From 08d735e6a91d327e1ddddb3d1b955422ad09d885 Mon Sep 17 00:00:00 2001
From: dan sinclair <dsinclair@chromium.org>
Date: Mon, 22 Aug 2022 19:23:24 +0000
Subject: [PATCH] Add missing relational_expression.post.unary_expression
 checks.

This CL adds the missing checks and tests for `==` and `!=` into
the `relational_expression.post.unary_expression` grammar elements.

Bug: tint:1633
Change-Id: Ib5fbb42994ea12af133ca531989421fddc2393f2
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/99940
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
---
 src/tint/reader/wgsl/parser_impl.cc           |  4 ++
 .../parser_impl_relational_expression_test.cc | 50 +++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/src/tint/reader/wgsl/parser_impl.cc b/src/tint/reader/wgsl/parser_impl.cc
index 13a8b64f48..99abd60a0e 100644
--- a/src/tint/reader/wgsl/parser_impl.cc
+++ b/src/tint/reader/wgsl/parser_impl.cc
@@ -3174,6 +3174,10 @@ Expect<const ast::Expression*> ParserImpl::expect_relational_expression_post_una
             op = ast::BinaryOp::kLessThanEqual;
         } else if (t.Is(Token::Type::kGreaterThanEqual)) {
             op = ast::BinaryOp::kGreaterThanEqual;
+        } else if (t.Is(Token::Type::kEqualEqual)) {
+            op = ast::BinaryOp::kEqual;
+        } else if (t.Is(Token::Type::kNotEqual)) {
+            op = ast::BinaryOp::kNotEqual;
         }
 
         auto& next = peek();
diff --git a/src/tint/reader/wgsl/parser_impl_relational_expression_test.cc b/src/tint/reader/wgsl/parser_impl_relational_expression_test.cc
index 1c47f879b6..59cddc6bf5 100644
--- a/src/tint/reader/wgsl/parser_impl_relational_expression_test.cc
+++ b/src/tint/reader/wgsl/parser_impl_relational_expression_test.cc
@@ -244,6 +244,56 @@ TEST_F(ParserImplTest, RelationalExpression_PostUnary_Parses_GreaterThanEqual) {
     ASSERT_TRUE(rel->rhs->As<ast::BoolLiteralExpression>()->value);
 }
 
+TEST_F(ParserImplTest, RelationalExpression_PostUnary_Parses_Equal) {
+    auto p = parser("a == true");
+    auto lhs = p->unary_expression();
+    auto e = p->expect_relational_expression_post_unary_expression(lhs.value);
+    EXPECT_FALSE(e.errored);
+    EXPECT_FALSE(p->has_error()) << p->error();
+    ASSERT_NE(e.value, nullptr);
+
+    EXPECT_EQ(e->source.range.begin.line, 1u);
+    EXPECT_EQ(e->source.range.begin.column, 3u);
+    EXPECT_EQ(e->source.range.end.line, 1u);
+    EXPECT_EQ(e->source.range.end.column, 5u);
+
+    ASSERT_TRUE(e->Is<ast::BinaryExpression>());
+    auto* rel = e->As<ast::BinaryExpression>();
+    EXPECT_EQ(ast::BinaryOp::kEqual, rel->op);
+
+    ASSERT_TRUE(rel->lhs->Is<ast::IdentifierExpression>());
+    auto* ident = rel->lhs->As<ast::IdentifierExpression>();
+    EXPECT_EQ(ident->symbol, p->builder().Symbols().Get("a"));
+
+    ASSERT_TRUE(rel->rhs->Is<ast::BoolLiteralExpression>());
+    ASSERT_TRUE(rel->rhs->As<ast::BoolLiteralExpression>()->value);
+}
+
+TEST_F(ParserImplTest, RelationalExpression_PostUnary_Parses_NotEqual) {
+    auto p = parser("a != true");
+    auto lhs = p->unary_expression();
+    auto e = p->expect_relational_expression_post_unary_expression(lhs.value);
+    EXPECT_FALSE(e.errored);
+    EXPECT_FALSE(p->has_error()) << p->error();
+    ASSERT_NE(e.value, nullptr);
+
+    EXPECT_EQ(e->source.range.begin.line, 1u);
+    EXPECT_EQ(e->source.range.begin.column, 3u);
+    EXPECT_EQ(e->source.range.end.line, 1u);
+    EXPECT_EQ(e->source.range.end.column, 5u);
+
+    ASSERT_TRUE(e->Is<ast::BinaryExpression>());
+    auto* rel = e->As<ast::BinaryExpression>();
+    EXPECT_EQ(ast::BinaryOp::kNotEqual, rel->op);
+
+    ASSERT_TRUE(rel->lhs->Is<ast::IdentifierExpression>());
+    auto* ident = rel->lhs->As<ast::IdentifierExpression>();
+    EXPECT_EQ(ident->symbol, p->builder().Symbols().Get("a"));
+
+    ASSERT_TRUE(rel->rhs->Is<ast::BoolLiteralExpression>());
+    ASSERT_TRUE(rel->rhs->As<ast::BoolLiteralExpression>()->value);
+}
+
 TEST_F(ParserImplTest, RelationalExpression_PostUnary_InvalidRHS) {
     auto p = parser("true < if (a) {}");
     auto lhs = p->unary_expression();