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| author | chriseth <chris@ethereum.org> | 2018-12-12 07:49:36 +0800 |
|---|---|---|
| committer | chriseth <chris@ethereum.org> | 2018-12-13 01:06:28 +0800 |
| commit | 9557dd7e74a801ebafaf4777d60a591b0c484779 (patch) | |
| tree | b55af218e8debaeb4a79670f932e1e66afb736b6 /libyul/optimiser/DataFlowAnalyzer.cpp | |
| parent | 5e0c312dad2daaae155486397bfbd26d6d172718 (diff) | |
| download | dexon-solidity-9557dd7e74a801ebafaf4777d60a591b0c484779.tar.gz dexon-solidity-9557dd7e74a801ebafaf4777d60a591b0c484779.tar.zst dexon-solidity-9557dd7e74a801ebafaf4777d60a591b0c484779.zip | |
Support unassigned variables in the SSA value tracker and the data flow analyzer.
Diffstat (limited to 'libyul/optimiser/DataFlowAnalyzer.cpp')
| -rw-r--r-- | libyul/optimiser/DataFlowAnalyzer.cpp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/libyul/optimiser/DataFlowAnalyzer.cpp b/libyul/optimiser/DataFlowAnalyzer.cpp index 64c67b38..7bff2c89 100644 --- a/libyul/optimiser/DataFlowAnalyzer.cpp +++ b/libyul/optimiser/DataFlowAnalyzer.cpp @@ -136,17 +136,22 @@ void DataFlowAnalyzer::operator()(Block& _block) void DataFlowAnalyzer::handleAssignment(set<YulString> const& _variables, Expression* _value) { + static Expression const zero{Literal{{}, LiteralKind::Number, YulString{"0"}, {}}}; clearValues(_variables); MovableChecker movableChecker; if (_value) movableChecker.visit(*_value); - if (_variables.size() == 1) + else + for (auto const& var: _variables) + m_value[var] = &zero; + + if (_value && _variables.size() == 1) { YulString name = *_variables.begin(); // Expression has to be movable and cannot contain a reference // to the variable that will be assigned to. - if (_value && movableChecker.movable() && !movableChecker.referencedVariables().count(name)) + if (movableChecker.movable() && !movableChecker.referencedVariables().count(name)) m_value[name] = _value; } |