RFR: 7903755: multi header support and special syntax for header file

[Maurizio Cimadamore]

On Wed, 19 Jun 2024 10:01:08 GMT, Athijegannathan Sundararajan <sundar at openjdk.org> wrote:

> jextract currently supports only one header file. If the user wants to extract more than one header file, s/he has to create a containing header that includes multiple headers and jextract the containing header.
> 
> With the current change, jextract supports more than one header file in the command line.
> When multiple headers are specified in command line, --header-class-name option is mandatory and it is enforced.
> 
> In addition to normal file names for header file names, a special syntax such as "<stdio.h>" is also supported. With this, user does not have to write long file name including directories such as /usr/include/stdio.h.
> 
> jextract generates multiple headers by generating a temporary header file. If the command line argument is of the form "<stdio.h>" then jextract generates "#include <stdio.h>" in the auto-generated containing header. If the header specified in of the normal/existing form (say foo.h), then containing header will have #include "foo.h" line.

Samples are much better - all the scripts are easier to understand.
I think we need to update the guide - as some of the command line option have changed:
* e.g. we now accept multiple headers
* headers can be provided with two different syntax (e.g. plain and "<>")
* if there's multiple headers, then the header class name option *must* be used

-------------

PR Review: https://git.openjdk.org/jextract/pull/249#pullrequestreview-2127796808