blob: bd8dd6580c46b520500ff3f74a1da2964a932cc5 [file] [log] [blame]
* Copyright 2021 Google LLC
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#include "src/sksl/ir/SkSLBlock.h"
#include "src/sksl/ir/SkSLNop.h"
#include <iterator>
namespace SkSL {
std::unique_ptr<Statement> Block::MakeUnscoped(int offset, StatementArray statements) {
// If the Block is completely empty, synthesize a Nop.
if (statements.empty()) {
return Nop::Make();
if (statements.size() > 1) {
// The statement array contains multiple statements, but some of those might be no-ops.
// If the statement array only contains one real statement, we can return that directly and
// avoid creating an additional Block node.
std::unique_ptr<Statement>* foundStatement = nullptr;
for (std::unique_ptr<Statement>& stmt : statements) {
if (!stmt->isEmpty()) {
if (!foundStatement) {
// We found a single non-empty statement. Remember it and keep looking.
foundStatement = &stmt;
// We found more than one non-empty statement. We actually do need a Block.
return std::make_unique<Block>(offset, std::move(statements),
/*symbols=*/nullptr, /*isScope=*/false);
// The array wrapped one valid Statement. Avoid allocating a Block by returning it directly.
if (foundStatement) {
return std::move(*foundStatement);
// The statement array contained nothing but empty statements!
// In this case, we don't actually need to allocate a Block.
// We can just return one of those empty statements. Fall through to...
return std::move(statements.front());
std::unique_ptr<Block> Block::Make(int offset,
StatementArray statements,
std::shared_ptr<SymbolTable> symbols,
bool isScope) {
// Nothing to optimize here--eliminating empty statements doesn't actually improve the generated
// code, and we promise to return a Block.
return std::make_unique<Block>(offset, std::move(statements), std::move(symbols), isScope);
std::unique_ptr<Statement> Block::clone() const {
StatementArray cloned;
for (const std::unique_ptr<Statement>& stmt : this->children()) {
return std::make_unique<Block>(fOffset,
String Block::description() const {
String result;
if (fIsScope) {
result += "{";
for (const std::unique_ptr<Statement>& stmt : this->children()) {
result += "\n";
result += stmt->description();
result += fIsScope ? "\n}\n" : "\n";
return result;
} // namespace SkSL