C Logging: use instead of printf for messages

- See `--log` help message for usage.
- Supports enabling categories.
- Color severity.
- Optionally logs to a file.
- Currently use to replace printf calls in wm module.

See D3120 for details.

3 files changed, 106 insertions, 0 deletions

diff --git a/source/creator/CMakeLists.txt b/source/creator/CMakeLists.txt
index a155f060335..a71c1bb1984 100644
--- a/source/creator/CMakeLists.txt
+++ b/source/creator/CMakeLists.txt
@@ -26,6 +26,7 @@
 setup_libdirs()
 
 blender_include_dirs(
+	../../intern/clog
 	../../intern/guardedalloc
 	../../intern/glew-mx
 	../blender/blenlib
diff --git a/source/creator/creator.c b/source/creator/creator.c
index a59a45f885c..962d6720760 100644
--- a/source/creator/creator.c
+++ b/source/creator/creator.c
@@ -42,6 +42,8 @@
 
 #include "MEM_guardedalloc.h"
 
+#include "CLG_log.h"
+
 #include "DNA_genfile.h"
 
 #include "BLI_args.h"
@@ -49,6 +51,7 @@
 #include "BLI_utildefines.h"
 #include "BLI_callbacks.h"
 #include "BLI_string.h"
+#include "BLI_system.h"
 
 /* mostly init functions */
 #include "BKE_appdir.h"
@@ -180,6 +183,11 @@ static void callback_main_atexit(void *user_data)
 #endif
 }
 
+static void callback_clg_fatal(void *fp)
+{
+	BLI_system_backtrace(fp);
+}
+
 /** \} */
 
 
@@ -304,6 +312,10 @@ int main(
 	sdlewInit();
 #endif
 
+	/* Initialize logging */
+	CLG_init();
+	CLG_fatal_fn_set(callback_clg_fatal);
+
 	C = CTX_create();
 
 #ifdef WITH_PYTHON_MODULE
diff --git a/source/creator/creator_args.c b/source/creator/creator_args.c
index 25f8d732c58..17fa18916fd 100644
--- a/source/creator/creator_args.c
+++ b/source/creator/creator_args.c
@@ -30,6 +30,8 @@
 
 #include "MEM_guardedalloc.h"
 
+#include "CLG_log.h"
+
 #ifdef WIN32
 #  include "BLI_winstuff.h"
 #endif
@@ -529,6 +531,11 @@ static int arg_handle_print_help(int UNUSED(argc), const char **UNUSED(argv), vo
 	BLI_argsPrintArgDoc(ba, "--python-exit-code");
 	BLI_argsPrintArgDoc(ba, "--addons");
 
+	printf("\n");
+	printf("Logging Options:\n");
+	BLI_argsPrintArgDoc(ba, "--log");
+	BLI_argsPrintArgDoc(ba, "--log-level");
+	BLI_argsPrintArgDoc(ba, "--log-file");
 
 	printf("\n");
 	printf("Debug Options:\n");
@@ -704,6 +711,88 @@ static int arg_handle_background_mode_set(int UNUSED(argc), const char **UNUSED(
 	return 0;
 }
 
+static const char arg_handle_log_level_set_doc[] =
+"\n\tSet the logging verbosity level (higher for more details) defaults to 1."
+;
+static int arg_handle_log_level_set(int argc, const char **argv, void *UNUSED(data))
+{
+	const char *arg_id = "--log-level";
+	if (argc > 1) {
+		const char *err_msg = NULL;
+		if (!parse_int_clamp(argv[1], NULL, 0, INT_MAX, &G.log.level, &err_msg)) {
+			printf("\nError: %s '%s %s'.\n", err_msg, arg_id, argv[1]);
+		}
+		return 1;
+	}
+	else {
+		printf("\nError: '%s' no args given.\n", arg_id);
+		return 0;
+	}
+}
+
+static const char arg_handle_log_file_set_doc[] =
+"\n\tSet a file to output the log to."
+;
+static int arg_handle_log_file_set(int argc, const char **argv, void *UNUSED(data))
+{
+	const char *arg_id = "--log-file";
+	if (argc > 1) {
+		errno = 0;
+		FILE *fp = BLI_fopen(argv[1], "w");
+		if (fp == NULL) {
+			const char *err_msg = errno ? strerror(errno) : "unknown";
+			printf("\nError: %s '%s %s'.\n", err_msg, arg_id, argv[1]);
+		}
+		else {
+			if (UNLIKELY(G.log.file != NULL)) {
+				fclose(G.log.file);
+			}
+			G.log.file = fp;
+			CLG_output_set(G.log.file);
+		}
+		return 1;
+	}
+	else {
+		printf("\nError: '%s' no args given.\n", arg_id);
+		return 0;
+	}
+}
+
+static const char arg_handle_log_set_doc[] =
+"\n\tEnable logging categories, taking a single comma separated argument.\n"
+"\tMultiple categories can be matched using a '.*' suffix, so '--log \"wm.*\"' logs every kind of window-manager message.\n"
+"\tUse \"*\" to log everything."
+;
+static int arg_handle_log_set(int argc, const char **argv, void *UNUSED(data))
+{
+	const char *arg_id = "--log";
+	if (argc > 1) {
+		const char *str_step = argv[1];
+		while (*str_step) {
+			const char *str_step_end = strchr(str_step, ',');
+			int str_step_len = str_step_end ? (str_step_end - str_step) : strlen(str_step);
+
+			CLG_type_filter(str_step, str_step_len);
+
+			if (str_step_end) {
+				/* typically only be one, but don't fail on multiple.*/
+				while (*str_step_end == ',') {
+					str_step_end++;
+				}
+				str_step = str_step_end;
+			}
+			else {
+				break;
+			}
+		}
+		return 1;
+	}
+	else {
+		printf("\nError: '%s' no args given.\n", arg_id);
+		return 0;
+	}
+}
+
 static const char arg_handle_debug_mode_set_doc[] =
 "\n"
 "\tTurn debugging on.\n"
@@ -1827,6 +1916,10 @@ void main_args_setup(bContext *C, bArgs *ba, SYS_SystemHandle *syshandle)
 
 	BLI_argsAdd(ba, 1, "-a", NULL, CB(arg_handle_playback_mode), NULL);
 
+	BLI_argsAdd(ba, 1, NULL, "--log-level", CB(arg_handle_log_level_set), ba);
+	BLI_argsAdd(ba, 1, NULL, "--log-file", CB(arg_handle_log_file_set), ba);
+	BLI_argsAdd(ba, 1, NULL, "--log", CB(arg_handle_log_set), ba);
+
 	BLI_argsAdd(ba, 1, "-d", "--debug", CB(arg_handle_debug_mode_set), ba);
 
 #ifdef WITH_FFMPEG