Merge branch 'ab/grep-preparatory-cleanup'

The internal implementation of "git grep" has seen some clean-up.

* ab/grep-preparatory-cleanup: (31 commits)
  grep: assert that threading is enabled when calling grep_{lock,unlock}
  grep: given --threads with NO_PTHREADS=YesPlease, warn
  pack-objects: fix buggy warning about threads
  pack-objects & index-pack: add test for --threads warning
  test-lib: add a PTHREADS prerequisite
  grep: move is_fixed() earlier to avoid forward declaration
  grep: change internal *pcre* variable & function names to be *pcre1*
  grep: change the internal PCRE macro names to be PCRE1
  grep: factor test for \0 in grep patterns into a function
  grep: remove redundant regflags assignments
  grep: catch a missing enum in switch statement
  perf: add a comparison test of log --grep regex engines with -F
  perf: add a comparison test of log --grep regex engines
  perf: add a comparison test of grep regex engines with -F
  perf: add a comparison test of grep regex engines
  perf: emit progress output when unpacking & building
  perf: add a GIT_PERF_MAKE_COMMAND for when *_MAKE_OPTS won't do
  grep: add tests to fix blind spots with \0 patterns
  grep: prepare for testing binary regexes containing rx metacharacters
  grep: add a test helper function for less verbose -f \0 tests
  ...

1 files changed, 56 insertions, 0 deletions

diff --git a/t/perf/p7820-grep-engines.sh b/t/perf/p7820-grep-engines.sh
new file mode 100755
index 0000000000..62aba19e76
--- /dev/null
+++ b/t/perf/p7820-grep-engines.sh
@@ -0,0 +1,56 @@
+#!/bin/sh
+
+test_description="Comparison of git-grep's regex engines
+
+Set GIT_PERF_7820_GREP_OPTS in the environment to pass options to
+git-grep. Make sure to include a leading space,
+e.g. GIT_PERF_7820_GREP_OPTS=' -i'. Some options to try:
+
+	-i
+	-w
+	-v
+	-vi
+	-vw
+	-viw
+"
+
+. ./perf-lib.sh
+
+test_perf_large_repo
+test_checkout_worktree
+
+for pattern in \
+	'how.to' \
+	'^how to' \
+	'[how] to' \
+	'\(e.t[^ ]*\|v.ry\) rare' \
+	'm\(ú\|u\)lt.b\(æ\|y\)te'
+do
+	for engine in basic extended perl
+	do
+		if test $engine != "basic"
+		then
+			# Poor man's basic -> extended converter.
+			pattern=$(echo "$pattern" | sed 's/\\//g')
+		fi
+		if test $engine = "perl" && ! test_have_prereq PCRE
+		then
+			prereq="PCRE"
+		else
+			prereq=""
+		fi
+		test_perf $prereq "$engine grep$GIT_PERF_7820_GREP_OPTS '$pattern'" "
+			git -c grep.patternType=$engine grep$GIT_PERF_7820_GREP_OPTS -- '$pattern' >'out.$engine' || :
+		"
+	done
+
+	test_expect_success "assert that all engines found the same for$GIT_PERF_7820_GREP_OPTS '$pattern'" '
+		test_cmp out.basic out.extended &&
+		if test_have_prereq PCRE
+		then
+			test_cmp out.basic out.perl
+		fi
+	'
+done
+
+test_done