GIANT CLUSTERFUCK OF A COMMIT

OK, this is epic.  I was basically just trying to a) support Clang and
b) add more test coverage.  _THREE MONTHS_ and a few hundred CI runs
later, this is what I came up with.  I don't know how it ended up being
what it is, but here we go.

Some highlights of the changes:

1) CI builds has been moved to GitHub Actions,
2) the entire notion of a toolchain has been reworked; it now supports
Clang on all platforms.

* .github: this directory contains the GitHub Actions workflow
scripts/actions.  In the process, I created like 6 external GitHub
actions, but it's still pretty massive.  An upside is that it covers
much more platform/toolchain combinations _and_ check a lot of the
expected post-conditions.  TODO: .ci/Makefile is obsolete now, as well
as .travis.yml and .appveyor.yml.

* common.cmake: added Clang support.  In the process, a great deal has
been learned about how CMake works; in particular, static runtime
support has been reworked to be more robust.

* project: the entire notion of a "toolchain" has been reworked.
Instead of a measly --mingw parameter, there's now a separate --toolset
parameter, which allows you to choose between GCC, Clang, MSVC, etc.
Both Boost and CMake build scripts were enhanced greatly to support
Clang and other toolchains in a more robust way.

1 files changed, 9 insertions, 7 deletions

diff --git a/project/mingw.py b/project/mingw.py
index 1e136cd..731cee9 100644
--- a/project/mingw.py
+++ b/project/mingw.py
@@ -3,8 +3,6 @@
 # For details, see https://github.com/egor-tensin/cmake-common.
 # Distributed under the MIT License.
 
-from project.os import on_windows_like
-
 
 def _get_compiler_prefix(platform):
     target_arch = platform.get_address_model()
@@ -17,11 +15,7 @@ def _get_compiler_prefix(platform):
 
 def _get(platform, what):
     prefix = _get_compiler_prefix(platform)
-    ext = ''
-    if on_windows_like():
-        # Boost.Build wants the .exe extension at the end on Cygwin.
-        ext = '.exe'
-    path = f'{prefix}-w64-mingw32-{what}{ext}'
+    path = f'{prefix}-w64-mingw32-{what}'
     return path
 
 
@@ -33,5 +27,13 @@ def get_gxx(platform):
     return _get(platform, 'g++')
 
 
+def get_ar(platform):
+    return _get(platform, 'gcc-ar')
+
+
+def get_ranlib(platform):
+    return _get(platform, 'gcc-ranlib')
+
+
 def get_windres(platform):
     return _get(platform, 'windres')