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Diffstat (limited to 'libjulia/optimiser/FullInliner.h')
-rw-r--r-- | libjulia/optimiser/FullInliner.h | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/libjulia/optimiser/FullInliner.h b/libjulia/optimiser/FullInliner.h new file mode 100644 index 00000000..e9a7e4fc --- /dev/null +++ b/libjulia/optimiser/FullInliner.h @@ -0,0 +1,180 @@ +/* + This file is part of solidity. + + solidity is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + solidity is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with solidity. If not, see <http://www.gnu.org/licenses/>. +*/ +/** + * Optimiser component that performs function inlining for arbitrary functions. + */ +#pragma once + +#include <libjulia/ASTDataForward.h> + +#include <libjulia/optimiser/ASTCopier.h> +#include <libjulia/optimiser/ASTWalker.h> + +#include <libsolidity/interface/Exceptions.h> + +#include <boost/variant.hpp> +#include <boost/optional.hpp> + +#include <set> + +namespace dev +{ +namespace julia +{ + +class NameCollector; + +struct NameDispenser +{ + std::string newName(std::string const& _prefix); + std::set<std::string> m_usedNames; +}; + + + +/** + * Optimiser component that modifies an AST in place, inlining arbitrary functions. + * + * Code of the form + * + * function f(a, b) -> c { ... } + * h(g(x(...), f(arg1(...), arg2(...)), y(...)), z(...)) + * + * is transformed into + * + * function f(a, b) -> c { ... } + * + * let z1 := z(...) let y1 := y(...) let a2 := arg2(...) let a1 := arg1(...) + * let c1 := 0 + * { code of f, with replacements: a -> a1, b -> a2, c -> c1, d -> d1 } + * h(g(x(...), c1, y1), z1) + * + * No temporary variable is created for expressions that are "movable" + * (i.e. they are "pure", have no side-effects and also do not depend on other code + * that might have side-effects). + * + * This component can only be used on sources with unique names and with hoisted functions, + * i.e. the root node has to be a block that itself contains a single block followed by all + * function definitions. + */ +class FullInliner: public ASTModifier +{ +public: + explicit FullInliner(Block& _ast); + + void run(); + + /// Perform inlining operations inside the given function. + void handleFunction(FunctionDefinition& _function); + + FunctionDefinition& function(std::string _name) { return *m_functions.at(_name); } + +private: + /// The AST to be modified. The root block itself will not be modified, because + /// we store pointers to functions. + Block& m_ast; + std::map<std::string, FunctionDefinition*> m_functions; + std::set<FunctionDefinition*> m_functionsToVisit; + NameDispenser m_nameDispenser; +}; + +/** + * Class that walks the AST of a block that does not contain function definitions and perform + * the actual code modifications. + */ +class InlineModifier: public ASTModifier +{ +public: + InlineModifier(FullInliner& _driver, NameDispenser& _nameDispenser, std::string _functionName): + m_currentFunction(std::move(_functionName)), + m_driver(_driver), + m_nameDispenser(_nameDispenser) + { } + ~InlineModifier() + { + solAssert(m_statementsToPrefix.empty(), ""); + } + + virtual void operator()(FunctionalInstruction&) override; + virtual void operator()(FunctionCall&) override; + virtual void operator()(ForLoop&) override; + virtual void operator()(Block& _block) override; + + using ASTModifier::visit; + virtual void visit(Expression& _expression) override; + +private: + + /// Visits a list of expressions (usually an argument list to a function call) and tries + /// to inline them. If one of them is inlined, all right of it have to be moved to the front + /// (to keep the order of evaluation). If @a _moveToFront is true, all elements are moved + /// to the front. @a _nameHints and @_types are used for the newly created variables, but + /// both can be empty. + void visitArguments( + std::vector<Expression>& _arguments, + std::vector<std::string> const& _nameHints = {}, + std::vector<std::string> const& _types = {}, + bool _moveToFront = false + ); + + /// Visits an expression, but saves and restores the current statements to prefix and returns + /// the statements that should be prefixed for @a _expression. + std::vector<Statement> visitRecursively(Expression& _expression); + + std::string newName(std::string const& _prefix); + + /// List of statements that should go in front of the currently visited AST element, + /// at the statement level. + std::vector<Statement> m_statementsToPrefix; + std::string m_currentFunction; + FullInliner& m_driver; + NameDispenser& m_nameDispenser; +}; + +/** + * Creates a copy of a block that is supposed to be the body of a function. + * Applies replacements to referenced variables and creates new names for + * variable declarations. + */ +class BodyCopier: public ASTCopier +{ +public: + BodyCopier( + NameDispenser& _nameDispenser, + std::string const& _varNamePrefix, + std::map<std::string, std::string> const& _variableReplacements + ): + m_nameDispenser(_nameDispenser), + m_varNamePrefix(_varNamePrefix), + m_variableReplacements(_variableReplacements) + {} + + using ASTCopier::operator (); + + virtual Statement operator()(VariableDeclaration const& _varDecl) override; + virtual Statement operator()(FunctionDefinition const& _funDef) override; + + virtual std::string translateIdentifier(std::string const& _name) override; + + NameDispenser& m_nameDispenser; + std::string const& m_varNamePrefix; + std::map<std::string, std::string> m_variableReplacements; +}; + + +} +} |