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Checks for uninitialized access to calldata variables.

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This commit is contained in:
chriseth 2020-05-25 19:58:50 +02:00
parent fb40a8abb8
commit 33450619b1
4 changed files with 45 additions and 2 deletions
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10
libsolidity/analysis/ControlFlowAnalyzer.cpp
View File

@ -94,7 +94,10 @@ void ControlFlowAnalyzer::checkUninitializedAccess(CFGNode const* _entry, CFGNod
case VariableOccurrence::Kind::Return:
if (unassignedVariables.count(&variableOccurrence.declaration()))
{
if (variableOccurrence.declaration().type()->dataStoredIn(DataLocation::Storage))
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).
@ -135,13 +138,16 @@ void ControlFlowAnalyzer::checkUninitializedAccess(CFGNode const* _entry, CFGNod
if (variableOccurrence->occurrence())
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() :
variableOccurrence->declaration().location(),
ssl,
string("This variable is of storage pointer type and can be ") +
"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."
);

10
test/libsolidity/syntaxTests/controlFlow/localCalldataVariables/if_declaration_err.sol Normal file
View File

@ -0,0 +1,10 @@
contract C {
function f(uint[] calldata _c) public pure {
uint[] calldata c;
if (_c[2] > 10)
c = _c;
c[2];
}
}
// ----
// TypeError: (141-142): This variable is of calldata pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.

11
test/libsolidity/syntaxTests/controlFlow/localCalldataVariables/if_declaration_fine.sol Normal file
View File

@ -0,0 +1,11 @@
contract C {
function f(uint[] calldata _c) public pure {
uint[] calldata c;
if (_c[2] > 10)
c = _c;
else
c = _c;
c[2];
}
}
// ----

16
test/libsolidity/syntaxTests/controlFlow/localCalldataVariables/smoke_declaration.sol Normal file
View File

@ -0,0 +1,16 @@
contract C {
function g() internal pure returns (bytes calldata) {
return msg.data;
}
function h(uint[] calldata _c) internal pure {
uint[] calldata c;
c = _c;
c[2];
}
function i(uint[] calldata _c) internal pure {
uint[] calldata c;
(c) = _c;
c[2];
}
}
// ----