Add break-if support.

This CL adds support for `break-if` to Tint.

Bug: tint:1633, tint:1451
Change-Id: I30dfd62a3e09255624ff76ebe0cdd3a3c7cf9c5f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/106420
Auto-Submit: Dan Sinclair <dsinclair@chromium.org>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: dan sinclair <dsinclair@google.com>

src/tint/ast/break_if_statement.cc

@@ -0,0 +1,43 @@
+// Copyright 2022 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/tint/ast/break_if_statement.h"
+
+#include "src/tint/program_builder.h"
+
+TINT_INSTANTIATE_TYPEINFO(tint::ast::BreakIfStatement);
+
+namespace tint::ast {
+
+BreakIfStatement::BreakIfStatement(ProgramID pid,
+                                   NodeID nid,
+                                   const Source& src,
+                                   const Expression* cond)
+    : Base(pid, nid, src), condition(cond) {
+    TINT_ASSERT(AST, condition);
+    TINT_ASSERT_PROGRAM_IDS_EQUAL_IF_VALID(AST, condition, program_id);
+}
+
+BreakIfStatement::BreakIfStatement(BreakIfStatement&&) = default;
+
+BreakIfStatement::~BreakIfStatement() = default;
+
+const BreakIfStatement* BreakIfStatement::Clone(CloneContext* ctx) const {
+    // Clone arguments outside of create() call to have deterministic ordering
+    auto src = ctx->Clone(source);
+    auto* cond = ctx->Clone(condition);
+    return ctx->dst->create<BreakIfStatement>(src, cond);
+}
+
+}  // namespace tint::ast

src/tint/ast/break_if_statement.h

@@ -0,0 +1,50 @@
+// Copyright 2022 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_TINT_AST_BREAK_IF_STATEMENT_H_
+#define SRC_TINT_AST_BREAK_IF_STATEMENT_H_
+
+#include <utility>
+
+#include "src/tint/ast/block_statement.h"
+#include "src/tint/ast/expression.h"
+
+namespace tint::ast {
+
+/// A break if statement
+class BreakIfStatement final : public Castable<BreakIfStatement, Statement> {
+  public:
+    /// Constructor
+    /// @param pid the identifier of the program that owns this node
+    /// @param nid the unique node identifier
+    /// @param src the source of this node
+    /// @param condition the if condition
+    BreakIfStatement(ProgramID pid, NodeID nid, const Source& src, const Expression* condition);
+
+    /// Move constructor
+    BreakIfStatement(BreakIfStatement&&);
+    ~BreakIfStatement() override;
+
+    /// Clones this node and all transitive child nodes using the `CloneContext` `ctx`.
+    /// @param ctx the clone context
+    /// @return the newly cloned node
+    const BreakIfStatement* Clone(CloneContext* ctx) const override;
+
+    /// The if condition or nullptr if none set
+    const Expression* const condition;
+};
+
+}  // namespace tint::ast
+
+#endif  // SRC_TINT_AST_BREAK_IF_STATEMENT_H_

src/tint/ast/break_if_statement_test.cc

@@ -0,0 +1,58 @@
+// Copyright 2022 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/tint/ast/break_if_statement.h"
+
+#include "gtest/gtest-spi.h"
+#include "src/tint/ast/test_helper.h"
+
+namespace tint::ast {
+namespace {
+
+using BreakIfStatementTest = TestHelper;
+
+TEST_F(BreakIfStatementTest, Creation) {
+    auto* cond = Expr("cond");
+    auto* stmt = BreakIf(Source{Source::Location{20, 2}}, cond);
+    auto src = stmt->source;
+    EXPECT_EQ(src.range.begin.line, 20u);
+    EXPECT_EQ(src.range.begin.column, 2u);
+}
+
+TEST_F(BreakIfStatementTest, IsBreakIf) {
+    auto* stmt = BreakIf(Expr(true));
+    EXPECT_TRUE(stmt->Is<BreakIfStatement>());
+}
+
+TEST_F(BreakIfStatementTest, Assert_Null_Condition) {
+    EXPECT_FATAL_FAILURE(
+        {
+            ProgramBuilder b;
+            b.BreakIf(nullptr);
+        },
+        "internal compiler error");
+}
+
+TEST_F(BreakIfStatementTest, Assert_DifferentProgramID_Cond) {
+    EXPECT_FATAL_FAILURE(
+        {
+            ProgramBuilder b1;
+            ProgramBuilder b2;
+            b1.BreakIf(b2.Expr(true));
+        },
+        "internal compiler error");
+}
+
+}  // namespace
+}  // namespace tint::ast