From 753ca2b9341b39d81e474065b92a958ad2aca021 Mon Sep 17 00:00:00 2001
From: Joel Rosdahl <joel@rosdahl.net>
Date: Sun, 21 Apr 2019 17:44:23 +0200
Subject: [PATCH] Use localtime_r instead of localtime

This pleases linters that dislike localtime(3).
---
 configure.ac   |  1 +
 src/ccache.c   |  3 +++
 src/ccache.h   |  3 +++
 src/hashutil.c |  9 +++++----
 src/stats.c    | 10 ++++++----
 src/util.c     | 19 +++++++++++++++----
 6 files changed, 33 insertions(+), 12 deletions(-)

diff --git a/configure.ac b/configure.ac
index 7df32ae66..78cc2a66f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -86,6 +86,7 @@ AC_CHECK_FUNCS(gethostname)
 AC_CHECK_FUNCS(getopt_long)
 AC_CHECK_FUNCS(getpwuid)
 AC_CHECK_FUNCS(gettimeofday)
+AC_CHECK_FUNCS(localtime_r)
 AC_CHECK_FUNCS(mkstemp)
 AC_CHECK_FUNCS(realpath)
 AC_CHECK_FUNCS(setenv)
diff --git a/src/ccache.c b/src/ccache.c
index c10c36ba2..b3f751c41 100644
--- a/src/ccache.c
+++ b/src/ccache.c
@@ -3688,6 +3688,9 @@ ccache(int argc, char *argv[])
 	set_up_signal_handlers();
 #endif
 
+	// Needed for portability when using localtime_r.
+	tzset();
+
 	orig_args = args_init(argc, argv);
 
 	initialize();
diff --git a/src/ccache.h b/src/ccache.h
index d9acf0310..d6bf18345 100644
--- a/src/ccache.h
+++ b/src/ccache.h
@@ -183,6 +183,9 @@ char *format_parsable_size_with_suffix(uint64_t size);
 bool parse_size_with_suffix(const char *str, uint64_t *size);
 char *x_realpath(const char *path);
 char *gnu_getcwd(void);
+#ifndef HAVE_LOCALTIME_R
+struct tm *localtime_r(const time_t *timep, struct tm *result);
+#endif
 #ifndef HAVE_STRTOK_R
 char *strtok_r(char *str, const char *delim, char **saveptr);
 #endif
diff --git a/src/hashutil.c b/src/hashutil.c
index 789bf437b..289ba1717 100644
--- a/src/hashutil.c
+++ b/src/hashutil.c
@@ -107,12 +107,13 @@ hash_source_code_string(
 		// Make sure that the hash sum changes if the (potential) expansion of
 		// __DATE__ changes.
 		time_t t = time(NULL);
-		struct tm *now = localtime(&t);
+		struct tm now;
+		localtime_r(&t, &now);
 		cc_log("Found __DATE__ in %s", path);
 		hash_delimiter(hash, "date");
-		hash_int(hash, now->tm_year);
-		hash_int(hash, now->tm_mon);
-		hash_int(hash, now->tm_mday);
+		hash_int(hash, now.tm_year);
+		hash_int(hash, now.tm_mon);
+		hash_int(hash, now.tm_mday);
 	}
 	if (result & HASH_SOURCE_CODE_FOUND_TIME) {
 		// We don't know for sure that the program actually uses the __TIME__
diff --git a/src/stats.c b/src/stats.c
index 1e8e4970a..aadb2ac15 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -300,9 +300,10 @@ static char *
 format_timestamp(uint64_t timestamp)
 {
 	if (timestamp > 0) {
-		struct tm *tm = localtime((time_t *)&timestamp);
+		struct tm tm;
+		localtime_r((time_t *)&timestamp, &tm);
 		char buffer[100];
-		strftime(buffer, sizeof(buffer), "%c", tm);
+		strftime(buffer, sizeof(buffer), "%c", &tm);
 		return format("    %s", buffer);
 	} else {
 		return NULL;
@@ -533,9 +534,10 @@ stats_summary(void)
 	printf("secondary config      (readonly)    %s\n",
 	       secondary_config_path ? secondary_config_path : "");
 	if (last_updated > 0) {
-		struct tm *tm = localtime(&last_updated);
+		struct tm tm;
+		localtime_r(&last_updated, &tm);
 		char timestamp[100];
-		strftime(timestamp, sizeof(timestamp), "%c", tm);
+		strftime(timestamp, sizeof(timestamp), "%c", &tm);
 		printf("stats updated                       %s\n", timestamp);
 	}
 
diff --git a/src/util.c b/src/util.c
index 7fa9fe6d4..961d3393c 100644
--- a/src/util.c
+++ b/src/util.c
@@ -94,15 +94,15 @@ log_prefix(bool log_updated_time)
 #ifdef HAVE_GETTIMEOFDAY
 	if (log_updated_time) {
 		char timestamp[100];
-		struct tm *tm;
+		struct tm tm;
 		struct timeval tv;
 		gettimeofday(&tv, NULL);
 #ifdef __MINGW64_VERSION_MAJOR
-		tm = localtime((time_t *)&tv.tv_sec);
+		localtime_r((time_t *)&tv.tv_sec, &tm);
 #else
-		tm = localtime(&tv.tv_sec);
+		localtime_r(&tv.tv_sec, &tm);
 #endif
-		strftime(timestamp, sizeof(timestamp), "%Y-%m-%dT%H:%M:%S", tm);
+		strftime(timestamp, sizeof(timestamp), "%Y-%m-%dT%H:%M:%S", &tm);
 		snprintf(prefix, sizeof(prefix),
 		         "[%s.%06d %-5d] ", timestamp, (int)tv.tv_usec, (int)getpid());
 	}
@@ -1223,6 +1223,17 @@ gnu_getcwd(void)
 	}
 }
 
+#ifndef HAVE_LOCALTIME_R
+// localtime_r replacement.
+struct tm *
+localtime_r(const time_t *timep, struct tm *result)
+{
+	struct tm *tm = localtime(timep);
+	*result = *tm;
+	return result;
+}
+#endif
+
 #ifndef HAVE_STRTOK_R
 // strtok_r replacement.
 char *
-- 
2.47.2