[hlsl-writer] Emit case statements.
This CL adds emission of case statements to the HLSL backend.
Bug: tint:7
Change-Id: I5d0dd7ecfe4ef032a03777c29f3d0d00e584a93a
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/25222
Reviewed-by: David Neto <dneto@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 11a1c8a..8947623 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1020,6 +1020,7 @@
sources = [
"src/writer/hlsl/generator_impl_binary_test.cc",
"src/writer/hlsl/generator_impl_break_test.cc",
+ "src/writer/hlsl/generator_impl_case_test.cc",
"src/writer/hlsl/generator_impl_continue_test.cc",
"src/writer/hlsl/generator_impl_identifier_test.cc",
"src/writer/hlsl/generator_impl_return_test.cc",
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a67b674..e1b5e85 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -544,6 +544,7 @@
list(APPEND TINT_TEST_SRCS
writer/hlsl/generator_impl_binary_test.cc
writer/hlsl/generator_impl_break_test.cc
+ writer/hlsl/generator_impl_case_test.cc
writer/hlsl/generator_impl_continue_test.cc
writer/hlsl/generator_impl_identifier_test.cc
writer/hlsl/generator_impl_return_test.cc
diff --git a/src/writer/hlsl/generator_impl.cc b/src/writer/hlsl/generator_impl.cc
index 741110f..e830366 100644
--- a/src/writer/hlsl/generator_impl.cc
+++ b/src/writer/hlsl/generator_impl.cc
@@ -15,13 +15,29 @@
#include "src/writer/hlsl/generator_impl.h"
#include "src/ast/binary_expression.h"
+#include "src/ast/bool_literal.h"
+#include "src/ast/case_statement.h"
+#include "src/ast/float_literal.h"
#include "src/ast/identifier_expression.h"
#include "src/ast/return_statement.h"
+#include "src/ast/sint_literal.h"
+#include "src/ast/uint_literal.h"
#include "src/ast/unary_op_expression.h"
namespace tint {
namespace writer {
namespace hlsl {
+namespace {
+
+bool last_is_break_or_fallthrough(const ast::StatementList& stmts) {
+ if (stmts.empty()) {
+ return false;
+ }
+
+ return stmts.back()->IsBreak() || stmts.back()->IsFallthrough();
+}
+
+} // namespace
GeneratorImpl::GeneratorImpl(ast::Module* module) : module_(module) {}
@@ -145,6 +161,50 @@
return true;
}
+bool GeneratorImpl::EmitCase(ast::CaseStatement* stmt) {
+ make_indent();
+
+ if (stmt->IsDefault()) {
+ out_ << "default:";
+ } else {
+ bool first = true;
+ for (const auto& selector : stmt->selectors()) {
+ if (!first) {
+ out_ << std::endl;
+ make_indent();
+ }
+ first = false;
+
+ out_ << "case ";
+ if (!EmitLiteral(selector.get())) {
+ return false;
+ }
+ out_ << ":";
+ }
+ }
+
+ out_ << " {" << std::endl;
+
+ increment_indent();
+
+ for (const auto& s : stmt->body()) {
+ if (!EmitStatement(s.get())) {
+ return false;
+ }
+ }
+
+ if (!last_is_break_or_fallthrough(stmt->body())) {
+ make_indent();
+ out_ << "break;" << std::endl;
+ }
+
+ decrement_indent();
+ make_indent();
+ out_ << "}" << std::endl;
+
+ return true;
+}
+
bool GeneratorImpl::EmitContinue(ast::ContinueStatement*) {
make_indent();
out_ << "continue;" << std::endl;
@@ -197,6 +257,31 @@
return true;
}
+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::EmitReturn(ast::ReturnStatement* stmt) {
make_indent();
@@ -224,6 +309,11 @@
if (stmt->IsContinue()) {
return EmitContinue(stmt->AsContinue());
}
+ if (stmt->IsFallthrough()) {
+ make_indent();
+ out_ << "/* fallthrough */" << std::endl;
+ return true;
+ }
if (stmt->IsReturn()) {
return EmitReturn(stmt->AsReturn());
}
diff --git a/src/writer/hlsl/generator_impl.h b/src/writer/hlsl/generator_impl.h
index 095165c..b11e61e 100644
--- a/src/writer/hlsl/generator_impl.h
+++ b/src/writer/hlsl/generator_impl.h
@@ -15,6 +15,7 @@
#ifndef SRC_WRITER_HLSL_GENERATOR_IMPL_H_
#define SRC_WRITER_HLSL_GENERATOR_IMPL_H_
+#include "src/ast/literal.h"
#include "src/ast/module.h"
#include "src/scope_stack.h"
#include "src/writer/hlsl/namer.h"
@@ -43,6 +44,10 @@
/// @param stmt the statement to emit
/// @returns true if the statement was emitted successfully
bool EmitBreak(ast::BreakStatement* stmt);
+ /// Handles a case statement
+ /// @param stmt the statement
+ /// @returns true if the statment was emitted successfully
+ bool EmitCase(ast::CaseStatement* stmt);
/// Handles a continue statement
/// @param stmt the statement to emit
/// @returns true if the statement was emitted successfully
@@ -51,6 +56,10 @@
/// @param expr the expression
/// @returns true if the expression was emitted
bool EmitExpression(ast::Expression* expr);
+ /// Handles a literal
+ /// @param lit the literal to emit
+ /// @returns true if the literal was successfully emitted
+ bool EmitLiteral(ast::Literal* lit);
/// Handles generating an identifier expression
/// @param expr the identifier expression
/// @returns true if the identifeir was emitted
diff --git a/src/writer/hlsl/generator_impl_case_test.cc b/src/writer/hlsl/generator_impl_case_test.cc
new file mode 100644
index 0000000..17803db
--- /dev/null
+++ b/src/writer/hlsl/generator_impl_case_test.cc
@@ -0,0 +1,141 @@
+// 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 "gtest/gtest.h"
+#include "src/ast/break_statement.h"
+#include "src/ast/case_statement.h"
+#include "src/ast/fallthrough_statement.h"
+#include "src/ast/identifier_expression.h"
+#include "src/ast/module.h"
+#include "src/ast/sint_literal.h"
+#include "src/ast/type/i32_type.h"
+#include "src/writer/hlsl/generator_impl.h"
+
+namespace tint {
+namespace writer {
+namespace hlsl {
+namespace {
+
+using HlslGeneratorImplTest = testing::Test;
+
+TEST_F(HlslGeneratorImplTest, Emit_Case) {
+ ast::type::I32Type i32;
+
+ ast::StatementList body;
+ body.push_back(std::make_unique<ast::BreakStatement>());
+
+ ast::CaseSelectorList lit;
+ lit.push_back(std::make_unique<ast::SintLiteral>(&i32, 5));
+ ast::CaseStatement c(std::move(lit), std::move(body));
+
+ ast::Module m;
+ GeneratorImpl g(&m);
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitCase(&c)) << g.error();
+ EXPECT_EQ(g.result(), R"( case 5: {
+ break;
+ }
+)");
+}
+
+TEST_F(HlslGeneratorImplTest, Emit_Case_BreaksByDefault) {
+ ast::type::I32Type i32;
+
+ ast::StatementList body;
+
+ ast::CaseSelectorList lit;
+ lit.push_back(std::make_unique<ast::SintLiteral>(&i32, 5));
+ ast::CaseStatement c(std::move(lit), std::move(body));
+
+ ast::Module m;
+ GeneratorImpl g(&m);
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitCase(&c)) << g.error();
+ EXPECT_EQ(g.result(), R"( case 5: {
+ break;
+ }
+)");
+}
+
+TEST_F(HlslGeneratorImplTest, Emit_Case_WithFallthrough) {
+ ast::type::I32Type i32;
+
+ ast::StatementList body;
+ body.push_back(std::make_unique<ast::FallthroughStatement>());
+
+ ast::CaseSelectorList lit;
+ lit.push_back(std::make_unique<ast::SintLiteral>(&i32, 5));
+ ast::CaseStatement c(std::move(lit), std::move(body));
+
+ ast::Module m;
+ GeneratorImpl g(&m);
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitCase(&c)) << g.error();
+ EXPECT_EQ(g.result(), R"( case 5: {
+ /* fallthrough */
+ }
+)");
+}
+
+TEST_F(HlslGeneratorImplTest, Emit_Case_MultipleSelectors) {
+ ast::type::I32Type i32;
+
+ ast::StatementList body;
+ body.push_back(std::make_unique<ast::BreakStatement>());
+
+ ast::CaseSelectorList lit;
+ lit.push_back(std::make_unique<ast::SintLiteral>(&i32, 5));
+ lit.push_back(std::make_unique<ast::SintLiteral>(&i32, 6));
+ ast::CaseStatement c(std::move(lit), std::move(body));
+
+ ast::Module m;
+ GeneratorImpl g(&m);
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitCase(&c)) << g.error();
+ EXPECT_EQ(g.result(), R"( case 5:
+ case 6: {
+ break;
+ }
+)");
+}
+
+TEST_F(HlslGeneratorImplTest, Emit_Case_Default) {
+ ast::CaseStatement c;
+
+ ast::StatementList body;
+ body.push_back(std::make_unique<ast::BreakStatement>());
+
+ c.set_body(std::move(body));
+
+ ast::Module m;
+ GeneratorImpl g(&m);
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitCase(&c)) << g.error();
+ EXPECT_EQ(g.result(), R"( default: {
+ break;
+ }
+)");
+}
+
+} // namespace
+} // namespace hlsl
+} // namespace writer
+} // namespace tint
