elog.h

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/*-------------------------------------------------------------------------
 *
 * elog.h
 *    POSTGRES error reporting/logging definitions.
 *
 *
 * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/utils/elog.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef ELOG_H
#define ELOG_H

#include <setjmp.h>

/* Error level codes */
#define DEBUG5      10          /* Debugging messages, in categories of
                                 * decreasing detail. */
#define DEBUG4      11
#define DEBUG3      12
#define DEBUG2      13
#define DEBUG1      14          /* used by GUC debug_* variables */
#define LOG         15          /* Server operational messages; sent only to
                                 * server log by default. */
#define COMMERROR   16          /* Client communication problems; same as LOG
                                 * for server reporting, but never sent to
                                 * client. */
#define INFO        17          /* Messages specifically requested by user (eg
                                 * VACUUM VERBOSE output); always sent to
                                 * client regardless of client_min_messages,
                                 * but by default not sent to server log. */
#define NOTICE      18          /* Helpful messages to users about query
                                 * operation; sent to client and server log by
                                 * default. */
#define WARNING     19          /* Warnings.  NOTICE is for expected messages
                                 * like implicit sequence creation by SERIAL.
                                 * WARNING is for unexpected messages. */
#define ERROR       20          /* user error - abort transaction; return to
                                 * known state */
/* Save ERROR value in PGERROR so it can be restored when Win32 includes
 * modify it.  We have to use a constant rather than ERROR because macros
 * are expanded only when referenced outside macros.
 */
#ifdef WIN32
#define PGERROR     20
#endif
#define FATAL       21          /* fatal error - abort process */
#define PANIC       22          /* take down the other backends with me */

 /* #define DEBUG DEBUG1 */ /* Backward compatibility with pre-7.3 */


/* macros for representing SQLSTATE strings compactly */
#define PGSIXBIT(ch)    (((ch) - '0') & 0x3F)
#define PGUNSIXBIT(val) (((val) & 0x3F) + '0')

#define MAKE_SQLSTATE(ch1,ch2,ch3,ch4,ch5)  \
    (PGSIXBIT(ch1) + (PGSIXBIT(ch2) << 6) + (PGSIXBIT(ch3) << 12) + \
     (PGSIXBIT(ch4) << 18) + (PGSIXBIT(ch5) << 24))

/* These macros depend on the fact that '0' becomes a zero in SIXBIT */
#define ERRCODE_TO_CATEGORY(ec)  ((ec) & ((1 << 12) - 1))
#define ERRCODE_IS_CATEGORY(ec)  (((ec) & ~((1 << 12) - 1)) == 0)

/* SQLSTATE codes for errors are defined in a separate file */
#include "utils/errcodes.h"


/* Which __func__ symbol do we have, if any? */
#ifdef HAVE_FUNCNAME__FUNC
#define PG_FUNCNAME_MACRO   __func__
#else
#ifdef HAVE_FUNCNAME__FUNCTION
#define PG_FUNCNAME_MACRO   __FUNCTION__
#else
#define PG_FUNCNAME_MACRO   NULL
#endif
#endif


/*----------
 * New-style error reporting API: to be used in this way:
 *      ereport(ERROR,
 *              (errcode(ERRCODE_UNDEFINED_CURSOR),
 *               errmsg("portal \"%s\" not found", stmt->portalname),
 *               ... other errxxx() fields as needed ...));
 *
 * The error level is required, and so is a primary error message (errmsg
 * or errmsg_internal).  All else is optional.  errcode() defaults to
 * ERRCODE_INTERNAL_ERROR if elevel is ERROR or more, ERRCODE_WARNING
 * if elevel is WARNING, or ERRCODE_SUCCESSFUL_COMPLETION if elevel is
 * NOTICE or below.
 *
 * ereport_domain() allows a message domain to be specified, for modules that
 * wish to use a different message catalog from the backend's.  To avoid having
 * one copy of the default text domain per .o file, we define it as NULL here
 * and have errstart insert the default text domain.  Modules can either use
 * ereport_domain() directly, or preferably they can override the TEXTDOMAIN
 * macro.
 *
 * If elevel >= ERROR, the call will not return; we try to inform the compiler
 * of that via pg_unreachable().  However, no useful optimization effect is
 * obtained unless the compiler sees elevel as a compile-time constant, else
 * we're just adding code bloat.  So, if __builtin_constant_p is available,
 * use that to cause the second if() to vanish completely for non-constant
 * cases.  We avoid using a local variable because it's not necessary and
 * prevents gcc from making the unreachability deduction at optlevel -O0.
 *----------
 */
#ifdef HAVE__BUILTIN_CONSTANT_P
#define ereport_domain(elevel, domain, rest)    \
    do { \
        if (errstart(elevel, __FILE__, __LINE__, PG_FUNCNAME_MACRO, domain)) \
            errfinish rest; \
        if (__builtin_constant_p(elevel) && (elevel) >= ERROR) \
            pg_unreachable(); \
    } while(0)
#else /* !HAVE__BUILTIN_CONSTANT_P */
#define ereport_domain(elevel, domain, rest)    \
    do { \
        const int elevel_ = (elevel); \
        if (errstart(elevel_, __FILE__, __LINE__, PG_FUNCNAME_MACRO, domain)) \
            errfinish rest; \
        if (elevel_ >= ERROR) \
            pg_unreachable(); \
    } while(0)
#endif /* HAVE__BUILTIN_CONSTANT_P */

#define ereport(elevel, rest)   \
    ereport_domain(elevel, TEXTDOMAIN, rest)

#define TEXTDOMAIN NULL

extern bool errstart(int elevel, const char *filename, int lineno,
         const char *funcname, const char *domain);
extern void errfinish(int dummy,...);

extern int  errcode(int sqlerrcode);

extern int  errcode_for_file_access(void);
extern int  errcode_for_socket_access(void);

extern int
errmsg(const char *fmt,...)
/* This extension allows gcc to check the format string for consistency with
   the supplied arguments. */
__attribute__((format(PG_PRINTF_ATTRIBUTE, 1, 2)));

extern int
errmsg_internal(const char *fmt,...)
/* This extension allows gcc to check the format string for consistency with
   the supplied arguments. */
__attribute__((format(PG_PRINTF_ATTRIBUTE, 1, 2)));

extern int
errmsg_plural(const char *fmt_singular, const char *fmt_plural,
              unsigned long n,...)
/* This extension allows gcc to check the format string for consistency with
   the supplied arguments. */
__attribute__((format(PG_PRINTF_ATTRIBUTE, 1, 4)))
__attribute__((format(PG_PRINTF_ATTRIBUTE, 2, 4)));

extern int
errdetail(const char *fmt,...)
/* This extension allows gcc to check the format string for consistency with
   the supplied arguments. */
__attribute__((format(PG_PRINTF_ATTRIBUTE, 1, 2)));

extern int
errdetail_internal(const char *fmt,...)
/* This extension allows gcc to check the format string for consistency with
   the supplied arguments. */
__attribute__((format(PG_PRINTF_ATTRIBUTE, 1, 2)));

extern int
errdetail_log(const char *fmt,...)
/* This extension allows gcc to check the format string for consistency with
   the supplied arguments. */
__attribute__((format(PG_PRINTF_ATTRIBUTE, 1, 2)));

extern int
errdetail_plural(const char *fmt_singular, const char *fmt_plural,
                 unsigned long n,...)
/* This extension allows gcc to check the format string for consistency with
   the supplied arguments. */
__attribute__((format(PG_PRINTF_ATTRIBUTE, 1, 4)))
__attribute__((format(PG_PRINTF_ATTRIBUTE, 2, 4)));

extern int
errhint(const char *fmt,...)
/* This extension allows gcc to check the format string for consistency with
   the supplied arguments. */
__attribute__((format(PG_PRINTF_ATTRIBUTE, 1, 2)));

/*
 * errcontext() is typically called in error context callback functions, not
 * within an ereport() invocation. The callback function can be in a different
 * module than the ereport() call, so the message domain passed in errstart()
 * is not usually the correct domain for translating the context message.
 * set_errcontext_domain() first sets the domain to be used, and
 * errcontext_msg() passes the actual message.
 */
#define errcontext  set_errcontext_domain(TEXTDOMAIN),  errcontext_msg

extern int  set_errcontext_domain(const char *domain);
extern int
errcontext_msg(const char *fmt,...)
/* This extension allows gcc to check the format string for consistency with
   the supplied arguments. */
__attribute__((format(PG_PRINTF_ATTRIBUTE, 1, 2)));

extern int  errhidestmt(bool hide_stmt);

extern int  errfunction(const char *funcname);
extern int  errposition(int cursorpos);

extern int  internalerrposition(int cursorpos);
extern int  internalerrquery(const char *query);

extern int  err_generic_string(int field, const char *str);

extern int  geterrcode(void);
extern int  geterrposition(void);
extern int  getinternalerrposition(void);


/*----------
 * Old-style error reporting API: to be used in this way:
 *      elog(ERROR, "portal \"%s\" not found", stmt->portalname);
 *----------
 */
#ifdef HAVE__VA_ARGS
/*
 * If we have variadic macros, we can give the compiler a hint about the
 * call not returning when elevel >= ERROR.  See comments for ereport().
 * Note that historically elog() has called elog_start (which saves errno)
 * before evaluating "elevel", so we preserve that behavior here.
 */
#ifdef HAVE__BUILTIN_CONSTANT_P
#define elog(elevel, ...)  \
    do { \
        elog_start(__FILE__, __LINE__, PG_FUNCNAME_MACRO); \
        elog_finish(elevel, __VA_ARGS__); \
        if (__builtin_constant_p(elevel) && (elevel) >= ERROR) \
            pg_unreachable(); \
    } while(0)
#else /* !HAVE__BUILTIN_CONSTANT_P */
#define elog(elevel, ...)  \
    do { \
        int     elevel_; \
        elog_start(__FILE__, __LINE__, PG_FUNCNAME_MACRO); \
        elevel_ = (elevel); \
        elog_finish(elevel_, __VA_ARGS__); \
        if (elevel_ >= ERROR) \
            pg_unreachable(); \
    } while(0)
#endif /* HAVE__BUILTIN_CONSTANT_P */
#else /* !HAVE__VA_ARGS */
#define elog  \
    elog_start(__FILE__, __LINE__, PG_FUNCNAME_MACRO), \
    elog_finish
#endif /* HAVE__VA_ARGS */

extern void elog_start(const char *filename, int lineno, const char *funcname);
extern void
elog_finish(int elevel, const char *fmt,...)
/* This extension allows gcc to check the format string for consistency with
   the supplied arguments. */
__attribute__((format(PG_PRINTF_ATTRIBUTE, 2, 3)));


/* Support for constructing error strings separately from ereport() calls */

extern void pre_format_elog_string(int errnumber, const char *domain);
extern char *
format_elog_string(const char *fmt,...)
/* This extension allows gcc to check the format string for consistency with
   the supplied arguments. */
__attribute__((format(PG_PRINTF_ATTRIBUTE, 1, 2)));


/* Support for attaching context information to error reports */

typedef struct ErrorContextCallback
{
    struct ErrorContextCallback *previous;
    void        (*callback) (void *arg);
    void       *arg;
} ErrorContextCallback;

extern PGDLLIMPORT ErrorContextCallback *error_context_stack;


/*----------
 * API for catching ereport(ERROR) exits.  Use these macros like so:
 *
 *      PG_TRY();
 *      {
 *          ... code that might throw ereport(ERROR) ...
 *      }
 *      PG_CATCH();
 *      {
 *          ... error recovery code ...
 *      }
 *      PG_END_TRY();
 *
 * (The braces are not actually necessary, but are recommended so that
 * pg_indent will indent the construct nicely.)  The error recovery code
 * can optionally do PG_RE_THROW() to propagate the same error outwards.
 *
 * Note: while the system will correctly propagate any new ereport(ERROR)
 * occurring in the recovery section, there is a small limit on the number
 * of levels this will work for.  It's best to keep the error recovery
 * section simple enough that it can't generate any new errors, at least
 * not before popping the error stack.
 *
 * Note: an ereport(FATAL) will not be caught by this construct; control will
 * exit straight through proc_exit().  Therefore, do NOT put any cleanup
 * of non-process-local resources into the error recovery section, at least
 * not without taking thought for what will happen during ereport(FATAL).
 * The PG_ENSURE_ERROR_CLEANUP macros provided by storage/ipc.h may be
 * helpful in such cases.
 *----------
 */
#define PG_TRY()  \
    do { \
        sigjmp_buf *save_exception_stack = PG_exception_stack; \
        ErrorContextCallback *save_context_stack = error_context_stack; \
        sigjmp_buf local_sigjmp_buf; \
        if (sigsetjmp(local_sigjmp_buf, 0) == 0) \
        { \
            PG_exception_stack = &local_sigjmp_buf

#define PG_CATCH()  \
        } \
        else \
        { \
            PG_exception_stack = save_exception_stack; \
            error_context_stack = save_context_stack

#define PG_END_TRY()  \
        } \
        PG_exception_stack = save_exception_stack; \
        error_context_stack = save_context_stack; \
    } while (0)

/*
 * gcc understands __attribute__((noreturn)); for other compilers, insert
 * pg_unreachable() so that the compiler gets the point.
 */
#ifdef __GNUC__
#define PG_RE_THROW()  \
    pg_re_throw()
#else
#define PG_RE_THROW()  \
    (pg_re_throw(), pg_unreachable())
#endif

extern PGDLLIMPORT sigjmp_buf *PG_exception_stack;


/* Stuff that error handlers might want to use */

/*
 * ErrorData holds the data accumulated during any one ereport() cycle.
 * Any non-NULL pointers must point to palloc'd data.
 * (The const pointers are an exception; we assume they point at non-freeable
 * constant strings.)
 */
typedef struct ErrorData
{
    int         elevel;         /* error level */
    bool        output_to_server;       /* will report to server log? */
    bool        output_to_client;       /* will report to client? */
    bool        show_funcname;  /* true to force funcname inclusion */
    bool        hide_stmt;      /* true to prevent STATEMENT: inclusion */
    const char *filename;       /* __FILE__ of ereport() call */
    int         lineno;         /* __LINE__ of ereport() call */
    const char *funcname;       /* __func__ of ereport() call */
    const char *domain;         /* message domain */
    const char *context_domain; /* message domain for context message */
    int         sqlerrcode;     /* encoded ERRSTATE */
    char       *message;        /* primary error message */
    char       *detail;         /* detail error message */
    char       *detail_log;     /* detail error message for server log only */
    char       *hint;           /* hint message */
    char       *context;        /* context message */
    char       *schema_name;    /* name of schema */
    char       *table_name;     /* name of table */
    char       *column_name;    /* name of column */
    char       *datatype_name;  /* name of datatype */
    char       *constraint_name;    /* name of constraint */
    int         cursorpos;      /* cursor index into query string */
    int         internalpos;    /* cursor index into internalquery */
    char       *internalquery;  /* text of internally-generated query */
    int         saved_errno;    /* errno at entry */
} ErrorData;

extern void EmitErrorReport(void);
extern ErrorData *CopyErrorData(void);
extern void FreeErrorData(ErrorData *edata);
extern void FlushErrorState(void);
extern void ReThrowError(ErrorData *edata) __attribute__((noreturn));
extern void pg_re_throw(void) __attribute__((noreturn));

/* Hook for intercepting messages before they are sent to the server log */
typedef void (*emit_log_hook_type) (ErrorData *edata);
extern PGDLLIMPORT emit_log_hook_type emit_log_hook;


/* GUC-configurable parameters */

typedef enum
{
    PGERROR_TERSE,              /* single-line error messages */
    PGERROR_DEFAULT,            /* recommended style */
    PGERROR_VERBOSE             /* all the facts, ma'am */
}   PGErrorVerbosity;

extern int  Log_error_verbosity;
extern char *Log_line_prefix;
extern int  Log_destination;

/* Log destination bitmap */
#define LOG_DESTINATION_STDERR   1
#define LOG_DESTINATION_SYSLOG   2
#define LOG_DESTINATION_EVENTLOG 4
#define LOG_DESTINATION_CSVLOG   8

/* Other exported functions */
extern void DebugFileOpen(void);
extern char *unpack_sql_state(int sql_state);
extern bool in_error_recursion_trouble(void);

#ifdef HAVE_SYSLOG
extern void set_syslog_parameters(const char *ident, int facility);
#endif

/*
 * Write errors to stderr (or by equal means when stderr is
 * not available). Used before ereport/elog can be used
 * safely (memory context, GUC load etc)
 */
extern void
write_stderr(const char *fmt,...)
/* This extension allows gcc to check the format string for consistency with
   the supplied arguments. */
__attribute__((format(PG_PRINTF_ATTRIBUTE, 1, 2)));

#endif   /* ELOG_H */