# p4lang-p4-hlir

**Repository Path**: monkey113/p4lang-p4-hlir

## Basic Information

- **Project Name**: p4lang-p4-hlir
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Apache-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2026-01-29
- **Last Updated**: 2026-01-29

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

p4-hlir
==========

***p4-hlir only supports the P4_14 version of the P4 programming language. If
   you need to compile P4_16 programs, you can use the new
   [p4lang/p4c](https://github.com/p4lang/p4c) compiler, written in C++, which
   supports both P4_14 and P4_16. We will keep maintaining p4-hlir for the
   foreseeable future, but there is no plan to add P4_16 support to it.***

The following dependencies are required to run `p4-validate` and `p4-graphs`:
- the Python `yaml` package
- the Python `ply` package
- the `dot` tool

`ply` will be installed automatically by `setup.py` when installing `p4-hlir`.

On Ubuntu, the following packages can be installed with `apt-get` to satisfy the
remaining dependencies:
- `python-yaml`
- `graphviz`

Installation and Usage
----------------------

To install:
```
sudo python setup.py install
```

To run validate tool:
```
p4-validate <path_to_p4_program>
```

To open a Python shell with an HLIR instance accessible:
```
p4-shell <path_to_p4_program>
```

To build the HLIR and access its objects:
```
from p4_hlir.main import HLIR
h = HLIR(<path_to_p4_program>)
h.build()
```

You can then access the different P4 top level objects using these Python
OrderedDict's:
```
h.p4_actions
h.p4_control_flows
h.p4_headers
h.p4_header_instances
h.p4_fields
h.p4_field_lists
h.p4_field_list_calculations
h.p4_parser_exceptions
h.p4_parse_value_sets
h.p4_parse_states
h.p4_counters
h.p4_meters
h.p4_registers
h.p4_nodes
h.p4_tables
h.p4_action_profiles
h.p4_action_selectors
h.p4_conditional_nodes
```

The ingress entry points are stored in a dictionary:
```
h.p4_ingress_ptr
```

The egress entry point is:
```
h.p4_egress_ptr
```


To access the P4 types you can use the following import:
```
import p4_hlir.hlir.p4 as p4
```


# Getting the graphs

To get the table graph or parse graph for a P4 program, use:
```
p4-graphs <path_to_p4_program>
```

# Compiling to EBPF

There are multiple back-ends that can consume the HLIR P4 program representation.
A compiler back-end which compiles programs expressed in a restricted subset of P4
into eBPF programs that can be run in the Linux kernel can be found at
https://github.com/iovisor/bcc/tree/master/src/cc/frontends/p4