Add type determination for constructors.

This CL adds type determination for the ScalarConstructorExpression and
TypeConstructorExpression.

Bug: tint:5
Change-Id: I46299140785eb420c3801de470d6423c25e9c700
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/18827
Reviewed-by: David Neto <dneto@google.com>

src/CMakeLists.txt

@@ -308,6 +308,7 @@ set(TINT_TEST_SRCS
   ast/variable_decl_statement_test.cc
   ast/variable_test.cc
   scope_stack_test.cc
+  type_determiner_test.cc
   type_manager_test.cc
   validator_impl_import_test.cc
 )

src/type_determiner.cc

@@ -14,6 +14,9 @@
 
 #include "src/type_determiner.h"
 
+#include "src/ast/scalar_constructor_expression.h"
+#include "src/ast/type_constructor_expression.h"
+
 namespace tint {
 
 TypeDeterminer::TypeDeterminer(Context* ctx) : ctx_(*ctx) {
@@ -77,8 +80,21 @@ bool TypeDeterminer::DetermineResultType(ast::Expression* expr) {
     return true;
   }
 
+  if (expr->IsConstructor()) {
+    return DetermineConstructor(expr->AsConstructor());
+  }
+
   error_ = "unknown expression for type determination";
   return false;
 }
 
+bool TypeDeterminer::DetermineConstructor(ast::ConstructorExpression* expr) {
+  if (expr->IsTypeConstructor()) {
+    expr->set_result_type(expr->AsTypeConstructor()->type());
+  } else {
+    expr->set_result_type(expr->AsScalarConstructor()->literal()->type());
+  }
+  return true;
+}
+
 }  // namespace tint

src/type_determiner.h

@@ -25,6 +25,7 @@
 namespace tint {
 namespace ast {
 
+class ConstructorExpression;
 class Function;
 class Variable;
 
@@ -67,6 +68,8 @@ class TypeDeterminer {
   bool DetermineResultType(ast::Expression* expr);
 
  private:
+  bool DetermineConstructor(ast::ConstructorExpression* expr);
+
   Context& ctx_;
   std::string error_;
   ScopeStack<ast::Variable*> variable_stack_;

src/type_determiner_test.cc

@@ -0,0 +1,74 @@
+// Copyright 2020 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "src/type_determiner.h"
+
+#include <memory>
+#include <utility>
+
+#include "gtest/gtest.h"
+#include "src/ast/float_literal.h"
+#include "src/ast/int_literal.h"
+#include "src/ast/scalar_constructor_expression.h"
+#include "src/ast/type/f32_type.h"
+#include "src/ast/type/vector_type.h"
+#include "src/ast/type_constructor_expression.h"
+
+namespace tint {
+namespace {
+
+class TypeDeterminerTest : public testing::Test {
+ public:
+  void SetUp() { td_ = std::make_unique<TypeDeterminer>(&ctx_); }
+
+  TypeDeterminer* td() const { return td_.get(); }
+
+ private:
+  Context ctx_;
+  std::unique_ptr<TypeDeterminer> td_;
+};
+
+TEST_F(TypeDeterminerTest, Expr_Constructor_Scalar) {
+  ast::type::F32Type f32;
+  ast::ScalarConstructorExpression s(
+      std::make_unique<ast::FloatLiteral>(&f32, 1.0f));
+
+  EXPECT_TRUE(td()->DetermineResultType(&s));
+  ASSERT_NE(s.result_type(), nullptr);
+  EXPECT_TRUE(s.result_type()->IsF32());
+}
+
+TEST_F(TypeDeterminerTest, Expr_Constructor_Type) {
+  ast::type::F32Type f32;
+  ast::type::VectorType vec(&f32, 3);
+
+  ast::ExpressionList vals;
+  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 1.0f)));
+  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 1.0f)));
+  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 3.0f)));
+
+  ast::TypeConstructorExpression tc(&vec, std::move(vals));
+
+  EXPECT_TRUE(td()->DetermineResultType(&tc));
+  ASSERT_NE(tc.result_type(), nullptr);
+  ASSERT_TRUE(tc.result_type()->IsVector());
+  EXPECT_TRUE(tc.result_type()->AsVector()->type()->IsF32());
+  EXPECT_EQ(tc.result_type()->AsVector()->size(), 3);
+}
+
+}  // namespace
+}  // namespace tint