[parser] Introduce a range for automatic semicolon insertion tokens

Change-Id: Ib41ddbf15c6f9395b747b78c081e466a9f2e44bd
Reviewed-on: https://chromium-review.googlesource.com/c/1286682
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56779}

src/parsing/parser-base.h

@@ -712,8 +712,8 @@ class ParserBase {
       Next();
       return;
     }
-    if (scanner()->HasLineTerminatorBeforeNext() || tok == Token::RBRACE ||
-        tok == Token::EOS) {
+    if (scanner()->HasLineTerminatorBeforeNext() ||
+        Token::IsAutoSemicolon(tok)) {
       return;
     }
 
@@ -5131,8 +5131,8 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseContinueStatement(
   Expect(Token::CONTINUE, CHECK_OK);
   IdentifierT label = impl()->NullIdentifier();
   Token::Value tok = peek();
-  if (!scanner()->HasLineTerminatorBeforeNext() && tok != Token::SEMICOLON &&
-      tok != Token::RBRACE && tok != Token::EOS) {
+  if (!scanner()->HasLineTerminatorBeforeNext() &&
+      !Token::IsAutoSemicolon(tok)) {
     // ECMA allows "eval" or "arguments" as labels even in strict mode.
     label = ParseIdentifier(kAllowRestrictedIdentifiers, CHECK_OK);
   }
@@ -5168,8 +5168,8 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseBreakStatement(
   Expect(Token::BREAK, CHECK_OK);
   IdentifierT label = impl()->NullIdentifier();
   Token::Value tok = peek();
-  if (!scanner()->HasLineTerminatorBeforeNext() && tok != Token::SEMICOLON &&
-      tok != Token::RBRACE && tok != Token::EOS) {
+  if (!scanner()->HasLineTerminatorBeforeNext() &&
+      !Token::IsAutoSemicolon(tok)) {
     // ECMA allows "eval" or "arguments" as labels even in strict mode.
     label = ParseIdentifier(kAllowRestrictedIdentifiers, CHECK_OK);
   }
@@ -5222,8 +5222,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseReturnStatement(
 
   Token::Value tok = peek();
   ExpressionT return_value = impl()->NullExpression();
-  if (scanner()->HasLineTerminatorBeforeNext() || tok == Token::SEMICOLON ||
-      tok == Token::RBRACE || tok == Token::EOS) {
+  if (scanner()->HasLineTerminatorBeforeNext() || Token::IsAutoSemicolon(tok)) {
     if (IsDerivedConstructor(function_state_->kind())) {
       return_value = impl()->ThisExpression(loc.beg_pos);
     }

src/parsing/token.h

@@ -55,8 +55,6 @@ namespace internal {
   T(name, string, precedence)
 
 #define TOKEN_LIST(T, K, C)                                        \
-  /* End of source indicator. */                                   \
-  T(EOS, "EOS", 0)                                                 \
                                                                    \
   /* BEGIN PropertyOrCall */                                       \
   /* ES6 Template Literals */                                      \
@@ -71,14 +69,18 @@ namespace internal {
   T(RPAREN, ")", 0)                                                \
   T(RBRACK, "]", 0)                                                \
   T(LBRACE, "{", 0)                                                \
-  T(RBRACE, "}", 0)                                                \
   T(COLON, ":", 0)                                                 \
-  T(SEMICOLON, ";", 0)                                             \
   T(ELLIPSIS, "...", 0)                                            \
   T(CONDITIONAL, "?", 3)                                           \
   T(INC, "++", 0)                                                  \
   T(DEC, "--", 0)                                                  \
   T(ARROW, "=>", 0)                                                \
+  /* BEGIN AutoSemicolon */                                        \
+  T(SEMICOLON, ";", 0)                                             \
+  T(RBRACE, "}", 0)                                                \
+  /* End of source indicator. */                                   \
+  T(EOS, "EOS", 0)                                                 \
+  /* END AutoSemicolon */                                          \
                                                                    \
   /* Assignment operators. */                                      \
   /* IsAssignmentOp() relies on this block of enum values being */ \
@@ -241,6 +243,10 @@ class Token {
 
   static bool IsCallable(Value token) { return IsInRange(token, SUPER, ENUM); }
 
+  static bool IsAutoSemicolon(Value token) {
+    return IsInRange(token, SEMICOLON, EOS);
+  }
+
   static bool IsAnyIdentifier(Value token) {
     return IsInRange(token, IDENTIFIER, ENUM);
   }

test/cctest/test-parsing.cc

@@ -79,6 +79,24 @@ TEST(IsContextualKeyword) {
   }
 }
 
+bool TokenIsAutoSemicolon(Token::Value token) {
+  switch (token) {
+    case Token::SEMICOLON:
+    case Token::EOS:
+    case Token::RBRACE:
+      return true;
+    default:
+      return false;
+  }
+}
+
+TEST(AutoSemicolonToken) {
+  for (int i = 0; i < Token::NUM_TOKENS; i++) {
+    Token::Value token = static_cast<Token::Value>(i);
+    CHECK_EQ(TokenIsAutoSemicolon(token), Token::IsAutoSemicolon(token));
+  }
+}
+
 bool TokenIsAnyIdentifier(Token::Value token) {
   switch (token) {
     case Token::IDENTIFIER: