mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-28 20:56:54 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 8

bpo-35494: Improve syntax error messages for unbalanced parentheses in f-string. (GH-11161)

Browse source
This commit is contained in:
Serhiy Storchaka 2019-01-12 09:46:50 +02:00 • committed by GitHub
parent 44cc4822bb
commit 58159ef856
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
3 changed files with 51 additions and 17 deletions
Download patch file Download diff file Expand all files Collapse all files

31
Python/ast.c
View file

@ -13,6 +13,8 @@
#include <assert.h>
#include <stdbool.h>
#define MAXLEVEL 200 /* Max parentheses level */
static int validate_stmts(asdl_seq *);
static int validate_exprs(asdl_seq *, expr_context_ty, int);
static int validate_nonempty_seq(asdl_seq *, const char *, const char *);
@ -4479,6 +4481,7 @@ fstring_find_expr(const char **str, const char *end, int raw, int recurse_lvl,
/* Keep track of nesting level for braces/parens/brackets in
expressions. */
Py_ssize_t nested_depth = 0;
char parenstack[MAXLEVEL];
/* Can only nest one level deep. */
if (recurse_lvl >= 2) {
@ -4553,10 +4556,12 @@ fstring_find_expr(const char **str, const char *end, int raw, int recurse_lvl,
/* Start looking for the end of the string. */
quote_char = ch;
} else if (ch == '[' || ch == '{' || ch == '(') {
if (nested_depth >= MAXLEVEL) {
ast_error(c, n, "f-string: too many nested parenthesis");
return -1;
}
parenstack[nested_depth] = ch;
nested_depth++;
} else if (nested_depth != 0 &&
(ch == ']' || ch == '}' || ch == ')')) {
nested_depth--;
} else if (ch == '#') {
/* Error: can't include a comment character, inside parens
or not. */
@ -4573,6 +4578,23 @@ fstring_find_expr(const char **str, const char *end, int raw, int recurse_lvl,
}
/* Normal way out of this loop. */
break;
} else if (ch == ']' || ch == '}' || ch == ')') {
if (!nested_depth) {
ast_error(c, n, "f-string: unmatched '%c'", ch);
return -1;
}
nested_depth--;
int opening = parenstack[nested_depth];
if (!((opening == '(' && ch == ')') ||
(opening == '[' && ch == ']') ||
(opening == '{' && ch == '}')))
{
ast_error(c, n,
"f-string: closing parenthesis '%c' "
"does not match opening parenthesis '%c'",
ch, opening);
return -1;
}
} else {
/* Just consume this char and loop around. */
}
@ -4587,7 +4609,8 @@ fstring_find_expr(const char **str, const char *end, int raw, int recurse_lvl,
return -1;
}
if (nested_depth) {
ast_error(c, n, "f-string: mismatched '(', '{', or '['");
int opening = parenstack[nested_depth - 1];
ast_error(c, n, "f-string: unmatched '%c'", opening);
return -1;
}