Emit Return statements.
This CL adds emitting return statements into the WGSL writer.
Bug: tint:4
Change-Id: Ia2331f7c20e3a3e3af1aa1553cef83bec315eae3
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/17260
Reviewed-by: David Neto <dneto@google.com>
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index cc8a03a..db81963 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -422,6 +422,7 @@
writer/wgsl/generator_impl_member_accessor_test.cc
writer/wgsl/generator_impl_nop_test.cc
writer/wgsl/generator_impl_relational_test.cc
+ writer/wgsl/generator_impl_return_test.cc
writer/wgsl/generator_impl_type_test.cc
writer/wgsl/generator_impl_unary_derivative_test.cc
writer/wgsl/generator_impl_unary_method_test.cc
diff --git a/src/ast/return_statement.h b/src/ast/return_statement.h
index 3c60d09..ada4844 100644
--- a/src/ast/return_statement.h
+++ b/src/ast/return_statement.h
@@ -50,6 +50,8 @@
}
/// @returns the value
Expression* value() const { return value_.get(); }
+ /// @returns true if the return has a value
+ bool has_value() const { return value_ != nullptr; }
/// @returns true if this is a return statement
bool IsReturn() const override { return true; }
diff --git a/src/ast/return_statement_test.cc b/src/ast/return_statement_test.cc
index 9d631f4..ebbcaab 100644
--- a/src/ast/return_statement_test.cc
+++ b/src/ast/return_statement_test.cc
@@ -44,6 +44,17 @@
EXPECT_TRUE(r.IsReturn());
}
+TEST_F(ReturnStatementTest, HasValue_WithoutValue) {
+ ReturnStatement r;
+ EXPECT_FALSE(r.has_value());
+}
+
+TEST_F(ReturnStatementTest, HasValue_WithValue) {
+ auto expr = std::make_unique<IdentifierExpression>("expr");
+ ReturnStatement r(std::move(expr));
+ EXPECT_TRUE(r.has_value());
+}
+
TEST_F(ReturnStatementTest, IsValid_WithoutValue) {
ReturnStatement r;
EXPECT_TRUE(r.IsValid());
diff --git a/src/writer/wgsl/generator_impl.cc b/src/writer/wgsl/generator_impl.cc
index d1d992d..d27d315 100644
--- a/src/writer/wgsl/generator_impl.cc
+++ b/src/writer/wgsl/generator_impl.cc
@@ -37,6 +37,7 @@
#include "src/ast/location_decoration.h"
#include "src/ast/member_accessor_expression.h"
#include "src/ast/relational_expression.h"
+#include "src/ast/return_statement.h"
#include "src/ast/set_decoration.h"
#include "src/ast/statement.h"
#include "src/ast/struct.h"
@@ -669,6 +670,9 @@
if (stmt->IsNop()) {
return EmitNop(stmt->AsNop());
}
+ if (stmt->IsReturn()) {
+ return EmitReturn(stmt->AsReturn());
+ }
error_ = "unknown statement type";
return false;
@@ -789,6 +793,20 @@
return true;
}
+bool GeneratorImpl::EmitReturn(ast::ReturnStatement* stmt) {
+ make_indent();
+
+ out_ << "return";
+ if (stmt->has_value()) {
+ out_ << " ";
+ if (!EmitExpression(stmt->value())) {
+ return false;
+ }
+ }
+ out_ << ";" << std::endl;
+ return true;
+}
+
} // namespace wgsl
} // namespace writer
} // namespace tint
diff --git a/src/writer/wgsl/generator_impl.h b/src/writer/wgsl/generator_impl.h
index 3503954..264aefd 100644
--- a/src/writer/wgsl/generator_impl.h
+++ b/src/writer/wgsl/generator_impl.h
@@ -150,6 +150,10 @@
/// @param expr the relational expression
/// @returns true if the expression was emitted, false otherwise
bool EmitRelational(ast::RelationalExpression* expr);
+ /// Handles return statements
+ /// @param stmt the statement to emit
+ /// @returns true if the statement was successfully emitted
+ bool EmitReturn(ast::ReturnStatement* stmt);
/// Handles statements
/// @param stmt the statement to emit
/// @returns true if the statement was emitted
diff --git a/src/writer/wgsl/generator_impl_return_test.cc b/src/writer/wgsl/generator_impl_return_test.cc
new file mode 100644
index 0000000..1ef0cd1
--- /dev/null
+++ b/src/writer/wgsl/generator_impl_return_test.cc
@@ -0,0 +1,54 @@
+// 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 <memory>
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "src/ast/identifier_expression.h"
+#include "src/ast/return_statement.h"
+#include "src/writer/wgsl/generator_impl.h"
+
+namespace tint {
+namespace writer {
+namespace wgsl {
+namespace {
+
+using GeneratorImplTest = testing::Test;
+
+TEST_F(GeneratorImplTest, Emit_Return) {
+ ast::ReturnStatement r;
+
+ GeneratorImpl g;
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitStatement(&r)) << g.error();
+ EXPECT_EQ(g.result(), " return;\n");
+}
+
+TEST_F(GeneratorImplTest, Emit_ReturnWithValue) {
+ auto expr = std::make_unique<ast::IdentifierExpression>("expr");
+ ast::ReturnStatement r(std::move(expr));
+
+ GeneratorImpl g;
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitStatement(&r)) << g.error();
+ EXPECT_EQ(g.result(), " return expr;\n");
+}
+
+} // namespace
+} // namespace wgsl
+} // namespace writer
+} // namespace tint
