[hlsl-writer] Emit discard.
This CL adds the discard statement to the HLSL writer.
Bug: tint:7, tint:166
Change-Id: I292e9b97a1246c9b79a9660ec229ff7855aeb2a9
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/25842
Reviewed-by: David Neto <dneto@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 9388949..c47c3d3 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1049,6 +1049,7 @@
"src/writer/hlsl/generator_impl_case_test.cc",
"src/writer/hlsl/generator_impl_constructor_test.cc",
"src/writer/hlsl/generator_impl_continue_test.cc",
+ "src/writer/hlsl/generator_impl_discard_test.cc",
"src/writer/hlsl/generator_impl_identifier_test.cc",
"src/writer/hlsl/generator_impl_return_test.cc",
"src/writer/hlsl/generator_impl_switch_test.cc",
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index ab5c4fa..7f07d7c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -557,6 +557,7 @@
writer/hlsl/generator_impl_case_test.cc
writer/hlsl/generator_impl_constructor_test.cc
writer/hlsl/generator_impl_continue_test.cc
+ writer/hlsl/generator_impl_discard_test.cc
writer/hlsl/generator_impl_identifier_test.cc
writer/hlsl/generator_impl_return_test.cc
writer/hlsl/generator_impl_switch_test.cc
diff --git a/src/writer/hlsl/generator_impl.cc b/src/writer/hlsl/generator_impl.cc
index 089c764..126be19 100644
--- a/src/writer/hlsl/generator_impl.cc
+++ b/src/writer/hlsl/generator_impl.cc
@@ -325,6 +325,14 @@
return true;
}
+bool GeneratorImpl::EmitDiscard(ast::DiscardStatement*) {
+ make_indent();
+ // TODO(dsinclair): Verify this is correct when the discard semantics are
+ // defined for WGSL (https://github.com/gpuweb/gpuweb/issues/361)
+ out_ << "discard;" << std::endl;
+ return true;
+}
+
bool GeneratorImpl::EmitExpression(ast::Expression* expr) {
if (expr->IsArrayAccessor()) {
return EmitArrayAccessor(expr->AsArrayAccessor());
@@ -450,6 +458,9 @@
if (stmt->IsContinue()) {
return EmitContinue(stmt->AsContinue());
}
+ if (stmt->IsDiscard()) {
+ return EmitDiscard(stmt->AsDiscard());
+ }
if (stmt->IsFallthrough()) {
make_indent();
out_ << "/* fallthrough */" << std::endl;
diff --git a/src/writer/hlsl/generator_impl.h b/src/writer/hlsl/generator_impl.h
index b8b1743..6d8856e 100644
--- a/src/writer/hlsl/generator_impl.h
+++ b/src/writer/hlsl/generator_impl.h
@@ -66,6 +66,10 @@
/// @param expr the constructor expression
/// @returns true if the expression was emitted
bool EmitConstructor(ast::ConstructorExpression* expr);
+ /// Handles generating a discard statement
+ /// @param stmt the discard statement
+ /// @returns true if the statement was successfully emitted
+ bool EmitDiscard(ast::DiscardStatement* stmt);
/// Handles generating a scalar constructor
/// @param expr the scalar constructor expression
/// @returns true if the scalar constructor is emitted
diff --git a/src/writer/hlsl/generator_impl_discard_test.cc b/src/writer/hlsl/generator_impl_discard_test.cc
new file mode 100644
index 0000000..4dfa099
--- /dev/null
+++ b/src/writer/hlsl/generator_impl_discard_test.cc
@@ -0,0 +1,41 @@
+// 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/discard_statement.h"
+#include "src/ast/module.h"
+#include "src/writer/hlsl/generator_impl.h"
+
+namespace tint {
+namespace writer {
+namespace hlsl {
+namespace {
+
+using HlslGeneratorImplTest = testing::Test;
+
+TEST_F(HlslGeneratorImplTest, Emit_Discard) {
+ ast::DiscardStatement stmt;
+
+ ast::Module m;
+ GeneratorImpl g(&m);
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitStatement(&stmt)) << g.error();
+ EXPECT_EQ(g.result(), " discard;\n");
+}
+
+} // namespace
+} // namespace hlsl
+} // namespace writer
+} // namespace tint
