Fix continue inside do-while.

This commit is contained in:
Daniel Kirchner 2018-05-14 15:26:10 +02:00 committed by chriseth
parent 90528a2867
commit f627dc77d0
3 changed files with 40 additions and 14 deletions

View File

@ -4,6 +4,7 @@
Breaking Changes:
* Disallow conversions between bytesX and uintY of different size.
* Commandline interface: Require ``-`` if standard input is used as source.
* 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.
* Type Checker: Disallow arithmetic operations for Boolean variables.
Features:

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@ -666,32 +666,36 @@ bool ContractCompiler::visit(WhileStatement const& _whileStatement)
{
StackHeightChecker checker(m_context);
CompilerContext::LocationSetter locationSetter(m_context, _whileStatement);
eth::AssemblyItem loopStart = m_context.newTag();
eth::AssemblyItem loopEnd = m_context.newTag();
m_continueTags.push_back(loopStart);
m_breakTags.push_back(loopEnd);
m_context << loopStart;
// While loops have the condition prepended
if (!_whileStatement.isDoWhile())
{
compileExpression(_whileStatement.condition());
m_context << Instruction::ISZERO;
m_context.appendConditionalJumpTo(loopEnd);
}
_whileStatement.body().accept(*this);
// Do-while loops have the condition appended
if (_whileStatement.isDoWhile())
{
eth::AssemblyItem condition = m_context.newTag();
m_continueTags.push_back(condition);
_whileStatement.body().accept(*this);
m_context << condition;
compileExpression(_whileStatement.condition());
m_context << Instruction::ISZERO << Instruction::ISZERO;
m_context.appendConditionalJumpTo(loopStart);
}
else
{
m_continueTags.push_back(loopStart);
compileExpression(_whileStatement.condition());
m_context << Instruction::ISZERO;
m_context.appendConditionalJumpTo(loopEnd);
}
m_context.appendJumpTo(loopStart);
_whileStatement.body().accept(*this);
m_context.appendJumpTo(loopStart);
}
m_context << loopEnd;
m_continueTags.pop_back();

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@ -482,6 +482,27 @@ BOOST_AUTO_TEST_CASE(do_while_loop)
testContractAgainstCppOnRange("f(uint256)", do_while_loop_cpp, 0, 5);
}
BOOST_AUTO_TEST_CASE(do_while_loop_continue)
{
char const* sourceCode = R"(
contract test {
function f() public pure returns(uint r) {
uint i = 0;
do
{
if (i > 0) return 0;
i++;
continue;
} while (false);
return 42;
}
}
)";
compileAndRun(sourceCode);
ABI_CHECK(callContractFunction("f()"), encodeArgs(42));
}
BOOST_AUTO_TEST_CASE(nested_loops)
{
// tests that break and continue statements in nested loops jump to the correct place