Merge pull request from ethereum/fix-unreachable-code-anaysis

Fix revert pruner modifying function flows wrong
This commit is contained in:
chriseth 2021-06-04 12:44:35 +02:00 committed by GitHub
commit 1f8f1a3db9
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9 changed files with 35 additions and 3 deletions

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@ -44,6 +44,7 @@ this nonsensical example::
// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.4.22 <0.9.0;
// This will report a warning
contract C {
function g(uint a) public pure returns (uint ret) { return a + f(); }
function f() internal pure returns (uint ret) { return g(7) + f(); }

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@ -260,6 +260,7 @@ bool ControlFlowBuilder::visit(PlaceholderStatement const&)
bool ControlFlowBuilder::visit(FunctionCall const& _functionCall)
{
solAssert(!!m_revertNode, "");
solAssert(!!m_currentNode, "");
solAssert(!!_functionCall.expression().annotation().type, "");
@ -267,30 +268,43 @@ bool ControlFlowBuilder::visit(FunctionCall const& _functionCall)
switch (functionType->kind())
{
case FunctionType::Kind::Revert:
solAssert(!!m_revertNode, "");
visitNode(_functionCall);
_functionCall.expression().accept(*this);
ASTNode::listAccept(_functionCall.arguments(), *this);
connect(m_currentNode, m_revertNode);
m_currentNode = newLabel();
return false;
case FunctionType::Kind::Require:
case FunctionType::Kind::Assert:
{
solAssert(!!m_revertNode, "");
visitNode(_functionCall);
_functionCall.expression().accept(*this);
ASTNode::listAccept(_functionCall.arguments(), *this);
connect(m_currentNode, m_revertNode);
auto nextNode = newLabel();
connect(m_currentNode, nextNode);
m_currentNode = nextNode;
return false;
}
case FunctionType::Kind::Internal:
{
visitNode(_functionCall);
_functionCall.expression().accept(*this);
ASTNode::listAccept(_functionCall.arguments(), *this);
m_currentNode->functionCalls.emplace_back(&_functionCall);
break;
auto nextNode = newLabel();
connect(m_currentNode, nextNode);
m_currentNode = nextNode;
return false;
}
default:
break;

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@ -20,6 +20,8 @@
#include <libsolutil/Algorithms.h>
#include <range/v3/algorithm/remove.hpp>
namespace solidity::frontend
{
@ -192,7 +194,11 @@ void ControlFlowRevertPruner::modifyFunctionFlows()
// change anymore, we treat all "unknown" states as
// "reverting", since they can only be caused by
// recursion.
for (CFGNode * node: _node->exits)
ranges::remove(node->entries, _node);
_node->exits = {functionFlow.revert};
functionFlow.revert->entries.push_back(_node);
return;
default:
break;

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@ -10,3 +10,4 @@ contract C {
// ====
// SMTEngine: all
// ----
// Warning 5740: (122-136): Unreachable code.

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@ -5,3 +5,4 @@ contract C {
}
}
// ----
// Warning 5740: (78-79): Unreachable code.

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@ -10,4 +10,5 @@ contract C {
function h() internal pure returns (bytes memory, string storage s) { s = s; }
}
// ----
// Warning 5740: (111-115): Unreachable code.
// Warning 6321: (250-262): Unnamed return variable can remain unassigned. Add an explicit return with value to all non-reverting code paths or name the variable.

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@ -3,4 +3,5 @@ contract test {
function f(uint256) public returns (uint out) { f(variable); test; out; }
}
// ----
// Warning 5740: (103-112): Unreachable code.
// Warning 6133: (103-107): Statement has no effect.

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@ -5,3 +5,9 @@ contract C {
function i() payable public { i(); h(); g(); f(); }
}
// ----
// Warning 5740: (102-105): Unreachable code.
// Warning 5740: (140-143): Unreachable code.
// Warning 5740: (145-148): Unreachable code.
// Warning 5740: (191-194): Unreachable code.
// Warning 5740: (196-199): Unreachable code.
// Warning 5740: (201-204): Unreachable code.

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@ -7,3 +7,4 @@ contract C {
}
}
// ----
// Warning 5740: (142-237): Unreachable code.