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
  ...

2 files changed, 22 insertions, 5 deletions

diff --git a/builtin/grep.c b/builtin/grep.c
index 72a19699a82..7df9c253eeb 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -73,14 +73,14 @@ static pthread_mutex_t grep_mutex;
 
 static inline void grep_lock(void)
 {
-	if (num_threads)
-		pthread_mutex_lock(&grep_mutex);
+	assert(num_threads);
+	pthread_mutex_lock(&grep_mutex);
 }
 
 static inline void grep_unlock(void)
 {
-	if (num_threads)
-		pthread_mutex_unlock(&grep_mutex);
+	assert(num_threads);
+	pthread_mutex_unlock(&grep_mutex);
 }
 
 /* Signalled when a new work_item is added to todo. */
@@ -289,6 +289,17 @@ static int grep_cmd_config(const char *var, const char *value, void *cb)
 		if (num_threads < 0)
 			die(_("invalid number of threads specified (%d) for %s"),
 			    num_threads, var);
+#ifdef NO_PTHREADS
+		else if (num_threads && num_threads != 1) {
+			/*
+			 * TRANSLATORS: %s is the configuration
+			 * variable for tweaking threads, currently
+			 * grep.threads
+			 */
+			warning(_("no threads support, ignoring %s"), var);
+			num_threads = 0;
+		}
+#endif
 	}
 
 	return st;
@@ -495,6 +506,8 @@ static void compile_submodule_options(const struct grep_opt *opt,
 		break;
 	case GREP_PATTERN_TYPE_UNSPECIFIED:
 		break;
+	default:
+		die("BUG: Added a new grep pattern type without updating switch statement");
 	}
 
 	for (pattern = opt->pattern_list; pattern != NULL;
@@ -1229,6 +1242,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 	else if (num_threads < 0)
 		die(_("invalid number of threads specified (%d)"), num_threads);
 #else
+	if (num_threads)
+		warning(_("no threads support, ignoring --threads"));
 	num_threads = 0;
 #endif
 
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 80439047aa2..f672225def0 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -2483,8 +2483,10 @@ static int git_pack_config(const char *k, const char *v, void *cb)
 			die("invalid number of threads specified (%d)",
 			    delta_search_threads);
 #ifdef NO_PTHREADS
-		if (delta_search_threads != 1)
+		if (delta_search_threads != 1) {
 			warning("no threads support, ignoring %s", k);
+			delta_search_threads = 0;
+		}
 #endif
 		return 0;
 	}