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Properly set storage and memory after erasing potentially destroyed keys

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This commit is contained in:
chriseth 2019-08-13 18:42:51 +02:00
parent abed8119fc
commit e396dc7246
3 changed files with 44 additions and 4 deletions
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6
libyul/optimiser/DataFlowAnalyzer.cpp
View File

@ -43,7 +43,6 @@ void DataFlowAnalyzer::operator()(ExpressionStatement& _statement)
if (auto vars = isSimpleStore(dev::eth::Instruction::SSTORE, _statement)) if (auto vars = isSimpleStore(dev::eth::Instruction::SSTORE, _statement))
{ {
ASTModifier::operator()(_statement); ASTModifier::operator()(_statement);
m_storage.set(vars->first, vars->second);
set<YulString> keysToErase; set<YulString> keysToErase;
for (auto const& item: m_storage.values) for (auto const& item: m_storage.values)
if (!( if (!(
@ -53,6 +52,7 @@ void DataFlowAnalyzer::operator()(ExpressionStatement& _statement)
keysToErase.insert(item.first); keysToErase.insert(item.first);
for (YulString const& key: keysToErase) for (YulString const& key: keysToErase)
m_storage.eraseKey(key); m_storage.eraseKey(key);
m_storage.set(vars->first, vars->second);
} }
else if (auto vars = isSimpleStore(dev::eth::Instruction::MSTORE, _statement)) else if (auto vars = isSimpleStore(dev::eth::Instruction::MSTORE, _statement))
{ {
@ -61,11 +61,9 @@ void DataFlowAnalyzer::operator()(ExpressionStatement& _statement)
for (auto const& item: m_memory.values) for (auto const& item: m_memory.values)
if (!m_knowledgeBase.knownToBeDifferentByAtLeast32(vars->first, item.first)) if (!m_knowledgeBase.knownToBeDifferentByAtLeast32(vars->first, item.first))
keysToErase.insert(item.first); keysToErase.insert(item.first);
// TODO is it fine to do that here?
// can we also move the storage above?
m_memory.set(vars->first, vars->second);
for (YulString const& key: keysToErase) for (YulString const& key: keysToErase)
m_memory.eraseKey(key); m_memory.eraseKey(key);
m_memory.set(vars->first, vars->second);
} }
else else
{ {

21
test/libyul/yulOptimizerTests/loadResolver/re_store_memory.yul Normal file
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@ -0,0 +1,21 @@
{
let a := 0
let b := 1
let c := 2
mstore(a, b)
sstore(0, mload(a))
mstore(a, c)
sstore(10, mload(a))
}
// ====
// step: loadResolver
// ----
// {
// let a := 0
// let b := 1
// let c := 2
// mstore(a, b)
// sstore(a, b)
// mstore(a, c)
// sstore(10, c)
// }

21
test/libyul/yulOptimizerTests/loadResolver/re_store_storage.yul Normal file
View File

@ -0,0 +1,21 @@
{
let a := 0
let b := 1
let c := 2
sstore(a, b)
mstore(0, sload(a))
sstore(a, c)
mstore(32, sload(a))
}
// ====
// step: loadResolver
// ----
// {
// let a := 0
// let b := 1
// let c := 2
// sstore(a, b)
// mstore(a, b)
// sstore(a, c)
// mstore(32, c)
// }