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.

Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at>
Discussion: https://www.postgresql.org/message-id/cee01d26fe55bc086b3bcf10bfe4e8d450e2f608.camel@cybertec.at

diff --git a/src/fe_utils/psqlscan.l b/src/fe_utils/psqlscan.l
index 4ec57e96a9d9a6a0d1495869754ce389fc81e2ed..991b7de0b5546ad37b452e6d420e3aaece5383be 100644 (file)
--- 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 91d7d4d5c6cd1bf40b5c01e2af591b421b2e30db..8ada9770927cc2164e04a9054a1ba8c4338abfb6 100644 (file)
--- 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,