Auto merge of #12987 - Veykril:ellipsis-recov, r=Veykril

Recover from missing ellipsis in record literals for path expressions

Author: bors

crates/parser/src/grammar/expressions.rs

@@ -564,8 +564,10 @@ fn path_expr(p: &mut Parser<'_>, r: Restrictions) -> (CompletedMarker, BlockLike
 // test record_lit
 // fn foo() {
 //     S {};
+//     S { x };
 //     S { x, y: 32, };
 //     S { x, y: 32, ..Default::default() };
+//     S { x: ::default() };
 //     TupleStruct { 0: 1 };
 // }
 pub(crate) fn record_expr_field_list(p: &mut Parser<'_>) {
@@ -582,16 +584,26 @@ pub(crate) fn record_expr_field_list(p: &mut Parser<'_>) {
 
         match p.current() {
             IDENT | INT_NUMBER => {
-                // test_err record_literal_before_ellipsis_recovery
+                // test_err record_literal_missing_ellipsis_recovery
                 // fn main() {
-                //     S { field ..S::default() }
+                //     S { S::default() }
                 // }
-                if p.nth_at(1, T![:]) || p.nth_at(1, T![..]) {
-                    name_ref_or_index(p);
-                    p.expect(T![:]);
+                if p.nth_at(1, T![::]) {
+                    m.abandon(p);
+                    p.expect(T![..]);
+                    expr(p);
+                } else {
+                    // test_err record_literal_before_ellipsis_recovery
+                    // fn main() {
+                    //     S { field ..S::default() }
+                    // }
+                    if p.nth_at(1, T![:]) || p.nth_at(1, T![..]) {
+                        name_ref_or_index(p);
+                        p.expect(T![:]);
+                    }
+                    expr(p);
+                    m.complete(p, RECORD_EXPR_FIELD);
                 }
-                expr(p);
-                m.complete(p, RECORD_EXPR_FIELD);
             }
             T![.] if p.at(T![..]) => {
                 m.abandon(p);

crates/parser/test_data/parser/inline/err/0014_record_literal_missing_ellipsis_recovery.rast

@@ -0,0 +1,43 @@
+SOURCE_FILE
+  FN
+    FN_KW "fn"
+    WHITESPACE " "
+    NAME
+      IDENT "main"
+    PARAM_LIST
+      L_PAREN "("
+      R_PAREN ")"
+    WHITESPACE " "
+    BLOCK_EXPR
+      STMT_LIST
+        L_CURLY "{"
+        WHITESPACE "\n    "
+        RECORD_EXPR
+          PATH
+            PATH_SEGMENT
+              NAME_REF
+                IDENT "S"
+          WHITESPACE " "
+          RECORD_EXPR_FIELD_LIST
+            L_CURLY "{"
+            WHITESPACE " "
+            CALL_EXPR
+              PATH_EXPR
+                PATH
+                  PATH
+                    PATH_SEGMENT
+                      NAME_REF
+                        IDENT "S"
+                  COLON2 "::"
+                  PATH_SEGMENT
+                    NAME_REF
+                      IDENT "default"
+              ARG_LIST
+                L_PAREN "("
+                R_PAREN ")"
+            WHITESPACE " "
+            R_CURLY "}"
+        WHITESPACE "\n"
+        R_CURLY "}"
+  WHITESPACE "\n"
+error 19: expected DOT2

crates/parser/test_data/parser/inline/err/0014_record_literal_missing_ellipsis_recovery.rs

@@ -0,0 +1,3 @@
+fn main() {
+    S { S::default() }
+}

crates/parser/test_data/parser/inline/ok/0061_record_lit.rast

@@ -24,6 +24,26 @@ SOURCE_FILE
               R_CURLY "}"
           SEMICOLON ";"
         WHITESPACE "\n    "
+        EXPR_STMT
+          RECORD_EXPR
+            PATH
+              PATH_SEGMENT
+                NAME_REF
+                  IDENT "S"
+            WHITESPACE " "
+            RECORD_EXPR_FIELD_LIST
+              L_CURLY "{"
+              WHITESPACE " "
+              RECORD_EXPR_FIELD
+                PATH_EXPR
+                  PATH
+                    PATH_SEGMENT
+                      NAME_REF
+                        IDENT "x"
+              WHITESPACE " "
+              R_CURLY "}"
+          SEMICOLON ";"
+        WHITESPACE "\n    "
         EXPR_STMT
           RECORD_EXPR
             PATH
@@ -100,6 +120,35 @@ SOURCE_FILE
               R_CURLY "}"
           SEMICOLON ";"
         WHITESPACE "\n    "
+        EXPR_STMT
+          RECORD_EXPR
+            PATH
+              PATH_SEGMENT
+                NAME_REF
+                  IDENT "S"
+            WHITESPACE " "
+            RECORD_EXPR_FIELD_LIST
+              L_CURLY "{"
+              WHITESPACE " "
+              RECORD_EXPR_FIELD
+                NAME_REF
+                  IDENT "x"
+                COLON ":"
+                WHITESPACE " "
+                CALL_EXPR
+                  PATH_EXPR
+                    PATH
+                      PATH_SEGMENT
+                        COLON2 "::"
+                        NAME_REF
+                          IDENT "default"
+                  ARG_LIST
+                    L_PAREN "("
+                    R_PAREN ")"
+              WHITESPACE " "
+              R_CURLY "}"
+          SEMICOLON ";"
+        WHITESPACE "\n    "
         EXPR_STMT
           RECORD_EXPR
             PATH

crates/parser/test_data/parser/inline/ok/0061_record_lit.rs

@@ -1,6 +1,8 @@
 fn foo() {
     S {};
+    S { x };
     S { x, y: 32, };
     S { x, y: 32, ..Default::default() };
+    S { x: ::default() };
     TupleStruct { 0: 1 };
 }