aboutsummaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/backend/commands/copyto.c8
-rw-r--r--src/backend/commands/createas.c8
-rw-r--r--src/backend/commands/explain.c14
-rw-r--r--src/backend/commands/extension.c1
-rw-r--r--src/backend/commands/foreigncmds.c3
-rw-r--r--src/backend/commands/policy.c8
-rw-r--r--src/backend/commands/portalcmds.c8
-rw-r--r--src/backend/commands/prepare.c5
-rw-r--r--src/backend/commands/schemacmds.c1
-rw-r--r--src/backend/commands/tablecmds.c3
-rw-r--r--src/backend/commands/view.c5
-rw-r--r--src/backend/executor/functions.c1
-rw-r--r--src/backend/executor/spi.c1
-rw-r--r--src/backend/parser/parse_utilcmd.c36
-rw-r--r--src/backend/tcop/pquery.c1
-rw-r--r--src/backend/tcop/utility.c23
-rw-r--r--src/include/tcop/utility.h6
17 files changed, 47 insertions, 85 deletions
diff --git a/src/backend/commands/copyto.c b/src/backend/commands/copyto.c
index 89a4f8f810e..b6eacd5baa8 100644
--- a/src/backend/commands/copyto.c
+++ b/src/backend/commands/copyto.c
@@ -438,14 +438,8 @@ BeginCopyTo(ParseState *pstate,
/*
* Run parse analysis and rewrite. Note this also acquires sufficient
* locks on the source table(s).
- *
- * Because the parser and planner tend to scribble on their input, we
- * make a preliminary copy of the source querytree. This prevents
- * problems in the case that the COPY is in a portal or plpgsql
- * function and is executed repeatedly. (See also the same hack in
- * DECLARE CURSOR and PREPARE.) XXX FIXME someday.
*/
- rewritten = pg_analyze_and_rewrite(copyObject(raw_query),
+ rewritten = pg_analyze_and_rewrite(raw_query,
pstate->p_sourcetext, NULL, 0,
NULL);
diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index dce882012e6..09828517153 100644
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -299,14 +299,8 @@ ExecCreateTableAs(ParseState *pstate, CreateTableAsStmt *stmt,
* rewriter. We do not do AcquireRewriteLocks: we assume the query
* either came straight from the parser, or suitable locks were
* acquired by plancache.c.
- *
- * Because the rewriter and planner tend to scribble on the input, we
- * make a preliminary copy of the source querytree. This prevents
- * problems in the case that CTAS is in a portal or plpgsql function
- * and is executed repeatedly. (See also the same hack in EXPLAIN and
- * PREPARE.)
*/
- rewritten = QueryRewrite(copyObject(query));
+ rewritten = QueryRewrite(query);
/* SELECT should never rewrite to more or less than one SELECT query */
if (list_length(rewritten) != 1)
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 9a60865d191..e81b9900925 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -256,14 +256,8 @@ ExplainQuery(ParseState *pstate, ExplainStmt *stmt,
* rewriter. We do not do AcquireRewriteLocks: we assume the query either
* came straight from the parser, or suitable locks were acquired by
* plancache.c.
- *
- * Because the rewriter and planner tend to scribble on the input, we make
- * a preliminary copy of the source querytree. This prevents problems in
- * the case that the EXPLAIN is in a portal or plpgsql function and is
- * executed repeatedly. (See also the same hack in DECLARE CURSOR and
- * PREPARE.) XXX FIXME someday.
*/
- rewritten = QueryRewrite(castNode(Query, copyObject(stmt->query)));
+ rewritten = QueryRewrite(castNode(Query, stmt->query));
/* emit opening boilerplate */
ExplainBeginOutput(es);
@@ -427,7 +421,8 @@ ExplainOneQuery(Query *query, int cursorOptions,
* "into" is NULL unless we are explaining the contents of a CreateTableAsStmt.
*
* This is exported because it's called back from prepare.c in the
- * EXPLAIN EXECUTE case.
+ * EXPLAIN EXECUTE case. In that case, we'll be dealing with a statement
+ * that's in the plan cache, so we have to ensure we don't modify it.
*/
void
ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
@@ -441,8 +436,7 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
{
/*
* We have to rewrite the contained SELECT and then pass it back to
- * ExplainOneQuery. It's probably not really necessary to copy the
- * contained parsetree another time, but let's be safe.
+ * ExplainOneQuery. Copy to be safe in the EXPLAIN EXECUTE case.
*/
CreateTableAsStmt *ctas = (CreateTableAsStmt *) utilityStmt;
List *rewritten;
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 008505368c4..41857feda9f 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -786,6 +786,7 @@ execute_sql_string(const char *sql)
ProcessUtility(stmt,
sql,
+ false,
PROCESS_UTILITY_QUERY,
NULL,
NULL,
diff --git a/src/backend/commands/foreigncmds.c b/src/backend/commands/foreigncmds.c
index eb7103fd3b1..bc36311d383 100644
--- a/src/backend/commands/foreigncmds.c
+++ b/src/backend/commands/foreigncmds.c
@@ -1570,8 +1570,7 @@ ImportForeignSchema(ImportForeignSchemaStmt *stmt)
pstmt->stmt_len = rs->stmt_len;
/* Execute statement */
- ProcessUtility(pstmt,
- cmd,
+ ProcessUtility(pstmt, cmd, false,
PROCESS_UTILITY_SUBCOMMAND, NULL, NULL,
None_Receiver, NULL);
diff --git a/src/backend/commands/policy.c b/src/backend/commands/policy.c
index 5cacc088cd8..5d469309ce1 100644
--- a/src/backend/commands/policy.c
+++ b/src/backend/commands/policy.c
@@ -747,12 +747,12 @@ CreatePolicy(CreatePolicyStmt *stmt)
addNSItemToQuery(with_check_pstate, nsitem, false, true, true);
qual = transformWhereClause(qual_pstate,
- copyObject(stmt->qual),
+ stmt->qual,
EXPR_KIND_POLICY,
"POLICY");
with_check_qual = transformWhereClause(with_check_pstate,
- copyObject(stmt->with_check),
+ stmt->with_check,
EXPR_KIND_POLICY,
"POLICY");
@@ -922,7 +922,7 @@ AlterPolicy(AlterPolicyStmt *stmt)
addNSItemToQuery(qual_pstate, nsitem, false, true, true);
- qual = transformWhereClause(qual_pstate, copyObject(stmt->qual),
+ qual = transformWhereClause(qual_pstate, stmt->qual,
EXPR_KIND_POLICY,
"POLICY");
@@ -946,7 +946,7 @@ AlterPolicy(AlterPolicyStmt *stmt)
addNSItemToQuery(with_check_pstate, nsitem, false, true, true);
with_check_qual = transformWhereClause(with_check_pstate,
- copyObject(stmt->with_check),
+ stmt->with_check,
EXPR_KIND_POLICY,
"POLICY");
diff --git a/src/backend/commands/portalcmds.c b/src/backend/commands/portalcmds.c
index d34cc39fdea..3ea30bcbc99 100644
--- a/src/backend/commands/portalcmds.c
+++ b/src/backend/commands/portalcmds.c
@@ -76,14 +76,8 @@ PerformCursorOpen(ParseState *pstate, DeclareCursorStmt *cstmt, ParamListInfo pa
* rewriter. We do not do AcquireRewriteLocks: we assume the query either
* came straight from the parser, or suitable locks were acquired by
* plancache.c.
- *
- * Because the rewriter and planner tend to scribble on the input, we make
- * a preliminary copy of the source querytree. This prevents problems in
- * the case that the DECLARE CURSOR is in a portal or plpgsql function and
- * is executed repeatedly. (See also the same hack in EXPLAIN and
- * PREPARE.) XXX FIXME someday.
*/
- rewritten = QueryRewrite((Query *) copyObject(query));
+ rewritten = QueryRewrite(query);
/* SELECT should never rewrite to more or less than one query */
if (list_length(rewritten) != 1)
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 65d8ac65b18..5e03c7c5aaa 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -78,12 +78,9 @@ PrepareQuery(ParseState *pstate, PrepareStmt *stmt,
/*
* Need to wrap the contained statement in a RawStmt node to pass it to
* parse analysis.
- *
- * Because parse analysis scribbles on the raw querytree, we must make a
- * copy to ensure we don't modify the passed-in tree. FIXME someday.
*/
rawstmt = makeNode(RawStmt);
- rawstmt->stmt = (Node *) copyObject(stmt->query);
+ rawstmt->stmt = stmt->query;
rawstmt->stmt_location = stmt_location;
rawstmt->stmt_len = stmt_len;
diff --git a/src/backend/commands/schemacmds.c b/src/backend/commands/schemacmds.c
index a60eb161e4a..6c6ab9ee349 100644
--- a/src/backend/commands/schemacmds.c
+++ b/src/backend/commands/schemacmds.c
@@ -191,6 +191,7 @@ CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString,
/* do this step */
ProcessUtility(wrapper,
queryString,
+ false,
PROCESS_UTILITY_SUBCOMMAND,
NULL,
NULL,
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 028e8ac46b3..4e23c7fce5f 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -4408,8 +4408,7 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
* Copy the original subcommand for each table. This avoids conflicts
* when different child tables need to make different parse
* transformations (for example, the same column may have different column
- * numbers in different children). It also ensures that we don't corrupt
- * the original parse tree, in case it is saved in plancache.
+ * numbers in different children).
*/
cmd = copyObject(cmd);
diff --git a/src/backend/commands/view.c b/src/backend/commands/view.c
index f2642dba6c9..4df05a0b33d 100644
--- a/src/backend/commands/view.c
+++ b/src/backend/commands/view.c
@@ -417,12 +417,9 @@ DefineView(ViewStmt *stmt, const char *queryString,
/*
* Run parse analysis to convert the raw parse tree to a Query. Note this
* also acquires sufficient locks on the source table(s).
- *
- * Since parse analysis scribbles on its input, copy the raw parse tree;
- * this ensures we don't corrupt a prepared statement, for example.
*/
rawstmt = makeNode(RawStmt);
- rawstmt->stmt = (Node *) copyObject(stmt->query);
+ rawstmt->stmt = stmt->query;
rawstmt->stmt_location = stmt_location;
rawstmt->stmt_len = stmt_len;
diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c
index e2ea51aafe5..296e54e60a4 100644
--- a/src/backend/executor/functions.c
+++ b/src/backend/executor/functions.c
@@ -886,6 +886,7 @@ postquel_getnext(execution_state *es, SQLFunctionCachePtr fcache)
{
ProcessUtility(es->qd->plannedstmt,
fcache->src,
+ false,
PROCESS_UTILITY_QUERY,
es->qd->params,
es->qd->queryEnv,
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index b8bd05e8942..bf619d3a65a 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -2545,6 +2545,7 @@ _SPI_execute_plan(SPIPlanPtr plan, ParamListInfo paramLI,
InitializeQueryCompletion(&qc);
ProcessUtility(stmt,
plansource->query_string,
+ true, /* protect plancache's node tree */
context,
paramLI,
_SPI_current->queryEnv,
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index c9708e38f46..81d3e7990c6 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -11,10 +11,6 @@
* Hence these functions are now called at the start of execution of their
* respective utility commands.
*
- * NOTE: in general we must avoid scribbling on the passed-in raw parse
- * tree, since it might be in a plan cache. The simplest solution is
- * a quick copyObject() call before manipulating the query tree.
- *
*
* Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
@@ -177,12 +173,6 @@ transformCreateStmt(CreateStmt *stmt, const char *queryString)
Oid existing_relid;
ParseCallbackState pcbstate;
- /*
- * We must not scribble on the passed-in CreateStmt, so copy it. (This is
- * overkill, but easy.)
- */
- stmt = copyObject(stmt);
-
/* Set up pstate */
pstate = make_parsestate(NULL);
pstate->p_sourcetext = queryString;
@@ -2824,12 +2814,6 @@ transformIndexStmt(Oid relid, IndexStmt *stmt, const char *queryString)
if (stmt->transformed)
return stmt;
- /*
- * We must not scribble on the passed-in IndexStmt, so copy it. (This is
- * overkill, but easy.)
- */
- stmt = copyObject(stmt);
-
/* Set up pstate */
pstate = make_parsestate(NULL);
pstate->p_sourcetext = queryString;
@@ -2925,12 +2909,6 @@ transformStatsStmt(Oid relid, CreateStatsStmt *stmt, const char *queryString)
if (stmt->transformed)
return stmt;
- /*
- * We must not scribble on the passed-in CreateStatsStmt, so copy it.
- * (This is overkill, but easy.)
- */
- stmt = copyObject(stmt);
-
/* Set up pstate */
pstate = make_parsestate(NULL);
pstate->p_sourcetext = queryString;
@@ -2993,9 +2971,6 @@ transformStatsStmt(Oid relid, CreateStatsStmt *stmt, const char *queryString)
*
* actions and whereClause are output parameters that receive the
* transformed results.
- *
- * Note that we must not scribble on the passed-in RuleStmt, so we do
- * copyObject() on the actions and WHERE clause.
*/
void
transformRuleStmt(RuleStmt *stmt, const char *queryString,
@@ -3070,7 +3045,7 @@ transformRuleStmt(RuleStmt *stmt, const char *queryString,
/* take care of the where clause */
*whereClause = transformWhereClause(pstate,
- (Node *) copyObject(stmt->whereClause),
+ stmt->whereClause,
EXPR_KIND_WHERE,
"WHERE");
/* we have to fix its collations too */
@@ -3142,8 +3117,7 @@ transformRuleStmt(RuleStmt *stmt, const char *queryString,
addNSItemToQuery(sub_pstate, newnsitem, false, true, false);
/* Transform the rule action statement */
- top_subqry = transformStmt(sub_pstate,
- (Node *) copyObject(action));
+ top_subqry = transformStmt(sub_pstate, action);
/*
* We cannot support utility-statement actions (eg NOTIFY) with
@@ -3325,12 +3299,6 @@ transformAlterTableStmt(Oid relid, AlterTableStmt *stmt,
AlterTableCmd *newcmd;
ParseNamespaceItem *nsitem;
- /*
- * We must not scribble on the passed-in AlterTableStmt, so copy it. (This
- * is overkill, but easy.)
- */
- stmt = copyObject(stmt);
-
/* Caller is responsible for locking the relation */
rel = relation_open(relid, NoLock);
tupdesc = RelationGetDescr(rel);
diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c
index f7f08e6c05f..ed43920264a 100644
--- a/src/backend/tcop/pquery.c
+++ b/src/backend/tcop/pquery.c
@@ -1146,6 +1146,7 @@ PortalRunUtility(Portal portal, PlannedStmt *pstmt,
ProcessUtility(pstmt,
portal->sourceText,
+ (portal->cplan != NULL), /* protect tree if in plancache */
isTopLevel ? PROCESS_UTILITY_TOPLEVEL : PROCESS_UTILITY_QUERY,
portal->portalParams,
portal->queryEnv,
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 1a8fc167733..7a2da9dab43 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -476,6 +476,7 @@ CheckRestrictedOperation(const char *cmdname)
*
* pstmt: PlannedStmt wrapper for the utility statement
* queryString: original source text of command
+ * readOnlyTree: if true, pstmt's node tree must not be modified
* context: identifies source of statement (toplevel client command,
* non-toplevel client command, subcommand of a larger utility command)
* params: parameters to use during execution
@@ -501,6 +502,7 @@ CheckRestrictedOperation(const char *cmdname)
void
ProcessUtility(PlannedStmt *pstmt,
const char *queryString,
+ bool readOnlyTree,
ProcessUtilityContext context,
ParamListInfo params,
QueryEnvironment *queryEnv,
@@ -518,11 +520,11 @@ ProcessUtility(PlannedStmt *pstmt,
* call standard_ProcessUtility().
*/
if (ProcessUtility_hook)
- (*ProcessUtility_hook) (pstmt, queryString,
+ (*ProcessUtility_hook) (pstmt, queryString, readOnlyTree,
context, params, queryEnv,
dest, qc);
else
- standard_ProcessUtility(pstmt, queryString,
+ standard_ProcessUtility(pstmt, queryString, readOnlyTree,
context, params, queryEnv,
dest, qc);
}
@@ -541,13 +543,14 @@ ProcessUtility(PlannedStmt *pstmt,
void
standard_ProcessUtility(PlannedStmt *pstmt,
const char *queryString,
+ bool readOnlyTree,
ProcessUtilityContext context,
ParamListInfo params,
QueryEnvironment *queryEnv,
DestReceiver *dest,
QueryCompletion *qc)
{
- Node *parsetree = pstmt->utilityStmt;
+ Node *parsetree;
bool isTopLevel = (context == PROCESS_UTILITY_TOPLEVEL);
bool isAtomicContext = (!(context == PROCESS_UTILITY_TOPLEVEL || context == PROCESS_UTILITY_QUERY_NONATOMIC) || IsTransactionBlock());
ParseState *pstate;
@@ -556,6 +559,18 @@ standard_ProcessUtility(PlannedStmt *pstmt,
/* This can recurse, so check for excessive recursion */
check_stack_depth();
+ /*
+ * If the given node tree is read-only, make a copy to ensure that parse
+ * transformations don't damage the original tree. This could be
+ * refactored to avoid making unnecessary copies in more cases, but it's
+ * not clear that it's worth a great deal of trouble over. Statements
+ * that are complex enough to be expensive to copy are exactly the ones
+ * we'd need to copy, so that only marginal savings seem possible.
+ */
+ if (readOnlyTree)
+ pstmt = copyObject(pstmt);
+ parsetree = pstmt->utilityStmt;
+
/* Prohibit read/write commands in read-only states. */
readonly_flags = ClassifyUtilityCommandAsReadOnly(parsetree);
if (readonly_flags != COMMAND_IS_STRICTLY_READ_ONLY &&
@@ -1211,6 +1226,7 @@ ProcessUtilitySlow(ParseState *pstate,
ProcessUtility(wrapper,
queryString,
+ false,
PROCESS_UTILITY_SUBCOMMAND,
params,
NULL,
@@ -1918,6 +1934,7 @@ ProcessUtilityForAlterTable(Node *stmt, AlterTableUtilityContext *context)
ProcessUtility(wrapper,
context->queryString,
+ false,
PROCESS_UTILITY_SUBCOMMAND,
context->params,
context->queryEnv,
diff --git a/src/include/tcop/utility.h b/src/include/tcop/utility.h
index 841062b4b35..212e9b32806 100644
--- a/src/include/tcop/utility.h
+++ b/src/include/tcop/utility.h
@@ -69,17 +69,21 @@ typedef struct AlterTableUtilityContext
/* Hook for plugins to get control in ProcessUtility() */
typedef void (*ProcessUtility_hook_type) (PlannedStmt *pstmt,
- const char *queryString, ProcessUtilityContext context,
+ const char *queryString,
+ bool readOnlyTree,
+ ProcessUtilityContext context,
ParamListInfo params,
QueryEnvironment *queryEnv,
DestReceiver *dest, QueryCompletion *qc);
extern PGDLLIMPORT ProcessUtility_hook_type ProcessUtility_hook;
extern void ProcessUtility(PlannedStmt *pstmt, const char *queryString,
+ bool readOnlyTree,
ProcessUtilityContext context, ParamListInfo params,
QueryEnvironment *queryEnv,
DestReceiver *dest, QueryCompletion *qc);
extern void standard_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
+ bool readOnlyTree,
ProcessUtilityContext context, ParamListInfo params,
QueryEnvironment *queryEnv,
DestReceiver *dest, QueryCompletion *qc);
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-31 15:02:39 +0000