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Some early work on error message editing. Operator-not-found and

function-not-found messages now distinguish the cases no-match and
ambiguous-match, and they follow the style guidelines too.
This commit is contained in:
Tom Lane
2003-07-04 02:51:34 +00:00
parent cdb8a844e6
commit 79fafdf49c
30 changed files with 387 additions and 365 deletions

View File

@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_oper.c,v 1.68 2003/06/29 00:33:43 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/parse_oper.c,v 1.69 2003/07/04 02:51:33 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -16,6 +16,7 @@
#include "postgres.h"
#include "catalog/pg_operator.h"
#include "lib/stringinfo.h"
#include "parser/parse_coerce.h"
#include "parser/parse_expr.h"
#include "parser/parse_func.h"
@@ -29,25 +30,32 @@
static Oid binary_oper_exact(Oid arg1, Oid arg2,
FuncCandidateList candidates);
static Oid oper_select_candidate(int nargs, Oid *input_typeids,
FuncCandidateList candidates);
static void op_error(List *op, Oid arg1, Oid arg2);
static void unary_op_error(List *op, Oid arg, bool is_left_op);
static FuncDetailCode oper_select_candidate(int nargs,
Oid *input_typeids,
FuncCandidateList candidates,
Oid *operOid);
static const char *op_signature_string(List *op, char oprkind,
Oid arg1, Oid arg2);
static void op_error(List *op, char oprkind, Oid arg1, Oid arg2,
FuncDetailCode fdresult);
/*
* LookupOperName
* Given a possibly-qualified operator name and exact input datatypes,
* look up the operator. Returns InvalidOid if no such operator.
* look up the operator.
*
* Pass oprleft = InvalidOid for a prefix op, oprright = InvalidOid for
* a postfix op.
*
* If the operator name is not schema-qualified, it is sought in the current
* namespace search path.
*
* If the operator is not found, we return InvalidOid if noError is true,
* else raise an error.
*/
Oid
LookupOperName(List *opername, Oid oprleft, Oid oprright)
LookupOperName(List *opername, Oid oprleft, Oid oprright, bool noError)
{
FuncCandidateList clist;
char oprkind;
@@ -68,22 +76,28 @@ LookupOperName(List *opername, Oid oprleft, Oid oprright)
clist = clist->next;
}
/* we don't use op_error here because only an exact match is wanted */
if (!noError)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_FUNCTION),
errmsg("operator does not exist: %s",
op_signature_string(opername, oprkind,
oprleft, oprright))));
return InvalidOid;
}
/*
* LookupOperNameTypeNames
* Like LookupOperName, but the argument types are specified by
* TypeName nodes. Also, if we fail to find the operator
* and caller is not NULL, then an error is reported.
* TypeName nodes.
*
* Pass oprleft = NULL for a prefix op, oprright = NULL for a postfix op.
*/
Oid
LookupOperNameTypeNames(List *opername, TypeName *oprleft,
TypeName *oprright, const char *caller)
TypeName *oprright, bool noError)
{
Oid operoid;
Oid leftoid,
rightoid;
@@ -93,7 +107,7 @@ LookupOperNameTypeNames(List *opername, TypeName *oprleft,
{
leftoid = LookupTypeName(oprleft);
if (!OidIsValid(leftoid))
elog(ERROR, "Type \"%s\" does not exist",
elog(ERROR, "type %s does not exist",
TypeNameToString(oprleft));
}
if (oprright == NULL)
@@ -102,30 +116,11 @@ LookupOperNameTypeNames(List *opername, TypeName *oprleft,
{
rightoid = LookupTypeName(oprright);
if (!OidIsValid(rightoid))
elog(ERROR, "Type \"%s\" does not exist",
elog(ERROR, "type %s does not exist",
TypeNameToString(oprright));
}
operoid = LookupOperName(opername, leftoid, rightoid);
if (!OidIsValid(operoid) && caller != NULL)
{
if (oprleft == NULL)
elog(ERROR, "%s: Prefix operator '%s' for type '%s' does not exist",
caller, NameListToString(opername),
TypeNameToString(oprright));
else if (oprright == NULL)
elog(ERROR, "%s: Postfix operator '%s' for type '%s' does not exist",
caller, NameListToString(opername),
TypeNameToString(oprleft));
else
elog(ERROR, "%s: Operator '%s' for types '%s' and '%s' does not exist",
caller, NameListToString(opername),
TypeNameToString(oprleft),
TypeNameToString(oprright));
}
return operoid;
return LookupOperName(opername, leftoid, rightoid, noError);
}
/*
@@ -183,7 +178,7 @@ equality_oper(Oid argtype, bool noError)
}
}
if (!noError)
elog(ERROR, "Unable to identify an equality operator for type %s",
elog(ERROR, "unable to identify an equality operator for type %s",
format_type_be(argtype));
return NULL;
}
@@ -244,7 +239,7 @@ ordering_oper(Oid argtype, bool noError)
}
}
if (!noError)
elog(ERROR, "Unable to identify an ordering operator for type %s"
elog(ERROR, "unable to identify an ordering operator for type %s"
"\n\tUse an explicit ordering operator or modify the query",
format_type_be(argtype));
return NULL;
@@ -347,17 +342,18 @@ binary_oper_exact(Oid arg1, Oid arg2,
* Given the input argtype array and one or more candidates
* for the operator, attempt to resolve the conflict.
*
* Returns the OID of the selected operator if the conflict can be resolved,
* otherwise returns InvalidOid.
* Returns FUNCDETAIL_NOTFOUND, FUNCDETAIL_MULTIPLE, or FUNCDETAIL_NORMAL.
* In the success case the Oid of the best candidate is stored in *operOid.
*
* Note that the caller has already determined that there is no candidate
* exactly matching the input argtype(s). Incompatible candidates are not yet
* pruned away, however.
*/
static Oid
static FuncDetailCode
oper_select_candidate(int nargs,
Oid *input_typeids,
FuncCandidateList candidates)
FuncCandidateList candidates,
Oid *operOid) /* output argument */
{
int ncandidates;
@@ -370,9 +366,15 @@ oper_select_candidate(int nargs,
/* Done if no candidate or only one candidate survives */
if (ncandidates == 0)
return InvalidOid;
{
*operOid = InvalidOid;
return FUNCDETAIL_NOTFOUND;
}
if (ncandidates == 1)
return candidates->oid;
{
*operOid = candidates->oid;
return FUNCDETAIL_NORMAL;
}
/*
* Use the same heuristics as for ambiguous functions to resolve
@@ -381,10 +383,14 @@ oper_select_candidate(int nargs,
candidates = func_select_candidate(nargs, input_typeids, candidates);
if (candidates)
return candidates->oid;
{
*operOid = candidates->oid;
return FUNCDETAIL_NORMAL;
}
return InvalidOid; /* failed to select a best candidate */
} /* oper_select_candidate() */
*operOid = InvalidOid;
return FUNCDETAIL_MULTIPLE; /* failed to select a best candidate */
}
/* oper() -- search for a binary operator
@@ -404,8 +410,9 @@ Operator
oper(List *opname, Oid ltypeId, Oid rtypeId, bool noError)
{
FuncCandidateList clist;
Oid operOid;
Oid inputOids[2];
Oid operOid;
FuncDetailCode fdresult = FUNCDETAIL_NOTFOUND;
HeapTuple tup = NULL;
/* Get binary operators of given name */
@@ -434,7 +441,7 @@ oper(List *opname, Oid ltypeId, Oid rtypeId, bool noError)
ltypeId = rtypeId;
inputOids[0] = ltypeId;
inputOids[1] = rtypeId;
operOid = oper_select_candidate(2, inputOids, clist);
fdresult = oper_select_candidate(2, inputOids, clist, &operOid);
}
if (OidIsValid(operOid))
tup = SearchSysCache(OPEROID,
@@ -443,7 +450,7 @@ oper(List *opname, Oid ltypeId, Oid rtypeId, bool noError)
}
if (!HeapTupleIsValid(tup) && !noError)
op_error(opname, ltypeId, rtypeId);
op_error(opname, 'b', ltypeId, rtypeId, fdresult);
return (Operator) tup;
}
@@ -476,7 +483,8 @@ compatible_oper(List *op, Oid arg1, Oid arg2, bool noError)
ReleaseSysCache(optup);
if (!noError)
op_error(op, arg1, arg2);
elog(ERROR, "operator requires run-time type coercion: %s",
op_signature_string(op, 'b', arg1, arg2));
return (Operator) NULL;
}
@@ -504,7 +512,7 @@ compatible_oper_opid(List *op, Oid arg1, Oid arg2, bool noError)
}
/* right_oper() -- search for a unary right operator (operator on right)
/* right_oper() -- search for a unary right operator (postfix operator)
* Given operator name and type of arg, return oper struct.
*
* IMPORTANT: the returned operator (if any) is only promised to be
@@ -522,6 +530,7 @@ right_oper(List *op, Oid arg, bool noError)
{
FuncCandidateList clist;
Oid operOid = InvalidOid;
FuncDetailCode fdresult = FUNCDETAIL_NOTFOUND;
HeapTuple tup = NULL;
/* Find candidates */
@@ -551,7 +560,7 @@ right_oper(List *op, Oid arg, bool noError)
* candidate, otherwise we may falsely return a
* non-type-compatible operator.
*/
operOid = oper_select_candidate(1, &arg, clist);
fdresult = oper_select_candidate(1, &arg, clist, &operOid);
}
if (OidIsValid(operOid))
tup = SearchSysCache(OPEROID,
@@ -560,13 +569,13 @@ right_oper(List *op, Oid arg, bool noError)
}
if (!HeapTupleIsValid(tup) && !noError)
unary_op_error(op, arg, FALSE);
op_error(op, 'r', arg, InvalidOid, fdresult);
return (Operator) tup;
}
/* left_oper() -- search for a unary left operator (operator on left)
/* left_oper() -- search for a unary left operator (prefix operator)
* Given operator name and type of arg, return oper struct.
*
* IMPORTANT: the returned operator (if any) is only promised to be
@@ -584,6 +593,7 @@ left_oper(List *op, Oid arg, bool noError)
{
FuncCandidateList clist;
Oid operOid = InvalidOid;
FuncDetailCode fdresult = FUNCDETAIL_NOTFOUND;
HeapTuple tup = NULL;
/* Find candidates */
@@ -618,7 +628,7 @@ left_oper(List *op, Oid arg, bool noError)
* candidate, otherwise we may falsely return a
* non-type-compatible operator.
*/
operOid = oper_select_candidate(1, &arg, clist);
fdresult = oper_select_candidate(1, &arg, clist, &operOid);
}
if (OidIsValid(operOid))
tup = SearchSysCache(OPEROID,
@@ -627,67 +637,59 @@ left_oper(List *op, Oid arg, bool noError)
}
if (!HeapTupleIsValid(tup) && !noError)
unary_op_error(op, arg, TRUE);
op_error(op, 'l', InvalidOid, arg, fdresult);
return (Operator) tup;
}
/* op_error()
* Give a somewhat useful error message when the operator for two types
* is not found.
/*
* op_signature_string
* Build a string representing an operator name, including arg type(s).
* The result is something like "integer + integer".
*
* This is typically used in the construction of operator-not-found error
* messages.
*/
static void
op_error(List *op, Oid arg1, Oid arg2)
static const char *
op_signature_string(List *op, char oprkind, Oid arg1, Oid arg2)
{
if (!typeidIsValid(arg1))
elog(ERROR, "Left hand side of operator '%s' has an unknown type"
"\n\tProbably a bad attribute name",
NameListToString(op));
StringInfoData argbuf;
if (!typeidIsValid(arg2))
elog(ERROR, "Right hand side of operator %s has an unknown type"
"\n\tProbably a bad attribute name",
NameListToString(op));
initStringInfo(&argbuf);
elog(ERROR, "Unable to identify an operator '%s' for types '%s' and '%s'"
"\n\tYou will have to retype this query using an explicit cast",
NameListToString(op),
format_type_be(arg1), format_type_be(arg2));
if (oprkind != 'l')
appendStringInfo(&argbuf, "%s ", format_type_be(arg1));
appendStringInfoString(&argbuf, NameListToString(op));
if (oprkind != 'r')
appendStringInfo(&argbuf, " %s", format_type_be(arg2));
return argbuf.data; /* return palloc'd string buffer */
}
/* unary_op_error()
* Give a somewhat useful error message when the operator for one type
* is not found.
/*
* op_error - utility routine to complain about an unresolvable operator
*/
static void
unary_op_error(List *op, Oid arg, bool is_left_op)
op_error(List *op, char oprkind, Oid arg1, Oid arg2, FuncDetailCode fdresult)
{
if (!typeidIsValid(arg))
{
if (is_left_op)
elog(ERROR, "operand of prefix operator '%s' has an unknown type"
"\n\t(probably an invalid column reference)",
NameListToString(op));
else
elog(ERROR, "operand of postfix operator '%s' has an unknown type"
"\n\t(probably an invalid column reference)",
NameListToString(op));
}
if (fdresult == FUNCDETAIL_MULTIPLE)
ereport(ERROR,
(errcode(ERRCODE_AMBIGUOUS_FUNCTION),
errmsg("operator is not unique: %s",
op_signature_string(op, oprkind, arg1, arg2)),
errhint("Unable to choose a best candidate operator. "
"You may need to add explicit typecasts.")));
else
{
if (is_left_op)
elog(ERROR, "Unable to identify a prefix operator '%s' for type '%s'"
"\n\tYou may need to add parentheses or an explicit cast",
NameListToString(op), format_type_be(arg));
else
elog(ERROR, "Unable to identify a postfix operator '%s' for type '%s'"
"\n\tYou may need to add parentheses or an explicit cast",
NameListToString(op), format_type_be(arg));
}
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_FUNCTION),
errmsg("operator does not exist: %s",
op_signature_string(op, oprkind, arg1, arg2)),
errhint("No operator matches the given name and argument type(s). "
"You may need to add explicit typecasts.")));
}
/*
* make_op()
* Operator expression construction.