[tarantool-patches] [PATCH] json: clarify bad syntax error messages
Roman Khabibov
roman.habibov at tarantool.org
Tue Sep 24 10:41:12 MSK 2019
Count lines in the json parsing structure. It is needed to print
the number of line and column where a mistake was made.
Closes #3316
---
Branch: https://github.com/tarantool/tarantool/tree/romanhabibov/gh-3316-json-decode
Issue: https://github.com/tarantool/tarantool/issues/3316
test/app-tap/json.test.lua | 26 ++++++++++++++++-
third_party/lua-cjson/lua_cjson.c | 47 ++++++++++++++++---------------
2 files changed, 50 insertions(+), 23 deletions(-)
diff --git a/test/app-tap/json.test.lua b/test/app-tap/json.test.lua
index 10f6f4ab2..f583ea653 100755
--- a/test/app-tap/json.test.lua
+++ b/test/app-tap/json.test.lua
@@ -22,7 +22,7 @@ end
tap.test("json", function(test)
local serializer = require('json')
- test:plan(32)
+ test:plan(37)
test:test("unsigned", common.test_unsigned, serializer)
test:test("signed", common.test_signed, serializer)
@@ -121,4 +121,28 @@ tap.test("json", function(test)
test:is(serializer.encode(rec4),
'{"a":{"a":null,"b":null},"b":{"a":null,"b":null}}')
serializer.cfg({encode_max_depth = orig_encode_max_depth})
+
+ --
+ -- gh-3316: Make sure that line number is printed in the error
+ -- message.
+ --
+ local _, err_msg
+ _, err_msg = pcall(serializer.decode, 'a{"hello": \n"world"}')
+ test:ok(string.find(err_msg, 'line 1 at character 1') ~= nil,
+ 'mistake on first line')
+ _, err_msg = pcall(serializer.decode, '{"hello": \n"world"a}')
+ test:ok(string.find(err_msg, 'line 2 at character 8') ~= nil,
+ 'mistake on second line')
+ _, err_msg = pcall(serializer.decode, '\n\n\n\n{"hello": "world"a}')
+ test:ok(string.find(err_msg, 'line 5 at character 18') ~= nil,
+ 'mistake on fifth line')
+ serializer.cfg{decode_max_depth = 1}
+ _, err_msg = pcall(serializer.decode,
+ '{"hello": {"world": {"hello": "world"}}}')
+ test:ok(string.find(err_msg, 'line 1 at character 11') ~= nil,
+ 'mistake on first line')
+ _, err_msg = pcall(serializer.decode,
+ '{"hello": \n{"world": {"hello": "world"}}}')
+ test:ok(string.find(err_msg, 'line 2 at character 1') ~= nil,
+ 'mistake on second line')
end)
diff --git a/third_party/lua-cjson/lua_cjson.c b/third_party/lua-cjson/lua_cjson.c
index 6b03e391a..0dee2deb9 100644
--- a/third_party/lua-cjson/lua_cjson.c
+++ b/third_party/lua-cjson/lua_cjson.c
@@ -66,6 +66,7 @@ typedef enum {
T_COMMA,
T_END,
T_WHITESPACE,
+ T_LINEFEED,
T_ERROR,
T_UNKNOWN
} json_token_type_t;
@@ -85,6 +86,7 @@ static const char *json_token_type_name[] = {
"T_COMMA",
"T_END",
"T_WHITESPACE",
+ "T_LINEFEED",
"T_ERROR",
"T_UNKNOWN",
NULL
@@ -105,11 +107,12 @@ typedef struct {
strbuf_t *tmp; /* Temporary storage for strings */
struct luaL_serializer *cfg;
int current_depth;
+ int line_count;
+ const char *cur_line_ptr;
} json_parse_t;
typedef struct {
json_token_type_t type;
- int index;
union {
const char *string;
double number;
@@ -195,7 +198,7 @@ static void json_create_tokens()
ch2token['\0'] = T_END;
ch2token[' '] = T_WHITESPACE;
ch2token['\t'] = T_WHITESPACE;
- ch2token['\n'] = T_WHITESPACE;
+ ch2token['\n'] = T_LINEFEED;
ch2token['\r'] = T_WHITESPACE;
/* Update characters that require further processing */
@@ -588,11 +591,9 @@ static int json_append_unicode_escape(json_parse_t *json)
return 0;
}
-static void json_set_token_error(json_token_t *token, json_parse_t *json,
- const char *errtype)
+static void json_set_token_error(json_token_t *token, const char *errtype)
{
token->type = T_ERROR;
- token->index = json->ptr - json->data;
token->value.string = errtype;
}
@@ -615,7 +616,7 @@ static void json_next_string_token(json_parse_t *json, json_token_t *token)
while ((ch = *json->ptr) != '"') {
if (!ch) {
/* Premature end of the string */
- json_set_token_error(token, json, "unexpected end of string");
+ json_set_token_error(token, "unexpected end of string");
return;
}
@@ -630,12 +631,11 @@ static void json_next_string_token(json_parse_t *json, json_token_t *token)
if (json_append_unicode_escape(json) == 0)
continue;
- json_set_token_error(token, json,
- "invalid unicode escape code");
+ json_set_token_error(token, "invalid unicode escape code");
return;
}
if (!ch) {
- json_set_token_error(token, json, "invalid escape code");
+ json_set_token_error(token, "invalid escape code");
return;
}
@@ -715,7 +715,7 @@ static void json_next_number_token(json_parse_t *json, json_token_t *token)
}
if (json->ptr == endptr)
- json_set_token_error(token, json, "invalid number");
+ json_set_token_error(token, "invalid number");
else
json->ptr = endptr; /* Skip the processed number */
}
@@ -732,18 +732,18 @@ static void json_next_token(json_parse_t *json, json_token_t *token)
while (1) {
ch = (unsigned char)*(json->ptr);
token->type = ch2token[ch];
- if (token->type != T_WHITESPACE)
+ if (token->type == T_LINEFEED) {
+ json->line_count++;
+ json->cur_line_ptr = json->ptr + 1;
+ } else if (token->type != T_WHITESPACE) {
break;
+ }
json->ptr++;
}
- /* Store location of new token. Required when throwing errors
- * for unexpected tokens (syntax errors). */
- token->index = json->ptr - json->data;
-
/* Don't advance the pointer for an error or the end */
if (token->type == T_ERROR) {
- json_set_token_error(token, json, "invalid token");
+ json_set_token_error(token, "invalid token");
return;
}
@@ -808,7 +808,7 @@ static void json_next_token(json_parse_t *json, json_token_t *token)
}
/* Token starts with t/f/n but isn't recognised above. */
- json_set_token_error(token, json, "invalid token");
+ json_set_token_error(token, "invalid token");
}
/* This function does not return.
@@ -829,9 +829,9 @@ static void json_throw_parse_error(lua_State *l, json_parse_t *json,
else
found = json_token_type_name[token->type];
- /* Note: token->index is 0 based, display starting from 1 */
- luaL_error(l, "Expected %s but found %s at character %d",
- exp, found, token->index + 1);
+ luaL_error(l, "Expected %s but found %s on line %d at character %d",
+ exp, found, json->line_count,
+ json->ptr - json->cur_line_ptr + 1);
}
static inline void json_decode_ascend(json_parse_t *json)
@@ -849,8 +849,9 @@ static void json_decode_descend(lua_State *l, json_parse_t *json, int slots)
}
strbuf_free(json->tmp);
- luaL_error(l, "Found too many nested data structures (%d) at character %d",
- json->current_depth, json->ptr - json->data);
+ luaL_error(l, "Found too many nested data structures (%d) on line %d at "
+ "character %d", json->current_depth, json->line_count,
+ json->ptr - json->cur_line_ptr);
}
static void json_parse_object_context(lua_State *l, json_parse_t *json)
@@ -1001,6 +1002,8 @@ static int json_decode(lua_State *l)
json.data = luaL_checklstring(l, 1, &json_len);
json.current_depth = 0;
json.ptr = json.data;
+ json.line_count = 1;
+ json.cur_line_ptr = json.data;
/* Detect Unicode other than UTF-8 (see RFC 4627, Sec 3)
*
--
2.20.1 (Apple Git-117)
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