Add macro for postfix operators. (#3504)

Per request on #3481, for consistency with prefix/infix.

toolchain/check/node_stack.h

@@ -333,7 +333,6 @@ class NodeStack {
       case Parse::NodeKind::MemberAccessExpr:
       case Parse::NodeKind::PackageExpr:
       case Parse::NodeKind::ParenExpr:
-      case Parse::NodeKind::PostfixOperatorStar:
       case Parse::NodeKind::ReturnType:
       case Parse::NodeKind::SelfTypeNameExpr:
       case Parse::NodeKind::SelfValueNameExpr:
@@ -387,6 +386,9 @@ class NodeStack {
 #define CARBON_PARSE_NODE_KIND_INFIX_OPERATOR(Name, ...) \
   case Parse::NodeKind::InfixOperator##Name:             \
     return IdKind::InstId;
+#define CARBON_PARSE_NODE_KIND_POSTFIX_OPERATOR(Name, ...) \
+  case Parse::NodeKind::PostfixOperator##Name:             \
+    return IdKind::InstId;
 #define CARBON_PARSE_NODE_KIND_PREFIX_OPERATOR(Name, ...) \
   case Parse::NodeKind::PrefixOperator##Name:             \
     return IdKind::InstId;

toolchain/parse/handle_expr.cpp

@@ -287,8 +287,22 @@ auto HandleExprLoop(Context& context) -> void {
     context.PushState(state);
     context.PushStateForExpr(operator_precedence);
   } else {
-    context.AddNode(NodeKind::PostfixOperatorStar, state.token,
-                    state.subtree_start, state.has_error);
+    NodeKind node_kind;
+    switch (operator_kind) {
+#define CARBON_PARSE_NODE_KIND(...)
+#define CARBON_PARSE_NODE_KIND_POSTFIX_OPERATOR(Name, ...) \
+  case Lex::TokenKind::Name:                               \
+    node_kind = NodeKind::PostfixOperator##Name;           \
+    break;
+#include "toolchain/parse/node_kind.def"
+
+      default:
+        CARBON_FATAL() << "Unexpected token kind for postfix operator: "
+                       << operator_kind;
+    }
+
+    context.AddNode(node_kind, state.token, state.subtree_start,
+                    state.has_error);
     state.has_error = false;
     context.PushState(state);
   }

toolchain/parse/node_kind.def

@@ -16,10 +16,12 @@
 //   - CARBON_PARSE_NODE_KIND_CHILD_COUNT(Name, ChildCount, LexTokenKind)
 //     Defines a parse node with a set number of children, often 0. This count
 //     must be correct even when the node contains errors.
-//     - CARBON_PARSE_NODE_KIND_INFIX_OPERATOR(Name)
-//       Defines a parse node for an infix operator, with the Name as token.
 //     - CARBON_PARSE_NODE_KIND_PREFIX_OPERATOR(Name)
 //       Defines a parse node for a prefix operator, with the Name as token.
+//     - CARBON_PARSE_NODE_KIND_INFIX_OPERATOR(Name)
+//       Defines a parse node for an infix operator, with the Name as token.
+//     - CARBON_PARSE_NODE_KIND_POSTFIX_OPERATOR(Name)
+//       Defines a parse node for a postfix operator, with the Name as token.
 //     - CARBON_PARSE_NODE_KIND_TOKEN_LITERAL(Name, LexTokenKind)
 //       Defines a parse node that corresponds to a token that is a single-token
 //       literal. The token is wrapped for LexTokenKinds.
@@ -56,6 +58,16 @@
   CARBON_PARSE_NODE_KIND(Name)
 #endif
 
+// This is expected to be used with something like:
+//
+//   // Use x-macros to handle modifier cases.
+//   #define CARBON_PARSE_NODE_KIND(...)
+//   #define CARBON_PARSE_NODE_KIND_PREFIX_OPERATOR(Name, ...) <code>
+#ifndef CARBON_PARSE_NODE_KIND_PREFIX_OPERATOR
+#define CARBON_PARSE_NODE_KIND_PREFIX_OPERATOR(Name) \
+  CARBON_PARSE_NODE_KIND_CHILD_COUNT(PrefixOperator##Name, 1, Name)
+#endif
+
 // This is expected to be used with something like:
 //
 //   // Use x-macros to handle modifier cases.
@@ -70,10 +82,10 @@
 //
 //   // Use x-macros to handle modifier cases.
 //   #define CARBON_PARSE_NODE_KIND(...)
-//   #define CARBON_PARSE_NODE_KIND_PREFIX_OPERATOR(Name, ...) <code>
-#ifndef CARBON_PARSE_NODE_KIND_PREFIX_OPERATOR
-#define CARBON_PARSE_NODE_KIND_PREFIX_OPERATOR(Name) \
-  CARBON_PARSE_NODE_KIND_CHILD_COUNT(PrefixOperator##Name, 1, Name)
+//   #define CARBON_PARSE_NODE_KIND_POSTFIX_OPERATOR(Name, ...) <code>
+#ifndef CARBON_PARSE_NODE_KIND_POSTFIX_OPERATOR
+#define CARBON_PARSE_NODE_KIND_POSTFIX_OPERATOR(Name) \
+  CARBON_PARSE_NODE_KIND_CHILD_COUNT(PostfixOperator##Name, 1, Name)
 #endif
 
 // This is expected to be used with something like:
@@ -472,8 +484,6 @@ CARBON_PARSE_NODE_KIND_TOKEN_LITERAL(FloatTypeLiteral, FloatTypeLiteral)
 CARBON_PARSE_NODE_KIND_TOKEN_LITERAL(StringTypeLiteral, StringTypeLiteral)
 CARBON_PARSE_NODE_KIND_TOKEN_LITERAL(TypeTypeLiteral, Type)
 
-// clang-format off
-
 // A prefix operator, such as `not`:
 //   _external_: expression
 // PrefixOperator<name>
@@ -520,7 +530,10 @@ CARBON_PARSE_NODE_KIND_INFIX_OPERATOR(SlashEqual)
 CARBON_PARSE_NODE_KIND_INFIX_OPERATOR(Star)
 CARBON_PARSE_NODE_KIND_INFIX_OPERATOR(StarEqual)
 
-// clang-format on
+// A postfix operator, currently only `*`:
+//   _external_: expression
+// PostfixOperator<name>
+CARBON_PARSE_NODE_KIND_POSTFIX_OPERATOR(Star)
 
 // A short-circuiting infix operator, such as `and`:
 //     _external_: expression
@@ -532,11 +545,6 @@ CARBON_PARSE_NODE_KIND_CHILD_COUNT(ShortCircuitOperandOr, 1, Or)
 CARBON_PARSE_NODE_KIND_CHILD_COUNT(ShortCircuitOperatorAnd, 2, And)
 CARBON_PARSE_NODE_KIND_CHILD_COUNT(ShortCircuitOperatorOr, 2, Or)
 
-// A postfix operator, currently only `*`:
-//   _external_: expression
-// PostfixOperatorStar
-CARBON_PARSE_NODE_KIND_CHILD_COUNT(PostfixOperatorStar, 1, Star)
-
 // `if` expression + `then` + `else`:
 //     _external_: expression
 //   IfExprIf
@@ -696,6 +704,7 @@ CARBON_PARSE_NODE_KIND_BRACKET(NamedConstraintDecl, NamedConstraintIntroducer,
 #undef CARBON_PARSE_NODE_KIND_BRACKET
 #undef CARBON_PARSE_NODE_KIND_CHILD_COUNT
 #undef CARBON_PARSE_NODE_KIND_INFIX_OPERATOR
+#undef CARBON_PARSE_NODE_KIND_POSTFIX_OPERATOR
 #undef CARBON_PARSE_NODE_KIND_PREFIX_OPERATOR
 #undef CARBON_PARSE_NODE_KIND_TOKEN_LITERAL
 #undef CARBON_PARSE_NODE_KIND_TOKEN_MODIFIER