[spirv-reader] use stack of statement lists
This is preparation for emitting nested control flow.
Bug: tint:3
Change-Id: I90fc7edba8cb9937f722e6f5e94c7f222d34c403
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/21801
Reviewed-by: dan sinclair <dsinclair@google.com>
diff --git a/src/reader/spirv/function.cc b/src/reader/spirv/function.cc
index 7970f84..ff4d80b 100644
--- a/src/reader/spirv/function.cc
+++ b/src/reader/spirv/function.cc
@@ -367,10 +367,22 @@
type_mgr_(ir_context_.get_type_mgr()),
fail_stream_(pi->fail_stream()),
namer_(pi->namer()),
- function_(function) {}
+ function_(function) {
+ statements_stack_.emplace_back(ast::StatementList{});
+}
FunctionEmitter::~FunctionEmitter() = default;
+const ast::StatementList& FunctionEmitter::ast_body() {
+ assert(!statements_stack_.empty());
+ return statements_stack_[0];
+}
+
+void FunctionEmitter::AddStatement(std::unique_ptr<ast::Statement> statement) {
+ assert(!statements_stack_.empty());
+ statements_stack_.back().emplace_back(std::move(statement));
+}
+
bool FunctionEmitter::Emit() {
if (failed()) {
return false;
@@ -389,7 +401,15 @@
}
// Set the body of the AST function node.
- parser_impl_.get_module().functions().back()->set_body(std::move(ast_body_));
+ if (statements_stack_.size() != 1) {
+ return Fail() << "internal error: statement-list stack should have 1 "
+ "element but has "
+ << statements_stack_.size();
+ }
+ ast::StatementList body(std::move(statements_stack_[0]));
+ parser_impl_.get_module().functions().back()->set_body(std::move(body));
+ // Maintain the invariant by repopulating the one and only element.
+ statements_stack_[0] = ast::StatementList{};
return success();
}
@@ -1363,7 +1383,7 @@
// TODO(dneto): Add the initializer via Variable::set_constructor.
auto var_decl_stmt =
std::make_unique<ast::VariableDeclStatement>(std::move(var));
- ast_body_.emplace_back(std::move(var_decl_stmt));
+ AddStatement(std::move(var_decl_stmt));
// Save this as an already-named value.
identifier_values_.insert(inst.result_id());
}
@@ -1445,7 +1465,7 @@
}
ast_const->set_constructor(std::move(ast_expr.expr));
ast_const->set_is_const(true);
- ast_body_.emplace_back(
+ AddStatement(
std::make_unique<ast::VariableDeclStatement>(std::move(ast_const)));
// Save this as an already-named value.
identifier_values_.insert(inst.result_id());
@@ -1476,7 +1496,7 @@
// TODO(dneto): Order of evaluation?
auto lhs = MakeExpression(inst.GetSingleWordInOperand(0));
auto rhs = MakeExpression(inst.GetSingleWordInOperand(1));
- ast_body_.emplace_back(std::make_unique<ast::AssignmentStatement>(
+ AddStatement(std::make_unique<ast::AssignmentStatement>(
std::move(lhs.expr), std::move(rhs.expr)));
return success();
}
diff --git a/src/reader/spirv/function.h b/src/reader/spirv/function.h
index 36490d4..9174259 100644
--- a/src/reader/spirv/function.h
+++ b/src/reader/spirv/function.h
@@ -172,8 +172,10 @@
/// @returns true if emission has failed.
bool failed() const { return !success(); }
+ /// Returns the body of the function. It is the bottom of the statement
+ /// stack.
/// @returns the body of the function.
- const ast::StatementList& ast_body() { return ast_body_; }
+ const ast::StatementList& ast_body();
/// Records failure.
/// @returns a FailStream on which to emit diagnostics.
@@ -188,7 +190,8 @@
/// @returns true if emission has not yet failed.
bool EmitFunctionDeclaration();
- /// Emits the function body, populating |ast_body_|
+ /// Emits the function body, populating the bottom entry of the statements
+ /// stack.
/// @returns false if emission failed.
bool EmitBody();
@@ -343,6 +346,9 @@
/// or nullptr
BlockInfo* HeaderIfBreakable(const Construct* c);
+ /// Appends a new statement to the top of the statement stack.
+ void AddStatement(std::unique_ptr<ast::Statement> statement);
+
ParserImpl& parser_impl_;
ast::Module& ast_module_;
spvtools::opt::IRContext& ir_context_;
@@ -352,7 +358,12 @@
FailStream& fail_stream_;
Namer& namer_;
const spvtools::opt::Function& function_;
- ast::StatementList ast_body_;
+
+ // A stack of statement lists. Each list is contained in a construct in
+ // the next deeper element of stack. The 0th entry represents the statements
+ // for the entire function. This stack is never empty.
+ std::vector<ast::StatementList> statements_stack_;
+
// The set of IDs that have already had an identifier name generated for it.
std::unordered_set<uint32_t> identifier_values_;
// Mapping from SPIR-V ID that is used at most once, to its AST expression.
