[metal-writer] Emit constructors.

This Cl adds the code to emit scalar and type constructors from the
Metal backend.

Bug: tint:8
Change-Id: I95c713568ae3a73b82f8c9e10119e29e3469893e
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/23707
Reviewed-by: David Neto <dneto@google.com>

BUILD.gn

@@ -887,6 +887,7 @@ source_set("tint_unittests_msl_writer_src") {
   sources = [
     "src/writer/msl/generator_impl_assign_test.cc",
     "src/writer/msl/generator_impl_binary_test.cc",
+    "src/writer/msl/generator_impl_constructor_test.cc",
     "src/writer/msl/generator_impl_function_test.cc",
     "src/writer/msl/generator_impl_identifier_test.cc",
     "src/writer/msl/generator_impl_return_test.cc",

samples/main.cc

@@ -452,7 +452,7 @@ int main(int argc, const char** argv) {
   }
 
   if (!writer->Generate()) {
-    std::cerr << "Failed to generate SPIR-V: " << writer->error() << std::endl;
+    std::cerr << "Failed to generate: " << writer->error() << std::endl;
     return 1;
   }
 

src/CMakeLists.txt

@@ -495,6 +495,7 @@ if(${TINT_BUILD_MSL_WRITER})
   list(APPEND TINT_TEST_SRCS
     writer/msl/generator_impl_assign_test.cc
     writer/msl/generator_impl_binary_test.cc
+    writer/msl/generator_impl_constructor_test.cc
     writer/msl/generator_impl_function_test.cc
     writer/msl/generator_impl_identifier_test.cc
     writer/msl/generator_impl_return_test.cc

src/writer/msl/generator.cc

@@ -25,7 +25,11 @@ Generator::Generator(ast::Module module) : Text(std::move(module)) {}
 Generator::~Generator() = default;
 
 bool Generator::Generate() {
-  return impl_.Generate(module_);
+  auto ret = impl_.Generate(module_);
+  if (!ret) {
+    error_ = impl_.error();
+  }
+  return ret;
 }
 
 }  // namespace msl

src/writer/msl/generator_impl.cc

@@ -16,9 +16,12 @@
 
 #include "src/ast/assignment_statement.h"
 #include "src/ast/binary_expression.h"
+#include "src/ast/bool_literal.h"
+#include "src/ast/float_literal.h"
 #include "src/ast/function.h"
 #include "src/ast/identifier_expression.h"
 #include "src/ast/return_statement.h"
+#include "src/ast/sint_literal.h"
 #include "src/ast/type/alias_type.h"
 #include "src/ast/type/array_type.h"
 #include "src/ast/type/bool_type.h"
@@ -30,6 +33,7 @@
 #include "src/ast/type/u32_type.h"
 #include "src/ast/type/vector_type.h"
 #include "src/ast/type/void_type.h"
+#include "src/ast/uint_literal.h"
 
 namespace tint {
 namespace writer {
@@ -148,10 +152,73 @@ bool GeneratorImpl::EmitBinary(ast::BinaryExpression* expr) {
   return true;
 }
 
+bool GeneratorImpl::EmitConstructor(ast::ConstructorExpression* expr) {
+  if (expr->IsScalarConstructor()) {
+    return EmitScalarConstructor(expr->AsScalarConstructor());
+  }
+  return EmitTypeConstructor(expr->AsTypeConstructor());
+}
+
+bool GeneratorImpl::EmitTypeConstructor(ast::TypeConstructorExpression* expr) {
+  if (!EmitType(expr->type(), "")) {
+    return false;
+  }
+
+  out_ << "(";
+
+  bool first = true;
+  for (const auto& e : expr->values()) {
+    if (!first) {
+      out_ << ", ";
+    }
+    first = false;
+
+    if (!EmitExpression(e.get())) {
+      return false;
+    }
+  }
+
+  out_ << ")";
+  return true;
+}
+
+bool GeneratorImpl::EmitScalarConstructor(
+    ast::ScalarConstructorExpression* expr) {
+  return EmitLiteral(expr->literal());
+}
+
+bool GeneratorImpl::EmitLiteral(ast::Literal* lit) {
+  if (lit->IsBool()) {
+    out_ << (lit->AsBool()->IsTrue() ? "true" : "false");
+  } else if (lit->IsFloat()) {
+    auto flags = out_.flags();
+    auto precision = out_.precision();
+
+    out_.flags(flags | std::ios_base::showpoint);
+    out_.precision(std::numeric_limits<float>::max_digits10);
+
+    out_ << lit->AsFloat()->value() << "f";
+
+    out_.precision(precision);
+    out_.flags(flags);
+  } else if (lit->IsSint()) {
+    out_ << lit->AsSint()->value();
+  } else if (lit->IsUint()) {
+    out_ << lit->AsUint()->value() << "u";
+  } else {
+    error_ = "unknown literal type";
+    return false;
+  }
+  return true;
+}
+
 bool GeneratorImpl::EmitExpression(ast::Expression* expr) {
   if (expr->IsBinary()) {
     return EmitBinary(expr->AsBinary());
   }
+  if (expr->IsConstructor()) {
+    return EmitConstructor(expr->AsConstructor());
+  }
   if (expr->IsIdentifier()) {
     return EmitIdentifier(expr->AsIdentifier());
   }

src/writer/msl/generator_impl.h

@@ -18,7 +18,10 @@
 #include <sstream>
 #include <string>
 
+#include "src/ast/literal.h"
 #include "src/ast/module.h"
+#include "src/ast/scalar_constructor_expression.h"
+#include "src/ast/type_constructor_expression.h"
 #include "src/writer/text_generator.h"
 
 namespace tint {
@@ -45,6 +48,10 @@ class GeneratorImpl : public TextGenerator {
   /// @param expr the binary expression
   /// @returns true if the expression was emitted, false otherwise
   bool EmitBinary(ast::BinaryExpression* expr);
+  /// Handles generating constructor expressions
+  /// @param expr the constructor expression
+  /// @returns true if the expression was emitted
+  bool EmitConstructor(ast::ConstructorExpression* expr);
   /// Handles generate an Expression
   /// @param expr the expression
   /// @returns true if the expression was emitted
@@ -57,10 +64,18 @@ class GeneratorImpl : public TextGenerator {
   /// @param expr the identifier expression
   /// @returns true if the identifeir was emitted
   bool EmitIdentifier(ast::IdentifierExpression* expr);
+  /// Handles a literal
+  /// @param lit the literal to emit
+  /// @returns true if the literal was successfully emitted
+  bool EmitLiteral(ast::Literal* lit);
   /// Handles return statements
   /// @param stmt the statement to emit
   /// @returns true if the statement was successfully emitted
   bool EmitReturn(ast::ReturnStatement* stmt);
+  /// Handles generating a scalar constructor
+  /// @param expr the scalar constructor expression
+  /// @returns true if the scalar constructor is emitted
+  bool EmitScalarConstructor(ast::ScalarConstructorExpression* expr);
   /// Handles a brace-enclosed list of statements.
   /// @param statements the statements to output
   /// @returns true if the statements were emitted
@@ -78,6 +93,10 @@ class GeneratorImpl : public TextGenerator {
   /// @param name the name of the variable, only used for array emission
   /// @returns true if the type is emitted
   bool EmitType(ast::type::Type* type, const std::string& name);
+  /// Handles emitting a type constructor
+  /// @param expr the type constructor expression
+  /// @returns true if the constructor is emitted
+  bool EmitTypeConstructor(ast::TypeConstructorExpression* expr);
 };
 
 }  // namespace msl

src/writer/msl/generator_impl_constructor_test.cc

@@ -0,0 +1,238 @@
+// 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 "gtest/gtest.h"
+#include "src/ast/bool_literal.h"
+#include "src/ast/float_literal.h"
+#include "src/ast/scalar_constructor_expression.h"
+#include "src/ast/sint_literal.h"
+#include "src/ast/type/array_type.h"
+#include "src/ast/type/bool_type.h"
+#include "src/ast/type/f32_type.h"
+#include "src/ast/type/i32_type.h"
+#include "src/ast/type/matrix_type.h"
+#include "src/ast/type/u32_type.h"
+#include "src/ast/type/vector_type.h"
+#include "src/ast/type_constructor_expression.h"
+#include "src/ast/uint_literal.h"
+#include "src/writer/msl/generator_impl.h"
+
+namespace tint {
+namespace writer {
+namespace msl {
+namespace {
+
+using MslGeneratorImplTest = testing::Test;
+
+TEST_F(MslGeneratorImplTest, EmitConstructor_Bool) {
+  ast::type::BoolType bool_type;
+  auto lit = std::make_unique<ast::BoolLiteral>(&bool_type, false);
+  ast::ScalarConstructorExpression expr(std::move(lit));
+
+  GeneratorImpl g;
+  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
+  EXPECT_EQ(g.result(), "false");
+}
+
+TEST_F(MslGeneratorImplTest, EmitConstructor_Int) {
+  ast::type::I32Type i32;
+  auto lit = std::make_unique<ast::SintLiteral>(&i32, -12345);
+  ast::ScalarConstructorExpression expr(std::move(lit));
+
+  GeneratorImpl g;
+  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
+  EXPECT_EQ(g.result(), "-12345");
+}
+
+TEST_F(MslGeneratorImplTest, EmitConstructor_UInt) {
+  ast::type::U32Type u32;
+  auto lit = std::make_unique<ast::UintLiteral>(&u32, 56779);
+  ast::ScalarConstructorExpression expr(std::move(lit));
+
+  GeneratorImpl g;
+  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
+  EXPECT_EQ(g.result(), "56779u");
+}
+
+TEST_F(MslGeneratorImplTest, EmitConstructor_Float) {
+  ast::type::F32Type f32;
+  auto lit = std::make_unique<ast::FloatLiteral>(&f32, 1.5e27);
+  ast::ScalarConstructorExpression expr(std::move(lit));
+
+  GeneratorImpl g;
+  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
+  EXPECT_EQ(g.result(), "1.49999995e+27f");
+}
+
+TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Float) {
+  ast::type::F32Type f32;
+
+  auto lit = std::make_unique<ast::FloatLiteral>(&f32, -1.2e-5);
+  ast::ExpressionList values;
+  values.push_back(
+      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit)));
+
+  ast::TypeConstructorExpression expr(&f32, std::move(values));
+
+  GeneratorImpl g;
+  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
+  EXPECT_EQ(g.result(), "float(-1.20000004e-05f)");
+}
+
+TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Bool) {
+  ast::type::BoolType b;
+
+  auto lit = std::make_unique<ast::BoolLiteral>(&b, true);
+  ast::ExpressionList values;
+  values.push_back(
+      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit)));
+
+  ast::TypeConstructorExpression expr(&b, std::move(values));
+
+  GeneratorImpl g;
+  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
+  EXPECT_EQ(g.result(), "bool(true)");
+}
+
+TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Int) {
+  ast::type::I32Type i32;
+
+  auto lit = std::make_unique<ast::SintLiteral>(&i32, -12345);
+  ast::ExpressionList values;
+  values.push_back(
+      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit)));
+
+  ast::TypeConstructorExpression expr(&i32, std::move(values));
+
+  GeneratorImpl g;
+  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
+  EXPECT_EQ(g.result(), "int(-12345)");
+}
+
+TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Uint) {
+  ast::type::U32Type u32;
+
+  auto lit = std::make_unique<ast::UintLiteral>(&u32, 12345);
+  ast::ExpressionList values;
+  values.push_back(
+      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit)));
+
+  ast::TypeConstructorExpression expr(&u32, std::move(values));
+
+  GeneratorImpl g;
+  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
+  EXPECT_EQ(g.result(), "uint(12345u)");
+}
+
+TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Vec) {
+  ast::type::F32Type f32;
+  ast::type::VectorType vec(&f32, 3);
+
+  auto lit1 = std::make_unique<ast::FloatLiteral>(&f32, 1.f);
+  auto lit2 = std::make_unique<ast::FloatLiteral>(&f32, 2.f);
+  auto lit3 = std::make_unique<ast::FloatLiteral>(&f32, 3.f);
+  ast::ExpressionList values;
+  values.push_back(
+      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit1)));
+  values.push_back(
+      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit2)));
+  values.push_back(
+      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit3)));
+
+  ast::TypeConstructorExpression expr(&vec, std::move(values));
+
+  GeneratorImpl g;
+  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
+  EXPECT_EQ(g.result(), "float3(1.00000000f, 2.00000000f, 3.00000000f)");
+}
+
+TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Mat) {
+  ast::type::F32Type f32;
+  ast::type::MatrixType mat(&f32, 3, 2);
+
+  ast::type::VectorType vec(&f32, 2);
+
+  ast::ExpressionList mat_values;
+
+  for (size_t i = 0; i < 3; i++) {
+    auto lit1 = std::make_unique<ast::FloatLiteral>(
+        &f32, static_cast<float>(1 + (i * 2)));
+    auto lit2 = std::make_unique<ast::FloatLiteral>(
+        &f32, static_cast<float>(2 + (i * 2)));
+
+    ast::ExpressionList values;
+    values.push_back(
+        std::make_unique<ast::ScalarConstructorExpression>(std::move(lit1)));
+    values.push_back(
+        std::make_unique<ast::ScalarConstructorExpression>(std::move(lit2)));
+
+    mat_values.push_back(std::make_unique<ast::TypeConstructorExpression>(
+        &vec, std::move(values)));
+  }
+
+  ast::TypeConstructorExpression expr(&mat, std::move(mat_values));
+
+  GeneratorImpl g;
+  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
+  EXPECT_EQ(g.result(),
+            std::string("float2x3(float2(1.00000000f, 2.00000000f), ") +
+                "float2(3.00000000f, 4.00000000f), " +
+                "float2(5.00000000f, 6.00000000f))");
+}
+
+// TODO(dsinclair): Verify
+TEST_F(MslGeneratorImplTest, DISABLED_EmitConstructor_Type_Array) {
+  ast::type::F32Type f32;
+  ast::type::VectorType vec(&f32, 3);
+  ast::type::ArrayType ary(&vec, 3);
+
+  ast::ExpressionList ary_values;
+
+  for (size_t i = 0; i < 3; i++) {
+    auto lit1 = std::make_unique<ast::FloatLiteral>(
+        &f32, static_cast<float>(1 + (i * 3)));
+    auto lit2 = std::make_unique<ast::FloatLiteral>(
+        &f32, static_cast<float>(2 + (i * 3)));
+    auto lit3 = std::make_unique<ast::FloatLiteral>(
+        &f32, static_cast<float>(3 + (i * 3)));
+
+    ast::ExpressionList values;
+    values.push_back(
+        std::make_unique<ast::ScalarConstructorExpression>(std::move(lit1)));
+    values.push_back(
+        std::make_unique<ast::ScalarConstructorExpression>(std::move(lit2)));
+    values.push_back(
+        std::make_unique<ast::ScalarConstructorExpression>(std::move(lit3)));
+
+    ary_values.push_back(std::make_unique<ast::TypeConstructorExpression>(
+        &vec, std::move(values)));
+  }
+
+  ast::TypeConstructorExpression expr(&ary, std::move(ary_values));
+
+  GeneratorImpl g;
+  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
+  EXPECT_EQ(g.result(), std::string("float3[3](") +
+                            "float3(1.00000000f, 2.00000000f, 3.00000000f), " +
+                            "float3(4.00000000f, 5.00000000f, 6.00000000f), " +
+                            "float3(7.00000000f, 8.00000000f, 9.00000000f))");
+}
+
+// TODO(dsinclair): Add struct constructor test.
+TEST_F(MslGeneratorImplTest, DISABLED_EmitConstructor_Type_Struct) {}
+
+}  // namespace
+}  // namespace msl
+}  // namespace writer
+}  // namespace tint

src/writer/wgsl/generator.cc

@@ -25,7 +25,11 @@ Generator::Generator(ast::Module module) : Text(std::move(module)) {}
 Generator::~Generator() = default;
 
 bool Generator::Generate() {
-  return impl_.Generate(module_);
+  auto ret = impl_.Generate(module_);
+  if (!ret) {
+    error_ = impl_.error();
+  }
+  return ret;
 }
 
 }  // namespace wgsl

test/function.wgsl

@@ -0,0 +1,17 @@
+# 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.
+
+fn main() -> f32 {
+    return ((2. * 3.) - 4.) / 5.;
+}