Remove parsing of StringLiteral.

The StringLiteral token was removed from the spec when all usage was
removed. This CL removes the remaining parsing bits from Tint.

Change-Id: I02f5dbdbad649c62c22c69a55616e0087a0f56d4
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/42440
Auto-Submit: dan sinclair <dsinclair@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>

src/reader/wgsl/lexer.cc

@@ -63,11 +63,6 @@ Token Lexer::next() {
     return t;
   }
 
-  t = try_string();
-  if (!t.IsUninitialized()) {
-    return t;
-  }
-
   t = try_punctuation();
   if (!t.IsUninitialized()) {
     return t;
@@ -334,29 +329,6 @@ Token Lexer::try_ident() {
   return {Token::Type::kIdentifier, source, str};
 }
 
-Token Lexer::try_string() {
-  if (!matches(pos_, R"(")"))
-    return {};
-
-  auto source = begin_source();
-
-  pos_++;
-  auto start = pos_;
-  while (pos_ < len_ && !matches(pos_, R"(")")) {
-    pos_++;
-  }
-  auto end = pos_;
-  if (matches(pos_, R"(")")) {
-    pos_++;
-  }
-  location_.column += (pos_ - start) + 1;
-
-  end_source(source);
-
-  return {Token::Type::kStringLiteral, source,
-          content_->data.substr(start, end - start)};
-}
-
 Token Lexer::try_punctuation() {
   auto source = begin_source();
   auto type = Token::Type::kUninitialized;

src/reader/wgsl/lexer.h

@@ -52,7 +52,6 @@ class Lexer {
   Token try_ident();
   Token try_integer();
   Token try_punctuation();
-  Token try_string();
 
   Source begin_source() const;
   void end_source(Source&) const;

src/reader/wgsl/lexer_test.cc

@@ -75,59 +75,6 @@ ident1 //ends with comment
   EXPECT_TRUE(t.IsEof());
 }
 
-TEST_F(LexerTest, StringTest_Parse) {
-  Source::FileContent content(R"(id "this is string content" id2)");
-  Lexer l("test.wgsl", &content);
-
-  auto t = l.next();
-  EXPECT_TRUE(t.IsIdentifier());
-  EXPECT_EQ(t.to_str(), "id");
-  EXPECT_EQ(t.source().range.begin.line, 1u);
-  EXPECT_EQ(t.source().range.begin.column, 1u);
-  EXPECT_EQ(t.source().range.end.line, 1u);
-  EXPECT_EQ(t.source().range.end.column, 3u);
-
-  t = l.next();
-  EXPECT_TRUE(t.IsStringLiteral());
-  EXPECT_EQ(t.to_str(), "this is string content");
-  EXPECT_EQ(t.source().range.begin.line, 1u);
-  EXPECT_EQ(t.source().range.begin.column, 4u);
-  EXPECT_EQ(t.source().range.end.line, 1u);
-  EXPECT_EQ(t.source().range.end.column, 28u);
-
-  t = l.next();
-  EXPECT_TRUE(t.IsIdentifier());
-  EXPECT_EQ(t.to_str(), "id2");
-  EXPECT_EQ(t.source().range.begin.line, 1u);
-  EXPECT_EQ(t.source().range.begin.column, 29u);
-  EXPECT_EQ(t.source().range.end.line, 1u);
-  EXPECT_EQ(t.source().range.end.column, 32u);
-}
-
-TEST_F(LexerTest, StringTest_Unterminated) {
-  Source::FileContent content(R"(id "this is string content)");
-  Lexer l("test.wgsl", &content);
-
-  auto t = l.next();
-  EXPECT_TRUE(t.IsIdentifier());
-  EXPECT_EQ(t.to_str(), "id");
-  EXPECT_EQ(t.source().range.begin.line, 1u);
-  EXPECT_EQ(t.source().range.begin.column, 1u);
-  EXPECT_EQ(t.source().range.end.line, 1u);
-  EXPECT_EQ(t.source().range.end.column, 3u);
-
-  t = l.next();
-  EXPECT_TRUE(t.IsStringLiteral());
-  EXPECT_EQ(t.to_str(), "this is string content");
-  EXPECT_EQ(t.source().range.begin.line, 1u);
-  EXPECT_EQ(t.source().range.begin.column, 4u);
-  EXPECT_EQ(t.source().range.end.line, 1u);
-  EXPECT_EQ(t.source().range.end.column, 27u);
-
-  t = l.next();
-  EXPECT_TRUE(t.IsEof());
-}
-
 struct FloatData {
   const char* input;
   float result;

src/reader/wgsl/token.cc

@@ -29,8 +29,6 @@ std::string Token::TypeToName(Type type) {
       return "kEOF";
     case Token::Type::kIdentifier:
       return "kIdentifier";
-    case Token::Type::kStringLiteral:
-      return "kStringLiteral";
     case Token::Type::kFloatLiteral:
       return "kFloatLiteral";
     case Token::Type::kSintLiteral:

src/reader/wgsl/token.h

@@ -42,8 +42,6 @@ class Token {
 
     /// An identifier
     kIdentifier,
-    /// A string value
-    kStringLiteral,
     /// A float value
     kFloatLiteral,
     /// An signed int value
@@ -381,8 +379,6 @@ class Token {
   bool IsEof() const { return type_ == Type::kEOF; }
   /// @returns true if the token is an identifier
   bool IsIdentifier() const { return type_ == Type::kIdentifier; }
-  /// @returns true if the token is a string
-  bool IsStringLiteral() const { return type_ == Type::kStringLiteral; }
   /// @returns true if the token is a float
   bool IsFloatLiteral() const { return type_ == Type::kFloatLiteral; }
   /// @returns true if the token is an signed int

src/reader/wgsl/token_test.cc

@@ -25,11 +25,6 @@ namespace {
 
 using TokenTest = testing::Test;
 
-TEST_F(TokenTest, ReturnsStr) {
-  Token t(Token::Type::kStringLiteral, Source{}, "test string");
-  EXPECT_EQ(t.to_str(), "test string");
-}
-
 TEST_F(TokenTest, ReturnsF32) {
   Token t1(Source{}, -2.345f);
   EXPECT_EQ(t1.to_f32(), -2.345f);