curl/docs/INTERNALS.md
Daniel Stenberg 78d6232f1f
gskit: remove
We remove support for building curl with gskit.

 - This is a niche TLS library, only running on some IBM systems
 - no regular curl contributors use this backend
 - no CI builds use or verify this backend
 - gskit, or the curl adaption for it, lacks many modern TLS features
   making it an inferior solution
 - build breakages in this code take weeks or more to get detected
 - fixing gskit code is mostly done "flying blind"

This removal has been advertized in DEPRECATED in Jan 2, 2023 and it has
been mentioned on the curl-library mailing list.

It could be brought back, this is not a ban. Given proper effort and
will, gskit support is welcome back into the curl TLS backend family.

Closes #11460
2023-08-07 20:57:48 +02:00

57 lines
1.7 KiB
Markdown

# curl internals
The canonical libcurl internals documentation is now in the [everything
curl](https://everything.curl.dev/internals) book. This file lists supported
versions of libs and build tools.
## Portability
We write curl and libcurl to compile with C89 compilers on 32-bit and up
machines. Most of libcurl assumes more or less POSIX compliance but that is
not a requirement.
We write libcurl to build and work with lots of third party tools, and we
want it to remain functional and buildable with these and later versions
(older versions may still work but is not what we work hard to maintain):
## Dependencies
We aim to support these or later versions.
- OpenSSL 0.9.7
- GnuTLS 3.1.10
- zlib 1.1.4
- libssh2 1.0
- c-ares 1.16.0
- libidn2 2.0.0
- wolfSSL 2.0.0
- OpenLDAP 2.0
- MIT Kerberos 1.2.4
- Heimdal ?
- nghttp2 1.15.0
- WinSock 2.2 (on Windows 95+ and Windows CE .NET 4.1+)
## Build tools
When writing code (mostly for generating stuff included in release tarballs)
we use a few "build tools" and we make sure that we remain functional with
these versions:
- GNU Libtool 1.4.2
- GNU Autoconf 2.59
- GNU Automake 1.7
- GNU M4 1.4
- perl 5.6
- roffit 0.5
- nroff any version that supports `-man [in] [out]`
- cmake 3.7
Library Symbols
===============
All symbols used internally in libcurl must use a `Curl_` prefix if they are
used in more than a single file. Single-file symbols must be made static.
Public ("exported") symbols must use a `curl_` prefix. Public API functions
are marked with `CURL_EXTERN` in the public header files so that all others
can be hidden on platforms where this is possible.