On 10.04.21 03:38, Laurenz Albe wrote:
On Fri, 2021-04-09 at 19:44 +0200, I wrote:
SQL-standard function body
psql needs some new intelligence to keep track of function body
boundaries so that it doesn't send off statements when it sees
semicolons that are inside a function body.
This causes psql to fail to recognize the semicolon in the following
statement as the end of a statement:
IMPORT FOREIGN SCHEMA x FROM SERVER y INTO z OPTIONS (case 'lower');
The cause is the "case", which is recognized as the start of a function
body.
Would it be an option to recognize BEGIN and CASE as starting a
function body only if they are *not* inside parentheses, like in
the attached?
Here is an improved patch, which treats END in the same fashion
(not properly indented for readability).
Thanks, I took another look at this and augmented your change with a
change that tracks whether the statement starts with CREATE [OR REPLACE]
{FUNCTION|PROCEDURE}. That should make it pretty safe. What do you think?
From 26251be9be89583278573ed28540e5f16f2616fb Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <[email protected]>
Date: Mon, 12 Apr 2021 17:19:59 +0200
Subject: [PATCH] psql: Refine lexing of BEGIN...END blocks in CREATE FUNCTION
statements
Only track BEGIN...END blocks if they are in a CREATE [OR REPLACE]
{FUNCTION|PROCEDURE} statement. Ignore if in parentheses.
Reported-by: Laurenz Albe <[email protected]>
---
src/fe_utils/psqlscan.l | 53 ++++++++++++++++++++++++-----
src/include/fe_utils/psqlscan_int.h | 8 ++++-
2 files changed, 52 insertions(+), 9 deletions(-)
diff --git a/src/fe_utils/psqlscan.l b/src/fe_utils/psqlscan.l
index 4ec57e96a9..991b7de0b5 100644
--- a/src/fe_utils/psqlscan.l
+++ b/src/fe_utils/psqlscan.l
@@ -870,18 +870,55 @@ other .
{identifier} {
- cur_state->identifier_count++;
- if (pg_strcasecmp(yytext, "begin") == 0
- || pg_strcasecmp(yytext,
"case") == 0)
+ /*
+ * We need to track if we are inside a
BEGIN .. END block
+ * in a function definition, so that
semicolons contained
+ * therein don't terminate the whole
statement. Short of
+ * writing a full parser here, the
following heuristic
+ * should work. First, we track
whether the beginning of
+ * the statement matches CREATE [OR
REPLACE]
+ * {FUNCTION|PROCEDURE}
+ */
+
+ if (cur_state->identifier_count == 0)
+ memset(cur_state->identifiers,
0, sizeof(cur_state->identifiers));
+
+ if (pg_strcasecmp(yytext, "create") ==
0 ||
+ pg_strcasecmp(yytext,
"function") == 0 ||
+ pg_strcasecmp(yytext,
"procedure") == 0 ||
+ pg_strcasecmp(yytext, "or") ==
0 ||
+ pg_strcasecmp(yytext,
"replace") == 0)
{
- if (cur_state->identifier_count
> 1)
-
cur_state->begin_depth++;
+ if (cur_state->identifier_count
< sizeof(cur_state->identifiers))
+
cur_state->identifiers[cur_state->identifier_count] = pg_tolower((unsigned
char) yytext[0]);
}
- else if (pg_strcasecmp(yytext, "end")
== 0)
+
+ cur_state->identifier_count++;
+
+ if (cur_state->identifiers[0] == 'c' &&
+ (cur_state->identifiers[1] ==
'f' || cur_state->identifiers[1] == 'p' ||
+ (cur_state->identifiers[1] ==
'o' && cur_state->identifiers[2] == 'r' &&
+ (cur_state->identifiers[3] ==
'f' || cur_state->identifiers[3] == 'p'))) &&
+ cur_state->paren_depth == 0)
{
- if (cur_state->begin_depth > 0)
-
cur_state->begin_depth--;
+ if (pg_strcasecmp(yytext,
"begin") == 0)
+
cur_state->begin_depth++;
+ else if (pg_strcasecmp(yytext,
"case") == 0)
+ {
+ /*
+ * CASE also ends with
END. We only need to track
+ * this if we are
already inside a BEGIN.
+ */
+ if
(cur_state->begin_depth >= 1)
+
cur_state->begin_depth++;
+ }
+ else if (pg_strcasecmp(yytext,
"end") == 0)
+ {
+ if
(cur_state->begin_depth > 0)
+
cur_state->begin_depth--;
+ }
}
+
ECHO;
}
diff --git a/src/include/fe_utils/psqlscan_int.h
b/src/include/fe_utils/psqlscan_int.h
index 91d7d4d5c6..434e554961 100644
--- a/src/include/fe_utils/psqlscan_int.h
+++ b/src/include/fe_utils/psqlscan_int.h
@@ -114,8 +114,14 @@ typedef struct PsqlScanStateData
int paren_depth; /* depth of nesting in
parentheses */
int xcdepth; /* depth of nesting in
slash-star comments */
char *dolqstart; /* current $foo$ quote start string */
+
+ /*
+ * State to track boundaries of BEGIN ... END blocks in function
+ * definitions, so that semicolons do not send query too early.
+ */
int identifier_count; /* identifiers since
start of statement */
- int begin_depth; /* depth of begin/end routine
body blocks */
+ char identifiers[4]; /* records the first few identifiers */
+ int begin_depth; /* depth of begin/end pairs */
/*
* Callback functions provided by the program making use of the lexer,
--
2.31.1
