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Print warning for unnamed return parameters and no return statement

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This commit is contained in:
Mathias Baumann
2020-10-13 13:11:29 +02:00
parent abfa136afb
commit 32b4f18023
54 changed files with 139 additions and 31 deletions
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libsolidity/analysis/ControlFlowAnalyzer.cpp
+25 -21
View File
@@ -37,13 +37,13 @@ bool ControlFlowAnalyzer::visit(FunctionDefinition const& _function)
if (_function.isImplemented())
{
auto const& functionFlow = m_cfg.functionFlow(_function);
checkUninitializedAccess(functionFlow.entry, functionFlow.exit);
checkUninitializedAccess(functionFlow.entry, functionFlow.exit, _function.body().statements().empty());
checkUnreachable(functionFlow.entry, functionFlow.exit, functionFlow.revert, functionFlow.transactionReturn);
}
return false;
}
void ControlFlowAnalyzer::checkUninitializedAccess(CFGNode const* _entry, CFGNode const* _exit) const
void ControlFlowAnalyzer::checkUninitializedAccess(CFGNode const* _entry, CFGNode const* _exit, bool _emptyBody) const
{
struct NodeInfo
{
@@ -95,14 +95,10 @@ void ControlFlowAnalyzer::checkUninitializedAccess(CFGNode const* _entry, CFGNod
case VariableOccurrence::Kind::Return:
if (unassignedVariables.count(&variableOccurrence.declaration()))
{
if (
variableOccurrence.declaration().type()->dataStoredIn(DataLocation::Storage) ||
variableOccurrence.declaration().type()->dataStoredIn(DataLocation::CallData)
)
// Merely store the unassigned access. We do not generate an error right away, since this
// path might still always revert. It is only an error if this is propagated to the exit
// node of the function (i.e. there is a path with an uninitialized access).
nodeInfo.uninitializedVariableAccesses.insert(&variableOccurrence);
// Merely store the unassigned access. We do not generate an error right away, since this
// path might still always revert. It is only an error if this is propagated to the exit
// node of the function (i.e. there is a path with an uninitialized access).
nodeInfo.uninitializedVariableAccesses.insert(&variableOccurrence);
}
break;
case VariableOccurrence::Kind::Declaration:
@@ -140,18 +136,26 @@ void ControlFlowAnalyzer::checkUninitializedAccess(CFGNode const* _entry, CFGNod
ssl.append("The variable was declared here.", variableOccurrence->declaration().location());
bool isStorage = variableOccurrence->declaration().type()->dataStoredIn(DataLocation::Storage);
m_errorReporter.typeError(
3464_error,
variableOccurrence->occurrence() ?
*variableOccurrence->occurrence() :
bool isCalldata = variableOccurrence->declaration().type()->dataStoredIn(DataLocation::CallData);
if (isStorage || isCalldata)
m_errorReporter.typeError(
3464_error,
variableOccurrence->occurrence() ?
*variableOccurrence->occurrence() :
variableOccurrence->declaration().location(),
ssl,
"This variable is of " +
string(isStorage ? "storage" : "calldata") +
" pointer type and can be " +
(variableOccurrence->kind() == VariableOccurrence::Kind::Return ? "returned" : "accessed") +
" without prior assignment, which would lead to undefined behaviour."
);
else if (!_emptyBody && variableOccurrence->declaration().name().empty())
m_errorReporter.warning(
6321_error,
variableOccurrence->declaration().location(),
ssl,
"This variable is of " +
string(isStorage ? "storage" : "calldata") +
" pointer type and can be " +
(variableOccurrence->kind() == VariableOccurrence::Kind::Return ? "returned" : "accessed") +
" without prior assignment, which would lead to undefined behaviour."
);
"Unnamed return variable can remain unassigned. Add an explicit return with value to all non-reverting code paths or name the variable."
);
}
}
}
libsolidity/analysis/ControlFlowAnalyzer.h
+1 -1
View File
@@ -36,7 +36,7 @@ public:
private:
/// Checks for uninitialized variable accesses in the control flow between @param _entry and @param _exit.
void checkUninitializedAccess(CFGNode const* _entry, CFGNode const* _exit) const;
void checkUninitializedAccess(CFGNode const* _entry, CFGNode const* _exit, bool _emptyBody) const;
/// Checks for unreachable code, i.e. code ending in @param _exit, @param _revert or @param _transactionReturn
/// that can not be reached from @param _entry.
void checkUnreachable(CFGNode const* _entry, CFGNode const* _exit, CFGNode const* _revert, CFGNode const* _transactionReturn) const;