[3.10] bpo-45727: Make the syntax error for missing comma more consistent (GH-29427) (GH-29647)

(cherry picked from commit 546cefcda75d7150b55c8bc1724bea35a1e12890)

Co-authored-by: Pablo Galindo Salgado <Pablogsal@gmail.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/Grammar/python.gram b/Grammar/python.gram
index 7934ccd..20cccfd 100644
--- a/Grammar/python.gram
+++ b/Grammar/python.gram
@@ -529,6 +529,7 @@ expressions[expr_ty]:
     | expression
 expression[expr_ty] (memo):
     | invalid_expression
+    | invalid_legacy_expression
     | a=disjunction 'if' b=disjunction 'else' c=expression { _PyAST_IfExp(b, a, c, EXTRA) }
     | disjunction
     | lambdef
@@ -666,7 +667,6 @@ await_primary[expr_ty] (memo):
     | AWAIT a=primary { CHECK_VERSION(expr_ty, 5, "Await expressions are", _PyAST_Await(a, EXTRA)) }
     | primary
 primary[expr_ty]:
-    | invalid_primary  # must be before 'primay genexp' because of invalid_genexp
     | a=primary '.' b=NAME { _PyAST_Attribute(a, b->v.Name.id, Load, EXTRA) }
     | a=primary b=genexp { _PyAST_Call(a, CHECK(asdl_expr_seq*, (asdl_expr_seq*)_PyPegen_singleton_seq(p, b)), NULL, EXTRA) }
     | a=primary '(' b=[arguments] ')' {
@@ -856,11 +856,11 @@ invalid_legacy_expression:
             "Missing parentheses in call to '%U'. Did you mean %U(...)?", a->v.Name.id, a->v.Name.id) : NULL}
 
 invalid_expression:
-   | invalid_legacy_expression
     # !(NAME STRING) is not matched so we don't show this error with some invalid string prefixes like: kf"dsfsdf"
     # Soft keywords need to also be ignored because they can be parsed as NAME NAME
    | !(NAME STRING | SOFT_KEYWORD) a=disjunction b=expression_without_invalid {
-        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Perhaps you forgot a comma?") }
+        _PyPegen_check_legacy_stmt(p, a) ? NULL : RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b,
+        "invalid syntax. Perhaps you forgot a comma?") }
    | a=disjunction 'if' b=disjunction !('else'|':') { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "expected 'else' after 'if' expression") }
 
 invalid_named_expression:
@@ -902,8 +902,6 @@ invalid_del_stmt:
         RAISE_SYNTAX_ERROR_INVALID_TARGET(DEL_TARGETS, a) }
 invalid_block:
     | NEWLINE !INDENT { RAISE_INDENTATION_ERROR("expected an indented block") }
-invalid_primary:
-    | primary a='{' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "invalid syntax") }
 invalid_comprehension:
     | ('[' | '(' | '{') a=starred_expression for_if_clauses {
         RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "iterable unpacking cannot be used in comprehension") }