This brings various concrete advantages over the previous system:
- consistent support for out-of-tree builds on all platforms
- more thorough support for Visual Studio IDE project files
- support for Ninja-based builds, which is particularly useful on
Windows where the alternative nmake has no parallel option
- a really simple set of build instructions that work the same way on
all the major platforms (look how much shorter README is!)
- better decoupling of the project configuration from the toolchain
configuration, so that my Windows cross-building doesn't need
(much) special treatment in CMakeLists.txt
- configure-time tests on Windows as well as Linux, so that a lot of
ad-hoc #ifdefs second-guessing a particular feature's presence from
the compiler version can now be replaced by tests of the feature
itself
Also some longer-term software-engineering advantages:
- other people have actually heard of CMake, so they'll be able to
produce patches to the new build setup more easily
- unlike the old mkfiles.pl, CMake is not my personal problem to
maintain
- most importantly, mkfiles.pl was just a horrible pile of
unmaintainable cruft, which even I found it painful to make changes
to or to use, and desperately needed throwing in the bin. I've
already thrown away all the variants of it I had in other projects
of mine, and was only delaying this one so we could make the 0.75
release branch first.
This change comes with a noticeable build-level restructuring. The
previous Recipe worked by compiling every object file exactly once,
and then making each executable by linking a precisely specified
subset of the same object files. But in CMake, that's not the natural
way to work - if you write the obvious command that puts the same
source file into two executable targets, CMake generates a makefile
that compiles it once per target. That can be an advantage, because it
gives you the freedom to compile it differently in each case (e.g.
with a #define telling it which program it's part of). But in a
project that has many executable targets and had carefully contrived
to _never_ need to build any module more than once, all it does is
bloat the build time pointlessly!
To avoid slowing down the build by a large factor, I've put most of
the modules of the code base into a collection of static libraries
organised vaguely thematically (SSH, other backends, crypto, network,
...). That means all those modules can still be compiled just once
each, because once each library is built it's reused unchanged for all
the executable targets.
One upside of this library-based structure is that now I don't have to
manually specify exactly which objects go into which programs any more
- it's enough to specify which libraries are needed, and the linker
will figure out the fine detail automatically. So there's less
maintenance to do in CMakeLists.txt when the source code changes.
But that reorganisation also adds fragility, because of the trad Unix
linker semantics of walking along the library list once each, so that
cyclic references between your libraries will provoke link errors. The
current setup builds successfully, but I suspect it only just manages
it.
(In particular, I've found that MinGW is the most finicky on this
score of the Windows compilers I've tried building with. So I've
included a MinGW test build in the new-look Buildscr, because
otherwise I think there'd be a significant risk of introducing
MinGW-only build failures due to library search order, which wasn't a
risk in the previous library-free build organisation.)
In the longer term I hope to be able to reduce the risk of that, via
gradual reorganisation (in particular, breaking up too-monolithic
modules, to reduce the risk of knock-on references when you included a
module for function A and it also contains function B with an
unsatisfied dependency you didn't really need). Ideally I want to
reach a state in which the libraries all have sensibly described
purposes, a clearly documented (partial) order in which they're
permitted to depend on each other, and a specification of what stubs
you have to put where if you're leaving one of them out (e.g.
nocrypto) and what callbacks you have to define in your non-library
objects to satisfy dependencies from things low in the stack (e.g.
out_of_memory()).
One thing that's gone completely missing in this migration,
unfortunately, is the unfinished MacOS port linked against Quartz GTK.
That's because it turned out that I can't currently build it myself,
on my own Mac: my previous installation of GTK had bit-rotted as a
side effect of an Xcode upgrade, and I haven't yet been able to
persuade jhbuild to make me a new one. So I can't even build the MacOS
port with the _old_ makefiles, and hence, I have no way of checking
that the new ones also work. I hope to bring that port back to life at
some point, but I don't want it to block the rest of this change.
These are all intended to ensure that the declarations of things in
header files are in scope where the same thing is subsequently
defined, to make it harder to define it in a way that doesn't match.
(For example, the new #include in winnet.c would have caught the
just-fixed mis-definition of platform_get_x11_unix_address.)
This is perhaps the more useful end of the mechanism I added in the
previous commit: now, when a developer runs a configure+make build
from a git checkout (rather than from a bob-built source tarball), the
Makefile will automatically run 'git rev-parse HEAD' and embed the
result in the binaries.
So now when I want to deploy my own bleeding-edge code for day-to-day
use on my own machine, I can easily check whether I've done it right
(e.g. did I install to the right prefix?), and also easily check
whether any given PuTTY or pterm has been restarted since I rolled out
a new version.
In order to arrange this (and in particular to force version.o to be
rebuilt when _any_ source file changes), I've had to reintroduce some
of the slightly painful Makefile nastiness that I removed in 4d8782e74
when I retired the 'manifest' system, namely having version.o depend
on a file empty.h, which in turn is trivially rebuilt by a custom make
rule whose dependencies include $(allsources). That's a bit
unfortunate, but I think acceptable: the main horribleness of the
manifest system was not that part, but the actual _manifests_, which
were there to arrange that if you modified the sources in a
distribution tarball the binaries would automatically switch to
reporting themselves as local builds rather than the version baked
into the tarball. I haven't reintroduced that part of the system: if
you check out a given git commit, modify the checked-out sources, and
build the result, the Makefile won't make any inconvenient attempts to
detect that, and the resulting build will still announce itself as the
git commit you started from.
The Windows binaries, and both Windows and Unix source archives,
output from a bob build will now include the full SHA-1 of the source
git commit in their buildinfo (hence in all the About boxes and
command-line version output).
This will be occasionally useful to me at release time (there was that
one embarrassing incident where I managed not to notice that I'd made
a release build from entirely the wrong commit), but mostly, it just
seems like an obviously useful thing to put in a general buildinfo
section now that there is one.
I can't believe this codebase is around 20 years old and has had
multiple giant const-fixing patches, and yet there are _still_ things
that should have been const for years and aren't.
I've shifted away from using the SVN revision number as a monotonic
version identifier (replacing it in the Windows version resource with
a count of days since an arbitrary epoch), and I've removed all uses
of SVN keyword expansion (replacing them with version information
written out by Buildscr).
While I'm at it, I've done a major rewrite of the affected code which
centralises all the computation of the assorted version numbers and
strings into Buildscr, so that they're all more or less alongside each
other rather than scattered across multiple source files.
I've also retired the MD5-based manifest file system. A long time ago,
it seemed like a good idea to arrange that binaries of PuTTY would
automatically cease to identify themselves as a particular upstream
version number if any changes were made to the source code, so that if
someone made a local tweak and distributed the result then I wouldn't
get blamed for the results. Since then I've decided the whole idea is
more trouble than it's worth, so now distribution tarballs will have
version information baked in and people can just cope with that.
[originally from svn r10262]
it's a pre-release of, and the revision number so you can tell two
pre-releases apart. I intend to use this for builds from branch-0.61
until I call it 0.62 proper.
[originally from svn r9343]
mkfiles.pl no longer generates a Makefile.in, but instead generates a
Makefile.am on which mkauto.sh runs automake. This means that the
autoconfigured makefile now does build-time dependency tracking (a
standard feature of automake-generated makefiles), and is generally
more like what Unix people will expect.
Some of the old-style make command-line settings (VER=-DRELEASE=foo,
XFLAGS=-DDEBUG) will still work; the COMPAT settings are better done
by autoconfiguration, and my habitual 'XFLAGS="-g -O0"' for an easily
debuggable build will actually not work any more because CFLAGS is
specified _after_ XFLAGS, so I should instead write 'make CFLAGS=-O0'
(-g is the default in automake, removed at 'make install' time).
The new makefile will automatically degrade into one that builds the
command-line tools only, in the case where GTK could not be found. In
principle, therefore, it should be an adequate replacement for _both_
the static Unix makefiles, Makefile.gtk and Makefile.ux. I haven't
actually retired those in this commit, but I'm pretty tempted.
[originally from svn r9239]
a fourth class of PuTTY version tags in addition to release,
snapshot and unidentified: we now have `Custom build r1234',
indicating a build made from that SVN revision in a context other
than that of a dated snapshot. The build script generates these when
it doesn't know what else to do; `unidentified builds' will now only
occur when you run nmake from the command line.
Also, the build script now generates sensible version data in the
installer to match this. So I _think_ we should now be set to use
bob to generate installer builds of the nightly snapshots, although
of course I'll have to wait until tomorrow to test one.
[originally from svn r7211]
but since Simon's made the corresponding change to the build process, this bit
needs checking in now (it should be harmless).
(The documentation in Recipe is slightly out of date; with luck I'll be
checking in `win-versioninfo' changes soon, and I can't be bothered to
disentangle the relevant changes in the meantime.)
[originally from svn r6367]
sensibly, as a release or a snapshot or a local build. With any luck
this should make bug reporting easier to handle, because anyone who
sends their Event Log should automatically include the version :-)
[originally from svn r1003]
