a9d5f30be3
actual argument type of ANYARRAY to match an argument declared ANYARRAY, so long as ANYELEMENT etc aren't used. I had overlooked the fact that this is a possible case while fixing bug #3852; but it is possible because pg_statistic contains columns declared ANYARRAY. Per gripe from Corey Horton.
2098 lines
64 KiB
C
2098 lines
64 KiB
C
/*-------------------------------------------------------------------------
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*
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* parse_coerce.c
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* handle type coercions/conversions for parser
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*
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* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.172 2008/12/14 19:45:52 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "catalog/pg_cast.h"
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#include "catalog/pg_proc.h"
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#include "catalog/pg_type.h"
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#include "nodes/makefuncs.h"
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#include "nodes/nodeFuncs.h"
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#include "parser/parse_coerce.h"
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#include "parser/parse_func.h"
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#include "parser/parse_relation.h"
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#include "parser/parse_type.h"
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#include "utils/builtins.h"
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#include "utils/fmgroids.h"
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#include "utils/lsyscache.h"
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#include "utils/syscache.h"
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#include "utils/typcache.h"
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static Node *coerce_type_typmod(Node *node,
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Oid targetTypeId, int32 targetTypMod,
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CoercionForm cformat, int location,
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bool isExplicit, bool hideInputCoercion);
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static void hide_coercion_node(Node *node);
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static Node *build_coercion_expression(Node *node,
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CoercionPathType pathtype,
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Oid funcId,
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Oid targetTypeId, int32 targetTypMod,
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CoercionForm cformat, int location,
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bool isExplicit);
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static Node *coerce_record_to_complex(ParseState *pstate, Node *node,
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Oid targetTypeId,
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CoercionContext ccontext,
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CoercionForm cformat,
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int location);
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static bool is_complex_array(Oid typid);
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/*
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* coerce_to_target_type()
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* Convert an expression to a target type and typmod.
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*
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* This is the general-purpose entry point for arbitrary type coercion
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* operations. Direct use of the component operations can_coerce_type,
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* coerce_type, and coerce_type_typmod should be restricted to special
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* cases (eg, when the conversion is expected to succeed).
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*
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* Returns the possibly-transformed expression tree, or NULL if the type
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* conversion is not possible. (We do this, rather than ereport'ing directly,
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* so that callers can generate custom error messages indicating context.)
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*
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* pstate - parse state (can be NULL, see coerce_type)
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* expr - input expression tree (already transformed by transformExpr)
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* exprtype - result type of expr
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* targettype - desired result type
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* targettypmod - desired result typmod
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* ccontext, cformat - context indicators to control coercions
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* location - parse location of the coercion request, or -1 if unknown/implicit
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*/
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Node *
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coerce_to_target_type(ParseState *pstate, Node *expr, Oid exprtype,
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Oid targettype, int32 targettypmod,
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CoercionContext ccontext,
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CoercionForm cformat,
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int location)
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{
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Node *result;
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if (!can_coerce_type(1, &exprtype, &targettype, ccontext))
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return NULL;
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result = coerce_type(pstate, expr, exprtype,
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targettype, targettypmod,
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ccontext, cformat, location);
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/*
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* If the target is a fixed-length type, it may need a length coercion as
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* well as a type coercion. If we find ourselves adding both, force the
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* inner coercion node to implicit display form.
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*/
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result = coerce_type_typmod(result,
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targettype, targettypmod,
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cformat, location,
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(cformat != COERCE_IMPLICIT_CAST),
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(result != expr && !IsA(result, Const)));
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return result;
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}
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/*
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* coerce_type()
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* Convert an expression to a different type.
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*
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* The caller should already have determined that the coercion is possible;
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* see can_coerce_type.
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*
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* Normally, no coercion to a typmod (length) is performed here. The caller
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* must call coerce_type_typmod as well, if a typmod constraint is wanted.
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* (But if the target type is a domain, it may internally contain a
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* typmod constraint, which will be applied inside coerce_to_domain.)
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* In some cases pg_cast specifies a type coercion function that also
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* applies length conversion, and in those cases only, the result will
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* already be properly coerced to the specified typmod.
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*
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* pstate is only used in the case that we are able to resolve the type of
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* a previously UNKNOWN Param. It is okay to pass pstate = NULL if the
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* caller does not want type information updated for Params.
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*/
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Node *
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coerce_type(ParseState *pstate, Node *node,
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Oid inputTypeId, Oid targetTypeId, int32 targetTypeMod,
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CoercionContext ccontext, CoercionForm cformat, int location)
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{
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Node *result;
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CoercionPathType pathtype;
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Oid funcId;
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if (targetTypeId == inputTypeId ||
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node == NULL)
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{
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/* no conversion needed */
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return node;
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}
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if (targetTypeId == ANYOID ||
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targetTypeId == ANYELEMENTOID ||
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targetTypeId == ANYNONARRAYOID ||
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(targetTypeId == ANYARRAYOID && inputTypeId != UNKNOWNOID) ||
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(targetTypeId == ANYENUMOID && inputTypeId != UNKNOWNOID))
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{
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/*
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* Assume can_coerce_type verified that implicit coercion is okay.
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*
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* Note: by returning the unmodified node here, we are saying that
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* it's OK to treat an UNKNOWN constant as a valid input for a
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* function accepting ANY, ANYELEMENT, or ANYNONARRAY. This should be
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* all right, since an UNKNOWN value is still a perfectly valid Datum.
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* However an UNKNOWN value is definitely *not* an array, and so we
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* mustn't accept it for ANYARRAY. (Instead, we will call anyarray_in
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* below, which will produce an error.) Likewise, UNKNOWN input is no
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* good for ANYENUM.
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*
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* NB: we do NOT want a RelabelType here.
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*/
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return node;
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}
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if (inputTypeId == UNKNOWNOID && IsA(node, Const))
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{
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/*
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* Input is a string constant with previously undetermined type. Apply
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* the target type's typinput function to it to produce a constant of
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* the target type.
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*
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* NOTE: this case cannot be folded together with the other
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* constant-input case, since the typinput function does not
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* necessarily behave the same as a type conversion function. For
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* example, int4's typinput function will reject "1.2", whereas
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* float-to-int type conversion will round to integer.
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*
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* XXX if the typinput function is not immutable, we really ought to
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* postpone evaluation of the function call until runtime. But there
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* is no way to represent a typinput function call as an expression
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* tree, because C-string values are not Datums. (XXX This *is*
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* possible as of 7.3, do we want to do it?)
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*/
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Const *con = (Const *) node;
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Const *newcon = makeNode(Const);
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Oid baseTypeId;
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int32 baseTypeMod;
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int32 inputTypeMod;
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Type targetType;
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ParseCallbackState pcbstate;
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/*
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* If the target type is a domain, we want to call its base type's
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* input routine, not domain_in(). This is to avoid premature failure
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* when the domain applies a typmod: existing input routines follow
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* implicit-coercion semantics for length checks, which is not always
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* what we want here. The needed check will be applied properly
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* inside coerce_to_domain().
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*/
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baseTypeMod = targetTypeMod;
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baseTypeId = getBaseTypeAndTypmod(targetTypeId, &baseTypeMod);
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/*
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* For most types we pass typmod -1 to the input routine, because
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* existing input routines follow implicit-coercion semantics for
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* length checks, which is not always what we want here. Any length
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* constraint will be applied later by our caller. An exception
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* however is the INTERVAL type, for which we *must* pass the typmod
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* or it won't be able to obey the bizarre SQL-spec input rules.
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* (Ugly as sin, but so is this part of the spec...)
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*/
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if (baseTypeId == INTERVALOID)
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inputTypeMod = baseTypeMod;
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else
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inputTypeMod = -1;
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targetType = typeidType(baseTypeId);
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newcon->consttype = baseTypeId;
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newcon->consttypmod = inputTypeMod;
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newcon->constlen = typeLen(targetType);
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newcon->constbyval = typeByVal(targetType);
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newcon->constisnull = con->constisnull;
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/* Use the leftmost of the constant's and coercion's locations */
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if (location < 0)
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newcon->location = con->location;
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else if (con->location >= 0 && con->location < location)
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newcon->location = con->location;
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else
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newcon->location = location;
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/*
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* Set up to point at the constant's text if the input routine
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* throws an error.
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*/
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setup_parser_errposition_callback(&pcbstate, pstate, con->location);
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/*
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* We assume here that UNKNOWN's internal representation is the same
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* as CSTRING.
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*/
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if (!con->constisnull)
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newcon->constvalue = stringTypeDatum(targetType,
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DatumGetCString(con->constvalue),
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inputTypeMod);
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else
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newcon->constvalue = stringTypeDatum(targetType,
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NULL,
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inputTypeMod);
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cancel_parser_errposition_callback(&pcbstate);
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result = (Node *) newcon;
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/* If target is a domain, apply constraints. */
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if (baseTypeId != targetTypeId)
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result = coerce_to_domain(result,
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baseTypeId, baseTypeMod,
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targetTypeId,
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cformat, location, false, false);
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ReleaseSysCache(targetType);
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return result;
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}
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if (inputTypeId == UNKNOWNOID && IsA(node, Param) &&
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((Param *) node)->paramkind == PARAM_EXTERN &&
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pstate != NULL && pstate->p_variableparams)
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{
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/*
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* Input is a Param of previously undetermined type, and we want to
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* update our knowledge of the Param's type. Find the topmost
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* ParseState and update the state.
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*/
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Param *param = (Param *) node;
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int paramno = param->paramid;
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ParseState *toppstate;
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toppstate = pstate;
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while (toppstate->parentParseState != NULL)
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toppstate = toppstate->parentParseState;
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if (paramno <= 0 || /* shouldn't happen, but... */
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paramno > toppstate->p_numparams)
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ereport(ERROR,
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(errcode(ERRCODE_UNDEFINED_PARAMETER),
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errmsg("there is no parameter $%d", paramno),
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parser_errposition(pstate, param->location)));
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if (toppstate->p_paramtypes[paramno - 1] == UNKNOWNOID)
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{
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/* We've successfully resolved the type */
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toppstate->p_paramtypes[paramno - 1] = targetTypeId;
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}
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else if (toppstate->p_paramtypes[paramno - 1] == targetTypeId)
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{
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/* We previously resolved the type, and it matches */
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}
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else
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{
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/* Ooops */
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ereport(ERROR,
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(errcode(ERRCODE_AMBIGUOUS_PARAMETER),
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errmsg("inconsistent types deduced for parameter $%d",
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paramno),
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errdetail("%s versus %s",
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format_type_be(toppstate->p_paramtypes[paramno - 1]),
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format_type_be(targetTypeId)),
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parser_errposition(pstate, param->location)));
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}
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param->paramtype = targetTypeId;
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|
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/*
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* Note: it is tempting here to set the Param's paramtypmod to
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* targetTypeMod, but that is probably unwise because we have no
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* infrastructure that enforces that the value delivered for a Param
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* will match any particular typmod. Leaving it -1 ensures that a
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* run-time length check/coercion will occur if needed.
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*/
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param->paramtypmod = -1;
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|
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/* Use the leftmost of the param's and coercion's locations */
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if (location >= 0 &&
|
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(param->location < 0 || location < param->location))
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param->location = location;
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return (Node *) param;
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}
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pathtype = find_coercion_pathway(targetTypeId, inputTypeId, ccontext,
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&funcId);
|
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if (pathtype != COERCION_PATH_NONE)
|
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{
|
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if (pathtype != COERCION_PATH_RELABELTYPE)
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{
|
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/*
|
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* Generate an expression tree representing run-time application
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* of the conversion function. If we are dealing with a domain
|
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* target type, the conversion function will yield the base type,
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* and we need to extract the correct typmod to use from the
|
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* domain's typtypmod.
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*/
|
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Oid baseTypeId;
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int32 baseTypeMod;
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baseTypeMod = targetTypeMod;
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baseTypeId = getBaseTypeAndTypmod(targetTypeId, &baseTypeMod);
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result = build_coercion_expression(node, pathtype, funcId,
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baseTypeId, baseTypeMod,
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cformat, location,
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(cformat != COERCE_IMPLICIT_CAST));
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|
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/*
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* If domain, coerce to the domain type and relabel with domain
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* type ID. We can skip the internal length-coercion step if the
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* selected coercion function was a type-and-length coercion.
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*/
|
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if (targetTypeId != baseTypeId)
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result = coerce_to_domain(result, baseTypeId, baseTypeMod,
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targetTypeId,
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cformat, location, true,
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exprIsLengthCoercion(result,
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NULL));
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}
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else
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{
|
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/*
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* We don't need to do a physical conversion, but we do need to
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* attach a RelabelType node so that the expression will be seen
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* to have the intended type when inspected by higher-level code.
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*
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* Also, domains may have value restrictions beyond the base type
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* that must be accounted for. If the destination is a domain
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* then we won't need a RelabelType node.
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*/
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result = coerce_to_domain(node, InvalidOid, -1, targetTypeId,
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cformat, location, false, false);
|
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if (result == node)
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{
|
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/*
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* XXX could we label result with exprTypmod(node) instead of
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* default -1 typmod, to save a possible length-coercion
|
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* later? Would work if both types have same interpretation of
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* typmod, which is likely but not certain.
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*/
|
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RelabelType *r = makeRelabelType((Expr *) result,
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targetTypeId, -1,
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cformat);
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r->location = location;
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result = (Node *) r;
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}
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}
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return result;
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}
|
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if (inputTypeId == RECORDOID &&
|
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ISCOMPLEX(targetTypeId))
|
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{
|
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/* Coerce a RECORD to a specific complex type */
|
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return coerce_record_to_complex(pstate, node, targetTypeId,
|
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ccontext, cformat, location);
|
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}
|
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if (targetTypeId == RECORDOID &&
|
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ISCOMPLEX(inputTypeId))
|
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{
|
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/* Coerce a specific complex type to RECORD */
|
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/* NB: we do NOT want a RelabelType here */
|
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return node;
|
|
}
|
|
#ifdef NOT_USED
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if (inputTypeId == RECORDARRAYOID &&
|
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is_complex_array(targetTypeId))
|
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{
|
|
/* Coerce record[] to a specific complex array type */
|
|
/* not implemented yet ... */
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|
}
|
|
#endif
|
|
if (targetTypeId == RECORDARRAYOID &&
|
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is_complex_array(inputTypeId))
|
|
{
|
|
/* Coerce a specific complex array type to record[] */
|
|
/* NB: we do NOT want a RelabelType here */
|
|
return node;
|
|
}
|
|
if (typeInheritsFrom(inputTypeId, targetTypeId))
|
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{
|
|
/*
|
|
* Input class type is a subclass of target, so generate an
|
|
* appropriate runtime conversion (removing unneeded columns and
|
|
* possibly rearranging the ones that are wanted).
|
|
*/
|
|
ConvertRowtypeExpr *r = makeNode(ConvertRowtypeExpr);
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|
|
|
r->arg = (Expr *) node;
|
|
r->resulttype = targetTypeId;
|
|
r->convertformat = cformat;
|
|
r->location = location;
|
|
return (Node *) r;
|
|
}
|
|
/* If we get here, caller blew it */
|
|
elog(ERROR, "failed to find conversion function from %s to %s",
|
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format_type_be(inputTypeId), format_type_be(targetTypeId));
|
|
return NULL; /* keep compiler quiet */
|
|
}
|
|
|
|
|
|
/*
|
|
* can_coerce_type()
|
|
* Can input_typeids be coerced to target_typeids?
|
|
*
|
|
* We must be told the context (CAST construct, assignment, implicit coercion)
|
|
* as this determines the set of available casts.
|
|
*/
|
|
bool
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|
can_coerce_type(int nargs, Oid *input_typeids, Oid *target_typeids,
|
|
CoercionContext ccontext)
|
|
{
|
|
bool have_generics = false;
|
|
int i;
|
|
|
|
/* run through argument list... */
|
|
for (i = 0; i < nargs; i++)
|
|
{
|
|
Oid inputTypeId = input_typeids[i];
|
|
Oid targetTypeId = target_typeids[i];
|
|
CoercionPathType pathtype;
|
|
Oid funcId;
|
|
|
|
/* no problem if same type */
|
|
if (inputTypeId == targetTypeId)
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|
continue;
|
|
|
|
/* accept if target is ANY */
|
|
if (targetTypeId == ANYOID)
|
|
continue;
|
|
|
|
/* accept if target is polymorphic, for now */
|
|
if (IsPolymorphicType(targetTypeId))
|
|
{
|
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have_generics = true; /* do more checking later */
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|
continue;
|
|
}
|
|
|
|
/*
|
|
* If input is an untyped string constant, assume we can convert it to
|
|
* anything.
|
|
*/
|
|
if (inputTypeId == UNKNOWNOID)
|
|
continue;
|
|
|
|
/*
|
|
* If pg_cast shows that we can coerce, accept. This test now covers
|
|
* both binary-compatible and coercion-function cases.
|
|
*/
|
|
pathtype = find_coercion_pathway(targetTypeId, inputTypeId, ccontext,
|
|
&funcId);
|
|
if (pathtype != COERCION_PATH_NONE)
|
|
continue;
|
|
|
|
/*
|
|
* If input is RECORD and target is a composite type, assume we can
|
|
* coerce (may need tighter checking here)
|
|
*/
|
|
if (inputTypeId == RECORDOID &&
|
|
ISCOMPLEX(targetTypeId))
|
|
continue;
|
|
|
|
/*
|
|
* If input is a composite type and target is RECORD, accept
|
|
*/
|
|
if (targetTypeId == RECORDOID &&
|
|
ISCOMPLEX(inputTypeId))
|
|
continue;
|
|
|
|
#ifdef NOT_USED /* not implemented yet */
|
|
/*
|
|
* If input is record[] and target is a composite array type,
|
|
* assume we can coerce (may need tighter checking here)
|
|
*/
|
|
if (inputTypeId == RECORDARRAYOID &&
|
|
is_complex_array(targetTypeId))
|
|
continue;
|
|
#endif
|
|
|
|
/*
|
|
* If input is a composite array type and target is record[], accept
|
|
*/
|
|
if (targetTypeId == RECORDARRAYOID &&
|
|
is_complex_array(inputTypeId))
|
|
continue;
|
|
|
|
/*
|
|
* If input is a class type that inherits from target, accept
|
|
*/
|
|
if (typeInheritsFrom(inputTypeId, targetTypeId))
|
|
continue;
|
|
|
|
/*
|
|
* Else, cannot coerce at this argument position
|
|
*/
|
|
return false;
|
|
}
|
|
|
|
/* If we found any generic argument types, cross-check them */
|
|
if (have_generics)
|
|
{
|
|
if (!check_generic_type_consistency(input_typeids, target_typeids,
|
|
nargs))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
/*
|
|
* Create an expression tree to represent coercion to a domain type.
|
|
*
|
|
* 'arg': input expression
|
|
* 'baseTypeId': base type of domain, if known (pass InvalidOid if caller
|
|
* has not bothered to look this up)
|
|
* 'baseTypeMod': base type typmod of domain, if known (pass -1 if caller
|
|
* has not bothered to look this up)
|
|
* 'typeId': target type to coerce to
|
|
* 'cformat': coercion format
|
|
* 'location': coercion request location
|
|
* 'hideInputCoercion': if true, hide the input coercion under this one.
|
|
* 'lengthCoercionDone': if true, caller already accounted for length,
|
|
* ie the input is already of baseTypMod as well as baseTypeId.
|
|
*
|
|
* If the target type isn't a domain, the given 'arg' is returned as-is.
|
|
*/
|
|
Node *
|
|
coerce_to_domain(Node *arg, Oid baseTypeId, int32 baseTypeMod, Oid typeId,
|
|
CoercionForm cformat, int location,
|
|
bool hideInputCoercion,
|
|
bool lengthCoercionDone)
|
|
{
|
|
CoerceToDomain *result;
|
|
|
|
/* Get the base type if it hasn't been supplied */
|
|
if (baseTypeId == InvalidOid)
|
|
baseTypeId = getBaseTypeAndTypmod(typeId, &baseTypeMod);
|
|
|
|
/* If it isn't a domain, return the node as it was passed in */
|
|
if (baseTypeId == typeId)
|
|
return arg;
|
|
|
|
/* Suppress display of nested coercion steps */
|
|
if (hideInputCoercion)
|
|
hide_coercion_node(arg);
|
|
|
|
/*
|
|
* If the domain applies a typmod to its base type, build the appropriate
|
|
* coercion step. Mark it implicit for display purposes, because we don't
|
|
* want it shown separately by ruleutils.c; but the isExplicit flag passed
|
|
* to the conversion function depends on the manner in which the domain
|
|
* coercion is invoked, so that the semantics of implicit and explicit
|
|
* coercion differ. (Is that really the behavior we want?)
|
|
*
|
|
* NOTE: because we apply this as part of the fixed expression structure,
|
|
* ALTER DOMAIN cannot alter the typtypmod. But it's unclear that that
|
|
* would be safe to do anyway, without lots of knowledge about what the
|
|
* base type thinks the typmod means.
|
|
*/
|
|
if (!lengthCoercionDone)
|
|
{
|
|
if (baseTypeMod >= 0)
|
|
arg = coerce_type_typmod(arg, baseTypeId, baseTypeMod,
|
|
COERCE_IMPLICIT_CAST, location,
|
|
(cformat != COERCE_IMPLICIT_CAST),
|
|
false);
|
|
}
|
|
|
|
/*
|
|
* Now build the domain coercion node. This represents run-time checking
|
|
* of any constraints currently attached to the domain. This also ensures
|
|
* that the expression is properly labeled as to result type.
|
|
*/
|
|
result = makeNode(CoerceToDomain);
|
|
result->arg = (Expr *) arg;
|
|
result->resulttype = typeId;
|
|
result->resulttypmod = -1; /* currently, always -1 for domains */
|
|
result->coercionformat = cformat;
|
|
result->location = location;
|
|
|
|
return (Node *) result;
|
|
}
|
|
|
|
|
|
/*
|
|
* coerce_type_typmod()
|
|
* Force a value to a particular typmod, if meaningful and possible.
|
|
*
|
|
* This is applied to values that are going to be stored in a relation
|
|
* (where we have an atttypmod for the column) as well as values being
|
|
* explicitly CASTed (where the typmod comes from the target type spec).
|
|
*
|
|
* The caller must have already ensured that the value is of the correct
|
|
* type, typically by applying coerce_type.
|
|
*
|
|
* cformat determines the display properties of the generated node (if any),
|
|
* while isExplicit may affect semantics. If hideInputCoercion is true
|
|
* *and* we generate a node, the input node is forced to IMPLICIT display
|
|
* form, so that only the typmod coercion node will be visible when
|
|
* displaying the expression.
|
|
*
|
|
* NOTE: this does not need to work on domain types, because any typmod
|
|
* coercion for a domain is considered to be part of the type coercion
|
|
* needed to produce the domain value in the first place. So, no getBaseType.
|
|
*/
|
|
static Node *
|
|
coerce_type_typmod(Node *node, Oid targetTypeId, int32 targetTypMod,
|
|
CoercionForm cformat, int location,
|
|
bool isExplicit, bool hideInputCoercion)
|
|
{
|
|
CoercionPathType pathtype;
|
|
Oid funcId;
|
|
|
|
/*
|
|
* A negative typmod is assumed to mean that no coercion is wanted. Also,
|
|
* skip coercion if already done.
|
|
*/
|
|
if (targetTypMod < 0 || targetTypMod == exprTypmod(node))
|
|
return node;
|
|
|
|
pathtype = find_typmod_coercion_function(targetTypeId, &funcId);
|
|
|
|
if (pathtype != COERCION_PATH_NONE)
|
|
{
|
|
/* Suppress display of nested coercion steps */
|
|
if (hideInputCoercion)
|
|
hide_coercion_node(node);
|
|
|
|
node = build_coercion_expression(node, pathtype, funcId,
|
|
targetTypeId, targetTypMod,
|
|
cformat, location,
|
|
isExplicit);
|
|
}
|
|
|
|
return node;
|
|
}
|
|
|
|
/*
|
|
* Mark a coercion node as IMPLICIT so it will never be displayed by
|
|
* ruleutils.c. We use this when we generate a nest of coercion nodes
|
|
* to implement what is logically one conversion; the inner nodes are
|
|
* forced to IMPLICIT_CAST format. This does not change their semantics,
|
|
* only display behavior.
|
|
*
|
|
* It is caller error to call this on something that doesn't have a
|
|
* CoercionForm field.
|
|
*/
|
|
static void
|
|
hide_coercion_node(Node *node)
|
|
{
|
|
if (IsA(node, FuncExpr))
|
|
((FuncExpr *) node)->funcformat = COERCE_IMPLICIT_CAST;
|
|
else if (IsA(node, RelabelType))
|
|
((RelabelType *) node)->relabelformat = COERCE_IMPLICIT_CAST;
|
|
else if (IsA(node, CoerceViaIO))
|
|
((CoerceViaIO *) node)->coerceformat = COERCE_IMPLICIT_CAST;
|
|
else if (IsA(node, ArrayCoerceExpr))
|
|
((ArrayCoerceExpr *) node)->coerceformat = COERCE_IMPLICIT_CAST;
|
|
else if (IsA(node, ConvertRowtypeExpr))
|
|
((ConvertRowtypeExpr *) node)->convertformat = COERCE_IMPLICIT_CAST;
|
|
else if (IsA(node, RowExpr))
|
|
((RowExpr *) node)->row_format = COERCE_IMPLICIT_CAST;
|
|
else if (IsA(node, CoerceToDomain))
|
|
((CoerceToDomain *) node)->coercionformat = COERCE_IMPLICIT_CAST;
|
|
else
|
|
elog(ERROR, "unsupported node type: %d", (int) nodeTag(node));
|
|
}
|
|
|
|
/*
|
|
* build_coercion_expression()
|
|
* Construct an expression tree for applying a pg_cast entry.
|
|
*
|
|
* This is used for both type-coercion and length-coercion operations,
|
|
* since there is no difference in terms of the calling convention.
|
|
*/
|
|
static Node *
|
|
build_coercion_expression(Node *node,
|
|
CoercionPathType pathtype,
|
|
Oid funcId,
|
|
Oid targetTypeId, int32 targetTypMod,
|
|
CoercionForm cformat, int location,
|
|
bool isExplicit)
|
|
{
|
|
int nargs = 0;
|
|
|
|
if (OidIsValid(funcId))
|
|
{
|
|
HeapTuple tp;
|
|
Form_pg_proc procstruct;
|
|
|
|
tp = SearchSysCache(PROCOID,
|
|
ObjectIdGetDatum(funcId),
|
|
0, 0, 0);
|
|
if (!HeapTupleIsValid(tp))
|
|
elog(ERROR, "cache lookup failed for function %u", funcId);
|
|
procstruct = (Form_pg_proc) GETSTRUCT(tp);
|
|
|
|
/*
|
|
* These Asserts essentially check that function is a legal coercion
|
|
* function. We can't make the seemingly obvious tests on prorettype
|
|
* and proargtypes[0], even in the COERCION_PATH_FUNC case, because of
|
|
* various binary-compatibility cases.
|
|
*/
|
|
/* Assert(targetTypeId == procstruct->prorettype); */
|
|
Assert(!procstruct->proretset);
|
|
Assert(!procstruct->proisagg);
|
|
nargs = procstruct->pronargs;
|
|
Assert(nargs >= 1 && nargs <= 3);
|
|
/* Assert(procstruct->proargtypes.values[0] == exprType(node)); */
|
|
Assert(nargs < 2 || procstruct->proargtypes.values[1] == INT4OID);
|
|
Assert(nargs < 3 || procstruct->proargtypes.values[2] == BOOLOID);
|
|
|
|
ReleaseSysCache(tp);
|
|
}
|
|
|
|
if (pathtype == COERCION_PATH_FUNC)
|
|
{
|
|
/* We build an ordinary FuncExpr with special arguments */
|
|
FuncExpr *fexpr;
|
|
List *args;
|
|
Const *cons;
|
|
|
|
Assert(OidIsValid(funcId));
|
|
|
|
args = list_make1(node);
|
|
|
|
if (nargs >= 2)
|
|
{
|
|
/* Pass target typmod as an int4 constant */
|
|
cons = makeConst(INT4OID,
|
|
-1,
|
|
sizeof(int32),
|
|
Int32GetDatum(targetTypMod),
|
|
false,
|
|
true);
|
|
|
|
args = lappend(args, cons);
|
|
}
|
|
|
|
if (nargs == 3)
|
|
{
|
|
/* Pass it a boolean isExplicit parameter, too */
|
|
cons = makeConst(BOOLOID,
|
|
-1,
|
|
sizeof(bool),
|
|
BoolGetDatum(isExplicit),
|
|
false,
|
|
true);
|
|
|
|
args = lappend(args, cons);
|
|
}
|
|
|
|
fexpr = makeFuncExpr(funcId, targetTypeId, args, cformat);
|
|
fexpr->location = location;
|
|
return (Node *) fexpr;
|
|
}
|
|
else if (pathtype == COERCION_PATH_ARRAYCOERCE)
|
|
{
|
|
/* We need to build an ArrayCoerceExpr */
|
|
ArrayCoerceExpr *acoerce = makeNode(ArrayCoerceExpr);
|
|
|
|
acoerce->arg = (Expr *) node;
|
|
acoerce->elemfuncid = funcId;
|
|
acoerce->resulttype = targetTypeId;
|
|
|
|
/*
|
|
* Label the output as having a particular typmod only if we are
|
|
* really invoking a length-coercion function, ie one with more than
|
|
* one argument.
|
|
*/
|
|
acoerce->resulttypmod = (nargs >= 2) ? targetTypMod : -1;
|
|
acoerce->isExplicit = isExplicit;
|
|
acoerce->coerceformat = cformat;
|
|
acoerce->location = location;
|
|
|
|
return (Node *) acoerce;
|
|
}
|
|
else if (pathtype == COERCION_PATH_COERCEVIAIO)
|
|
{
|
|
/* We need to build a CoerceViaIO node */
|
|
CoerceViaIO *iocoerce = makeNode(CoerceViaIO);
|
|
|
|
Assert(!OidIsValid(funcId));
|
|
|
|
iocoerce->arg = (Expr *) node;
|
|
iocoerce->resulttype = targetTypeId;
|
|
iocoerce->coerceformat = cformat;
|
|
iocoerce->location = location;
|
|
|
|
return (Node *) iocoerce;
|
|
}
|
|
else
|
|
{
|
|
elog(ERROR, "unsupported pathtype %d in build_coercion_expression",
|
|
(int) pathtype);
|
|
return NULL; /* keep compiler quiet */
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* coerce_record_to_complex
|
|
* Coerce a RECORD to a specific composite type.
|
|
*
|
|
* Currently we only support this for inputs that are RowExprs or whole-row
|
|
* Vars.
|
|
*/
|
|
static Node *
|
|
coerce_record_to_complex(ParseState *pstate, Node *node,
|
|
Oid targetTypeId,
|
|
CoercionContext ccontext,
|
|
CoercionForm cformat,
|
|
int location)
|
|
{
|
|
RowExpr *rowexpr;
|
|
TupleDesc tupdesc;
|
|
List *args = NIL;
|
|
List *newargs;
|
|
int i;
|
|
int ucolno;
|
|
ListCell *arg;
|
|
|
|
if (node && IsA(node, RowExpr))
|
|
{
|
|
/*
|
|
* Since the RowExpr must be of type RECORD, we needn't worry about it
|
|
* containing any dropped columns.
|
|
*/
|
|
args = ((RowExpr *) node)->args;
|
|
}
|
|
else if (node && IsA(node, Var) &&
|
|
((Var *) node)->varattno == InvalidAttrNumber)
|
|
{
|
|
int rtindex = ((Var *) node)->varno;
|
|
int sublevels_up = ((Var *) node)->varlevelsup;
|
|
int vlocation = ((Var *) node)->location;
|
|
RangeTblEntry *rte;
|
|
|
|
rte = GetRTEByRangeTablePosn(pstate, rtindex, sublevels_up);
|
|
expandRTE(rte, rtindex, sublevels_up, vlocation, false,
|
|
NULL, &args);
|
|
}
|
|
else
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_CANNOT_COERCE),
|
|
errmsg("cannot cast type %s to %s",
|
|
format_type_be(RECORDOID),
|
|
format_type_be(targetTypeId)),
|
|
parser_coercion_errposition(pstate, location, node)));
|
|
|
|
tupdesc = lookup_rowtype_tupdesc(targetTypeId, -1);
|
|
newargs = NIL;
|
|
ucolno = 1;
|
|
arg = list_head(args);
|
|
for (i = 0; i < tupdesc->natts; i++)
|
|
{
|
|
Node *expr;
|
|
Node *cexpr;
|
|
Oid exprtype;
|
|
|
|
/* Fill in NULLs for dropped columns in rowtype */
|
|
if (tupdesc->attrs[i]->attisdropped)
|
|
{
|
|
/*
|
|
* can't use atttypid here, but it doesn't really matter what type
|
|
* the Const claims to be.
|
|
*/
|
|
newargs = lappend(newargs, makeNullConst(INT4OID, -1));
|
|
continue;
|
|
}
|
|
|
|
if (arg == NULL)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_CANNOT_COERCE),
|
|
errmsg("cannot cast type %s to %s",
|
|
format_type_be(RECORDOID),
|
|
format_type_be(targetTypeId)),
|
|
errdetail("Input has too few columns."),
|
|
parser_coercion_errposition(pstate, location, node)));
|
|
expr = (Node *) lfirst(arg);
|
|
exprtype = exprType(expr);
|
|
|
|
cexpr = coerce_to_target_type(pstate,
|
|
expr, exprtype,
|
|
tupdesc->attrs[i]->atttypid,
|
|
tupdesc->attrs[i]->atttypmod,
|
|
ccontext,
|
|
COERCE_IMPLICIT_CAST,
|
|
-1);
|
|
if (cexpr == NULL)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_CANNOT_COERCE),
|
|
errmsg("cannot cast type %s to %s",
|
|
format_type_be(RECORDOID),
|
|
format_type_be(targetTypeId)),
|
|
errdetail("Cannot cast type %s to %s in column %d.",
|
|
format_type_be(exprtype),
|
|
format_type_be(tupdesc->attrs[i]->atttypid),
|
|
ucolno),
|
|
parser_coercion_errposition(pstate, location, expr)));
|
|
newargs = lappend(newargs, cexpr);
|
|
ucolno++;
|
|
arg = lnext(arg);
|
|
}
|
|
if (arg != NULL)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_CANNOT_COERCE),
|
|
errmsg("cannot cast type %s to %s",
|
|
format_type_be(RECORDOID),
|
|
format_type_be(targetTypeId)),
|
|
errdetail("Input has too many columns."),
|
|
parser_coercion_errposition(pstate, location, node)));
|
|
|
|
ReleaseTupleDesc(tupdesc);
|
|
|
|
rowexpr = makeNode(RowExpr);
|
|
rowexpr->args = newargs;
|
|
rowexpr->row_typeid = targetTypeId;
|
|
rowexpr->row_format = cformat;
|
|
rowexpr->colnames = NIL; /* not needed for named target type */
|
|
rowexpr->location = location;
|
|
return (Node *) rowexpr;
|
|
}
|
|
|
|
/*
|
|
* coerce_to_boolean()
|
|
* Coerce an argument of a construct that requires boolean input
|
|
* (AND, OR, NOT, etc). Also check that input is not a set.
|
|
*
|
|
* Returns the possibly-transformed node tree.
|
|
*
|
|
* As with coerce_type, pstate may be NULL if no special unknown-Param
|
|
* processing is wanted.
|
|
*/
|
|
Node *
|
|
coerce_to_boolean(ParseState *pstate, Node *node,
|
|
const char *constructName)
|
|
{
|
|
Oid inputTypeId = exprType(node);
|
|
|
|
if (inputTypeId != BOOLOID)
|
|
{
|
|
Node *newnode;
|
|
|
|
newnode = coerce_to_target_type(pstate, node, inputTypeId,
|
|
BOOLOID, -1,
|
|
COERCION_ASSIGNMENT,
|
|
COERCE_IMPLICIT_CAST,
|
|
-1);
|
|
if (newnode == NULL)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
/* translator: first %s is name of a SQL construct, eg WHERE */
|
|
errmsg("argument of %s must be type boolean, not type %s",
|
|
constructName, format_type_be(inputTypeId)),
|
|
parser_errposition(pstate, exprLocation(node))));
|
|
node = newnode;
|
|
}
|
|
|
|
if (expression_returns_set(node))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
/* translator: %s is name of a SQL construct, eg WHERE */
|
|
errmsg("argument of %s must not return a set",
|
|
constructName),
|
|
parser_errposition(pstate, exprLocation(node))));
|
|
|
|
return node;
|
|
}
|
|
|
|
/*
|
|
* coerce_to_specific_type()
|
|
* Coerce an argument of a construct that requires a specific data type.
|
|
* Also check that input is not a set.
|
|
*
|
|
* Returns the possibly-transformed node tree.
|
|
*
|
|
* As with coerce_type, pstate may be NULL if no special unknown-Param
|
|
* processing is wanted.
|
|
*/
|
|
Node *
|
|
coerce_to_specific_type(ParseState *pstate, Node *node,
|
|
Oid targetTypeId,
|
|
const char *constructName)
|
|
{
|
|
Oid inputTypeId = exprType(node);
|
|
|
|
if (inputTypeId != targetTypeId)
|
|
{
|
|
Node *newnode;
|
|
|
|
newnode = coerce_to_target_type(pstate, node, inputTypeId,
|
|
targetTypeId, -1,
|
|
COERCION_ASSIGNMENT,
|
|
COERCE_IMPLICIT_CAST,
|
|
-1);
|
|
if (newnode == NULL)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
/* translator: first %s is name of a SQL construct, eg LIMIT */
|
|
errmsg("argument of %s must be type %s, not type %s",
|
|
constructName,
|
|
format_type_be(targetTypeId),
|
|
format_type_be(inputTypeId)),
|
|
parser_errposition(pstate, exprLocation(node))));
|
|
node = newnode;
|
|
}
|
|
|
|
if (expression_returns_set(node))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
/* translator: %s is name of a SQL construct, eg LIMIT */
|
|
errmsg("argument of %s must not return a set",
|
|
constructName),
|
|
parser_errposition(pstate, exprLocation(node))));
|
|
|
|
return node;
|
|
}
|
|
|
|
|
|
/*
|
|
* parser_coercion_errposition - report coercion error location, if possible
|
|
*
|
|
* We prefer to point at the coercion request (CAST, ::, etc) if possible;
|
|
* but there may be no such location in the case of an implicit coercion.
|
|
* In that case point at the input expression.
|
|
*
|
|
* XXX possibly this is more generally useful than coercion errors;
|
|
* if so, should rename and place with parser_errposition.
|
|
*/
|
|
int
|
|
parser_coercion_errposition(ParseState *pstate,
|
|
int coerce_location,
|
|
Node *input_expr)
|
|
{
|
|
if (coerce_location >= 0)
|
|
return parser_errposition(pstate, coerce_location);
|
|
else
|
|
return parser_errposition(pstate, exprLocation(input_expr));
|
|
}
|
|
|
|
|
|
/*
|
|
* select_common_type()
|
|
* Determine the common supertype of a list of input expressions.
|
|
* This is used for determining the output type of CASE, UNION,
|
|
* and similar constructs.
|
|
*
|
|
* 'exprs' is a *nonempty* list of expressions. Note that earlier items
|
|
* in the list will be preferred if there is doubt.
|
|
* 'context' is a phrase to use in the error message if we fail to select
|
|
* a usable type. Pass NULL to have the routine return InvalidOid
|
|
* rather than throwing an error on failure.
|
|
* 'which_expr': if not NULL, receives a pointer to the particular input
|
|
* expression from which the result type was taken.
|
|
*/
|
|
Oid
|
|
select_common_type(ParseState *pstate, List *exprs, const char *context,
|
|
Node **which_expr)
|
|
{
|
|
Node *pexpr;
|
|
Oid ptype;
|
|
TYPCATEGORY pcategory;
|
|
bool pispreferred;
|
|
ListCell *lc;
|
|
|
|
Assert(exprs != NIL);
|
|
pexpr = (Node *) linitial(exprs);
|
|
lc = lnext(list_head(exprs));
|
|
ptype = exprType(pexpr);
|
|
|
|
/*
|
|
* If all input types are valid and exactly the same, just pick that type.
|
|
* This is the only way that we will resolve the result as being a domain
|
|
* type; otherwise domains are smashed to their base types for comparison.
|
|
*/
|
|
if (ptype != UNKNOWNOID)
|
|
{
|
|
for_each_cell(lc, lc)
|
|
{
|
|
Node *nexpr = (Node *) lfirst(lc);
|
|
Oid ntype = exprType(nexpr);
|
|
|
|
if (ntype != ptype)
|
|
break;
|
|
}
|
|
if (lc == NULL) /* got to the end of the list? */
|
|
{
|
|
if (which_expr)
|
|
*which_expr = pexpr;
|
|
return ptype;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Nope, so set up for the full algorithm. Note that at this point,
|
|
* lc points to the first list item with type different from pexpr's;
|
|
* we need not re-examine any items the previous loop advanced over.
|
|
*/
|
|
ptype = getBaseType(ptype);
|
|
get_type_category_preferred(ptype, &pcategory, &pispreferred);
|
|
|
|
for_each_cell(lc, lc)
|
|
{
|
|
Node *nexpr = (Node *) lfirst(lc);
|
|
Oid ntype = getBaseType(exprType(nexpr));
|
|
|
|
/* move on to next one if no new information... */
|
|
if (ntype != UNKNOWNOID && ntype != ptype)
|
|
{
|
|
TYPCATEGORY ncategory;
|
|
bool nispreferred;
|
|
|
|
get_type_category_preferred(ntype, &ncategory, &nispreferred);
|
|
if (ptype == UNKNOWNOID)
|
|
{
|
|
/* so far, only unknowns so take anything... */
|
|
pexpr = nexpr;
|
|
ptype = ntype;
|
|
pcategory = ncategory;
|
|
pispreferred = nispreferred;
|
|
}
|
|
else if (ncategory != pcategory)
|
|
{
|
|
/*
|
|
* both types in different categories? then not much hope...
|
|
*/
|
|
if (context == NULL)
|
|
return InvalidOid;
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
/*------
|
|
translator: first %s is name of a SQL construct, eg CASE */
|
|
errmsg("%s types %s and %s cannot be matched",
|
|
context,
|
|
format_type_be(ptype),
|
|
format_type_be(ntype)),
|
|
parser_errposition(pstate, exprLocation(nexpr))));
|
|
}
|
|
else if (!pispreferred &&
|
|
can_coerce_type(1, &ptype, &ntype, COERCION_IMPLICIT) &&
|
|
!can_coerce_type(1, &ntype, &ptype, COERCION_IMPLICIT))
|
|
{
|
|
/*
|
|
* take new type if can coerce to it implicitly but not the
|
|
* other way; but if we have a preferred type, stay on it.
|
|
*/
|
|
pexpr = nexpr;
|
|
ptype = ntype;
|
|
pcategory = ncategory;
|
|
pispreferred = nispreferred;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If all the inputs were UNKNOWN type --- ie, unknown-type literals ---
|
|
* then resolve as type TEXT. This situation comes up with constructs
|
|
* like SELECT (CASE WHEN foo THEN 'bar' ELSE 'baz' END); SELECT 'foo'
|
|
* UNION SELECT 'bar'; It might seem desirable to leave the construct's
|
|
* output type as UNKNOWN, but that really doesn't work, because we'd
|
|
* probably end up needing a runtime coercion from UNKNOWN to something
|
|
* else, and we usually won't have it. We need to coerce the unknown
|
|
* literals while they are still literals, so a decision has to be made
|
|
* now.
|
|
*/
|
|
if (ptype == UNKNOWNOID)
|
|
ptype = TEXTOID;
|
|
|
|
if (which_expr)
|
|
*which_expr = pexpr;
|
|
return ptype;
|
|
}
|
|
|
|
/*
|
|
* coerce_to_common_type()
|
|
* Coerce an expression to the given type.
|
|
*
|
|
* This is used following select_common_type() to coerce the individual
|
|
* expressions to the desired type. 'context' is a phrase to use in the
|
|
* error message if we fail to coerce.
|
|
*
|
|
* As with coerce_type, pstate may be NULL if no special unknown-Param
|
|
* processing is wanted.
|
|
*/
|
|
Node *
|
|
coerce_to_common_type(ParseState *pstate, Node *node,
|
|
Oid targetTypeId, const char *context)
|
|
{
|
|
Oid inputTypeId = exprType(node);
|
|
|
|
if (inputTypeId == targetTypeId)
|
|
return node; /* no work */
|
|
if (can_coerce_type(1, &inputTypeId, &targetTypeId, COERCION_IMPLICIT))
|
|
node = coerce_type(pstate, node, inputTypeId, targetTypeId, -1,
|
|
COERCION_IMPLICIT, COERCE_IMPLICIT_CAST, -1);
|
|
else
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_CANNOT_COERCE),
|
|
/* translator: first %s is name of a SQL construct, eg CASE */
|
|
errmsg("%s could not convert type %s to %s",
|
|
context,
|
|
format_type_be(inputTypeId),
|
|
format_type_be(targetTypeId)),
|
|
parser_errposition(pstate, exprLocation(node))));
|
|
return node;
|
|
}
|
|
|
|
/*
|
|
* check_generic_type_consistency()
|
|
* Are the actual arguments potentially compatible with a
|
|
* polymorphic function?
|
|
*
|
|
* The argument consistency rules are:
|
|
*
|
|
* 1) All arguments declared ANYARRAY must have matching datatypes,
|
|
* and must in fact be varlena arrays.
|
|
* 2) All arguments declared ANYELEMENT must have matching datatypes.
|
|
* 3) If there are arguments of both ANYELEMENT and ANYARRAY, make sure
|
|
* the actual ANYELEMENT datatype is in fact the element type for
|
|
* the actual ANYARRAY datatype.
|
|
* 4) ANYENUM is treated the same as ANYELEMENT except that if it is used
|
|
* (alone or in combination with plain ANYELEMENT), we add the extra
|
|
* condition that the ANYELEMENT type must be an enum.
|
|
* 5) ANYNONARRAY is treated the same as ANYELEMENT except that if it is used,
|
|
* we add the extra condition that the ANYELEMENT type must not be an array.
|
|
* (This is a no-op if used in combination with ANYARRAY or ANYENUM, but
|
|
* is an extra restriction if not.)
|
|
*
|
|
* If we have UNKNOWN input (ie, an untyped literal) for any polymorphic
|
|
* argument, assume it is okay.
|
|
*
|
|
* If an input is of type ANYARRAY (ie, we know it's an array, but not
|
|
* what element type), we will accept it as a match to an argument declared
|
|
* ANYARRAY, so long as we don't have to determine an element type ---
|
|
* that is, so long as there is no use of ANYELEMENT. This is mostly for
|
|
* backwards compatibility with the pre-7.4 behavior of ANYARRAY.
|
|
*
|
|
* We do not ereport here, but just return FALSE if a rule is violated.
|
|
*/
|
|
bool
|
|
check_generic_type_consistency(Oid *actual_arg_types,
|
|
Oid *declared_arg_types,
|
|
int nargs)
|
|
{
|
|
int j;
|
|
Oid elem_typeid = InvalidOid;
|
|
Oid array_typeid = InvalidOid;
|
|
Oid array_typelem;
|
|
bool have_anyelement = false;
|
|
bool have_anynonarray = false;
|
|
bool have_anyenum = false;
|
|
|
|
/*
|
|
* Loop through the arguments to see if we have any that are polymorphic.
|
|
* If so, require the actual types to be consistent.
|
|
*/
|
|
for (j = 0; j < nargs; j++)
|
|
{
|
|
Oid decl_type = declared_arg_types[j];
|
|
Oid actual_type = actual_arg_types[j];
|
|
|
|
if (decl_type == ANYELEMENTOID ||
|
|
decl_type == ANYNONARRAYOID ||
|
|
decl_type == ANYENUMOID)
|
|
{
|
|
have_anyelement = true;
|
|
if (decl_type == ANYNONARRAYOID)
|
|
have_anynonarray = true;
|
|
else if (decl_type == ANYENUMOID)
|
|
have_anyenum = true;
|
|
if (actual_type == UNKNOWNOID)
|
|
continue;
|
|
if (OidIsValid(elem_typeid) && actual_type != elem_typeid)
|
|
return false;
|
|
elem_typeid = actual_type;
|
|
}
|
|
else if (decl_type == ANYARRAYOID)
|
|
{
|
|
if (actual_type == UNKNOWNOID)
|
|
continue;
|
|
if (OidIsValid(array_typeid) && actual_type != array_typeid)
|
|
return false;
|
|
array_typeid = actual_type;
|
|
}
|
|
}
|
|
|
|
/* Get the element type based on the array type, if we have one */
|
|
if (OidIsValid(array_typeid))
|
|
{
|
|
if (array_typeid == ANYARRAYOID)
|
|
{
|
|
/* Special case for ANYARRAY input: okay iff no ANYELEMENT */
|
|
if (have_anyelement)
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
array_typelem = get_element_type(array_typeid);
|
|
if (!OidIsValid(array_typelem))
|
|
return false; /* should be an array, but isn't */
|
|
|
|
if (!OidIsValid(elem_typeid))
|
|
{
|
|
/*
|
|
* if we don't have an element type yet, use the one we just got
|
|
*/
|
|
elem_typeid = array_typelem;
|
|
}
|
|
else if (array_typelem != elem_typeid)
|
|
{
|
|
/* otherwise, they better match */
|
|
return false;
|
|
}
|
|
}
|
|
|
|
if (have_anynonarray)
|
|
{
|
|
/* require the element type to not be an array */
|
|
if (type_is_array(elem_typeid))
|
|
return false;
|
|
}
|
|
|
|
if (have_anyenum)
|
|
{
|
|
/* require the element type to be an enum */
|
|
if (!type_is_enum(elem_typeid))
|
|
return false;
|
|
}
|
|
|
|
/* Looks valid */
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* enforce_generic_type_consistency()
|
|
* Make sure a polymorphic function is legally callable, and
|
|
* deduce actual argument and result types.
|
|
*
|
|
* If any polymorphic pseudotype is used in a function's arguments or
|
|
* return type, we make sure the actual data types are consistent with
|
|
* each other. The argument consistency rules are shown above for
|
|
* check_generic_type_consistency().
|
|
*
|
|
* If we have UNKNOWN input (ie, an untyped literal) for any polymorphic
|
|
* argument, we attempt to deduce the actual type it should have. If
|
|
* successful, we alter that position of declared_arg_types[] so that
|
|
* make_fn_arguments will coerce the literal to the right thing.
|
|
*
|
|
* Rules are applied to the function's return type (possibly altering it)
|
|
* if it is declared as a polymorphic type:
|
|
*
|
|
* 1) If return type is ANYARRAY, and any argument is ANYARRAY, use the
|
|
* argument's actual type as the function's return type.
|
|
* 2) If return type is ANYARRAY, no argument is ANYARRAY, but any argument
|
|
* is ANYELEMENT, use the actual type of the argument to determine
|
|
* the function's return type, i.e. the element type's corresponding
|
|
* array type.
|
|
* 3) If return type is ANYARRAY, no argument is ANYARRAY or ANYELEMENT,
|
|
* generate an ERROR. This condition is prevented by CREATE FUNCTION
|
|
* and is therefore not expected here.
|
|
* 4) If return type is ANYELEMENT, and any argument is ANYELEMENT, use the
|
|
* argument's actual type as the function's return type.
|
|
* 5) If return type is ANYELEMENT, no argument is ANYELEMENT, but any
|
|
* argument is ANYARRAY, use the actual type of the argument to determine
|
|
* the function's return type, i.e. the array type's corresponding
|
|
* element type.
|
|
* 6) If return type is ANYELEMENT, no argument is ANYARRAY or ANYELEMENT,
|
|
* generate an ERROR. This condition is prevented by CREATE FUNCTION
|
|
* and is therefore not expected here.
|
|
* 7) ANYENUM is treated the same as ANYELEMENT except that if it is used
|
|
* (alone or in combination with plain ANYELEMENT), we add the extra
|
|
* condition that the ANYELEMENT type must be an enum.
|
|
* 8) ANYNONARRAY is treated the same as ANYELEMENT except that if it is used,
|
|
* we add the extra condition that the ANYELEMENT type must not be an array.
|
|
* (This is a no-op if used in combination with ANYARRAY or ANYENUM, but
|
|
* is an extra restriction if not.)
|
|
*
|
|
* When allow_poly is false, we are not expecting any of the actual_arg_types
|
|
* to be polymorphic, and we should not return a polymorphic result type
|
|
* either. When allow_poly is true, it is okay to have polymorphic "actual"
|
|
* arg types, and we can return ANYARRAY or ANYELEMENT as the result. (This
|
|
* case is currently used only to check compatibility of an aggregate's
|
|
* declaration with the underlying transfn.)
|
|
*
|
|
* A special case is that we could see ANYARRAY as an actual_arg_type even
|
|
* when allow_poly is false (this is possible only because pg_statistic has
|
|
* columns shown as anyarray in the catalogs). We allow this to match a
|
|
* declared ANYARRAY argument, but only if there is no ANYELEMENT argument
|
|
* or result (since we can't determine a specific element type to match to
|
|
* ANYELEMENT). Note this means that functions taking ANYARRAY had better
|
|
* behave sanely if applied to the pg_statistic columns; they can't just
|
|
* assume that successive inputs are of the same actual element type.
|
|
*/
|
|
Oid
|
|
enforce_generic_type_consistency(Oid *actual_arg_types,
|
|
Oid *declared_arg_types,
|
|
int nargs,
|
|
Oid rettype,
|
|
bool allow_poly)
|
|
{
|
|
int j;
|
|
bool have_generics = false;
|
|
bool have_unknowns = false;
|
|
Oid elem_typeid = InvalidOid;
|
|
Oid array_typeid = InvalidOid;
|
|
Oid array_typelem;
|
|
bool have_anyelement = (rettype == ANYELEMENTOID ||
|
|
rettype == ANYNONARRAYOID ||
|
|
rettype == ANYENUMOID);
|
|
bool have_anynonarray = (rettype == ANYNONARRAYOID);
|
|
bool have_anyenum = (rettype == ANYENUMOID);
|
|
|
|
/*
|
|
* Loop through the arguments to see if we have any that are polymorphic.
|
|
* If so, require the actual types to be consistent.
|
|
*/
|
|
for (j = 0; j < nargs; j++)
|
|
{
|
|
Oid decl_type = declared_arg_types[j];
|
|
Oid actual_type = actual_arg_types[j];
|
|
|
|
if (decl_type == ANYELEMENTOID ||
|
|
decl_type == ANYNONARRAYOID ||
|
|
decl_type == ANYENUMOID)
|
|
{
|
|
have_generics = have_anyelement = true;
|
|
if (decl_type == ANYNONARRAYOID)
|
|
have_anynonarray = true;
|
|
else if (decl_type == ANYENUMOID)
|
|
have_anyenum = true;
|
|
if (actual_type == UNKNOWNOID)
|
|
{
|
|
have_unknowns = true;
|
|
continue;
|
|
}
|
|
if (allow_poly && decl_type == actual_type)
|
|
continue; /* no new information here */
|
|
if (OidIsValid(elem_typeid) && actual_type != elem_typeid)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
errmsg("arguments declared \"anyelement\" are not all alike"),
|
|
errdetail("%s versus %s",
|
|
format_type_be(elem_typeid),
|
|
format_type_be(actual_type))));
|
|
elem_typeid = actual_type;
|
|
}
|
|
else if (decl_type == ANYARRAYOID)
|
|
{
|
|
have_generics = true;
|
|
if (actual_type == UNKNOWNOID)
|
|
{
|
|
have_unknowns = true;
|
|
continue;
|
|
}
|
|
if (allow_poly && decl_type == actual_type)
|
|
continue; /* no new information here */
|
|
if (OidIsValid(array_typeid) && actual_type != array_typeid)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
errmsg("arguments declared \"anyarray\" are not all alike"),
|
|
errdetail("%s versus %s",
|
|
format_type_be(array_typeid),
|
|
format_type_be(actual_type))));
|
|
array_typeid = actual_type;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Fast Track: if none of the arguments are polymorphic, return the
|
|
* unmodified rettype. We assume it can't be polymorphic either.
|
|
*/
|
|
if (!have_generics)
|
|
return rettype;
|
|
|
|
/* Get the element type based on the array type, if we have one */
|
|
if (OidIsValid(array_typeid))
|
|
{
|
|
if (array_typeid == ANYARRAYOID && !have_anyelement)
|
|
{
|
|
/* Special case for ANYARRAY input: okay iff no ANYELEMENT */
|
|
array_typelem = InvalidOid;
|
|
}
|
|
else
|
|
{
|
|
array_typelem = get_element_type(array_typeid);
|
|
if (!OidIsValid(array_typelem))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
errmsg("argument declared \"anyarray\" is not an array but type %s",
|
|
format_type_be(array_typeid))));
|
|
}
|
|
|
|
if (!OidIsValid(elem_typeid))
|
|
{
|
|
/*
|
|
* if we don't have an element type yet, use the one we just got
|
|
*/
|
|
elem_typeid = array_typelem;
|
|
}
|
|
else if (array_typelem != elem_typeid)
|
|
{
|
|
/* otherwise, they better match */
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
errmsg("argument declared \"anyarray\" is not consistent with argument declared \"anyelement\""),
|
|
errdetail("%s versus %s",
|
|
format_type_be(array_typeid),
|
|
format_type_be(elem_typeid))));
|
|
}
|
|
}
|
|
else if (!OidIsValid(elem_typeid))
|
|
{
|
|
if (allow_poly)
|
|
{
|
|
array_typeid = ANYARRAYOID;
|
|
elem_typeid = ANYELEMENTOID;
|
|
}
|
|
else
|
|
{
|
|
/* Only way to get here is if all the generic args are UNKNOWN */
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
errmsg("could not determine polymorphic type because input has type \"unknown\"")));
|
|
}
|
|
}
|
|
|
|
if (have_anynonarray && elem_typeid != ANYELEMENTOID)
|
|
{
|
|
/* require the element type to not be an array */
|
|
if (type_is_array(elem_typeid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
errmsg("type matched to anynonarray is an array type: %s",
|
|
format_type_be(elem_typeid))));
|
|
}
|
|
|
|
if (have_anyenum && elem_typeid != ANYELEMENTOID)
|
|
{
|
|
/* require the element type to be an enum */
|
|
if (!type_is_enum(elem_typeid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
errmsg("type matched to anyenum is not an enum type: %s",
|
|
format_type_be(elem_typeid))));
|
|
}
|
|
|
|
/*
|
|
* If we had any unknown inputs, re-scan to assign correct types
|
|
*/
|
|
if (have_unknowns)
|
|
{
|
|
for (j = 0; j < nargs; j++)
|
|
{
|
|
Oid decl_type = declared_arg_types[j];
|
|
Oid actual_type = actual_arg_types[j];
|
|
|
|
if (actual_type != UNKNOWNOID)
|
|
continue;
|
|
|
|
if (decl_type == ANYELEMENTOID ||
|
|
decl_type == ANYNONARRAYOID ||
|
|
decl_type == ANYENUMOID)
|
|
declared_arg_types[j] = elem_typeid;
|
|
else if (decl_type == ANYARRAYOID)
|
|
{
|
|
if (!OidIsValid(array_typeid))
|
|
{
|
|
array_typeid = get_array_type(elem_typeid);
|
|
if (!OidIsValid(array_typeid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_UNDEFINED_OBJECT),
|
|
errmsg("could not find array type for data type %s",
|
|
format_type_be(elem_typeid))));
|
|
}
|
|
declared_arg_types[j] = array_typeid;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* if we return ANYARRAY use the appropriate argument type */
|
|
if (rettype == ANYARRAYOID)
|
|
{
|
|
if (!OidIsValid(array_typeid))
|
|
{
|
|
array_typeid = get_array_type(elem_typeid);
|
|
if (!OidIsValid(array_typeid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_UNDEFINED_OBJECT),
|
|
errmsg("could not find array type for data type %s",
|
|
format_type_be(elem_typeid))));
|
|
}
|
|
return array_typeid;
|
|
}
|
|
|
|
/* if we return ANYELEMENT use the appropriate argument type */
|
|
if (rettype == ANYELEMENTOID ||
|
|
rettype == ANYNONARRAYOID ||
|
|
rettype == ANYENUMOID)
|
|
return elem_typeid;
|
|
|
|
/* we don't return a generic type; send back the original return type */
|
|
return rettype;
|
|
}
|
|
|
|
/*
|
|
* resolve_generic_type()
|
|
* Deduce an individual actual datatype on the assumption that
|
|
* the rules for polymorphic types are being followed.
|
|
*
|
|
* declared_type is the declared datatype we want to resolve.
|
|
* context_actual_type is the actual input datatype to some argument
|
|
* that has declared datatype context_declared_type.
|
|
*
|
|
* If declared_type isn't polymorphic, we just return it. Otherwise,
|
|
* context_declared_type must be polymorphic, and we deduce the correct
|
|
* return type based on the relationship of the two polymorphic types.
|
|
*/
|
|
Oid
|
|
resolve_generic_type(Oid declared_type,
|
|
Oid context_actual_type,
|
|
Oid context_declared_type)
|
|
{
|
|
if (declared_type == ANYARRAYOID)
|
|
{
|
|
if (context_declared_type == ANYARRAYOID)
|
|
{
|
|
/* Use actual type, but it must be an array */
|
|
Oid array_typelem = get_element_type(context_actual_type);
|
|
|
|
if (!OidIsValid(array_typelem))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
errmsg("argument declared \"anyarray\" is not an array but type %s",
|
|
format_type_be(context_actual_type))));
|
|
return context_actual_type;
|
|
}
|
|
else if (context_declared_type == ANYELEMENTOID ||
|
|
context_declared_type == ANYNONARRAYOID ||
|
|
context_declared_type == ANYENUMOID)
|
|
{
|
|
/* Use the array type corresponding to actual type */
|
|
Oid array_typeid = get_array_type(context_actual_type);
|
|
|
|
if (!OidIsValid(array_typeid))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_UNDEFINED_OBJECT),
|
|
errmsg("could not find array type for data type %s",
|
|
format_type_be(context_actual_type))));
|
|
return array_typeid;
|
|
}
|
|
}
|
|
else if (declared_type == ANYELEMENTOID ||
|
|
declared_type == ANYNONARRAYOID ||
|
|
declared_type == ANYENUMOID)
|
|
{
|
|
if (context_declared_type == ANYARRAYOID)
|
|
{
|
|
/* Use the element type corresponding to actual type */
|
|
Oid array_typelem = get_element_type(context_actual_type);
|
|
|
|
if (!OidIsValid(array_typelem))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DATATYPE_MISMATCH),
|
|
errmsg("argument declared \"anyarray\" is not an array but type %s",
|
|
format_type_be(context_actual_type))));
|
|
return array_typelem;
|
|
}
|
|
else if (context_declared_type == ANYELEMENTOID ||
|
|
context_declared_type == ANYNONARRAYOID ||
|
|
context_declared_type == ANYENUMOID)
|
|
{
|
|
/* Use the actual type; it doesn't matter if array or not */
|
|
return context_actual_type;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* declared_type isn't polymorphic, so return it as-is */
|
|
return declared_type;
|
|
}
|
|
/* If we get here, declared_type is polymorphic and context isn't */
|
|
/* NB: this is a calling-code logic error, not a user error */
|
|
elog(ERROR, "could not determine polymorphic type because context isn't polymorphic");
|
|
return InvalidOid; /* keep compiler quiet */
|
|
}
|
|
|
|
|
|
/* TypeCategory()
|
|
* Assign a category to the specified type OID.
|
|
*
|
|
* NB: this must not return TYPCATEGORY_INVALID.
|
|
*/
|
|
TYPCATEGORY
|
|
TypeCategory(Oid type)
|
|
{
|
|
char typcategory;
|
|
bool typispreferred;
|
|
|
|
get_type_category_preferred(type, &typcategory, &typispreferred);
|
|
Assert(typcategory != TYPCATEGORY_INVALID);
|
|
return (TYPCATEGORY) typcategory;
|
|
}
|
|
|
|
|
|
/* IsPreferredType()
|
|
* Check if this type is a preferred type for the given category.
|
|
*
|
|
* If category is TYPCATEGORY_INVALID, then we'll return TRUE for preferred
|
|
* types of any category; otherwise, only for preferred types of that
|
|
* category.
|
|
*/
|
|
bool
|
|
IsPreferredType(TYPCATEGORY category, Oid type)
|
|
{
|
|
char typcategory;
|
|
bool typispreferred;
|
|
|
|
get_type_category_preferred(type, &typcategory, &typispreferred);
|
|
if (category == typcategory || category == TYPCATEGORY_INVALID)
|
|
return typispreferred;
|
|
else
|
|
return false;
|
|
}
|
|
|
|
|
|
/* IsBinaryCoercible()
|
|
* Check if srctype is binary-coercible to targettype.
|
|
*
|
|
* This notion allows us to cheat and directly exchange values without
|
|
* going through the trouble of calling a conversion function. Note that
|
|
* in general, this should only be an implementation shortcut. Before 7.4,
|
|
* this was also used as a heuristic for resolving overloaded functions and
|
|
* operators, but that's basically a bad idea.
|
|
*
|
|
* As of 7.3, binary coercibility isn't hardwired into the code anymore.
|
|
* We consider two types binary-coercible if there is an implicitly
|
|
* invokable, no-function-needed pg_cast entry. Also, a domain is always
|
|
* binary-coercible to its base type, though *not* vice versa (in the other
|
|
* direction, one must apply domain constraint checks before accepting the
|
|
* value as legitimate). We also need to special-case various polymorphic
|
|
* types.
|
|
*
|
|
* This function replaces IsBinaryCompatible(), which was an inherently
|
|
* symmetric test. Since the pg_cast entries aren't necessarily symmetric,
|
|
* the order of the operands is now significant.
|
|
*/
|
|
bool
|
|
IsBinaryCoercible(Oid srctype, Oid targettype)
|
|
{
|
|
HeapTuple tuple;
|
|
Form_pg_cast castForm;
|
|
bool result;
|
|
|
|
/* Fast path if same type */
|
|
if (srctype == targettype)
|
|
return true;
|
|
|
|
/* If srctype is a domain, reduce to its base type */
|
|
if (OidIsValid(srctype))
|
|
srctype = getBaseType(srctype);
|
|
|
|
/* Somewhat-fast path for domain -> base type case */
|
|
if (srctype == targettype)
|
|
return true;
|
|
|
|
/* Also accept any array type as coercible to ANYARRAY */
|
|
if (targettype == ANYARRAYOID)
|
|
if (type_is_array(srctype))
|
|
return true;
|
|
|
|
/* Also accept any non-array type as coercible to ANYNONARRAY */
|
|
if (targettype == ANYNONARRAYOID)
|
|
if (!type_is_array(srctype))
|
|
return true;
|
|
|
|
/* Also accept any enum type as coercible to ANYENUM */
|
|
if (targettype == ANYENUMOID)
|
|
if (type_is_enum(srctype))
|
|
return true;
|
|
|
|
/* Also accept any composite type as coercible to RECORD */
|
|
if (targettype == RECORDOID)
|
|
if (ISCOMPLEX(srctype))
|
|
return true;
|
|
|
|
/* Also accept any composite array type as coercible to RECORD[] */
|
|
if (targettype == RECORDARRAYOID)
|
|
if (is_complex_array(srctype))
|
|
return true;
|
|
|
|
/* Else look in pg_cast */
|
|
tuple = SearchSysCache(CASTSOURCETARGET,
|
|
ObjectIdGetDatum(srctype),
|
|
ObjectIdGetDatum(targettype),
|
|
0, 0);
|
|
if (!HeapTupleIsValid(tuple))
|
|
return false; /* no cast */
|
|
castForm = (Form_pg_cast) GETSTRUCT(tuple);
|
|
|
|
result = (castForm->castfunc == InvalidOid &&
|
|
castForm->castcontext == COERCION_CODE_IMPLICIT);
|
|
|
|
ReleaseSysCache(tuple);
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
/*
|
|
* find_coercion_pathway
|
|
* Look for a coercion pathway between two types.
|
|
*
|
|
* Currently, this deals only with scalar-type cases; it does not consider
|
|
* polymorphic types nor casts between composite types. (Perhaps fold
|
|
* those in someday?)
|
|
*
|
|
* ccontext determines the set of available casts.
|
|
*
|
|
* The possible result codes are:
|
|
* COERCION_PATH_NONE: failed to find any coercion pathway
|
|
* *funcid is set to InvalidOid
|
|
* COERCION_PATH_FUNC: apply the coercion function returned in *funcid
|
|
* COERCION_PATH_RELABELTYPE: binary-compatible cast, no function needed
|
|
* *funcid is set to InvalidOid
|
|
* COERCION_PATH_ARRAYCOERCE: need an ArrayCoerceExpr node
|
|
* *funcid is set to the element cast function, or InvalidOid
|
|
* if the array elements are binary-compatible
|
|
* COERCION_PATH_COERCEVIAIO: need a CoerceViaIO node
|
|
* *funcid is set to InvalidOid
|
|
*
|
|
* Note: COERCION_PATH_RELABELTYPE does not necessarily mean that no work is
|
|
* needed to do the coercion; if the target is a domain then we may need to
|
|
* apply domain constraint checking. If you want to check for a zero-effort
|
|
* conversion then use IsBinaryCoercible().
|
|
*/
|
|
CoercionPathType
|
|
find_coercion_pathway(Oid targetTypeId, Oid sourceTypeId,
|
|
CoercionContext ccontext,
|
|
Oid *funcid)
|
|
{
|
|
CoercionPathType result = COERCION_PATH_NONE;
|
|
HeapTuple tuple;
|
|
|
|
*funcid = InvalidOid;
|
|
|
|
/* Perhaps the types are domains; if so, look at their base types */
|
|
if (OidIsValid(sourceTypeId))
|
|
sourceTypeId = getBaseType(sourceTypeId);
|
|
if (OidIsValid(targetTypeId))
|
|
targetTypeId = getBaseType(targetTypeId);
|
|
|
|
/* Domains are always coercible to and from their base type */
|
|
if (sourceTypeId == targetTypeId)
|
|
return COERCION_PATH_RELABELTYPE;
|
|
|
|
/* Look in pg_cast */
|
|
tuple = SearchSysCache(CASTSOURCETARGET,
|
|
ObjectIdGetDatum(sourceTypeId),
|
|
ObjectIdGetDatum(targetTypeId),
|
|
0, 0);
|
|
|
|
if (HeapTupleIsValid(tuple))
|
|
{
|
|
Form_pg_cast castForm = (Form_pg_cast) GETSTRUCT(tuple);
|
|
CoercionContext castcontext;
|
|
|
|
/* convert char value for castcontext to CoercionContext enum */
|
|
switch (castForm->castcontext)
|
|
{
|
|
case COERCION_CODE_IMPLICIT:
|
|
castcontext = COERCION_IMPLICIT;
|
|
break;
|
|
case COERCION_CODE_ASSIGNMENT:
|
|
castcontext = COERCION_ASSIGNMENT;
|
|
break;
|
|
case COERCION_CODE_EXPLICIT:
|
|
castcontext = COERCION_EXPLICIT;
|
|
break;
|
|
default:
|
|
elog(ERROR, "unrecognized castcontext: %d",
|
|
(int) castForm->castcontext);
|
|
castcontext = 0; /* keep compiler quiet */
|
|
break;
|
|
}
|
|
|
|
/* Rely on ordering of enum for correct behavior here */
|
|
if (ccontext >= castcontext)
|
|
{
|
|
switch (castForm->castmethod)
|
|
{
|
|
case COERCION_METHOD_FUNCTION:
|
|
result = COERCION_PATH_FUNC;
|
|
*funcid = castForm->castfunc;
|
|
break;
|
|
case COERCION_METHOD_INOUT:
|
|
result = COERCION_PATH_COERCEVIAIO;
|
|
break;
|
|
case COERCION_METHOD_BINARY:
|
|
result = COERCION_PATH_RELABELTYPE;
|
|
break;
|
|
default:
|
|
elog(ERROR, "unrecognized castmethod: %d",
|
|
(int) castForm->castmethod);
|
|
break;
|
|
}
|
|
}
|
|
|
|
ReleaseSysCache(tuple);
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* If there's no pg_cast entry, perhaps we are dealing with a pair of
|
|
* array types. If so, and if the element types have a suitable cast,
|
|
* report that we can coerce with an ArrayCoerceExpr.
|
|
*
|
|
* Hack: disallow coercions to oidvector and int2vector, which
|
|
* otherwise tend to capture coercions that should go to "real" array
|
|
* types. We want those types to be considered "real" arrays for many
|
|
* purposes, but not this one. (Also, ArrayCoerceExpr isn't
|
|
* guaranteed to produce an output that meets the restrictions of
|
|
* these datatypes, such as being 1-dimensional.)
|
|
*/
|
|
if (targetTypeId != OIDVECTOROID && targetTypeId != INT2VECTOROID)
|
|
{
|
|
Oid targetElem;
|
|
Oid sourceElem;
|
|
|
|
if ((targetElem = get_element_type(targetTypeId)) != InvalidOid &&
|
|
(sourceElem = get_element_type(sourceTypeId)) != InvalidOid)
|
|
{
|
|
CoercionPathType elempathtype;
|
|
Oid elemfuncid;
|
|
|
|
elempathtype = find_coercion_pathway(targetElem,
|
|
sourceElem,
|
|
ccontext,
|
|
&elemfuncid);
|
|
if (elempathtype != COERCION_PATH_NONE &&
|
|
elempathtype != COERCION_PATH_ARRAYCOERCE)
|
|
{
|
|
*funcid = elemfuncid;
|
|
if (elempathtype == COERCION_PATH_COERCEVIAIO)
|
|
result = COERCION_PATH_COERCEVIAIO;
|
|
else
|
|
result = COERCION_PATH_ARRAYCOERCE;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we still haven't found a possibility, consider automatic casting
|
|
* using I/O functions. We allow assignment casts to string types
|
|
* and explicit casts from string types to be handled this way. (The
|
|
* CoerceViaIO mechanism is a lot more general than that, but this is
|
|
* all we want to allow in the absence of a pg_cast entry.) It would
|
|
* probably be better to insist on explicit casts in both directions,
|
|
* but this is a compromise to preserve something of the pre-8.3
|
|
* behavior that many types had implicit (yipes!) casts to text.
|
|
*/
|
|
if (result == COERCION_PATH_NONE)
|
|
{
|
|
if (ccontext >= COERCION_ASSIGNMENT &&
|
|
TypeCategory(targetTypeId) == TYPCATEGORY_STRING)
|
|
result = COERCION_PATH_COERCEVIAIO;
|
|
else if (ccontext >= COERCION_EXPLICIT &&
|
|
TypeCategory(sourceTypeId) == TYPCATEGORY_STRING)
|
|
result = COERCION_PATH_COERCEVIAIO;
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
/*
|
|
* find_typmod_coercion_function -- does the given type need length coercion?
|
|
*
|
|
* If the target type possesses a pg_cast function from itself to itself,
|
|
* it must need length coercion.
|
|
*
|
|
* "bpchar" (ie, char(N)) and "numeric" are examples of such types.
|
|
*
|
|
* If the given type is a varlena array type, we do not look for a coercion
|
|
* function associated directly with the array type, but instead look for
|
|
* one associated with the element type. An ArrayCoerceExpr node must be
|
|
* used to apply such a function.
|
|
*
|
|
* We use the same result enum as find_coercion_pathway, but the only possible
|
|
* result codes are:
|
|
* COERCION_PATH_NONE: no length coercion needed
|
|
* COERCION_PATH_FUNC: apply the function returned in *funcid
|
|
* COERCION_PATH_ARRAYCOERCE: apply the function using ArrayCoerceExpr
|
|
*/
|
|
CoercionPathType
|
|
find_typmod_coercion_function(Oid typeId,
|
|
Oid *funcid)
|
|
{
|
|
CoercionPathType result;
|
|
Type targetType;
|
|
Form_pg_type typeForm;
|
|
HeapTuple tuple;
|
|
|
|
*funcid = InvalidOid;
|
|
result = COERCION_PATH_FUNC;
|
|
|
|
targetType = typeidType(typeId);
|
|
typeForm = (Form_pg_type) GETSTRUCT(targetType);
|
|
|
|
/* Check for a varlena array type (and not a domain) */
|
|
if (typeForm->typelem != InvalidOid &&
|
|
typeForm->typlen == -1 &&
|
|
typeForm->typtype != TYPTYPE_DOMAIN)
|
|
{
|
|
/* Yes, switch our attention to the element type */
|
|
typeId = typeForm->typelem;
|
|
result = COERCION_PATH_ARRAYCOERCE;
|
|
}
|
|
ReleaseSysCache(targetType);
|
|
|
|
/* Look in pg_cast */
|
|
tuple = SearchSysCache(CASTSOURCETARGET,
|
|
ObjectIdGetDatum(typeId),
|
|
ObjectIdGetDatum(typeId),
|
|
0, 0);
|
|
|
|
if (HeapTupleIsValid(tuple))
|
|
{
|
|
Form_pg_cast castForm = (Form_pg_cast) GETSTRUCT(tuple);
|
|
|
|
*funcid = castForm->castfunc;
|
|
ReleaseSysCache(tuple);
|
|
}
|
|
|
|
if (!OidIsValid(*funcid))
|
|
result = COERCION_PATH_NONE;
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* is_complex_array
|
|
* Is this type an array of composite?
|
|
*
|
|
* Note: this will not return true for record[]; check for RECORDARRAYOID
|
|
* separately if needed.
|
|
*/
|
|
static bool
|
|
is_complex_array(Oid typid)
|
|
{
|
|
Oid elemtype = get_element_type(typid);
|
|
|
|
return (OidIsValid(elemtype) && ISCOMPLEX(elemtype));
|
|
}
|