libicu is an internal dependency of libpsl, so if an executable
uses libicu directly, linking on libpsl is not enough, it must also
link on libicu.
Closes: #115
Clang compilation targets may support `__declspec` attributes. Because of that it has a `__has_declspec_attribute` [check](https://clang.llvm.org/docs/LanguageExtensions.html#has-declspec-attribute).
Currently libpsl just assumes that `__declspec` is Windows only. This adds a compatibility macro and checks whether `dllimport` and `dllexport` are available.
This adds a set of Visual Studio NMake Makefiles that can be used to
build libpsl, either as a DLL or as a static .lib. Building of the psl
tool and the tests in tests/ (but not fuzz, since those tests use
fmemopen(), that is not supported on Windows) are also supported.
A simplified "install" target is provided that copies the build
results to a default or set prefix with the pkg-config file so that
other packages (such as libsoup) with build systems that depend on this
.pc file can be built.
These files make use of autotools stuff so that they have the up-to-date
version info upon a release.
Currently, only builds using the ICU runtime/builtin or with no
runtime/builtin are supported with Visual Studio builds.
When not explictly given --enable-runtime/--enable-builtin,
./configure tries to first detect libidn2, then libicu, then
libidn. If none found, it fals back to --disable-runtime and
--disable-builtin.
Reported-by: Chun-wei Fan
Visual Studio does not come with unistd.h, so only include it when we
have HAVE_UNISTD_H. It also does not like including locale.h within
main() for some reason, so include that with the other system headers.
fmemopen() is a function that is only provided with *NIX systems, so we
ought to check for its presence in order to build and run the tests
in fuzz/ fully, otherwise, we just skip the tests.
Also include headers according to how they are found, and add fallbacks
for Visual Studio that do not have stdint.h yet.
Tim Rühsen
Xavier Claessens
Don
Chun-wei Fan