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authorChristian Parpart <christian@ethereum.org>2018-10-15 17:52:35 +0800
committerChristian Parpart <christian@ethereum.org>2018-10-15 17:52:35 +0800
commit9a4bec7e474a310c7f93ff3b84928e0e9ba9cce6 (patch)
tree2668ab22a40aad2448081f7bf22c7235d4b4c963 /libjulia/optimiser/UnusedPruner.cpp
parentb965fd6e17f77e94afeb070a27182251b85b8ab3 (diff)
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Renaming libjulia to libyul
Diffstat (limited to 'libjulia/optimiser/UnusedPruner.cpp')
-rw-r--r--libjulia/optimiser/UnusedPruner.cpp117
1 files changed, 0 insertions, 117 deletions
diff --git a/libjulia/optimiser/UnusedPruner.cpp b/libjulia/optimiser/UnusedPruner.cpp
deleted file mode 100644
index af503712..00000000
--- a/libjulia/optimiser/UnusedPruner.cpp
+++ /dev/null
@@ -1,117 +0,0 @@
-/*(
- 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/>.
-*/
-/**
- * Optimisation stage that removes unused variables and functions.
- */
-
-#include <libjulia/optimiser/UnusedPruner.h>
-
-#include <libjulia/optimiser/NameCollector.h>
-#include <libjulia/optimiser/Semantics.h>
-#include <libjulia/optimiser/Utilities.h>
-#include <libjulia/Exceptions.h>
-
-#include <libsolidity/inlineasm/AsmData.h>
-
-#include <boost/algorithm/cxx11/none_of.hpp>
-
-using namespace std;
-using namespace dev;
-using namespace dev::julia;
-
-UnusedPruner::UnusedPruner(Block& _ast)
-{
- ReferencesCounter counter;
- counter(_ast);
-
- m_references = counter.references();
-}
-
-void UnusedPruner::operator()(Block& _block)
-{
- for (auto&& statement: _block.statements)
- if (statement.type() == typeid(FunctionDefinition))
- {
- FunctionDefinition& funDef = boost::get<FunctionDefinition>(statement);
- if (!used(funDef.name))
- {
- subtractReferences(ReferencesCounter::countReferences(funDef.body));
- statement = Block{std::move(funDef.location), {}};
- }
- }
- else if (statement.type() == typeid(VariableDeclaration))
- {
- VariableDeclaration& varDecl = boost::get<VariableDeclaration>(statement);
- // Multi-variable declarations are special. We can only remove it
- // if all vairables are unused and the right-hand-side is either
- // movable or it return a single value. In the latter case, we
- // replace `let a := f()` by `pop(f())` (in pure Yul, this will be
- // `drop(f())`).
- if (boost::algorithm::none_of(
- varDecl.variables,
- [=](TypedName const& _typedName) { return used(_typedName.name); }
- ))
- {
- if (!varDecl.value)
- statement = Block{std::move(varDecl.location), {}};
- else if (MovableChecker(*varDecl.value).movable())
- {
- subtractReferences(ReferencesCounter::countReferences(*varDecl.value));
- statement = Block{std::move(varDecl.location), {}};
- }
- else if (varDecl.variables.size() == 1)
- // In pure Yul, this should be replaced by a function call to `drop`
- // instead of `pop`.
- statement = ExpressionStatement{varDecl.location, FunctionalInstruction{
- varDecl.location,
- solidity::Instruction::POP,
- {*std::move(varDecl.value)}
- }};
- }
- }
-
- removeEmptyBlocks(_block);
-
- ASTModifier::operator()(_block);
-}
-
-void UnusedPruner::runUntilStabilised(Block& _ast)
-{
- while (true)
- {
- UnusedPruner pruner(_ast);
- pruner(_ast);
- if (!pruner.shouldRunAgain())
- return;
- }
-}
-
-bool UnusedPruner::used(string const& _name) const
-{
- return m_references.count(_name) && m_references.at(_name) > 0;
-}
-
-void UnusedPruner::subtractReferences(map<string, size_t> const& _subtrahend)
-{
- for (auto const& ref: _subtrahend)
- {
- assertThrow(m_references.count(ref.first), OptimizerException, "");
- assertThrow(m_references.at(ref.first) >= ref.second, OptimizerException, "");
- m_references[ref.first] -= ref.second;
- m_shouldRunAgain = true;
- }
-}