diff options
Diffstat (limited to 'src/include/nodes/parsenodes.h')
| -rw-r--r-- | src/include/nodes/parsenodes.h | 65 |
1 files changed, 50 insertions, 15 deletions
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index 7ceaa22c33b..edb5cd21521 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -7,7 +7,9 @@ * This is a byte (not character) offset in the original source text, to be * used for positioning an error cursor when there is an error related to * the node. Access to the original source text is needed to make use of - * the location. + * the location. At the topmost (statement) level, we also provide a + * statement length, likewise measured in bytes, for convenience in + * identifying statement boundaries in multi-statement source strings. * * * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group @@ -89,9 +91,7 @@ typedef uint32 AclMode; /* a bitmask of privilege bits */ * for further processing by the rewriter and planner. * * Utility statements (i.e. non-optimizable statements) have the - * utilityStmt field set, and the Query itself is mostly dummy. - * DECLARE CURSOR is a special case: it is represented like a SELECT, - * but the original DeclareCursorStmt is stored in utilityStmt. + * utilityStmt field set, and the rest of the Query is mostly dummy. * * Planning converts a Query tree into a Plan tree headed by a PlannedStmt * node --- the Query structure is not used by the executor. @@ -108,8 +108,7 @@ typedef struct Query bool canSetTag; /* do I set the command result tag? */ - Node *utilityStmt; /* non-null if this is DECLARE CURSOR or a - * non-optimizable statement */ + Node *utilityStmt; /* non-null if commandType == CMD_UTILITY */ int resultRelation; /* rtable index of target relation for * INSERT/UPDATE/DELETE; 0 for SELECT */ @@ -162,6 +161,15 @@ typedef struct Query * are only added during rewrite and * therefore are not written out as * part of Query. */ + + /* + * The following two fields identify the portion of the source text string + * containing this query. They are typically only populated in top-level + * Queries, not in sub-queries. When not set, they might both be zero, or + * both be -1 meaning "unknown". + */ + int stmt_location; /* start location, or -1 if unknown */ + int stmt_len; /* length in bytes; 0 means "rest of string" */ } Query; @@ -1308,6 +1316,30 @@ typedef struct TriggerTransition } TriggerTransition; /***************************************************************************** + * Raw Grammar Output Statements + *****************************************************************************/ + +/* + * RawStmt --- container for any one statement's raw parse tree + * + * Parse analysis converts a raw parse tree headed by a RawStmt node into + * an analyzed statement headed by a Query node. For optimizable statements, + * the conversion is complex. For utility statements, the parser usually just + * transfers the raw parse tree (sans RawStmt) into the utilityStmt field of + * the Query node, and all the useful work happens at execution time. + * + * stmt_location/stmt_len identify the portion of the source text string + * containing this raw statement (useful for multi-statement strings). + */ +typedef struct RawStmt +{ + NodeTag type; + Node *stmt; /* raw parse tree */ + int stmt_location; /* start location, or -1 if unknown */ + int stmt_len; /* length in bytes; 0 means "rest of string" */ +} RawStmt; + +/***************************************************************************** * Optimizable Statements *****************************************************************************/ @@ -1474,6 +1506,9 @@ typedef struct SetOperationStmt * statements do need attention from parse analysis, and this is * done by routines in parser/parse_utilcmd.c after ProcessUtility * receives the command for execution. + * DECLARE CURSOR, EXPLAIN, and CREATE TABLE AS are special cases: + * they contain optimizable statements, which get processed normally + * by parser/analyze.c. *****************************************************************************/ /* @@ -1794,7 +1829,7 @@ typedef struct CopyStmt NodeTag type; RangeVar *relation; /* the relation to copy */ Node *query; /* the query (SELECT or DML statement with - * RETURNING) to copy */ + * RETURNING) to copy, as a raw parse tree */ List *attlist; /* List of column names (as Strings), or NIL * for all columns */ bool is_from; /* TO or FROM */ @@ -2472,9 +2507,9 @@ typedef struct SecLabelStmt /* ---------------------- * Declare Cursor Statement * - * Note: the "query" field of DeclareCursorStmt is only used in the raw grammar - * output. After parse analysis it's set to null, and the Query points to the - * DeclareCursorStmt, not vice versa. + * The "query" field is initially a raw parse tree, and is converted to a + * Query node during parse analysis. Note that rewriting and planning + * of the query are always postponed until execution. * ---------------------- */ #define CURSOR_OPT_BINARY 0x0001 /* BINARY */ @@ -2493,7 +2528,7 @@ typedef struct DeclareCursorStmt NodeTag type; char *portalname; /* name of the portal (cursor) */ int options; /* bitmask of options (see above) */ - Node *query; /* the raw SELECT query */ + Node *query; /* the query (see comments above) */ } DeclareCursorStmt; /* ---------------------- @@ -2841,7 +2876,7 @@ typedef struct ViewStmt NodeTag type; RangeVar *view; /* the view to be created */ List *aliases; /* target column names */ - Node *query; /* the SELECT query */ + Node *query; /* the SELECT query (as a raw parse tree) */ bool replace; /* replace an existing view? */ List *options; /* options from WITH clause */ ViewCheckOption withCheckOption; /* WITH CHECK OPTION */ @@ -2950,9 +2985,9 @@ typedef struct VacuumStmt /* ---------------------- * Explain Statement * - * The "query" field is either a raw parse tree (SelectStmt, InsertStmt, etc) - * or a Query node if parse analysis has been done. Note that rewriting and - * planning of the query are always postponed until execution of EXPLAIN. + * The "query" field is initially a raw parse tree, and is converted to a + * Query node during parse analysis. Note that rewriting and planning + * of the query are always postponed until execution. * ---------------------- */ typedef struct ExplainStmt |