Method Error

lobster/src/vm.cpp:290–336

This function is now way less important than it was when the language was still dynamically typed. But ok to leave it as-is for "index out of range" and other errors that are still dynamic.

// This function is now way less important than it was when the language was still dynamically
// typed. But ok to leave it as-is for "index out of range" and other errors that are still dynamic.
Value VM::Error(string err, const RefObj *a, const RefObj *b) {
    if (trace == TraceMode::TAIL && trace_output.size()) {
        string s;
        for (size_t i = trace_ring_idx; i < trace_output.size(); i++) s += trace_output[i].str();
        for (size_t i = 0; i < trace_ring_idx; i++) s += trace_output[i].str();
        s += err;
        THROW_OR_ABORT(s);
    }
    ostringstream ss;
    #ifndef VM_COMPILED_CODE_MODE
        DumpFileLine(ip, ss);
        ss << ": ";
    #endif
    ss << "VM error: " << err;
    if (a) { ss << "\n   arg: "; RefToString(*this, ss, a, debugpp); }
    if (b) { ss << "\n   arg: "; RefToString(*this, ss, b, debugpp); }
    while (sp >= 0 && (!stackframes.size() || sp != stackframes.back().spstart)) {
        // Sadly can't print this properly.
        ss << "\n   stack: ";
        to_string_hex(ss, (size_t)VM_TOP().any());
        if (pool.pointer_is_in_allocator(VM_TOP().any())) {
            ss << ", maybe: ";
            RefToString(*this, ss, VM_TOP().ref(), debugpp);
        }
        VM_POP();  // We don't DEC here, as we can't know what type it is.
                // This is ok, as we ignore leaks in case of an error anyway.
    }
    for (;;) {
        if (!stackframes.size()) break;
        int deffun = *(stackframes.back().funstart);
        if (deffun >= 0) {
            ss << "\nin function: " << bcf->functions()->Get(deffun)->name()->string_view();
        } else {
            ss << "\nin block";
        }
        #ifndef VM_COMPILED_CODE_MODE
        ss << " -> ";
        DumpFileLine(ip, ss);
        #endif
        VarCleanup<1>(ss.tellp() < 10000 ? &ss : nullptr, -2 /* clean up temps always */);
    }
    ss << "\nglobals:";
    for (size_t i = 0; i < bcf->specidents()->size(); ) {
        i += DumpVar(ss, vars[i], i, true);
    }
    THROW_OR_ABORT(ss.str());
}

void VM::VMAssert(const char *what)  {
    Error(string("VM internal assertion failure: ") + what);