fpp to fpp

This tool parses FPP source files into an abstract syntax tree (AST), optionally transforms the AST, and writes out the AST as formatted source code.

The main purpose of this tool is to rewrite FPP constructs such as include specifiers and template expansions into a standard form. It also writes formatted output, and it can be used for that purpose. It is not a true formatter, in that (1) it requires syntactically valid FPP source as input and (2) it erases comments. However, it may be useful for some formatting tasks.

To preserve comments on their own lines that precede annotatable elements, you can run this script:

#!/bin/sh
sed 's/^\( *\)#/\1@ #/' | fpp-to-fpp $@ | sed 's/^\( *\)@ #/\1#/'

It converts comments to annotations, runs fpp-to-fpp, and converts the annotations back to comments.

Options:

1. -i: Resolve include specifiers.

2. -e: Expand syntax. Resolve include specifiers as if -i were specified; also generate state machine enums and expand templates.

Input: A list fl of files: either the single file stdin or a list of files specified on the command line.

Output: Formatted FPP source code, minus comments, written to standard output.

Procedure:

1. Parse each of the files in fl to a translation unit tu, reporting any errors that occur.

2. If -i or -e is present, then recursively resolve include specifiers. Check for include cycles. Upon detecting an include cycle, halt with an error message.

3. If -e is present, then generate state machine enums and resolve templates. Halt with an error message if template resolution fails.

4. Write out the formatted source code.