Hello,
Here is a v5.
While adding a basic function call syntax to expressions, a noticed that it
would be useful to access the "detail" field of syntax errors so as to
report the name of the unknown function. This version just adds the hook
(expr_yyerror_detailed) that could be called later for this purpose.
Let's not add code that isn't doing anything yet. We can patch the
system more later if we need to.
Ok.
+/* better error reporting with bison */
+%define parse.lac full
+%define parse.error verbose
What does this do?
It adds an explanation on syntax errors, instead of the laconic "syntax
error" which is akin to a boolean.
The comments should explain, I think.
I thought it did with the sentence "better error reporting with bison".
Does it work on all versions of bison >= the minimum version we support?
Good question. After some digging, it seems to be 1.85 since pg 7.4... It
does not seem to have a '%define' directive yet. That's too bad, because I
like the better messages. So I put the define in a comment.
Maybe some conditional activation from configure generated macro could be
possible, but I did not find anything about bison version.
+void syntax_error(const char *source, const int lineno,
+ if (line) {
Not project style.
Indeed.
How about having syntax_error using appendPQExpBuffer() and friends
instead of printing data one character at a time?
This is just a basic error message printed before exiting. The simpler and
more straightforward the better, IMHO. Pgbench relies on basic
"fprintf(stderr, ...)" for error messages everywhere, I tried to blend in,
eg I avoided "fputc" for printing alignment spaces for instance. PQ buffer
stuff is not used anywhere else in pgbench. It seems to me overkill to
introduce it there just for this function. I'll do it only if required.
+/* error message generation helper */
+#define SYNTAX_ERROR(msg, more, col) \
+ syntax_error(source, lineno, my_commands->line, \
+ my_commands->argv[0], msg, more, col)
+
I don't like this. Just substitute the expansion. Otherwise there's
a non-obvious dependency on my_commands.
I wanted to have one line calls and to avoid repeating the same list of
arguments over and over again, especially with the very long "my_commands"
variable name.
Once expanded, the result is either two long lines or three
under-80-column lines per call. Not sure which one of these ugly choices
is best. I took the first option.
+ /* stop "set" argument parsing the variable name */
This comment addition isn't related to the purpose of this patch, and
I also can't understand what the new comment is supposed to mean.
It's the value we don't want to strtok()-ify, not the name.
I wanted to write: "stop set argument parsing after the variable name"
(I forgot "after") because I had to figure out the max_args management
and a minimal comment would have helped. Maybe not with this comment
though. I removed it.
--
Fabien.
diff --git a/contrib/pgbench/exprparse.y b/contrib/pgbench/exprparse.y
index 243c6b9..7173448 100644
--- a/contrib/pgbench/exprparse.y
+++ b/contrib/pgbench/exprparse.y
@@ -26,6 +26,13 @@ static PgBenchExpr *make_op(char operator, PgBenchExpr *lexpr,
%expect 0
%name-prefix="expr_yy"
+/*
+// improve bison generated syntax error messages
+// *but* not available with PostgreSQL mimimal bison 1.875
+%define parse.lac full
+%define parse.error verbose
+*/
+
%union
{
int64 ival;
diff --git a/contrib/pgbench/exprscan.l b/contrib/pgbench/exprscan.l
index 4c9229c..9de7dab 100644
--- a/contrib/pgbench/exprscan.l
+++ b/contrib/pgbench/exprscan.l
@@ -18,6 +18,13 @@ static YY_BUFFER_STATE scanbufhandle;
static char *scanbuf;
static int scanbuflen;
+/* context information for error reporting */
+static char *expr_source = NULL;
+static int expr_lineno = 0;
+static char *expr_full_line = NULL;
+static char *expr_command = NULL;
+static int expr_col = 0;
+
/* flex 2.5.4 doesn't bother with a decl for this */
int expr_yylex(void);
@@ -52,7 +59,9 @@ space [ \t\r\f]
. {
yycol += yyleng;
- fprintf(stderr, "unexpected character '%s'\n", yytext);
+ syntax_error(expr_source, expr_lineno, expr_full_line, expr_command,
+ "unexpected character", yytext, expr_col + yycol);
+ /* dead code, exit is called from syntax_error */
return CHAR_ERROR;
}
%%
@@ -60,21 +69,27 @@ space [ \t\r\f]
void
yyerror(const char *message)
{
- /* yyline is always 1 as pgbench calls the parser for each line...
- * so the interesting location information is the column number */
- fprintf(stderr, "%s at column %d\n", message, yycol);
- /* go on to raise the error from pgbench with more information */
- /* exit(1); */
+ syntax_error(expr_source, expr_lineno, expr_full_line, expr_command,
+ message, NULL, expr_col + yycol);
}
/*
* Called before any actual parsing is done
*/
void
-expr_scanner_init(const char *str)
+expr_scanner_init(const char *str, const char *source,
+ const int lineno, const char *line,
+ const char *cmd, const int ecol)
{
Size slen = strlen(str);
+ /* save context informations for error messages */
+ expr_source = (char *) source;
+ expr_lineno = (int) lineno;
+ expr_full_line = (char *) line;
+ expr_command = (char *) cmd;
+ expr_col = (int) ecol;
+
/*
* Might be left over after error
*/
@@ -102,4 +117,9 @@ expr_scanner_finish(void)
{
yy_delete_buffer(scanbufhandle);
pg_free(scanbuf);
+ expr_source = NULL;
+ expr_lineno = 0;
+ expr_full_line = NULL;
+ expr_command = NULL;
+ expr_col = 0;
}
diff --git a/contrib/pgbench/pgbench.c b/contrib/pgbench/pgbench.c
index 706fdf5..ed3c786 100644
--- a/contrib/pgbench/pgbench.c
+++ b/contrib/pgbench/pgbench.c
@@ -291,6 +291,7 @@ typedef struct
int type; /* command type (SQL_COMMAND or META_COMMAND) */
int argc; /* number of command words */
char *argv[MAX_ARGS]; /* command word list */
+ int cols[MAX_ARGS]; /* corresponding column starting from 1 */
PgBenchExpr *expr; /* parsed expression */
} Command;
@@ -2189,6 +2190,29 @@ parseQuery(Command *cmd, const char *raw_sql)
return true;
}
+void
+syntax_error(const char *source, const int lineno,
+ const char *line, const char *command,
+ const char *msg, const char *more, const int column)
+{
+ fprintf(stderr, "%s:%d: %s", source, lineno, msg);
+ if (more != NULL)
+ fprintf(stderr, " (%s)", more);
+ if (column != -1)
+ fprintf(stderr, " at column %d", column);
+ fprintf(stderr, " in command \"%s\"\n", command);
+ if (line != NULL) {
+ fprintf(stderr, "%s\n", line);
+ if (column != -1) {
+ int i;
+ for (i = 0; i < column - 1; i++)
+ fprintf(stderr, " ");
+ fprintf(stderr, "^ error found here\n");
+ }
+ }
+ exit(1);
+}
+
/* Parse a command; return a Command struct, or NULL if it's a comment */
static Command *
process_commands(char *buf, const char *source, const int lineno)
@@ -2233,6 +2257,7 @@ process_commands(char *buf, const char *source, const int lineno)
while (tok != NULL)
{
+ my_commands->cols[j] = tok - buf + 1;
my_commands->argv[j++] = pg_strdup(tok);
my_commands->argc++;
if (max_args >= 0 && my_commands->argc >= max_args)
@@ -2250,9 +2275,10 @@ process_commands(char *buf, const char *source, const int lineno)
if (my_commands->argc < 4)
{
- fprintf(stderr, "%s: missing argument\n", my_commands->argv[0]);
- exit(1);
+ syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
+ "missing arguments", NULL, -1);
}
+
/* argc >= 4 */
if (my_commands->argc == 4 || /* uniform without/with "uniform" keyword */
@@ -2267,41 +2293,38 @@ process_commands(char *buf, const char *source, const int lineno)
{
if (my_commands->argc < 6)
{
- fprintf(stderr, "%s(%s): missing threshold argument\n", my_commands->argv[0], my_commands->argv[4]);
- exit(1);
+ syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
+ "missing threshold argument", my_commands->argv[4], -1);
}
else if (my_commands->argc > 6)
{
- fprintf(stderr, "%s(%s): too many arguments (extra:",
- my_commands->argv[0], my_commands->argv[4]);
- for (j = 6; j < my_commands->argc; j++)
- fprintf(stderr, " %s", my_commands->argv[j]);
- fprintf(stderr, ")\n");
- exit(1);
+ syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
+ "too many arguments", my_commands->argv[4],
+ my_commands->cols[6]);
}
}
else /* cannot parse, unexpected arguments */
{
- fprintf(stderr, "%s: unexpected arguments (bad:", my_commands->argv[0]);
- for (j = 4; j < my_commands->argc; j++)
- fprintf(stderr, " %s", my_commands->argv[j]);
- fprintf(stderr, ")\n");
- exit(1);
+ syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
+ "unexpected argument", my_commands->argv[4],
+ my_commands->cols[4]);
}
}
else if (pg_strcasecmp(my_commands->argv[0], "set") == 0)
{
if (my_commands->argc < 3)
{
- fprintf(stderr, "%s: missing argument\n", my_commands->argv[0]);
- exit(1);
+ syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
+ "missing argument", NULL, -1);
}
- expr_scanner_init(my_commands->argv[2]);
+ expr_scanner_init(my_commands->argv[2], source, lineno,
+ my_commands->line, my_commands->argv[0],
+ my_commands->cols[2] - 1);
if (expr_yyparse() != 0)
{
- fprintf(stderr, "%s: parse error\n", my_commands->argv[0]);
+ /* dead code: exit done from syntax_error called by yyerror */
exit(1);
}
@@ -2313,8 +2336,8 @@ process_commands(char *buf, const char *source, const int lineno)
{
if (my_commands->argc < 2)
{
- fprintf(stderr, "%s: missing argument\n", my_commands->argv[0]);
- exit(1);
+ syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
+ "missing argument", NULL, -1);
}
/*
@@ -2343,12 +2366,13 @@ process_commands(char *buf, const char *source, const int lineno)
pg_strcasecmp(my_commands->argv[2], "ms") != 0 &&
pg_strcasecmp(my_commands->argv[2], "s") != 0)
{
- fprintf(stderr, "%s: unknown time unit '%s' - must be us, ms or s\n",
- my_commands->argv[0], my_commands->argv[2]);
- exit(1);
+ syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
+ "unknown time unit, must be us, ms or s",
+ my_commands->argv[2], my_commands->cols[2]);
}
}
+ /* this should be an error?! */
for (j = 3; j < my_commands->argc; j++)
fprintf(stderr, "%s: extra argument \"%s\" ignored\n",
my_commands->argv[0], my_commands->argv[j]);
@@ -2357,22 +2381,22 @@ process_commands(char *buf, const char *source, const int lineno)
{
if (my_commands->argc < 3)
{
- fprintf(stderr, "%s: missing argument\n", my_commands->argv[0]);
- exit(1);
+ syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
+ "missing argument", NULL, -1);
}
}
else if (pg_strcasecmp(my_commands->argv[0], "shell") == 0)
{
if (my_commands->argc < 1)
{
- fprintf(stderr, "%s: missing command\n", my_commands->argv[0]);
- exit(1);
+ syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
+ "missing command", NULL, -1);
}
}
else
{
- fprintf(stderr, "Invalid command %s\n", my_commands->argv[0]);
- exit(1);
+ syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
+ "invalid command", NULL, -1);
}
}
else
diff --git a/contrib/pgbench/pgbench.h b/contrib/pgbench/pgbench.h
index 128bf11..9143a17 100644
--- a/contrib/pgbench/pgbench.h
+++ b/contrib/pgbench/pgbench.h
@@ -48,7 +48,12 @@ extern PgBenchExpr *expr_parse_result;
extern int expr_yyparse(void);
extern int expr_yylex(void);
extern void expr_yyerror(const char *str);
-extern void expr_scanner_init(const char *str);
+extern void expr_scanner_init(const char *str, const char *source,
+ const int lineno, const char *line,
+ const char *cmd, const int ecol);
+extern void syntax_error(const char* source, const int lineno, const char* line,
+ const char* cmd, const char* msg, const char* more,
+ const int col);
extern void expr_scanner_finish(void);
extern int64 strtoint64(const char *str);
--
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