Add a call ast statement.

This CL adds CallStatement to the AST to allow wrapping a CallExpression
into a statement.

Bug: tint:45
Change-Id: I5a9525514344fcc2cf9900eb2cd78c1fb94ca2ef
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/25320
Reviewed-by: David Neto <dneto@google.com>

BUILD.gn

@@ -239,6 +239,8 @@ source_set("libtint_core_src") {
     "src/ast/builtin_decoration.h",
     "src/ast/call_expression.cc",
     "src/ast/call_expression.h",
+    "src/ast/call_statement.cc",
+    "src/ast/call_statement.h",
     "src/ast/case_statement.cc",
     "src/ast/case_statement.h",
     "src/ast/cast_expression.cc",
@@ -655,6 +657,7 @@ source_set("tint_unittests_core_src") {
     "src/ast/break_statement_test.cc",
     "src/ast/builtin_decoration_test.cc",
     "src/ast/call_expression_test.cc",
+    "src/ast/call_statement_test.cc",
     "src/ast/case_statement_test.cc",
     "src/ast/cast_expression_test.cc",
     "src/ast/continue_statement_test.cc",

src/CMakeLists.txt

@@ -58,6 +58,8 @@ set(TINT_LIB_SRCS
   ast/builtin_decoration.h
   ast/call_expression.cc
   ast/call_expression.h
+  ast/call_statement.cc
+  ast/call_statement.h
   ast/case_statement.cc
   ast/case_statement.h
   ast/cast_expression.cc
@@ -278,6 +280,7 @@ set(TINT_TEST_SRCS
   ast/break_statement_test.cc
   ast/builtin_decoration_test.cc
   ast/call_expression_test.cc
+  ast/call_statement_test.cc
   ast/case_statement_test.cc
   ast/cast_expression_test.cc
   ast/continue_statement_test.cc

src/ast/call_statement.cc

@@ -0,0 +1,44 @@
+// 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/ast/call_statement.h"
+
+#include "src/ast/call_expression.h"
+
+namespace tint {
+namespace ast {
+
+CallStatement::CallStatement() : Statement() {}
+
+CallStatement::CallStatement(std::unique_ptr<CallExpression> call)
+    : Statement(), call_(std::move(call)) {}
+
+CallStatement::CallStatement(CallStatement&&) = default;
+
+CallStatement::~CallStatement() = default;
+
+bool CallStatement::IsCall() const {
+  return true;
+}
+
+bool CallStatement::IsValid() const {
+  return call_ != nullptr && call_->IsValid();
+}
+
+void CallStatement::to_str(std::ostream& out, size_t indent) const {
+  call_->to_str(out, indent);
+}
+
+}  // namespace ast
+}  // namespace tint

src/ast/call_statement.h

@@ -0,0 +1,67 @@
+// 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.
+
+#ifndef SRC_AST_CALL_STATEMENT_H_
+#define SRC_AST_CALL_STATEMENT_H_
+
+#include <memory>
+#include <utility>
+
+#include "src/ast/call_expression.h"
+#include "src/ast/statement.h"
+
+namespace tint {
+namespace ast {
+
+/// A call expression
+class CallStatement : public Statement {
+ public:
+  /// Constructor
+  CallStatement();
+  /// Constructor
+  /// @param call the function
+  explicit CallStatement(std::unique_ptr<CallExpression> call);
+  /// Move constructor
+  CallStatement(CallStatement&&);
+  ~CallStatement() override;
+
+  /// Sets the call expression
+  /// @param call the call
+  void set_expr(std::unique_ptr<CallExpression> call) {
+    call_ = std::move(call);
+  }
+  /// @returns the call expression
+  CallExpression* expr() const { return call_.get(); }
+
+  /// @returns true if this is a call statement
+  bool IsCall() const override;
+
+  /// @returns true if the node is valid
+  bool IsValid() const override;
+
+  /// Writes a representation of the node to the output stream
+  /// @param out the stream to write to
+  /// @param indent number of spaces to indent the node when writing
+  void to_str(std::ostream& out, size_t indent) const override;
+
+ private:
+  CallStatement(const CallStatement&) = delete;
+
+  std::unique_ptr<CallExpression> call_;
+};
+
+}  // namespace ast
+}  // namespace tint
+
+#endif  // SRC_AST_CALL_STATEMENT_H_

src/ast/call_statement_test.cc

@@ -0,0 +1,73 @@
+// 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/ast/call_statement.h"
+
+#include "gtest/gtest.h"
+#include "src/ast/call_expression.h"
+#include "src/ast/identifier_expression.h"
+
+namespace tint {
+namespace ast {
+namespace {
+
+using CallStatementTest = testing::Test;
+
+TEST_F(CallStatementTest, Creation) {
+  auto expr = std::make_unique<ast::CallExpression>(
+      std::make_unique<ast::IdentifierExpression>("func"), ExpressionList{});
+  auto* expr_ptr = expr.get();
+
+  CallStatement c(std::move(expr));
+  EXPECT_EQ(c.expr(), expr_ptr);
+}
+
+TEST_F(CallStatementTest, IsCall) {
+  CallStatement c;
+  EXPECT_TRUE(c.IsCall());
+}
+
+TEST_F(CallStatementTest, IsValid) {
+  CallStatement c(std::make_unique<ast::CallExpression>(
+      std::make_unique<ast::IdentifierExpression>("func"), ExpressionList{}));
+  EXPECT_TRUE(c.IsValid());
+}
+
+TEST_F(CallStatementTest, IsValid_MissingExpr) {
+  CallStatement c;
+  EXPECT_FALSE(c.IsValid());
+}
+
+TEST_F(CallStatementTest, IsValid_InvalidExpr) {
+  CallStatement c(std::make_unique<ast::CallExpression>());
+  EXPECT_FALSE(c.IsValid());
+}
+
+TEST_F(CallStatementTest, ToStr) {
+  CallStatement c(std::make_unique<ast::CallExpression>(
+      std::make_unique<ast::IdentifierExpression>("func"), ExpressionList{}));
+
+  std::ostringstream out;
+  c.to_str(out, 2);
+  EXPECT_EQ(out.str(), R"(  Call{
+    Identifier{func}
+    (
+    )
+  }
+)");
+}
+
+}  // namespace
+}  // namespace ast
+}  // namespace tint

src/ast/statement.cc

@@ -18,6 +18,7 @@
 
 #include "src/ast/assignment_statement.h"
 #include "src/ast/break_statement.h"
+#include "src/ast/call_statement.h"
 #include "src/ast/case_statement.h"
 #include "src/ast/continue_statement.h"
 #include "src/ast/else_statement.h"
@@ -52,6 +53,10 @@ bool Statement::IsCase() const {
   return false;
 }
 
+bool Statement::IsCall() const {
+  return false;
+}
+
 bool Statement::IsContinue() const {
   return false;
 }
@@ -98,6 +103,11 @@ const BreakStatement* Statement::AsBreak() const {
   return static_cast<const BreakStatement*>(this);
 }
 
+const CallStatement* Statement::AsCall() const {
+  assert(IsCall());
+  return static_cast<const CallStatement*>(this);
+}
+
 const CaseStatement* Statement::AsCase() const {
   assert(IsCase());
   return static_cast<const CaseStatement*>(this);
@@ -158,6 +168,11 @@ BreakStatement* Statement::AsBreak() {
   return static_cast<BreakStatement*>(this);
 }
 
+CallStatement* Statement::AsCall() {
+  assert(IsCall());
+  return static_cast<CallStatement*>(this);
+}
+
 CaseStatement* Statement::AsCase() {
   assert(IsCase());
   return static_cast<CaseStatement*>(this);

src/ast/statement.h

@@ -25,6 +25,7 @@ namespace ast {
 
 class AssignmentStatement;
 class BreakStatement;
+class CallStatement;
 class CaseStatement;
 class ContinueStatement;
 class ElseStatement;
@@ -45,6 +46,8 @@ class Statement : public Node {
   virtual bool IsAssign() const;
   /// @returns true if this is a break statement
   virtual bool IsBreak() const;
+  /// @returns true if this is a call statement
+  virtual bool IsCall() const;
   /// @returns true if this is a case statement
   virtual bool IsCase() const;
   /// @returns true if this is a continue statement
@@ -70,6 +73,8 @@ class Statement : public Node {
   const AssignmentStatement* AsAssign() const;
   /// @returns the statement as a const break statement
   const BreakStatement* AsBreak() const;
+  /// @returns the statement as a const call statement
+  const CallStatement* AsCall() const;
   /// @returns the statement as a const case statement
   const CaseStatement* AsCase() const;
   /// @returns the statement as a const continue statement
@@ -95,6 +100,8 @@ class Statement : public Node {
   AssignmentStatement* AsAssign();
   /// @returns the statement as a break statement
   BreakStatement* AsBreak();
+  /// @returns the statement as a call statement
+  CallStatement* AsCall();
   /// @returns the statement as a case statement
   CaseStatement* AsCase();
   /// @returns the statement as a continue statement