1 files changed, 156 insertions, 0 deletions
diff --git a/src/include/common/logging.h b/src/include/common/logging.h
new file mode 100644
index 0000000..9f426c3
--- /dev/null
+++ b/src/include/common/logging.h
@@ -0,0 +1,156 @@
+/*-------------------------------------------------------------------------
+ * Logging framework for frontend programs
+ *
+ * Copyright (c) 2018-2022, PostgreSQL Global Development Group
+ *
+ * src/include/common/logging.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef COMMON_LOGGING_H
+#define COMMON_LOGGING_H
+
+/*
+ * Log levels are informational only.  They do not affect program flow.
+ */
+enum pg_log_level
+{
+	/*
+	 * Not initialized yet (not to be used as an actual message log level).
+	 */
+	PG_LOG_NOTSET = 0,
+
+	/*
+	 * Low level messages that are normally off by default.
+	 */
+	PG_LOG_DEBUG,
+
+	/*
+	 * Any program messages that go to stderr, shown by default.  (The
+	 * program's normal output should go to stdout and not use the logging
+	 * system.)
+	 */
+	PG_LOG_INFO,
+
+	/*
+	 * Warnings and "almost" errors, depends on the program
+	 */
+	PG_LOG_WARNING,
+
+	/*
+	 * Errors
+	 */
+	PG_LOG_ERROR,
+
+	/*
+	 * Turn all logging off (not to be used as an actual message log level).
+	 */
+	PG_LOG_OFF,
+};
+
+/*
+ * __pg_log_level is the minimum log level that will actually be shown.
+ */
+extern enum pg_log_level __pg_log_level;
+
+/*
+ * A log message can have several parts.  The primary message is required,
+ * others are optional.  When emitting multiple parts, do so in the order of
+ * this enum, for consistency.
+ */
+enum pg_log_part
+{
+	/*
+	 * The primary message.  Try to keep it to one line; follow the backend's
+	 * style guideline for primary messages.
+	 */
+	PG_LOG_PRIMARY,
+
+	/*
+	 * Additional detail.  Follow the backend's style guideline for detail
+	 * messages.
+	 */
+	PG_LOG_DETAIL,
+
+	/*
+	 * Hint (not guaranteed correct) about how to fix the problem.  Follow the
+	 * backend's style guideline for hint messages.
+	 */
+	PG_LOG_HINT,
+};
+
+/*
+ * Kind of a hack to be able to produce the psql output exactly as required by
+ * the regression tests.
+ */
+#define PG_LOG_FLAG_TERSE	1
+
+void		pg_logging_init(const char *argv0);
+void		pg_logging_config(int new_flags);
+void		pg_logging_set_level(enum pg_log_level new_level);
+void		pg_logging_increase_verbosity(void);
+void		pg_logging_set_pre_callback(void (*cb) (void));
+void		pg_logging_set_locus_callback(void (*cb) (const char **filename, uint64 *lineno));
+
+void		pg_log_generic(enum pg_log_level level, enum pg_log_part part,
+						   const char *pg_restrict fmt,...)
+			pg_attribute_printf(3, 4);
+void		pg_log_generic_v(enum pg_log_level level, enum pg_log_part part,
+							 const char *pg_restrict fmt, va_list ap)
+			pg_attribute_printf(3, 0);
+
+/*
+ * Preferred style is to use these macros to perform logging; don't call
+ * pg_log_generic[_v] directly, except perhaps in error interface code.
+ */
+#define pg_log_error(...) \
+	pg_log_generic(PG_LOG_ERROR, PG_LOG_PRIMARY, __VA_ARGS__)
+
+#define pg_log_error_detail(...) \
+	pg_log_generic(PG_LOG_ERROR, PG_LOG_DETAIL, __VA_ARGS__)
+
+#define pg_log_error_hint(...) \
+	pg_log_generic(PG_LOG_ERROR, PG_LOG_HINT, __VA_ARGS__)
+
+#define pg_log_warning(...) \
+	pg_log_generic(PG_LOG_WARNING, PG_LOG_PRIMARY, __VA_ARGS__)
+
+#define pg_log_warning_detail(...) \
+	pg_log_generic(PG_LOG_WARNING, PG_LOG_DETAIL, __VA_ARGS__)
+
+#define pg_log_warning_hint(...) \
+	pg_log_generic(PG_LOG_WARNING, PG_LOG_HINT, __VA_ARGS__)
+
+#define pg_log_info(...) \
+	pg_log_generic(PG_LOG_INFO, PG_LOG_PRIMARY, __VA_ARGS__)
+
+#define pg_log_info_detail(...) \
+	pg_log_generic(PG_LOG_INFO, PG_LOG_DETAIL, __VA_ARGS__)
+
+#define pg_log_info_hint(...) \
+	pg_log_generic(PG_LOG_INFO, PG_LOG_HINT, __VA_ARGS__)
+
+#define pg_log_debug(...) do { \
+		if (unlikely(__pg_log_level <= PG_LOG_DEBUG)) \
+			pg_log_generic(PG_LOG_DEBUG, PG_LOG_PRIMARY, __VA_ARGS__); \
+	} while(0)
+
+#define pg_log_debug_detail(...) do { \
+		if (unlikely(__pg_log_level <= PG_LOG_DEBUG)) \
+			pg_log_generic(PG_LOG_DEBUG, PG_LOG_DETAIL, __VA_ARGS__); \
+	} while(0)
+
+#define pg_log_debug_hint(...) do { \
+		if (unlikely(__pg_log_level <= PG_LOG_DEBUG)) \
+			pg_log_generic(PG_LOG_DEBUG, PG_LOG_HINT, __VA_ARGS__); \
+	} while(0)
+
+/*
+ * A common shortcut: pg_log_error() and immediately exit(1).
+ */
+#define pg_fatal(...) do { \
+		pg_log_generic(PG_LOG_ERROR, PG_LOG_PRIMARY, __VA_ARGS__); \
+		exit(1); \
+	} while(0)
+
+#endif							/* COMMON_LOGGING_H */