[Python-checkins] bpo-40176: Improve error messages for trailing comma on from import (GH-20294)
Batuhan Taskaya
webhook-mailer at python.org
Thu May 21 16:42:02 EDT 2020
https://github.com/python/cpython/commit/72e0aa2fd2b9c6da2caa5a9ef54f6495fc2890b0
commit: 72e0aa2fd2b9c6da2caa5a9ef54f6495fc2890b0
branch: master
author: Batuhan Taskaya <batuhanosmantaskaya at gmail.com>
committer: GitHub <noreply at github.com>
date: 2020-05-21T21:41:58+01:00
summary:
bpo-40176: Improve error messages for trailing comma on from import (GH-20294)
files:
M Grammar/python.gram
M Lib/test/test_syntax.py
M Parser/pegen/parse.c
diff --git a/Grammar/python.gram b/Grammar/python.gram
index 40e7818d49602..9bf2697a7e2d3 100644
--- a/Grammar/python.gram
+++ b/Grammar/python.gram
@@ -134,8 +134,9 @@ import_from[stmt_ty]:
_Py_ImportFrom(NULL, b, _PyPegen_seq_count_dots(a), EXTRA) }
import_from_targets[asdl_seq*]:
| '(' a=import_from_as_names [','] ')' { a }
- | import_from_as_names
+ | import_from_as_names !','
| '*' { _PyPegen_singleton_seq(p, CHECK(_PyPegen_alias_for_star(p))) }
+ | invalid_import_from_targets
import_from_as_names[asdl_seq*]:
| a=','.import_from_as_name+ { a }
import_from_as_name[alias_ty]:
@@ -670,3 +671,6 @@ invalid_double_type_comments:
invalid_del_target:
| a=star_expression &del_target_end {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot delete %s", _PyPegen_get_expr_name(a)) }
+invalid_import_from_targets:
+ | import_from_as_names ',' {
+ RAISE_SYNTAX_ERROR("trailing comma not allowed without surrounding parentheses") }
diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py
index a82b444b67a27..6d9c4e4b55e1c 100644
--- a/Lib/test/test_syntax.py
+++ b/Lib/test/test_syntax.py
@@ -641,6 +641,14 @@
Traceback (most recent call last):
SyntaxError: cannot assign to f-string expression
+>>> from t import x,
+Traceback (most recent call last):
+SyntaxError: trailing comma not allowed without surrounding parentheses
+
+>>> from t import x,y,
+Traceback (most recent call last):
+SyntaxError: trailing comma not allowed without surrounding parentheses
+
Corner-cases that used to fail to raise the correct error:
>>> def f(*, x=lambda __debug__:0): pass
diff --git a/Parser/pegen/parse.c b/Parser/pegen/parse.c
index 286f72111e351..75aefa4d89365 100644
--- a/Parser/pegen/parse.c
+++ b/Parser/pegen/parse.c
@@ -221,154 +221,155 @@ static KeywordToken *reserved_keywords[] = {
#define invalid_lambda_star_etc_type 1150
#define invalid_double_type_comments_type 1151
#define invalid_del_target_type 1152
-#define _loop0_1_type 1153
-#define _loop0_2_type 1154
-#define _loop0_4_type 1155
-#define _gather_3_type 1156
-#define _loop0_6_type 1157
-#define _gather_5_type 1158
-#define _loop0_8_type 1159
-#define _gather_7_type 1160
-#define _loop0_10_type 1161
-#define _gather_9_type 1162
-#define _loop1_11_type 1163
-#define _loop0_13_type 1164
-#define _gather_12_type 1165
-#define _tmp_14_type 1166
-#define _tmp_15_type 1167
-#define _tmp_16_type 1168
-#define _tmp_17_type 1169
-#define _tmp_18_type 1170
-#define _tmp_19_type 1171
-#define _tmp_20_type 1172
-#define _tmp_21_type 1173
-#define _loop1_22_type 1174
-#define _tmp_23_type 1175
-#define _tmp_24_type 1176
-#define _loop0_26_type 1177
-#define _gather_25_type 1178
-#define _loop0_28_type 1179
-#define _gather_27_type 1180
-#define _tmp_29_type 1181
-#define _loop0_30_type 1182
-#define _loop1_31_type 1183
-#define _loop0_33_type 1184
-#define _gather_32_type 1185
-#define _tmp_34_type 1186
-#define _loop0_36_type 1187
-#define _gather_35_type 1188
-#define _tmp_37_type 1189
-#define _loop0_39_type 1190
-#define _gather_38_type 1191
-#define _loop0_41_type 1192
-#define _gather_40_type 1193
-#define _loop0_43_type 1194
-#define _gather_42_type 1195
-#define _loop0_45_type 1196
-#define _gather_44_type 1197
-#define _tmp_46_type 1198
-#define _loop1_47_type 1199
-#define _tmp_48_type 1200
-#define _tmp_49_type 1201
-#define _tmp_50_type 1202
-#define _tmp_51_type 1203
-#define _tmp_52_type 1204
-#define _loop0_53_type 1205
-#define _loop0_54_type 1206
-#define _loop0_55_type 1207
-#define _loop1_56_type 1208
-#define _loop0_57_type 1209
-#define _loop1_58_type 1210
-#define _loop1_59_type 1211
-#define _loop1_60_type 1212
-#define _loop0_61_type 1213
-#define _loop1_62_type 1214
-#define _loop0_63_type 1215
-#define _loop1_64_type 1216
-#define _loop0_65_type 1217
-#define _loop1_66_type 1218
-#define _loop1_67_type 1219
-#define _tmp_68_type 1220
-#define _loop0_70_type 1221
-#define _gather_69_type 1222
-#define _loop1_71_type 1223
-#define _loop0_73_type 1224
-#define _gather_72_type 1225
-#define _loop1_74_type 1226
-#define _loop0_75_type 1227
-#define _loop0_76_type 1228
-#define _loop0_77_type 1229
-#define _loop1_78_type 1230
-#define _loop0_79_type 1231
-#define _loop1_80_type 1232
-#define _loop1_81_type 1233
-#define _loop1_82_type 1234
-#define _loop0_83_type 1235
-#define _loop1_84_type 1236
-#define _loop0_85_type 1237
-#define _loop1_86_type 1238
-#define _loop0_87_type 1239
-#define _loop1_88_type 1240
-#define _loop1_89_type 1241
-#define _loop1_90_type 1242
-#define _loop1_91_type 1243
-#define _tmp_92_type 1244
-#define _loop0_94_type 1245
-#define _gather_93_type 1246
-#define _tmp_95_type 1247
-#define _tmp_96_type 1248
-#define _tmp_97_type 1249
-#define _tmp_98_type 1250
-#define _loop1_99_type 1251
-#define _tmp_100_type 1252
-#define _tmp_101_type 1253
-#define _loop0_103_type 1254
-#define _gather_102_type 1255
-#define _loop1_104_type 1256
-#define _loop0_105_type 1257
-#define _loop0_106_type 1258
-#define _tmp_107_type 1259
-#define _tmp_108_type 1260
-#define _loop0_110_type 1261
-#define _gather_109_type 1262
-#define _loop0_112_type 1263
-#define _gather_111_type 1264
-#define _loop0_114_type 1265
-#define _gather_113_type 1266
-#define _loop0_116_type 1267
-#define _gather_115_type 1268
-#define _loop0_117_type 1269
-#define _loop0_119_type 1270
-#define _gather_118_type 1271
-#define _tmp_120_type 1272
-#define _loop0_122_type 1273
-#define _gather_121_type 1274
-#define _loop0_124_type 1275
-#define _gather_123_type 1276
-#define _tmp_125_type 1277
-#define _loop0_126_type 1278
-#define _tmp_127_type 1279
-#define _tmp_128_type 1280
-#define _tmp_129_type 1281
-#define _tmp_130_type 1282
-#define _loop0_131_type 1283
-#define _tmp_132_type 1284
-#define _tmp_133_type 1285
-#define _tmp_134_type 1286
-#define _tmp_135_type 1287
-#define _tmp_136_type 1288
-#define _tmp_137_type 1289
-#define _tmp_138_type 1290
-#define _tmp_139_type 1291
-#define _tmp_140_type 1292
-#define _tmp_141_type 1293
-#define _tmp_142_type 1294
-#define _tmp_143_type 1295
-#define _tmp_144_type 1296
-#define _tmp_145_type 1297
-#define _loop1_146_type 1298
-#define _tmp_147_type 1299
-#define _tmp_148_type 1300
+#define invalid_import_from_targets_type 1153
+#define _loop0_1_type 1154
+#define _loop0_2_type 1155
+#define _loop0_4_type 1156
+#define _gather_3_type 1157
+#define _loop0_6_type 1158
+#define _gather_5_type 1159
+#define _loop0_8_type 1160
+#define _gather_7_type 1161
+#define _loop0_10_type 1162
+#define _gather_9_type 1163
+#define _loop1_11_type 1164
+#define _loop0_13_type 1165
+#define _gather_12_type 1166
+#define _tmp_14_type 1167
+#define _tmp_15_type 1168
+#define _tmp_16_type 1169
+#define _tmp_17_type 1170
+#define _tmp_18_type 1171
+#define _tmp_19_type 1172
+#define _tmp_20_type 1173
+#define _tmp_21_type 1174
+#define _loop1_22_type 1175
+#define _tmp_23_type 1176
+#define _tmp_24_type 1177
+#define _loop0_26_type 1178
+#define _gather_25_type 1179
+#define _loop0_28_type 1180
+#define _gather_27_type 1181
+#define _tmp_29_type 1182
+#define _loop0_30_type 1183
+#define _loop1_31_type 1184
+#define _loop0_33_type 1185
+#define _gather_32_type 1186
+#define _tmp_34_type 1187
+#define _loop0_36_type 1188
+#define _gather_35_type 1189
+#define _tmp_37_type 1190
+#define _loop0_39_type 1191
+#define _gather_38_type 1192
+#define _loop0_41_type 1193
+#define _gather_40_type 1194
+#define _loop0_43_type 1195
+#define _gather_42_type 1196
+#define _loop0_45_type 1197
+#define _gather_44_type 1198
+#define _tmp_46_type 1199
+#define _loop1_47_type 1200
+#define _tmp_48_type 1201
+#define _tmp_49_type 1202
+#define _tmp_50_type 1203
+#define _tmp_51_type 1204
+#define _tmp_52_type 1205
+#define _loop0_53_type 1206
+#define _loop0_54_type 1207
+#define _loop0_55_type 1208
+#define _loop1_56_type 1209
+#define _loop0_57_type 1210
+#define _loop1_58_type 1211
+#define _loop1_59_type 1212
+#define _loop1_60_type 1213
+#define _loop0_61_type 1214
+#define _loop1_62_type 1215
+#define _loop0_63_type 1216
+#define _loop1_64_type 1217
+#define _loop0_65_type 1218
+#define _loop1_66_type 1219
+#define _loop1_67_type 1220
+#define _tmp_68_type 1221
+#define _loop0_70_type 1222
+#define _gather_69_type 1223
+#define _loop1_71_type 1224
+#define _loop0_73_type 1225
+#define _gather_72_type 1226
+#define _loop1_74_type 1227
+#define _loop0_75_type 1228
+#define _loop0_76_type 1229
+#define _loop0_77_type 1230
+#define _loop1_78_type 1231
+#define _loop0_79_type 1232
+#define _loop1_80_type 1233
+#define _loop1_81_type 1234
+#define _loop1_82_type 1235
+#define _loop0_83_type 1236
+#define _loop1_84_type 1237
+#define _loop0_85_type 1238
+#define _loop1_86_type 1239
+#define _loop0_87_type 1240
+#define _loop1_88_type 1241
+#define _loop1_89_type 1242
+#define _loop1_90_type 1243
+#define _loop1_91_type 1244
+#define _tmp_92_type 1245
+#define _loop0_94_type 1246
+#define _gather_93_type 1247
+#define _tmp_95_type 1248
+#define _tmp_96_type 1249
+#define _tmp_97_type 1250
+#define _tmp_98_type 1251
+#define _loop1_99_type 1252
+#define _tmp_100_type 1253
+#define _tmp_101_type 1254
+#define _loop0_103_type 1255
+#define _gather_102_type 1256
+#define _loop1_104_type 1257
+#define _loop0_105_type 1258
+#define _loop0_106_type 1259
+#define _tmp_107_type 1260
+#define _tmp_108_type 1261
+#define _loop0_110_type 1262
+#define _gather_109_type 1263
+#define _loop0_112_type 1264
+#define _gather_111_type 1265
+#define _loop0_114_type 1266
+#define _gather_113_type 1267
+#define _loop0_116_type 1268
+#define _gather_115_type 1269
+#define _loop0_117_type 1270
+#define _loop0_119_type 1271
+#define _gather_118_type 1272
+#define _tmp_120_type 1273
+#define _loop0_122_type 1274
+#define _gather_121_type 1275
+#define _loop0_124_type 1276
+#define _gather_123_type 1277
+#define _tmp_125_type 1278
+#define _loop0_126_type 1279
+#define _tmp_127_type 1280
+#define _tmp_128_type 1281
+#define _tmp_129_type 1282
+#define _tmp_130_type 1283
+#define _loop0_131_type 1284
+#define _tmp_132_type 1285
+#define _tmp_133_type 1286
+#define _tmp_134_type 1287
+#define _tmp_135_type 1288
+#define _tmp_136_type 1289
+#define _tmp_137_type 1290
+#define _tmp_138_type 1291
+#define _tmp_139_type 1292
+#define _tmp_140_type 1293
+#define _tmp_141_type 1294
+#define _tmp_142_type 1295
+#define _tmp_143_type 1296
+#define _tmp_144_type 1297
+#define _tmp_145_type 1298
+#define _loop1_146_type 1299
+#define _tmp_147_type 1300
+#define _tmp_148_type 1301
static mod_ty file_rule(Parser *p);
static mod_ty interactive_rule(Parser *p);
@@ -523,6 +524,7 @@ static void *invalid_star_etc_rule(Parser *p);
static void *invalid_lambda_star_etc_rule(Parser *p);
static void *invalid_double_type_comments_rule(Parser *p);
static void *invalid_del_target_rule(Parser *p);
+static void *invalid_import_from_targets_rule(Parser *p);
static asdl_seq *_loop0_1_rule(Parser *p);
static asdl_seq *_loop0_2_rule(Parser *p);
static asdl_seq *_loop0_4_rule(Parser *p);
@@ -2592,7 +2594,11 @@ import_from_rule(Parser *p)
return _res;
}
-// import_from_targets: '(' import_from_as_names ','? ')' | import_from_as_names | '*'
+// import_from_targets:
+// | '(' import_from_as_names ','? ')'
+// | import_from_as_names !','
+// | '*'
+// | invalid_import_from_targets
static asdl_seq*
import_from_targets_rule(Parser *p)
{
@@ -2629,13 +2635,15 @@ import_from_targets_rule(Parser *p)
}
p->mark = _mark;
}
- { // import_from_as_names
+ { // import_from_as_names !','
if (p->error_indicator) {
return NULL;
}
asdl_seq* import_from_as_names_var;
if (
(import_from_as_names_var = import_from_as_names_rule(p)) // import_from_as_names
+ &&
+ _PyPegen_lookahead_with_int(0, _PyPegen_expect_token, p, 12) // token=','
)
{
_res = import_from_as_names_var;
@@ -2661,6 +2669,20 @@ import_from_targets_rule(Parser *p)
}
p->mark = _mark;
}
+ { // invalid_import_from_targets
+ if (p->error_indicator) {
+ return NULL;
+ }
+ void *invalid_import_from_targets_var;
+ if (
+ (invalid_import_from_targets_var = invalid_import_from_targets_rule(p)) // invalid_import_from_targets
+ )
+ {
+ _res = invalid_import_from_targets_var;
+ goto done;
+ }
+ p->mark = _mark;
+ }
_res = NULL;
done:
return _res;
@@ -12213,6 +12235,41 @@ invalid_del_target_rule(Parser *p)
return _res;
}
+// invalid_import_from_targets: import_from_as_names ','
+static void *
+invalid_import_from_targets_rule(Parser *p)
+{
+ if (p->error_indicator) {
+ return NULL;
+ }
+ void * _res = NULL;
+ int _mark = p->mark;
+ { // import_from_as_names ','
+ if (p->error_indicator) {
+ return NULL;
+ }
+ Token * _literal;
+ asdl_seq* import_from_as_names_var;
+ if (
+ (import_from_as_names_var = import_from_as_names_rule(p)) // import_from_as_names
+ &&
+ (_literal = _PyPegen_expect_token(p, 12)) // token=','
+ )
+ {
+ _res = RAISE_SYNTAX_ERROR ( "trailing comma not allowed without surrounding parentheses" );
+ if (_res == NULL && PyErr_Occurred()) {
+ p->error_indicator = 1;
+ return NULL;
+ }
+ goto done;
+ }
+ p->mark = _mark;
+ }
+ _res = NULL;
+ done:
+ return _res;
+}
+
// _loop0_1: NEWLINE
static asdl_seq *
_loop0_1_rule(Parser *p)
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