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.

108 files changed, 610 insertions, 501 deletions

diff --git a/common/background-image.c b/common/background-image.c
index 72f39a79..d15c2989 100644
--- a/common/background-image.c
+++ b/common/background-image.c
@@ -1,8 +1,8 @@
 #include <assert.h>
 #include <stdbool.h>
-#include <wlr/util/log.h>
 #include "background-image.h"
 #include "cairo.h"
+#include "log.h"
 
 enum background_mode parse_background_mode(const char *mode) {
 	if (strcmp(mode, "stretch") == 0) {
@@ -18,7 +18,7 @@ enum background_mode parse_background_mode(const char *mode) {
 	} else if (strcmp(mode, "solid_color") == 0) {
 		return BACKGROUND_MODE_SOLID_COLOR;
 	}
-	wlr_log(WLR_ERROR, "Unsupported background mode: %s", mode);
+	sway_log(SWAY_ERROR, "Unsupported background mode: %s", mode);
 	return BACKGROUND_MODE_INVALID;
 }
 
@@ -28,7 +28,7 @@ cairo_surface_t *load_background_image(const char *path) {
 	GError *err = NULL;
 	GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file(path, &err);
 	if (!pixbuf) {
-		wlr_log(WLR_ERROR, "Failed to load background image (%s).",
+		sway_log(SWAY_ERROR, "Failed to load background image (%s).",
 				err->message);
 		return false;
 	}
@@ -38,11 +38,11 @@ cairo_surface_t *load_background_image(const char *path) {
 	image = cairo_image_surface_create_from_png(path);
 #endif // HAVE_GDK_PIXBUF
 	if (!image) {
-		wlr_log(WLR_ERROR, "Failed to read background image.");
+		sway_log(SWAY_ERROR, "Failed to read background image.");
 		return NULL;
 	}
 	if (cairo_surface_status(image) != CAIRO_STATUS_SUCCESS) {
-		wlr_log(WLR_ERROR, "Failed to read background image: %s."
+		sway_log(SWAY_ERROR, "Failed to read background image: %s."
 #if !HAVE_GDK_PIXBUF
 				"\nSway was compiled without gdk_pixbuf support, so only"
 				"\nPNG images can be loaded. This is the likely cause."
diff --git a/common/ipc-client.c b/common/ipc-client.c
index 79ed3555..13e2dfa3 100644
--- a/common/ipc-client.c
+++ b/common/ipc-client.c
@@ -111,7 +111,7 @@ error_2:
 	free(response);
 	free(payload);
 error_1:
-	wlr_log(WLR_ERROR, "Unable to allocate memory for IPC response");
+	sway_log(SWAY_ERROR, "Unable to allocate memory for IPC response");
 	return NULL;
 }
 
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;
+}
diff --git a/common/loop.c b/common/loop.c
index 295f3a30..aecad2f3 100644
--- a/common/loop.c
+++ b/common/loop.c
@@ -34,7 +34,7 @@ struct loop {
 struct loop *loop_create(void) {
 	struct loop *loop = calloc(1, sizeof(struct loop));
 	if (!loop) {
-		wlr_log(WLR_ERROR, "Unable to allocate memory for loop");
+		sway_log(SWAY_ERROR, "Unable to allocate memory for loop");
 		return NULL;
 	}
 	loop->fd_capacity = 10;
@@ -107,7 +107,7 @@ void loop_add_fd(struct loop *loop, int fd, short mask,
 		void (*callback)(int fd, short mask, void *data), void *data) {
 	struct loop_fd_event *event = calloc(1, sizeof(struct loop_fd_event));
 	if (!event) {
-		wlr_log(WLR_ERROR, "Unable to allocate memory for event");
+		sway_log(SWAY_ERROR, "Unable to allocate memory for event");
 		return;
 	}
 	event->callback = callback;
@@ -129,7 +129,7 @@ struct loop_timer *loop_add_timer(struct loop *loop, int ms,
 		void (*callback)(void *data), void *data) {
 	struct loop_timer *timer = calloc(1, sizeof(struct loop_timer));
 	if (!timer) {
-		wlr_log(WLR_ERROR, "Unable to allocate memory for timer");
+		sway_log(SWAY_ERROR, "Unable to allocate memory for timer");
 		return NULL;
 	}
 	timer->callback = callback;
diff --git a/common/pango.c b/common/pango.c
index 7e164043..fc3d0688 100644
--- a/common/pango.c
+++ b/common/pango.c
@@ -61,7 +61,7 @@ PangoLayout *get_pango_layout(cairo_t *cairo, const char