1 /*-------------------------------------------------------------------------
2  *
3  * elog.h
4  *	  POSTGRES error reporting/logging definitions.
5  *
6  *
7  * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/utils/elog.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef ELOG_H
15 #define ELOG_H
16 
17 #include <setjmp.h>
18 
19 /* Error level codes */
20 #define DEBUG5		10			/* Debugging messages, in categories of
21 								 * decreasing detail. */
22 #define DEBUG4		11
23 #define DEBUG3		12
24 #define DEBUG2		13
25 #define DEBUG1		14			/* used by GUC debug_* variables */
26 #define LOG			15			/* Server operational messages; sent only to
27 								 * server log by default. */
28 #define LOG_SERVER_ONLY 16		/* Same as LOG for server reporting, but never
29 								 * sent to client. */
30 #define COMMERROR	LOG_SERVER_ONLY /* Client communication problems; same as
31 									 * LOG for server reporting, but never
32 									 * sent to client. */
33 #define INFO		17			/* Messages specifically requested by user (eg
34 								 * VACUUM VERBOSE output); always sent to
35 								 * client regardless of client_min_messages,
36 								 * but by default not sent to server log. */
37 #define NOTICE		18			/* Helpful messages to users about query
38 								 * operation; sent to client and not to server
39 								 * log by default. */
40 #define WARNING		19			/* Warnings.  NOTICE is for expected messages
41 								 * like implicit sequence creation by SERIAL.
42 								 * WARNING is for unexpected messages. */
43 #define ERROR		20			/* user error - abort transaction; return to
44 								 * known state */
45 /* Save ERROR value in PGERROR so it can be restored when Win32 includes
46  * modify it.  We have to use a constant rather than ERROR because macros
47  * are expanded only when referenced outside macros.
48  */
49 #ifdef WIN32
50 #define PGERROR		20
51 #endif
52 #define FATAL		21			/* fatal error - abort process */
53 #define PANIC		22			/* take down the other backends with me */
54 
55  /* #define DEBUG DEBUG1 */	/* Backward compatibility with pre-7.3 */
56 
57 
58 /* macros for representing SQLSTATE strings compactly */
59 #define PGSIXBIT(ch)	(((ch) - '0') & 0x3F)
60 #define PGUNSIXBIT(val) (((val) & 0x3F) + '0')
61 
62 #define MAKE_SQLSTATE(ch1,ch2,ch3,ch4,ch5)	\
63 	(PGSIXBIT(ch1) + (PGSIXBIT(ch2) << 6) + (PGSIXBIT(ch3) << 12) + \
64 	 (PGSIXBIT(ch4) << 18) + (PGSIXBIT(ch5) << 24))
65 
66 /* These macros depend on the fact that '0' becomes a zero in SIXBIT */
67 #define ERRCODE_TO_CATEGORY(ec)  ((ec) & ((1 << 12) - 1))
68 #define ERRCODE_IS_CATEGORY(ec)  (((ec) & ~((1 << 12) - 1)) == 0)
69 
70 /* SQLSTATE codes for errors are defined in a separate file */
71 #include "utils/errcodes.h"
72 
73 /*
74  * Provide a way to prevent "errno" from being accidentally used inside an
75  * elog() or ereport() invocation.  Since we know that some operating systems
76  * define errno as something involving a function call, we'll put a local
77  * variable of the same name as that function in the local scope to force a
78  * compile error.  On platforms that don't define errno in that way, nothing
79  * happens, so we get no warning ... but we can live with that as long as it
80  * happens on some popular platforms.
81  */
82 #if defined(errno) && defined(__linux__)
83 #define pg_prevent_errno_in_scope() int __errno_location pg_attribute_unused()
84 #elif defined(errno) && (defined(__darwin__) || defined(__freebsd__))
85 #define pg_prevent_errno_in_scope() int __error pg_attribute_unused()
86 #else
87 #define pg_prevent_errno_in_scope()
88 #endif
89 
90 
91 /*----------
92  * New-style error reporting API: to be used in this way:
93  *		ereport(ERROR,
94  *				errcode(ERRCODE_UNDEFINED_CURSOR),
95  *				errmsg("portal \"%s\" not found", stmt->portalname),
96  *				... other errxxx() fields as needed ...);
97  *
98  * The error level is required, and so is a primary error message (errmsg
99  * or errmsg_internal).  All else is optional.  errcode() defaults to
100  * ERRCODE_INTERNAL_ERROR if elevel is ERROR or more, ERRCODE_WARNING
101  * if elevel is WARNING, or ERRCODE_SUCCESSFUL_COMPLETION if elevel is
102  * NOTICE or below.
103  *
104  * Before Postgres v12, extra parentheses were required around the
105  * list of auxiliary function calls; that's now optional.
106  *
107  * ereport_domain() allows a message domain to be specified, for modules that
108  * wish to use a different message catalog from the backend's.  To avoid having
109  * one copy of the default text domain per .o file, we define it as NULL here
110  * and have errstart insert the default text domain.  Modules can either use
111  * ereport_domain() directly, or preferably they can override the TEXTDOMAIN
112  * macro.
113  *
114  * If elevel >= ERROR, the call will not return; we try to inform the compiler
115  * of that via pg_unreachable().  However, no useful optimization effect is
116  * obtained unless the compiler sees elevel as a compile-time constant, else
117  * we're just adding code bloat.  So, if __builtin_constant_p is available,
118  * use that to cause the second if() to vanish completely for non-constant
119  * cases.  We avoid using a local variable because it's not necessary and
120  * prevents gcc from making the unreachability deduction at optlevel -O0.
121  *----------
122  */
123 #ifdef HAVE__BUILTIN_CONSTANT_P
124 #define ereport_domain(elevel, domain, ...)	\
125 	do { \
126 		pg_prevent_errno_in_scope(); \
127 		if (errstart(elevel, __FILE__, __LINE__, PG_FUNCNAME_MACRO, domain)) \
128 			__VA_ARGS__, errfinish(0); \
129 		if (__builtin_constant_p(elevel) && (elevel) >= ERROR) \
130 			pg_unreachable(); \
131 	} while(0)
132 #else							/* !HAVE__BUILTIN_CONSTANT_P */
133 #define ereport_domain(elevel, domain, ...)	\
134 	do { \
135 		const int elevel_ = (elevel); \
136 		pg_prevent_errno_in_scope(); \
137 		if (errstart(elevel_, __FILE__, __LINE__, PG_FUNCNAME_MACRO, domain)) \
138 			__VA_ARGS__, errfinish(0); \
139 		if (elevel_ >= ERROR) \
140 			pg_unreachable(); \
141 	} while(0)
142 #endif							/* HAVE__BUILTIN_CONSTANT_P */
143 
144 #define ereport(elevel, ...)	\
145 	ereport_domain(elevel, TEXTDOMAIN, __VA_ARGS__)
146 
147 #define TEXTDOMAIN NULL
148 
149 extern bool errstart(int elevel, const char *filename, int lineno,
150 					 const char *funcname, const char *domain);
151 extern void errfinish(int dummy,...);
152 
153 extern int	errcode(int sqlerrcode);
154 
155 extern int	errcode_for_file_access(void);
156 extern int	errcode_for_socket_access(void);
157 
158 extern int	errmsg(const char *fmt,...) pg_attribute_printf(1, 2);
159 extern int	errmsg_internal(const char *fmt,...) pg_attribute_printf(1, 2);
160 
161 extern int	errmsg_plural(const char *fmt_singular, const char *fmt_plural,
162 						  unsigned long n,...) pg_attribute_printf(1, 4) pg_attribute_printf(2, 4);
163 
164 extern int	errdetail(const char *fmt,...) pg_attribute_printf(1, 2);
165 extern int	errdetail_internal(const char *fmt,...) pg_attribute_printf(1, 2);
166 
167 extern int	errdetail_log(const char *fmt,...) pg_attribute_printf(1, 2);
168 
169 extern int	errdetail_log_plural(const char *fmt_singular,
170 								 const char *fmt_plural,
171 								 unsigned long n,...) pg_attribute_printf(1, 4) pg_attribute_printf(2, 4);
172 
173 extern int	errdetail_plural(const char *fmt_singular, const char *fmt_plural,
174 							 unsigned long n,...) pg_attribute_printf(1, 4) pg_attribute_printf(2, 4);
175 
176 extern int	errhint(const char *fmt,...) pg_attribute_printf(1, 2);
177 
178 /*
179  * errcontext() is typically called in error context callback functions, not
180  * within an ereport() invocation. The callback function can be in a different
181  * module than the ereport() call, so the message domain passed in errstart()
182  * is not usually the correct domain for translating the context message.
183  * set_errcontext_domain() first sets the domain to be used, and
184  * errcontext_msg() passes the actual message.
185  */
186 #define errcontext	set_errcontext_domain(TEXTDOMAIN),	errcontext_msg
187 
188 extern int	set_errcontext_domain(const char *domain);
189 
190 extern int	errcontext_msg(const char *fmt,...) pg_attribute_printf(1, 2);
191 
192 extern int	errhidestmt(bool hide_stmt);
193 extern int	errhidecontext(bool hide_ctx);
194 
195 extern int	errfunction(const char *funcname);
196 extern int	errposition(int cursorpos);
197 
198 extern int	internalerrposition(int cursorpos);
199 extern int	internalerrquery(const char *query);
200 
201 extern int	err_generic_string(int field, const char *str);
202 
203 extern int	geterrcode(void);
204 extern int	geterrposition(void);
205 extern int	getinternalerrposition(void);
206 
207 
208 /*----------
209  * Old-style error reporting API: to be used in this way:
210  *		elog(ERROR, "portal \"%s\" not found", stmt->portalname);
211  *----------
212  */
213 /*
214  * Using variadic macros, we can give the compiler a hint about the
215  * call not returning when elevel >= ERROR.  See comments for ereport().
216  * Note that historically elog() has called elog_start (which saves errno)
217  * before evaluating "elevel", so we preserve that behavior here.
218  */
219 #ifdef HAVE__BUILTIN_CONSTANT_P
220 #define elog(elevel, ...)  \
221 	do { \
222 		pg_prevent_errno_in_scope(); \
223 		elog_start(__FILE__, __LINE__, PG_FUNCNAME_MACRO); \
224 		elog_finish(elevel, __VA_ARGS__); \
225 		if (__builtin_constant_p(elevel) && (elevel) >= ERROR) \
226 			pg_unreachable(); \
227 	} while(0)
228 #else							/* !HAVE__BUILTIN_CONSTANT_P */
229 #define elog(elevel, ...)  \
230 	do { \
231 		pg_prevent_errno_in_scope(); \
232 		elog_start(__FILE__, __LINE__, PG_FUNCNAME_MACRO); \
233 		{ \
234 			const int elevel_ = (elevel); \
235 			elog_finish(elevel_, __VA_ARGS__); \
236 			if (elevel_ >= ERROR) \
237 				pg_unreachable(); \
238 		} \
239 	} while(0)
240 #endif							/* HAVE__BUILTIN_CONSTANT_P */
241 
242 extern void elog_start(const char *filename, int lineno, const char *funcname);
243 extern void elog_finish(int elevel, const char *fmt,...) pg_attribute_printf(2, 3);
244 
245 
246 /* Support for constructing error strings separately from ereport() calls */
247 
248 extern void pre_format_elog_string(int errnumber, const char *domain);
249 extern char *format_elog_string(const char *fmt,...) pg_attribute_printf(1, 2);
250 
251 
252 /* Support for attaching context information to error reports */
253 
254 typedef struct ErrorContextCallback
255 {
256 	struct ErrorContextCallback *previous;
257 	void		(*callback) (void *arg);
258 	void	   *arg;
259 } ErrorContextCallback;
260 
261 extern PGDLLIMPORT ErrorContextCallback *error_context_stack;
262 
263 
264 /*----------
265  * API for catching ereport(ERROR) exits.  Use these macros like so:
266  *
267  *		PG_TRY();
268  *		{
269  *			... code that might throw ereport(ERROR) ...
270  *		}
271  *		PG_CATCH();
272  *		{
273  *			... error recovery code ...
274  *		}
275  *		PG_END_TRY();
276  *
277  * (The braces are not actually necessary, but are recommended so that
278  * pgindent will indent the construct nicely.)  The error recovery code
279  * can either do PG_RE_THROW to propagate the error outwards, or do a
280  * (sub)transaction abort. Failure to do so may leave the system in an
281  * inconsistent state for further processing.
282  *
283  * Note: while the system will correctly propagate any new ereport(ERROR)
284  * occurring in the recovery section, there is a small limit on the number
285  * of levels this will work for.  It's best to keep the error recovery
286  * section simple enough that it can't generate any new errors, at least
287  * not before popping the error stack.
288  *
289  * Note: an ereport(FATAL) will not be caught by this construct; control will
290  * exit straight through proc_exit().  Therefore, do NOT put any cleanup
291  * of non-process-local resources into the error recovery section, at least
292  * not without taking thought for what will happen during ereport(FATAL).
293  * The PG_ENSURE_ERROR_CLEANUP macros provided by storage/ipc.h may be
294  * helpful in such cases.
295  *
296  * Note: if a local variable of the function containing PG_TRY is modified
297  * in the PG_TRY section and used in the PG_CATCH section, that variable
298  * must be declared "volatile" for POSIX compliance.  This is not mere
299  * pedantry; we have seen bugs from compilers improperly optimizing code
300  * away when such a variable was not marked.  Beware that gcc's -Wclobbered
301  * warnings are just about entirely useless for catching such oversights.
302  *----------
303  */
304 #define PG_TRY()  \
305 	do { \
306 		sigjmp_buf *save_exception_stack = PG_exception_stack; \
307 		ErrorContextCallback *save_context_stack = error_context_stack; \
308 		sigjmp_buf local_sigjmp_buf; \
309 		if (sigsetjmp(local_sigjmp_buf, 0) == 0) \
310 		{ \
311 			PG_exception_stack = &local_sigjmp_buf
312 
313 #define PG_CATCH()	\
314 		} \
315 		else \
316 		{ \
317 			PG_exception_stack = save_exception_stack; \
318 			error_context_stack = save_context_stack
319 
320 #define PG_END_TRY()  \
321 		} \
322 		PG_exception_stack = save_exception_stack; \
323 		error_context_stack = save_context_stack; \
324 	} while (0)
325 
326 /*
327  * Some compilers understand pg_attribute_noreturn(); for other compilers,
328  * insert pg_unreachable() so that the compiler gets the point.
329  */
330 #ifdef HAVE_PG_ATTRIBUTE_NORETURN
331 #define PG_RE_THROW()  \
332 	pg_re_throw()
333 #else
334 #define PG_RE_THROW()  \
335 	(pg_re_throw(), pg_unreachable())
336 #endif
337 
338 extern PGDLLIMPORT sigjmp_buf *PG_exception_stack;
339 
340 
341 /* Stuff that error handlers might want to use */
342 
343 /*
344  * ErrorData holds the data accumulated during any one ereport() cycle.
345  * Any non-NULL pointers must point to palloc'd data.
346  * (The const pointers are an exception; we assume they point at non-freeable
347  * constant strings.)
348  */
349 typedef struct ErrorData
350 {
351 	int			elevel;			/* error level */
352 	bool		output_to_server;	/* will report to server log? */
353 	bool		output_to_client;	/* will report to client? */
354 	bool		show_funcname;	/* true to force funcname inclusion */
355 	bool		hide_stmt;		/* true to prevent STATEMENT: inclusion */
356 	bool		hide_ctx;		/* true to prevent CONTEXT: inclusion */
357 	const char *filename;		/* __FILE__ of ereport() call */
358 	int			lineno;			/* __LINE__ of ereport() call */
359 	const char *funcname;		/* __func__ of ereport() call */
360 	const char *domain;			/* message domain */
361 	const char *context_domain; /* message domain for context message */
362 	int			sqlerrcode;		/* encoded ERRSTATE */
363 	char	   *message;		/* primary error message (translated) */
364 	char	   *detail;			/* detail error message */
365 	char	   *detail_log;		/* detail error message for server log only */
366 	char	   *hint;			/* hint message */
367 	char	   *context;		/* context message */
368 	const char *message_id;		/* primary message's id (original string) */
369 	char	   *schema_name;	/* name of schema */
370 	char	   *table_name;		/* name of table */
371 	char	   *column_name;	/* name of column */
372 	char	   *datatype_name;	/* name of datatype */
373 	char	   *constraint_name;	/* name of constraint */
374 	int			cursorpos;		/* cursor index into query string */
375 	int			internalpos;	/* cursor index into internalquery */
376 	char	   *internalquery;	/* text of internally-generated query */
377 	int			saved_errno;	/* errno at entry */
378 
379 	/* context containing associated non-constant strings */
380 	struct MemoryContextData *assoc_context;
381 } ErrorData;
382 
383 extern void EmitErrorReport(void);
384 extern ErrorData *CopyErrorData(void);
385 extern void FreeErrorData(ErrorData *edata);
386 extern void FlushErrorState(void);
387 extern void ReThrowError(ErrorData *edata) pg_attribute_noreturn();
388 extern void ThrowErrorData(ErrorData *edata);
389 extern void pg_re_throw(void) pg_attribute_noreturn();
390 
391 extern char *GetErrorContextStack(void);
392 
393 /* Hook for intercepting messages before they are sent to the server log */
394 typedef void (*emit_log_hook_type) (ErrorData *edata);
395 extern PGDLLIMPORT emit_log_hook_type emit_log_hook;
396 
397 
398 /* GUC-configurable parameters */
399 
400 typedef enum
401 {
402 	PGERROR_TERSE,				/* single-line error messages */
403 	PGERROR_DEFAULT,			/* recommended style */
404 	PGERROR_VERBOSE				/* all the facts, ma'am */
405 }			PGErrorVerbosity;
406 
407 extern int	Log_error_verbosity;
408 extern char *Log_line_prefix;
409 extern int	Log_destination;
410 extern char *Log_destination_string;
411 extern bool syslog_sequence_numbers;
412 extern bool syslog_split_messages;
413 
414 /* Log destination bitmap */
415 #define LOG_DESTINATION_STDERR	 1
416 #define LOG_DESTINATION_SYSLOG	 2
417 #define LOG_DESTINATION_EVENTLOG 4
418 #define LOG_DESTINATION_CSVLOG	 8
419 
420 /* Other exported functions */
421 extern void DebugFileOpen(void);
422 extern char *unpack_sql_state(int sql_state);
423 extern bool in_error_recursion_trouble(void);
424 
425 #ifdef HAVE_SYSLOG
426 extern void set_syslog_parameters(const char *ident, int facility);
427 #endif
428 
429 /*
430  * Write errors to stderr (or by equal means when stderr is
431  * not available). Used before ereport/elog can be used
432  * safely (memory context, GUC load etc)
433  */
434 extern void write_stderr(const char *fmt,...) pg_attribute_printf(1, 2);
435 
436 #endif							/* ELOG_H */
437