# Diagnostics

## General Output Options

All diagnostic messages, including errors and warnings, can be suppressed with the `--quiet` option. To report errors and warnings but not other assembly status information, pass the `--no-stats` option. The `--checksum` option prints an MD5 hash of the code generated.

## Controlling Error and Warning Output

Options exist specifically for controlling error and warning reporting. To suppress only warnings but not errors, use the `--no-warn` option. To output error and warning messages to a file (without using the operating system's built-in facilities for this), you can also set the `-e`/`--error` option.

```
6502.net.exe source.asm -o program.prg --error=errors.txt
```

When an error or warning is reported to the standard output, typically the source where the error occurred is highlighted.

```
-$ dotnet 6502.net.dll x86code.s

x86code.s(1:12): error: Addressing mode or operation not supported for CPU.
1 |     mov eax,ebx
  |         ^^^^^^^
```

Use `--no-highlighting` to disable this feature.

### Warning Options

There are several options specific to warning messages. To enable all warning types, set the option `--Wall`, while to treat all warnings as errors, pass `--werror`. See the reference on options for full information on all warning options available.

## Assertions and Conditional and Custom Errors

The developer can make assertions in their code, optionally adding a custom message if the assertion fails

```
        .assert * < $100 // make sure we are in zero page
        .assert * < $100, "Zero Page Boundary Crossed!" // add a helpful message
```

In a similar vein, the `.errorif` directive will raise an error but with the condition being met and a custom error being required.

```
        .errorif * >= $0100, "Zero Page Boundary Crossed!"
```

This can be turned into warning using `.warnif`.

```
        .warnif * >= $0100, "Zero Page Boundary Crossed!"
```

Errors and warnings can be raised unconditionally.

```
        .error "This does not work!"
```

```
        .warn "We need to refactor this!"
```

## Other Topics

* [Getting Started](/Docs/GettingStarted.md)
* [Memory And Addressing](/Docs/MemoryAndAddressing.md)
* [CPU Specific Assembly](/Docs/CPUSpecificAssembly.md)
* [Data Generation](/Docs/DataGeneration.md)
* [Expressions](/Docs/Expressions.md)
* [Symbols And Scopes](/Docs/SymbolsAndScopes.md)
* [Built-In Symbols](/Docs/BuiltInSymbols.md)
* [Output And Listings](/Docs/OutputAndListings.md)
* [Control Assembly](/Docs/ControlAssembly.md)
* [Macros](/Docs/Macros.md)
* [File Inclusions](/Docs/FileInclusions.md)
* [Disassembler](/Docs/Disassembler.md)
* [Command-line Options](/Docs/CommandLineOptions.md)