porting libcurl

The basic approach I use when porting libcurl to another OS when the existing configure or cmake build setups are not suitable.

Build

Write a build script/Makefile that builds all C files under lib/. If possible, use the lib/Makefile.inc that lists all files in Makefile variables.

In the Makefile, make sure you define what OS you build for: -D[OPERATING SYSTEM], or similar. Perhaps the compiler in use already define a standard one? Then you might not need to define your own.

Add the new OS

In the lib/curl_config.h header file, in the section for when HAVE_CONFIG_H is not defined (starting at around line 150), add a new conditional include in this style:

#ifdef [OPERATING SYSTEM]
#  include "config-operatingsystem.h"
#endif

Create lib/config-operatingsystem.h. You might want to start with copying a another config-* file and then start trimming according to what your environment supports.

Build it

When you run into compiler warnings or errors, the lib/config-operatingsystem.h file should be where you should focus your work and edits.

A recommended approach is to define a lot of the CURL_DISABLE_* defines (see the CURL-DISABLE document) initially to help narrow down the initial work as that can save you from having to give attention to areas of the code that you do not care for in your port.