Nathan Typanski wrote:
On 08/14, Tim Hollebeek wrote:
Have you considered moving to CMake? It makes lots of the issues
you discuss in the document just go away. cmake should work on the
vast majority of supported operating systems, if not all of them ...
Cmake has disadvantages. I haven't actually used it enough to comment
on what it's like to use, but I can link to a project that has:
<https://wiki.openoffice.org/wiki/Build_System_Analysis#CMake>
OpenOffice was trying to solve the recursive make problem in their
project, much like OpenSSL is attempting. They ultimately decided
against CMake and gave a good writeup of their reasoning.
There's also a nice debate at LWN.net about GNU Make/CMake and the
related tradeoffs.
<http://lwn.net/Articles/466137/>
Also, consider the scenario:
- I'm an embedded developer and I want to compile OpenSSL on my
embedded system (or any platform that isn't my workstation). It
doesn't have CMake, I can't get CMake on it or don't have the
resources (or desire) to get CMake installed on the target platform.
- To solve this, I download OpenSSL on my workstation and tell CMake
to generate a GNU Makefile for me. I copy the source over to the
platform I want to build OpenSSL on.
- I do `./configure && make && make install` and pray.
- The build fails and dumps and unhelpful error message. I go digging
into the generated Makefile looking for the build error and realize
CMake has built absolute paths into everything.
- I go on the CMake wiki and read this:
<http://www.cmake.org/Wiki/CMake_FAQ#Why_does_CMake_use_full_paths.2C_or_can_I_copy_my_build_tree.3F>
where the answer is basically "no, you can't use CMake like that. Go
install CMake on your embedded device, or figure out how the hell to
cross-compile a CMake build".
- Researching cross-compiling CMake turns up this:
<http://blog.beuc.net/posts/Cross-compiling_with_CMake/>
- I come complain on this mailing list because OpenSSL has rejected
both GNU and UNIX-like standards in favor of this stupid "more
advanced" build system.
Maybe I'm biased, but from what I've seen with projects using CMake,
CMake is only portable in the sense that KDE is portable: yes, if
you're willing to enforce complete buy-in from the
users/packagers/maintainers, people can build OpenSSL easily on more
than one system.
But from my eyes it doesn't look like a low-level, relatively tiny C
library has any good reason to switch to CMake.
FWIW: my experience with CMake is quite negative.
A few years ago I had to package some software for scientific grid
computing and the cmake based ones were always the hardest ones. If a
cmake build was working then it wasn't so bad but if you need to debug
it or if you need to cross-compile then it is (IMHO) an absolute nightmare.
I'd consider it a step backwards if openssl moved in the direction of
cmake.
JM2CW,
JJK / Jan Just Keijser
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