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76 lines
2.3 KiB
C++
76 lines
2.3 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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#ifndef CARBON_EXPLORER_INTERPRETER_RESOLVE_UNFORMED_H_
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#define CARBON_EXPLORER_INTERPRETER_RESOLVE_UNFORMED_H_
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#include <string>
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#include <unordered_map>
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#include "explorer/ast/ast.h"
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#include "explorer/base/nonnull.h"
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#include "explorer/base/trace_stream.h"
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namespace Carbon {
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// Maps AST nodes to flow facts within a function.
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class FlowFacts {
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public:
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explicit FlowFacts(Nonnull<TraceStream*> trace_stream)
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: trace_stream_(trace_stream) {}
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enum class ActionType {
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// Adds a must-be-formed flow fact.
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// Used at `VariableDefinition` with initialization.
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AddInit,
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// Adds an unformed flow fact.
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// Used at `VariableDefinition` without initialization.
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AddUninit,
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// Marks an unformed flow fact as may-be-formed.
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// Used at AST nodes that potentially initializes a variable.
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Form,
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// Returns compilation error if the AST node is impossible to be formed.
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// Used at AST nodes that uses a variable.
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Check,
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// Used in traversing children nodes without an acion to take.
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None,
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};
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auto action_type_string(ActionType action) const -> std::string_view;
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// Take action on flow facts based on `ActionType`.
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auto TakeAction(Nonnull<const AstNode*> node, ActionType action,
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SourceLocation source_loc, const std::string& name)
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-> ErrorOr<Success>;
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private:
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enum class FormedState {
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MustBeFormed,
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MayBeFormed,
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Unformed,
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};
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// Aggregate information about a AstNode being analyzed.
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struct Fact {
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FormedState formed_state;
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};
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void AddFact(Nonnull<const AstNode*> node, const FormedState state) {
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CARBON_CHECK(facts_.find(node) == facts_.end());
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facts_.insert({node, {state}});
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}
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std::unordered_map<Nonnull<const AstNode*>, Fact> facts_;
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Nonnull<TraceStream*> trace_stream_;
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};
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// An intraprocedural forward analysis that checks the may-be-formed states on
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// local variables. Returns compilation error on usage of must-be-unformed
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// variables.
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auto ResolveUnformed(Nonnull<TraceStream*> trace_stream, const AST& ast)
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-> ErrorOr<Success>;
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} // namespace Carbon
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#endif // CARBON_EXPLORER_INTERPRETER_RESOLVE_UNFORMED_H_
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