03.gen.external.md

External Generators

It's possible to implement custom generators without modifying HVCC. For this, you need to:

• subclass hvcc.types.compiler.Generator abstract class in your module (e.g. a Python file)
• add -G your_module_name command-line argument when executing hvcc

It's recommended to have only one Generator subclass per module, otherwise any one of them can be executed.

Check out hvcc.generators.c2daisy.c2daisy or hvcc.generators.c2dpf.c2dpf modules for reference implementations.

Example

This example demonstrates how to create a custom generator that prints a message into stdout.

This is example_hvcc_generator.py:

import time

from typing import Dict, Optional

from hvcc.types.compiler import CompilerResp, ExternInfo, Generator
from hvcc.types.meta import Meta


class ExampleHvccGenerator(Generator):
    @classmethod
    def compile(
            cls,
            c_src_dir: str,
            out_dir: str,
            externs: ExternInfo,
            patch_name: Optional[str] = None,
            patch_meta: Meta = Meta(),
            num_input_channels: int = 0,
            num_output_channels: int = 0,
            copyright: Optional[str] = None,
            verbose: Optional[bool] = False
    ) -> CompilerResp:
        begin_time = time.time()
        print("--> Invoking ExampleHvccGenerator")
        time.sleep(1)
        end_time = time.time()

        # Please see code example on how CompilerResp class is used and adapt to your case.
        return CompilerResp(
            stage='example_hvcc_generator',  # module name
            compile_time=end_time - begin_time,
            in_dir=c_src_dir,
            out_dir=out_dir
        )

With this file in your current directory, execute the following command:

hvcc patch.pd -G example_hvcc_generator