> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sifr.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# SIFR-FLOW-0901: Unreachable statement ignored during lowering.

> Unreachable statement ignored during lowering.

`SIFR-FLOW-0901` belongs to the **Control flow** diagnostic family. It means: unreachable statement ignored during lowering.

## Why It Happens

The control-flow graph cannot satisfy Sifr's static rules. Repair unsupported statements, invalid loop control, non-boolean conditions, missing returns, or unreachable code.

<Info>
  Use `sifr --explain SIFR-FLOW-0901` locally to see the renderer's exact message template and any machine-applicable suggestions for the compiler version you are running.
</Info>

## Erroneous Code

```python theme={null}
def label(value: int) -> str:
    if value > 0:
        return "positive"
```

## How To Fix It

Repair the control-flow shape: put break/continue inside loops, return on every required path, and use supported loop and assignment forms.

## Fixed Code

```python theme={null}
def label(value: int) -> str:
    if value > 0:
        return "positive"
    return "zero or negative"
```

## Details

| Field                  | Value                                                                                                                               |
| ---------------------- | ----------------------------------------------------------------------------------------------------------------------------------- |
| Code                   | `SIFR-FLOW-0901`                                                                                                                    |
| Family                 | `FLOW`                                                                                                                              |
| Severity               | Warning                                                                                                                             |
| Stability              | stable                                                                                                                              |
| Owner                  | `sifr_lowering::lower::statements`                                                                                                  |
| Representative fixture | `crates/sifr_driver/src/tests/single_file_frontend.rs::test_type_check_source_surfaces_unreachable_statement_as_structured_warning` |

See the [Error Codes index](/diagnostics/error-codes) for the complete catalog.