bool Why3Translator::visit(FunctionDefinition const& _function)
{
if (!_function.isImplemented())
{
error(_function, "Unimplemented functions not supported.");
return false;
}
if (_function.name().empty())
{
error(_function, "Fallback functions not supported.");
return false;
}
if (!_function.modifiers().empty())
{
error(_function, "Modifiers not supported.");
return false;
}
m_localVariables.clear();
for (auto const& var: _function.parameters())
m_localVariables[var->name()] = var.get();
for (auto const& var: _function.returnParameters())
m_localVariables[var->name()] = var.get();
for (auto const& var: _function.localVariables())
m_localVariables[var->name()] = var;
add("let rec _" + _function.name());
add(" (this: account)");
for (auto const& param: _function.parameters())
{
string paramType;
try
{
paramType = toFormalType(*param->annotation().type);
}
catch (NoFormalType &err)
{
string const* typeName = boost::get_error_info<errinfo_noFormalTypeFrom>(err);
error(*param, "Parameter type \"" + (typeName ? *typeName : "") + "\" not supported.");
}
if (param->name().empty())
error(*param, "Anonymous function parameters not supported.");
add(" (arg_" + param->name() + ": " + paramType + ")");
}
add(":");
indent();
indent();
string retString = "(";
for (auto const& retParam: _function.returnParameters())
{
string paramType;
try
{
paramType = toFormalType(*retParam->annotation().type);
}
catch (NoFormalType &err)
{
string const* typeName = boost::get_error_info<errinfo_noFormalTypeFrom>(err);
error(*retParam, "Parameter type " + (typeName ? *typeName : "") + " not supported.");
}
if (retString.size() != 1)
retString += ", ";
retString += paramType;
}
add(retString + ")");
unindent();
addSourceFromDocStrings(_function.annotation());
if (!m_currentContract.contract)
error(_function, "Only functions inside contracts allowed.");
addSourceFromDocStrings(m_currentContract.contract->annotation());
if (_function.isDeclaredConst())
addLine("ensures { (old this) = this }");
else
addLine("writes { this }");
addLine("=");
// store the prestate in the case we need to revert
addLine("let prestate = {balance = this.balance; storage = " + copyOfStorage() + "} in ");
// initialise local variables
for (auto const& variable: _function.parameters())
addLine("let _" + variable->name() + " = ref arg_" + variable->name() + " in");
for (auto const& variable: _function.returnParameters())
{
if (variable->name().empty())
error(*variable, "Unnamed return variables not yet supported.");
string varType;
try
{
varType = toFormalType(*variable->annotation().type);
}
catch (NoFormalType &err)
{
string const* typeNamePtr = boost::get_error_info<errinfo_noFormalTypeFrom>(err);
error(*variable, "Type " + (typeNamePtr ? *typeNamePtr : "") + "in return parameter not yet supported.");
}
addLine("let _" + variable->name() + ": ref " + varType + " = ref (of_int 0) in");
}
for (VariableDeclaration const* variable: _function.localVariables())
{
if (variable->name().empty())
error(*variable, "Unnamed variables not yet supported.");
string varType;
try
{
varType = toFormalType(*variable->annotation().type);
}
catch (NoFormalType &err)
{
string const* typeNamePtr = boost::get_error_info<errinfo_noFormalTypeFrom>(err);
error(*variable, "Type " + (typeNamePtr ? *typeNamePtr : "") + "in variable declaration not yet supported.");
}
addLine("let _" + variable->name() + ": ref " + varType + " = ref (of_int 0) in");
}
addLine("try");
_function.body().accept(*this);
add(";");
addLine("raise Return");
string retVals;
for (auto const& variable: _function.returnParameters())
{
if (!retVals.empty())
retVals += ", ";
retVals += "!_" + variable->name();
}
addLine("with Return -> (" + retVals + ") |");
string reversion = " Revert -> this.balance <- prestate.balance; ";
for (auto const* variable: m_currentContract.stateVariables)
reversion += "this.storage._" + variable->name() + " <- prestate.storage._" + variable->name() + "; ";
//@TODO in case of reversion the return values are wrong - we need to change the
// return type to include a bool to signify if an exception was thrown.
reversion += "(" + retVals + ")";
addLine(reversion);
unindent();
addLine("end");
addLine("");
return false;
}
bool DocStringAnalyser::visit(FunctionDefinition const& _node)
{
handleCallable(_node, _node, _node.annotation());
return true;
}
