Replace wlr_log with sway_log

This commit mostly duplicates the wlr_log functions, although
with a sway_* prefix. (This is very similar to PR #2009.)
However, the logging function no longer needs to be replaceable,
so sway_log_init's second argument is used to set the exit
callback for sway_abort.

wlr_log_init is still invoked in sway/main.c

This commit makes it easier to remove the wlroots dependency for
the helper programs swaymsg, swaybg, swaybar, and swaynag.

1 files changed, 85 insertions, 4 deletions

diff --git a/common/log.c b/common/log.c
index 847f3952..669fd360 100644
--- a/common/log.c
+++ b/common/log.c
@@ -1,16 +1,20 @@
+#define _POSIX_C_SOURCE 199506L
 #include <signal.h>
 #include <stdarg.h>
+#include <stdio.h>
 #include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
 #include "log.h"
 
-void sway_terminate(int code);
+static terminate_callback_t log_terminate = exit;
 
 void _sway_abort(const char *format, ...) {
         va_list args;
         va_start(args, format);
-        _wlr_vlog(WLR_ERROR, format, args);
+        _sway_vlog(SWAY_ERROR, format, args);
         va_end(args);
-        sway_terminate(EXIT_FAILURE);
+        log_terminate(EXIT_FAILURE);
 }
 
 bool _sway_assert(bool condition, const char *format, ...) {
@@ -20,7 +24,7 @@ bool _sway_assert(bool condition, const char *format, ...) {
 
         va_list args;
         va_start(args, format);
-        _wlr_vlog(WLR_ERROR, format, args);
+        _sway_vlog(SWAY_ERROR, format, args);
         va_end(args);
 
 #ifndef NDEBUG
@@ -29,3 +33,80 @@ bool _sway_assert(bool condition, const char *format, ...) {
 
         return false;
 }
+
+static bool colored = true;
+static sway_log_importance_t log_importance = SWAY_ERROR;
+
+static const char *verbosity_colors[] = {
+        [SWAY_SILENT] = "",
+        [SWAY_ERROR ] = "\x1B[1;31m",
+        [SWAY_INFO  ] = "\x1B[1;34m",
+        [SWAY_DEBUG ] = "\x1B[1;30m",
+};
+
+static void sway_log_stderr(sway_log_importance_t verbosity, const char *fmt,
+                va_list args) {
+        if (verbosity > log_importance) {
+                return;
+        }
+        // prefix the time to the log message
+        struct tm result;
+        time_t t = time(NULL);
+        struct tm *tm_info = localtime_r(&t, &result);
+        char buffer[26];
+
+        // generate time prefix
+        strftime(buffer, sizeof(buffer), "%F %T - ", tm_info);
+        fprintf(stderr, "%s", buffer);
+
+        unsigned c = (verbosity < SWAY_LOG_IMPORTANCE_LAST) ? verbosity :
+                SWAY_LOG_IMPORTANCE_LAST - 1;
+
+        if (colored && isatty(STDERR_FILENO)) {
+                fprintf(stderr, "%s", verbosity_colors[c]);
+        }
+
+        vfprintf(stderr, fmt, args);
+
+        if (colored && isatty(STDERR_FILENO)) {
+                fprintf(stderr, "\x1B[0m");
+        }
+        fprintf(stderr, "\n");
+}
+
+void sway_log_init(sway_log_importance_t verbosity, terminate_callback_t callback) {
+        if (verbosity < SWAY_LOG_IMPORTANCE_LAST) {
+                log_importance = verbosity;
+        }
+        if (callback) {
+                log_terminate = callback;
+        }
+}
+
+void _sway_vlog(sway_log_importance_t verbosity, const char *fmt, va_list args) {
+        sway_log_stderr(verbosity, fmt, args);
+}
+
+void _sway_log(sway_log_importance_t verbosity, const char *fmt, ...) {
+        va_list args;
+        va_start(args, fmt);
+        sway_log_stderr(verbosity, fmt, args);
+        va_end(args);
+}
+
+// strips the path prefix from filepath
+// will try to strip SWAY_SRC_DIR as well as a relative src dir
+// e.g. '/src/build/sway/util/log.c' and
+// '../util/log.c' will both be stripped to
+// 'util/log.c'
+const char *_sway_strip_path(const char *filepath) {
+        static int srclen = sizeof(SWAY_SRC_DIR);
+        if (strstr(filepath, SWAY_SRC_DIR) == filepath) {
+                filepath += srclen;
+        } else if (*filepath == '.') {
+                while (*filepath == '.' || *filepath == '/') {
+                        ++filepath;
+                }
+        }
+        return filepath;
+}