the big time handling overhaul

this commit has two major user-visible parts: zoneinfo-format time
zones are now supported, and overflow handling is intended to be
complete in the sense that all functions return a correct result if
and only if the result fits in the destination type, and otherwise
return an error. also, some noticable bugs in the way DST detection
and normalization worked have been fixed, and performance may be
better than before, but it has not been tested.

1 files changed, 20 insertions, 0 deletions

diff --git a/src/time/__map_file.c b/src/time/__map_file.c
new file mode 100644
index 00000000..b6bf272a
--- /dev/null
+++ b/src/time/__map_file.c
@@ -0,0 +1,20 @@
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include "syscall.h"
+
+void *__mmap(void *, size_t, int, int, int, off_t);
+
+const char unsigned *__map_file(const char *pathname, size_t *size)
+{
+	struct stat st;
+	const unsigned char *map = MAP_FAILED;
+	int flags = O_RDONLY|O_LARGEFILE|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK;
+	int fd = __syscall(SYS_open, pathname, flags);
+	if (fd < 0) return 0;
+	if (!__syscall(SYS_fstat, fd, &st))
+		map = __mmap(0, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
+	__syscall(SYS_close);
+	*size = st.st_size;
+	return map == MAP_FAILED ? 0 : map;
+}