Strip ANSI escape codes from file logging

Text editors cannot display ANSI escape codes, so these should be
stripped from log files to ensure readability.

Since this uses a regex, this works both for `print_rich()`
and manually inserted ANSI escape codes.

Co-authored-by: bruvzg <[email protected]>

core/io/logger.cpp

@@ -37,6 +37,8 @@
 #include "core/os/time.h"
 #include "core/string/print_string.h"
 
+#include "modules/modules_enabled.gen.h" // For regex.
+
 #if defined(MINGW_ENABLED) || defined(_MSC_VER)
 #define sprintf sprintf_s
 #endif
@@ -180,6 +182,12 @@ RotatedFileLogger::RotatedFileLogger(const String &p_base_path, int p_max_files)
 		base_path(p_base_path.simplify_path()),
 		max_files(p_max_files > 0 ? p_max_files : 1) {
 	rotate_file();
+
+#ifdef MODULE_REGEX_ENABLED
+	strip_ansi_regex.instantiate();
+	strip_ansi_regex->detach_from_objectdb(); // Note: This RegEx instance will exist longer than ObjectDB, therefore can't be registered in ObjectDB.
+	strip_ansi_regex->compile("\u001b\\[((?:\\d|;)*)([a-zA-Z])");
+#endif // MODULE_REGEX_ENABLED
 }
 
 void RotatedFileLogger::logv(const char *p_format, va_list p_list, bool p_err) {
@@ -199,7 +207,15 @@ void RotatedFileLogger::logv(const char *p_format, va_list p_list, bool p_err) {
 			vsnprintf(buf, len + 1, p_format, list_copy);
 		}
 		va_end(list_copy);
+
+#ifdef MODULE_REGEX_ENABLED
+		// Strip ANSI escape codes (such as those inserted by `print_rich()`)
+		// before writing to file, as text editors cannot display those
+		// correctly.
+		file->store_string(strip_ansi_regex->sub(String(buf), "", true));
+#else
 		file->store_buffer((uint8_t *)buf, len);
+#endif // MODULE_REGEX_ENABLED
 
 		if (len >= static_buf_size) {
 			Memory::free_static(buf);

core/io/logger.h

@@ -34,6 +34,10 @@
 #include "core/io/file_access.h"
 #include "core/string/ustring.h"
 #include "core/templates/vector.h"
+#include "modules/modules_enabled.gen.h" // For regex.
+#ifdef MODULE_REGEX_ENABLED
+#include "modules/regex/regex.h"
+#endif // MODULE_REGEX_ENABLED
 
 #include <stdarg.h>
 
@@ -86,6 +90,10 @@ class RotatedFileLogger : public Logger {
 	void clear_old_backups();
 	void rotate_file();
 
+#ifdef MODULE_REGEX_ENABLED
+	Ref<RegEx> strip_ansi_regex;
+#endif // MODULE_REGEX_ENABLED
+
 public:
 	explicit RotatedFileLogger(const String &p_base_path, int p_max_files = 10);