/.travis.yml b/.travis.yml
 index 0e569bc..c2b76f9 100644
 --- a/.travis.yml
 +++ b/.travis.yml
 @@ -82,7 +82,9 @@ before_install:
        brew tap homebrew/binary --quiet
        brew_force_set_latest_binary_hash perforce
        brew_force_set_latest_binary_hash perforce-server
 -      brew install git-lfs perforce-server perforce gettext gnu-time
 +      # Uncomment this if you want to run perf tests:
 +      # brew install gnu-time
 +      brew install git-lfs perforce-server perforce gettext
        brew link --force gettext
        ;;
      esac;


diff --git a/.travis.yml b/.travis.yml
index c20ec54..c2b76f9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -82,6 +82,8 @@ before_install:
       brew tap homebrew/binary --quiet
       brew_force_set_latest_binary_hash perforce
       brew_force_set_latest_binary_hash perforce-server
+      # Uncomment this if you want to run perf tests:
+      # brew install gnu-time
       brew install git-lfs perforce-server perforce gettext
       brew link --force gettext
       ;;
diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index 18c363e..773f955 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -127,11 +127,15 @@ test_checkout_worktree () {
 # Performance tests should never fail.  If they do, stop immediately
 immediate=t
 
+# Perf tests require GNU time
+case "$(uname -s)" in Darwin) GTIME="${GTIME:-gtime}";; esac
+GTIME="${GTIME:-/usr/bin/time}"
+
 test_run_perf_ () {
 	test_cleanup=:
 	test_export_="test_cleanup"
 	export test_cleanup test_export_
-	/usr/bin/time -f "%E %U %S" -o test_time.$i "$SHELL" -c '
+	"$GTIME" -f "%E %U %S" -o test_time.$i "$SHELL" -c '
 . '"$TEST_DIRECTORY"/test-lib-functions.sh'
 test_export () {
 	[ $# != 0 ] || return 0
-- 
2.9.0.118.g0e1a633

base-commit: ab7797dbe95fff38d9265869ea367020046db118