void Resolver::resolveBody(Compiler& compiler, Module& module, gc<Expr> body,
int& maxLocals, int& numClosures)
{
// Make a fake procedure so we can track closures.
ResolvedProcedure procedure;
maxLocals = resolve(compiler, module, NULL, &procedure, true, NULL, NULL,
NULL, body);
numClosures = procedure.closures().count();
}
void ExprCompiler::compileClosures(gc<SourcePos> pos,
ResolvedProcedure& procedure)
{
// When a procedure is created, it needs to capture references to any
// variables declared outside of itself that it (or one of its nested
// procedures) accesses. We do this by compiling a series of
// pseudo-instructions. Each one describes which upvar from the outer
// procedure should be captured.
for (int i = 0; i < procedure.closures().count(); i++)
{
int index = procedure.closures()[i];
if (index == -1)
{
// This closure is a new one in this function so there's nothing to
// Capture. So just add a "do nothing" pseudo-op.
write(pos, OP_GET_UPVAR, 0, 0, 0);
}
else
{
// Capture the upvar from the outer scope.
write(pos, OP_GET_UPVAR, index, 0, 1);
}
}
}
