1 /*-------------------------------------------------------------------------
2  *
3  * elog.h
4  *	  POSTGRES error reporting/logging definitions.
5  *
6  *
7  * Portions Copyright (c) 1996-2017, 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 /*----------
75  * New-style error reporting API: to be used in this way:
76  *		ereport(ERROR,
77  *				(errcode(ERRCODE_UNDEFINED_CURSOR),
78  *				 errmsg("portal \"%s\" not found", stmt->portalname),
79  *				 ... other errxxx() fields as needed ...));
80  *
81  * The error level is required, and so is a primary error message (errmsg
82  * or errmsg_internal).  All else is optional.  errcode() defaults to
83  * ERRCODE_INTERNAL_ERROR if elevel is ERROR or more, ERRCODE_WARNING
84  * if elevel is WARNING, or ERRCODE_SUCCESSFUL_COMPLETION if elevel is
85  * NOTICE or below.
86  *
87  * ereport_domain() allows a message domain to be specified, for modules that
88  * wish to use a different message catalog from the backend's.  To avoid having
89  * one copy of the default text domain per .o file, we define it as NULL here
90  * and have errstart insert the default text domain.  Modules can either use
91  * ereport_domain() directly, or preferably they can override the TEXTDOMAIN
92  * macro.
93  *
94  * If elevel >= ERROR, the call will not return; we try to inform the compiler
95  * of that via pg_unreachable().  However, no useful optimization effect is
96  * obtained unless the compiler sees elevel as a compile-time constant, else
97  * we're just adding code bloat.  So, if __builtin_constant_p is available,
98  * use that to cause the second if() to vanish completely for non-constant
99  * cases.  We avoid using a local variable because it's not necessary and
100  * prevents gcc from making the unreachability deduction at optlevel -O0.
101  *----------
102  */
103 #ifdef HAVE__BUILTIN_CONSTANT_P
104 #define ereport_domain(elevel, domain, rest)	\
105 	do { \
106 		if (errstart(elevel, __FILE__, __LINE__, PG_FUNCNAME_MACRO, domain)) \
107 			errfinish rest; \
108 		if (__builtin_constant_p(elevel) && (elevel) >= ERROR) \
109 			pg_unreachable(); \
110 	} while(0)
111 #else							/* !HAVE__BUILTIN_CONSTANT_P */
112 #define ereport_domain(elevel, domain, rest)	\
113 	do { \
114 		const int elevel_ = (elevel); \
115 		if (errstart(elevel_, __FILE__, __LINE__, PG_FUNCNAME_MACRO, domain)) \
116 			errfinish rest; \
117 		if (elevel_ >= ERROR) \
118 			pg_unreachable(); \
119 	} while(0)
120 #endif							/* HAVE__BUILTIN_CONSTANT_P */
121 
122 #define ereport(elevel, rest)	\
123 	ereport_domain(elevel, TEXTDOMAIN, rest)
124 
125 #define TEXTDOMAIN NULL
126 
127 extern bool errstart(int elevel, const char *filename, int lineno,
128 		 const char *funcname, const char *domain);
129 extern void errfinish(int dummy,...);
130 
131 extern int	errcode(int sqlerrcode);
132 
133 extern int	errcode_for_file_access(void);
134 extern int	errcode_for_socket_access(void);
135 
136 extern int	errmsg(const char *fmt,...) pg_attribute_printf(1, 2);
137 extern int	errmsg_internal(const char *fmt,...) pg_attribute_printf(1, 2);
138 
139 extern int errmsg_plural(const char *fmt_singular, const char *fmt_plural,
140 			  unsigned long n,...) pg_attribute_printf(1, 4) pg_attribute_printf(2, 4);
141 
142 extern int	errdetail(const char *fmt,...) pg_attribute_printf(1, 2);
143 extern int	errdetail_internal(const char *fmt,...) pg_attribute_printf(1, 2);
144 
145 extern int	errdetail_log(const char *fmt,...) pg_attribute_printf(1, 2);
146 
147 extern int errdetail_log_plural(const char *fmt_singular,
148 					 const char *fmt_plural,
149 					 unsigned long n,...) pg_attribute_printf(1, 4) pg_attribute_printf(2, 4);
150 
151 extern int errdetail_plural(const char *fmt_singular, const char *fmt_plural,
152 				 unsigned long n,...) pg_attribute_printf(1, 4) pg_attribute_printf(2, 4);
153 
154 extern int	errhint(const char *fmt,...) pg_attribute_printf(1, 2);
155 
156 /*
157  * errcontext() is typically called in error context callback functions, not
158  * within an ereport() invocation. The callback function can be in a different
159  * module than the ereport() call, so the message domain passed in errstart()
160  * is not usually the correct domain for translating the context message.
161  * set_errcontext_domain() first sets the domain to be used, and
162  * errcontext_msg() passes the actual message.
163  */
164 #define errcontext	set_errcontext_domain(TEXTDOMAIN),	errcontext_msg
165 
166 extern int	set_errcontext_domain(const char *domain);
167 
168 extern int	errcontext_msg(const char *fmt,...) pg_attribute_printf(1, 2);
169 
170 extern int	errhidestmt(bool hide_stmt);
171 extern int	errhidecontext(bool hide_ctx);
172 
173 extern int	errfunction(const char *funcname);
174 extern int	errposition(int cursorpos);
175 
176 extern int	internalerrposition(int cursorpos);
177 extern int	internalerrquery(const char *query);
178 
179 extern int	err_generic_string(int field, const char *str);
180 
181 extern int	geterrcode(void);
182 extern int	geterrposition(void);
183 extern int	getinternalerrposition(void);
184 
185 
186 /*----------
187  * Old-style error reporting API: to be used in this way:
188  *		elog(ERROR, "portal \"%s\" not found", stmt->portalname);
189  *----------
190  */
191 #ifdef HAVE__VA_ARGS
192 /*
193  * If we have variadic macros, we can give the compiler a hint about the
194  * call not returning when elevel >= ERROR.  See comments for ereport().
195  * Note that historically elog() has called elog_start (which saves errno)
196  * before evaluating "elevel", so we preserve that behavior here.
197  */
198 #ifdef HAVE__BUILTIN_CONSTANT_P
199 #define elog(elevel, ...)  \
200 	do { \
201 		elog_start(__FILE__, __LINE__, PG_FUNCNAME_MACRO); \
202 		elog_finish(elevel, __VA_ARGS__); \
203 		if (__builtin_constant_p(elevel) && (elevel) >= ERROR) \
204 			pg_unreachable(); \
205 	} while(0)
206 #else							/* !HAVE__BUILTIN_CONSTANT_P */
207 #define elog(elevel, ...)  \
208 	do { \
209 		elog_start(__FILE__, __LINE__, PG_FUNCNAME_MACRO); \
210 		{ \
211 			const int elevel_ = (elevel); \
212 			elog_finish(elevel_, __VA_ARGS__); \
213 			if (elevel_ >= ERROR) \
214 				pg_unreachable(); \
215 		} \
216 	} while(0)
217 #endif							/* HAVE__BUILTIN_CONSTANT_P */
218 #else							/* !HAVE__VA_ARGS */
219 #define elog  \
220 	elog_start(__FILE__, __LINE__, PG_FUNCNAME_MACRO), \
221 	elog_finish
222 #endif							/* HAVE__VA_ARGS */
223 
224 extern void elog_start(const char *filename, int lineno, const char *funcname);
225 extern void elog_finish(int elevel, const char *fmt,...) pg_attribute_printf(2, 3);
226 
227 
228 /* Support for constructing error strings separately from ereport() calls */
229 
230 extern void pre_format_elog_string(int errnumber, const char *domain);
231 extern char *format_elog_string(const char *fmt,...) pg_attribute_printf(1, 2);
232 
233 
234 /* Support for attaching context information to error reports */
235 
236 typedef struct ErrorContextCallback
237 {
238 	struct ErrorContextCallback *previous;
239 	void		(*callback) (void *arg);
240 	void	   *arg;
241 } ErrorContextCallback;
242 
243 extern PGDLLIMPORT ErrorContextCallback *error_context_stack;
244 
245 
246 /*----------
247  * API for catching ereport(ERROR) exits.  Use these macros like so:
248  *
249  *		PG_TRY();
250  *		{
251  *			... code that might throw ereport(ERROR) ...
252  *		}
253  *		PG_CATCH();
254  *		{
255  *			... error recovery code ...
256  *		}
257  *		PG_END_TRY();
258  *
259  * (The braces are not actually necessary, but are recommended so that
260  * pgindent will indent the construct nicely.)	The error recovery code
261  * can optionally do PG_RE_THROW() to propagate the same error outwards.
262  *
263  * Note: while the system will correctly propagate any new ereport(ERROR)
264  * occurring in the recovery section, there is a small limit on the number
265  * of levels this will work for.  It's best to keep the error recovery
266  * section simple enough that it can't generate any new errors, at least
267  * not before popping the error stack.
268  *
269  * Note: an ereport(FATAL) will not be caught by this construct; control will
270  * exit straight through proc_exit().  Therefore, do NOT put any cleanup
271  * of non-process-local resources into the error recovery section, at least
272  * not without taking thought for what will happen during ereport(FATAL).
273  * The PG_ENSURE_ERROR_CLEANUP macros provided by storage/ipc.h may be
274  * helpful in such cases.
275  *
276  * Note: if a local variable of the function containing PG_TRY is modified
277  * in the PG_TRY section and used in the PG_CATCH section, that variable
278  * must be declared "volatile" for POSIX compliance.  This is not mere
279  * pedantry; we have seen bugs from compilers improperly optimizing code
280  * away when such a variable was not marked.  Beware that gcc's -Wclobbered
281  * warnings are just about entirely useless for catching such oversights.
282  *----------
283  */
284 #define PG_TRY()  \
285 	do { \
286 		sigjmp_buf *save_exception_stack = PG_exception_stack; \
287 		ErrorContextCallback *save_context_stack = error_context_stack; \
288 		sigjmp_buf local_sigjmp_buf; \
289 		if (sigsetjmp(local_sigjmp_buf, 0) == 0) \
290 		{ \
291 			PG_exception_stack = &local_sigjmp_buf
292 
293 #define PG_CATCH()	\
294 		} \
295 		else \
296 		{ \
297 			PG_exception_stack = save_exception_stack; \
298 			error_context_stack = save_context_stack
299 
300 #define PG_END_TRY()  \
301 		} \
302 		PG_exception_stack = save_exception_stack; \
303 		error_context_stack = save_context_stack; \
304 	} while (0)
305 
306 /*
307  * Some compilers understand pg_attribute_noreturn(); for other compilers,
308  * insert pg_unreachable() so that the compiler gets the point.
309  */
310 #ifdef HAVE_PG_ATTRIBUTE_NORETURN
311 #define PG_RE_THROW()  \
312 	pg_re_throw()
313 #else
314 #define PG_RE_THROW()  \
315 	(pg_re_throw(), pg_unreachable())
316 #endif
317 
318 extern PGDLLIMPORT sigjmp_buf *PG_exception_stack;
319 
320 
321 /* Stuff that error handlers might want to use */
322 
323 /*
324  * ErrorData holds the data accumulated during any one ereport() cycle.
325  * Any non-NULL pointers must point to palloc'd data.
326  * (The const pointers are an exception; we assume they point at non-freeable
327  * constant strings.)
328  */
329 typedef struct ErrorData
330 {
331 	int			elevel;			/* error level */
332 	bool		output_to_server;	/* will report to server log? */
333 	bool		output_to_client;	/* will report to client? */
334 	bool		show_funcname;	/* true to force funcname inclusion */
335 	bool		hide_stmt;		/* true to prevent STATEMENT: inclusion */
336 	bool		hide_ctx;		/* true to prevent CONTEXT: inclusion */
337 	const char *filename;		/* __FILE__ of ereport() call */
338 	int			lineno;			/* __LINE__ of ereport() call */
339 	const char *funcname;		/* __func__ of ereport() call */
340 	const char *domain;			/* message domain */
341 	const char *context_domain; /* message domain for context message */
342 	int			sqlerrcode;		/* encoded ERRSTATE */
343 	char	   *message;		/* primary error message (translated) */
344 	char	   *detail;			/* detail error message */
345 	char	   *detail_log;		/* detail error message for server log only */
346 	char	   *hint;			/* hint message */
347 	char	   *context;		/* context message */
348 	const char *message_id;		/* primary message's id (original string) */
349 	char	   *schema_name;	/* name of schema */
350 	char	   *table_name;		/* name of table */
351 	char	   *column_name;	/* name of column */
352 	char	   *datatype_name;	/* name of datatype */
353 	char	   *constraint_name;	/* name of constraint */
354 	int			cursorpos;		/* cursor index into query string */
355 	int			internalpos;	/* cursor index into internalquery */
356 	char	   *internalquery;	/* text of internally-generated query */
357 	int			saved_errno;	/* errno at entry */
358 
359 	/* context containing associated non-constant strings */
360 	struct MemoryContextData *assoc_context;
361 } ErrorData;
362 
363 extern void EmitErrorReport(void);
364 extern ErrorData *CopyErrorData(void);
365 extern void FreeErrorData(ErrorData *edata);
366 extern void FlushErrorState(void);
367 extern void ReThrowError(ErrorData *edata) pg_attribute_noreturn();
368 extern void ThrowErrorData(ErrorData *edata);
369 extern void pg_re_throw(void) pg_attribute_noreturn();
370 
371 extern char *GetErrorContextStack(void);
372 
373 /* Hook for intercepting messages before they are sent to the server log */
374 typedef void (*emit_log_hook_type) (ErrorData *edata);
375 extern PGDLLIMPORT emit_log_hook_type emit_log_hook;
376 
377 
378 /* GUC-configurable parameters */
379 
380 typedef enum
381 {
382 	PGERROR_TERSE,				/* single-line error messages */
383 	PGERROR_DEFAULT,			/* recommended style */
384 	PGERROR_VERBOSE				/* all the facts, ma'am */
385 }			PGErrorVerbosity;
386 
387 extern int	Log_error_verbosity;
388 extern char *Log_line_prefix;
389 extern int	Log_destination;
390 extern char *Log_destination_string;
391 extern bool syslog_sequence_numbers;
392 extern bool syslog_split_messages;
393 
394 /* Log destination bitmap */
395 #define LOG_DESTINATION_STDERR	 1
396 #define LOG_DESTINATION_SYSLOG	 2
397 #define LOG_DESTINATION_EVENTLOG 4
398 #define LOG_DESTINATION_CSVLOG	 8
399 
400 /* Other exported functions */
401 extern void DebugFileOpen(void);
402 extern char *unpack_sql_state(int sql_state);
403 extern bool in_error_recursion_trouble(void);
404 
405 #ifdef HAVE_SYSLOG
406 extern void set_syslog_parameters(const char *ident, int facility);
407 #endif
408 
409 /*
410  * Write errors to stderr (or by equal means when stderr is
411  * not available). Used before ereport/elog can be used
412  * safely (memory context, GUC load etc)
413  */
414 extern void write_stderr(const char *fmt,...) pg_attribute_printf(1, 2);
415 
416 #endif							/* ELOG_H */
417