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c9d5298485
Invent new RawParseModes that allow the core grammar to handle
pl/pgsql expressions and assignments directly, and thereby get rid
of a lot of hackery in pl/pgsql's parser. This moves a good deal
of knowledge about pl/pgsql into the core code: notably, we have to
invent a CoercionContext that matches pl/pgsql's (rather dubious)
historical behavior for assignment coercions. That's getting away
from the original idea of pl/pgsql as an arm's-length extension of
the core, but really we crossed that bridge a long time ago.
The main advantage of doing this is that we can now use the core
parser to generate FieldStore and/or SubscriptingRef nodes to handle
assignments to pl/pgsql variables that are records or arrays. That
fixes a number of cases that had never been implemented in pl/pgsql
assignment, such as nested records and array slicing, and it allows
pl/pgsql assignment to support the datatype-specific subscripting
behaviors introduced in commit c7aba7c14.
There are cosmetic benefits too: when a syntax error occurs in a
pl/pgsql expression, the error report no longer includes the confusing
"SELECT" keyword that used to get prefixed to the expression text.
Also, there seem to be some small speed gains.
Discussion: https://postgr.es/m/4165684.1607707277@sss.pgh.pa.us
59 lines
2.1 KiB
C
59 lines
2.1 KiB
C
/*-------------------------------------------------------------------------
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*
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* parse_target.h
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* handle target lists
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*
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*
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* Portions Copyright (c) 1996-2021, 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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* src/include/parser/parse_target.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef PARSE_TARGET_H
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#define PARSE_TARGET_H
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#include "parser/parse_node.h"
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extern List *transformTargetList(ParseState *pstate, List *targetlist,
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ParseExprKind exprKind);
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extern List *transformExpressionList(ParseState *pstate, List *exprlist,
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ParseExprKind exprKind, bool allowDefault);
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extern void resolveTargetListUnknowns(ParseState *pstate, List *targetlist);
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extern void markTargetListOrigins(ParseState *pstate, List *targetlist);
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extern TargetEntry *transformTargetEntry(ParseState *pstate,
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Node *node, Node *expr, ParseExprKind exprKind,
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char *colname, bool resjunk);
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extern Expr *transformAssignedExpr(ParseState *pstate, Expr *expr,
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ParseExprKind exprKind,
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const char *colname,
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int attrno,
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List *indirection,
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int location);
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extern void updateTargetListEntry(ParseState *pstate, TargetEntry *tle,
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char *colname, int attrno,
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List *indirection,
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int location);
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extern Node *transformAssignmentIndirection(ParseState *pstate,
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Node *basenode,
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const char *targetName,
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bool targetIsSubscripting,
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Oid targetTypeId,
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int32 targetTypMod,
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Oid targetCollation,
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List *indirection,
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ListCell *indirection_cell,
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Node *rhs,
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CoercionContext ccontext,
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int location);
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extern List *checkInsertTargets(ParseState *pstate, List *cols,
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List **attrnos);
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extern TupleDesc expandRecordVariable(ParseState *pstate, Var *var,
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int levelsup);
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extern char *FigureColname(Node *node);
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extern char *FigureIndexColname(Node *node);
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#endif /* PARSE_TARGET_H */
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