Merge pull request #4664 from ethereum/uninitializedStorageReturn

Turn warning about uninitialized storage returns into an error.
This commit is contained in:
chriseth 2018-08-03 10:45:50 +02:00 committed by GitHub
commit da6cefd475
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23 changed files with 184 additions and 183 deletions

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@ -17,6 +17,7 @@ Breaking Changes:
* Commandline interface: Remove obsolete ``--formal`` option.
* Commandline interface: Rename the ``--julia`` option to ``--yul``.
* Commandline interface: Require ``-`` if standard input is used as source.
* Control Flow Analyzer: Turn warning about returning uninitialized storage pointers into an error.
* General: ``continue`` in a ``do...while`` loop jumps to the condition (it used to jump to the loop body). Warning: this may silently change the semantics of existing code.
* General: Disallow declaring empty structs.
* General: Disallow raw ``callcode`` (was already deprecated in 0.4.12). It is still possible to use it via inline assembly.

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@ -144,12 +144,12 @@ void ControlFlowAnalyzer::checkUnassignedStorageReturnValues(
ssl.append("Problematic end of function:", _function.location());
}
m_errorReporter.warning(
m_errorReporter.typeError(
returnVal->location(),
"This variable is of storage pointer type and might be returned without assignment. "
"This can cause storage corruption. Assign the variable (potentially from itself) "
"to remove this warning.",
ssl
ssl,
"This variable is of storage pointer type and might be returned without assignment and "
"could be used uninitialized. Assign the variable (potentially from itself) "
"to fix this error."
);
}
}

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@ -756,7 +756,7 @@ BOOST_AUTO_TEST_CASE(library_function)
char const* sourceCode = R"(
library test {
struct StructType { uint a; }
function f(StructType storage b, uint[] storage c, test d) public returns (uint[] memory e, StructType storage f) {}
function f(StructType storage b, uint[] storage c, test d) public returns (uint[] memory e, StructType storage f) { f = f; }
}
)";

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@ -0,0 +1,10 @@
contract C {
struct S { bool f; }
S s;
function f() internal pure returns (S storage) {
assembly {
}
}
}
// ----
// TypeError: (87-88): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.

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@ -8,7 +8,7 @@ contract C {
}
function g(bool flag) internal returns (S storage c) {
// control flow in assembly will not be analyzed for now,
// so this will not issue a warning
// so this will not issue an error
assembly {
if flag {
sstore(c_slot, sload(s_slot))
@ -17,7 +17,7 @@ contract C {
}
function h() internal returns (S storage c) {
// any reference from assembly will be sufficient for now,
// so this will not issue a warning
// so this will not issue an error
assembly {
sstore(s_slot, sload(c_slot))
}

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@ -1,10 +0,0 @@
contract C {
struct S { bool f; }
S s;
function f() internal pure returns (S storage) {
assembly {
}
}
}
// ----
// Warning: (87-88): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.

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@ -0,0 +1,52 @@
contract C {
struct S { bool f; }
S s;
function f() internal view returns (S storage c) {
do {
break;
c = s;
} while(false);
}
function g() internal view returns (S storage c) {
do {
if (s.f) {
continue;
c = s;
}
else {
}
} while(false);
}
function h() internal view returns (S storage c) {
do {
if (s.f) {
break;
}
else {
c = s;
}
} while(false);
}
function i() internal view returns (S storage c) {
do {
if (s.f) {
continue;
}
else {
c = s;
}
} while(false);
}
function j() internal view returns (S storage c) {
do {
continue;
c = s;
} while(false);
}
}
// ----
// TypeError: (87-98): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (223-234): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (440-451): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (654-665): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (871-882): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.

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@ -1,52 +0,0 @@
contract C {
struct S { bool f; }
S s;
function f() internal view returns (S storage c) {
do {
break;
c = s;
} while(false);
}
function g() internal view returns (S storage c) {
do {
if (s.f) {
continue;
c = s;
}
else {
}
} while(false);
}
function h() internal view returns (S storage c) {
do {
if (s.f) {
break;
}
else {
c = s;
}
} while(false);
}
function i() internal view returns (S storage c) {
do {
if (s.f) {
continue;
}
else {
c = s;
}
} while(false);
}
function j() internal view returns (S storage c) {
do {
continue;
c = s;
} while(false);
}
}
// ----
// Warning: (87-98): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (223-234): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (440-451): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (654-665): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (871-882): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.

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@ -0,0 +1,14 @@
contract C {
struct S { bool f; }
S s;
function f() internal pure returns (S storage) { return; }
function g() internal view returns (S storage c, S storage) { c = s; return; }
function h() internal view returns (S storage, S storage d) { d = s; return; }
function i() internal pure returns (S storage, S storage) { return; }
}
// ----
// TypeError: (87-88): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (163-164): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (233-234): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (316-317): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (327-328): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.

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@ -2,5 +2,6 @@ contract C {
struct S { bool f; }
S s;
function f() internal view returns (S storage c, S storage d) { c = s; d = s; return; }
function g() internal view returns (S storage, S storage) { return (s,s); }
}
// ----

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@ -1,15 +0,0 @@
contract C {
struct S { bool f; }
S s;
function f() internal pure returns (S storage) { return; }
function g() internal view returns (S storage c, S storage) { c = s; return; }
function h() internal view returns (S storage, S storage d) { d = s; return; }
function i() internal pure returns (S storage, S storage) { return; }
function j() internal view returns (S storage, S storage) { return (s,s); }
}
// ----
// Warning: (87-88): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (163-164): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (233-234): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (316-317): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (327-328): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.

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@ -0,0 +1,16 @@
contract C {
struct S { bool f; }
S s;
function f() internal view returns (S storage c) {
for(;; c = s) {
}
}
function g() internal view returns (S storage c) {
for(;;) {
c = s;
}
}
}
// ----
// TypeError: (87-98): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (182-193): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.

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@ -1,16 +0,0 @@
contract C {
struct S { bool f; }
S s;
function f() internal view returns (S storage c) {
for(;; c = s) {
}
}
function g() internal view returns (S storage c) {
for(;;) {
c = s;
}
}
}
// ----
// Warning: (87-98): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (182-193): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.

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@ -0,0 +1,18 @@
contract C {
struct S { bool f; }
S s;
function f(bool flag) internal view returns (S storage c) {
if (flag) c = s;
}
function g(bool flag) internal returns (S storage c) {
if (flag) c = s;
else
{
if (!flag) c = s;
else s.f = true;
}
}
}
// ----
// TypeError: (96-107): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (186-197): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.

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@ -1,18 +0,0 @@
contract C {
struct S { bool f; }
S s;
function f(bool flag) internal view returns (S storage c) {
if (flag) c = s;
}
function g(bool flag) internal returns (S storage c) {
if (flag) c = s;
else
{
if (!flag) c = s;
else s.f = true;
}
}
}
// ----
// Warning: (96-107): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (186-197): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.

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@ -0,0 +1,22 @@
contract C {
modifier revertIfNoReturn() {
_;
revert();
}
modifier ifFlag(bool flag) {
if (flag)
_;
}
struct S { uint a; }
S s;
function f(bool flag) ifFlag(flag) internal view returns(S storage) {
return s;
}
function g(bool flag) ifFlag(flag) revertIfNoReturn() internal view returns(S storage) {
return s;
}
}
// ----
// TypeError: (249-250): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (367-368): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.

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@ -1,22 +0,0 @@
contract C {
modifier revertIfNoReturn() {
_;
revert();
}
modifier ifFlag(bool flag) {
if (flag)
_;
}
struct S { uint a; }
S s;
function f(bool flag) ifFlag(flag) internal view returns(S storage) {
return s;
}
function g(bool flag) ifFlag(flag) revertIfNoReturn() internal view returns(S storage) {
return s;
}
}
// ----
// Warning: (249-250): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (367-368): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.

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@ -0,0 +1,18 @@
contract C {
struct S { bool f; }
S s;
function f() internal view returns (S storage c) {
false && (c = s).f;
}
function g() internal view returns (S storage c) {
true || (c = s).f;
}
function h() internal view returns (S storage c) {
// expect error, although this is always fine
true && (false || (c = s).f);
}
}
// ----
// TypeError: (87-98): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (176-187): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (264-275): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.

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@ -1,18 +0,0 @@
contract C {
struct S { bool f; }
S s;
function f() internal view returns (S storage c) {
false && (c = s).f;
}
function g() internal view returns (S storage c) {
true || (c = s).f;
}
function h() internal view returns (S storage c) {
// expect warning, although this is always fine
true && (false || (c = s).f);
}
}
// ----
// Warning: (87-98): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (176-187): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (264-275): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.

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@ -0,0 +1,13 @@
contract C {
struct S { bool f; }
S s;
function f(bool flag) internal view returns (S storage c) {
flag ? (c = s).f : false;
}
function g(bool flag) internal view returns (S storage c) {
flag ? false : (c = s).f;
}
}
// ----
// TypeError: (96-107): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.
// TypeError: (200-211): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.

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@ -1,13 +0,0 @@
contract C {
struct S { bool f; }
S s;
function f(bool flag) internal view returns (S storage c) {
flag ? (c = s).f : false;
}
function g(bool flag) internal view returns (S storage c) {
flag ? false : (c = s).f;
}
}
// ----
// Warning: (96-107): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.
// Warning: (200-211): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.

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@ -0,0 +1,11 @@
contract C {
struct S { bool f; }
S s;
function f() internal view returns (S storage c) {
while(false) {
c = s;
}
}
}
// ----
// TypeError: (87-98): This variable is of storage pointer type and might be returned without assignment and could be used uninitialized. Assign the variable (potentially from itself) to fix this error.

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@ -1,11 +0,0 @@
contract C {
struct S { bool f; }
S s;
function f() internal view returns (S storage c) {
while(false) {
c = s;
}
}
}
// ----
// Warning: (87-98): This variable is of storage pointer type and might be returned without assignment. This can cause storage corruption. Assign the variable (potentially from itself) to remove this warning.