Files
postgresql/src/include/catalog/namespace.h
Tom Lane 83a5641945 Provide more-specific error details/hints for function lookup failures.
Up to now we've contented ourselves with a one-size-fits-all error
hint when we fail to find any match to a function or procedure call.
That was mostly okay in the beginning, but it was never great, and
since the introduction of named arguments it's really not adequate.
We at least ought to distinguish "function name doesn't exist" from
"function name exists, but not with those argument names".  And the
rules for named-argument matching are arcane enough that some more
detail seems warranted if we match the argument names but the call
still doesn't work.

This patch creates a framework for dealing with these problems:
FuncnameGetCandidates and related code will now pass back a bitmask of
flags showing how far the match succeeded.  This allows a considerable
amount of granularity in the reports.  The set-bits-in-a-bitmask
approach means that when there are multiple candidate functions, the
report will reflect the match(es) that got the furthest, which seems
correct.  Also, we can avoid mentioning "maybe add casts" unless
failure to match argument types is actually the issue.

Extend the same return-a-bitmask approach to OpernameGetCandidates.
The issues around argument names don't apply to operator syntax,
but it still seems worth distinguishing between "there is no
operator of that name" and "we couldn't match the argument types".

While at it, adjust these messages and related ones to more strictly
separate "detail" from "hint", following our message style guidelines'
distinction between those.

Reported-by: Dominique Devienne <ddevienne@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/1756041.1754616558@sss.pgh.pa.us
2025-09-16 12:17:02 -04:00

210 lines
8.3 KiB
C

/*-------------------------------------------------------------------------
*
* namespace.h
* prototypes for functions in backend/catalog/namespace.c
*
*
* Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/catalog/namespace.h
*
*-------------------------------------------------------------------------
*/
#ifndef NAMESPACE_H
#define NAMESPACE_H
#include "nodes/primnodes.h"
#include "storage/lock.h"
#include "storage/procnumber.h"
/*
* This structure holds a list of possible functions or operators
* found by namespace lookup. Each function/operator is identified
* by OID and by argument types; the list must be pruned by type
* resolution rules that are embodied in the parser, not here.
* See FuncnameGetCandidates's comments for more info.
*/
typedef struct _FuncCandidateList
{
struct _FuncCandidateList *next;
int pathpos; /* for internal use of namespace lookup */
Oid oid; /* the function or operator's OID */
int nominalnargs; /* either pronargs or length(proallargtypes) */
int nargs; /* number of arg types returned */
int nvargs; /* number of args to become variadic array */
int ndargs; /* number of defaulted args */
int *argnumbers; /* args' positional indexes, if named call */
Oid args[FLEXIBLE_ARRAY_MEMBER]; /* arg types */
} *FuncCandidateList;
/*
* FuncnameGetCandidates also returns a bitmask containing these flags,
* which report on what it found or didn't find. They can help callers
* produce better error reports after a function lookup failure.
*/
#define FGC_SCHEMA_GIVEN 0x0001 /* Func name includes a schema */
#define FGC_SCHEMA_EXISTS 0x0002 /* Found the explicitly-specified schema */
#define FGC_NAME_EXISTS 0x0004 /* Found a routine by that name */
#define FGC_NAME_VISIBLE 0x0008 /* Found a routine name/schema match */
#define FGC_ARGCOUNT_MATCH 0x0010 /* Found a func with right # of args */
/* These bits relate only to calls using named or mixed arguments: */
#define FGC_ARGNAMES_MATCH 0x0020 /* Found a func matching all argnames */
#define FGC_ARGNAMES_NONDUP 0x0040 /* argnames don't overlap positional args */
#define FGC_ARGNAMES_ALL 0x0080 /* Found a func with no missing args */
#define FGC_ARGNAMES_VALID 0x0100 /* Found a fully-valid use of argnames */
/* These bits are actually filled by func_get_detail: */
#define FGC_VARIADIC_FAIL 0x0200 /* Disallowed VARIADIC with named args */
/*
* Result of checkTempNamespaceStatus
*/
typedef enum TempNamespaceStatus
{
TEMP_NAMESPACE_NOT_TEMP, /* nonexistent, or non-temp namespace */
TEMP_NAMESPACE_IDLE, /* exists, belongs to no active session */
TEMP_NAMESPACE_IN_USE, /* belongs to some active session */
} TempNamespaceStatus;
/*
* Structure for xxxSearchPathMatcher functions
*
* The generation counter is private to namespace.c and shouldn't be touched
* by other code. It can be initialized to zero if necessary (that means
* "not known equal to the current active path").
*/
typedef struct SearchPathMatcher
{
List *schemas; /* OIDs of explicitly named schemas */
bool addCatalog; /* implicitly prepend pg_catalog? */
bool addTemp; /* implicitly prepend temp schema? */
uint64 generation; /* for quick detection of equality to active */
} SearchPathMatcher;
/*
* Option flag bits for RangeVarGetRelidExtended().
*/
typedef enum RVROption
{
RVR_MISSING_OK = 1 << 0, /* don't error if relation doesn't exist */
RVR_NOWAIT = 1 << 1, /* error if relation cannot be locked */
RVR_SKIP_LOCKED = 1 << 2, /* skip if relation cannot be locked */
} RVROption;
typedef void (*RangeVarGetRelidCallback) (const RangeVar *relation, Oid relId,
Oid oldRelId, void *callback_arg);
#define RangeVarGetRelid(relation, lockmode, missing_ok) \
RangeVarGetRelidExtended(relation, lockmode, \
(missing_ok) ? RVR_MISSING_OK : 0, NULL, NULL)
extern Oid RangeVarGetRelidExtended(const RangeVar *relation,
LOCKMODE lockmode, uint32 flags,
RangeVarGetRelidCallback callback,
void *callback_arg);
extern Oid RangeVarGetCreationNamespace(const RangeVar *newRelation);
extern Oid RangeVarGetAndCheckCreationNamespace(RangeVar *relation,
LOCKMODE lockmode,
Oid *existing_relation_id);
extern void RangeVarAdjustRelationPersistence(RangeVar *newRelation, Oid nspid);
extern Oid RelnameGetRelid(const char *relname);
extern bool RelationIsVisible(Oid relid);
extern Oid TypenameGetTypid(const char *typname);
extern Oid TypenameGetTypidExtended(const char *typname, bool temp_ok);
extern bool TypeIsVisible(Oid typid);
extern FuncCandidateList FuncnameGetCandidates(List *names,
int nargs, List *argnames,
bool expand_variadic,
bool expand_defaults,
bool include_out_arguments,
bool missing_ok,
int *fgc_flags);
extern bool FunctionIsVisible(Oid funcid);
extern Oid OpernameGetOprid(List *names, Oid oprleft, Oid oprright);
extern FuncCandidateList OpernameGetCandidates(List *names, char oprkind,
bool missing_schema_ok,
int *fgc_flags);
extern bool OperatorIsVisible(Oid oprid);
extern Oid OpclassnameGetOpcid(Oid amid, const char *opcname);
extern bool OpclassIsVisible(Oid opcid);
extern Oid OpfamilynameGetOpfid(Oid amid, const char *opfname);
extern bool OpfamilyIsVisible(Oid opfid);
extern Oid CollationGetCollid(const char *collname);
extern bool CollationIsVisible(Oid collid);
extern Oid ConversionGetConid(const char *conname);
extern bool ConversionIsVisible(Oid conid);
extern Oid get_statistics_object_oid(List *names, bool missing_ok);
extern bool StatisticsObjIsVisible(Oid stxid);
extern Oid get_ts_parser_oid(List *names, bool missing_ok);
extern bool TSParserIsVisible(Oid prsId);
extern Oid get_ts_dict_oid(List *names, bool missing_ok);
extern bool TSDictionaryIsVisible(Oid dictId);
extern Oid get_ts_template_oid(List *names, bool missing_ok);
extern bool TSTemplateIsVisible(Oid tmplId);
extern Oid get_ts_config_oid(List *names, bool missing_ok);
extern bool TSConfigIsVisible(Oid cfgid);
extern void DeconstructQualifiedName(const List *names,
char **nspname_p,
char **objname_p);
extern Oid LookupNamespaceNoError(const char *nspname);
extern Oid LookupExplicitNamespace(const char *nspname, bool missing_ok);
extern Oid get_namespace_oid(const char *nspname, bool missing_ok);
extern Oid LookupCreationNamespace(const char *nspname);
extern void CheckSetNamespace(Oid oldNspOid, Oid nspOid);
extern Oid QualifiedNameGetCreationNamespace(const List *names, char **objname_p);
extern RangeVar *makeRangeVarFromNameList(const List *names);
extern char *NameListToString(const List *names);
extern char *NameListToQuotedString(const List *names);
extern bool isTempNamespace(Oid namespaceId);
extern bool isTempToastNamespace(Oid namespaceId);
extern bool isTempOrTempToastNamespace(Oid namespaceId);
extern bool isAnyTempNamespace(Oid namespaceId);
extern bool isOtherTempNamespace(Oid namespaceId);
extern TempNamespaceStatus checkTempNamespaceStatus(Oid namespaceId);
extern ProcNumber GetTempNamespaceProcNumber(Oid namespaceId);
extern Oid GetTempToastNamespace(void);
extern void GetTempNamespaceState(Oid *tempNamespaceId,
Oid *tempToastNamespaceId);
extern void SetTempNamespaceState(Oid tempNamespaceId,
Oid tempToastNamespaceId);
extern void ResetTempTableNamespace(void);
extern SearchPathMatcher *GetSearchPathMatcher(MemoryContext context);
extern SearchPathMatcher *CopySearchPathMatcher(SearchPathMatcher *path);
extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
extern Oid FindDefaultConversionProc(int32 for_encoding, int32 to_encoding);
/* initialization & transaction cleanup code */
extern void InitializeSearchPath(void);
extern void AtEOXact_Namespace(bool isCommit, bool parallel);
extern void AtEOSubXact_Namespace(bool isCommit, SubTransactionId mySubid,
SubTransactionId parentSubid);
/* stuff for search_path GUC variable */
extern PGDLLIMPORT char *namespace_search_path;
extern List *fetch_search_path(bool includeImplicit);
extern int fetch_search_path_array(Oid *sarray, int sarray_len);
#endif /* NAMESPACE_H */