This commit contains several changes to the naming and versioning of
shared and static libraries. The details are documented at:
https://github.com/mesonbuild/meson/pull/417
Here's a brief summary:
* The results of binary and compiler detection via environment functions
are now cached so that they can be called repeatedly without
performance penalty. This is necessary because every
build.SharedLibrary object has to know whether the compiler is MSVC or
not (output filenames depend on that), and so the compiler detection
has to be called for each object instantiation.
* Linux shared libraries don't always have a library version. Sometimes
only soversions are specified (and vice-versa), so support both.
* Don't use versioned filenames when generating DLLs, DLLs are never
versioned using the suffix in the way that .so libraries are. Hence,
they don't use "aliases". Only Linux shared libraries use those.
* OS X dylibs do not use filename aliases at all. They only use the
soversion in the dylib name (libfoo.X.dylib), and that's it. If
there's no soversion specified, the dylib is called libfoo.dylib.
Further versioning in dylibs is supposed to be done with the
-current_version argument to clang, but this is TBD.
https://developer.apple.com/library/mac/documentation/DeveloperTools/Conceptual/DynamicLibraries/100-Articles/DynamicLibraryDesignGuidelines.html#//apple_ref/doc/uid/TP40002013-SW23
* Install DLLs into bindir and import libraries into libdir
* Static libraries are now always called libfoo.a, even with MSVC
* .lib import libraries are always generated when building with MSVC
* .dll.a import libraries are always generated when building with
MinGW/GCC or MinGW/clang
* TODO: Use dlltool if available to generate .dll.a when .lib is
generated and vice-versa.
* Library and executable suffix/prefixes are now always correctly
overriden by the values of the 'name_prefix' and 'name_suffix' keyword
arguments.
This causes intermittent build failures in the MSVC CI because of a race
with the default anti-virus that ships with Windows while writing the
.pdb file: https://ci.appveyor.com/project/jpakkane/meson/build/1.0.58
There's a separate fix for that in the works that will fix this in the
general case, but for compiler tests we don't need to generate the pdb
file at all. So, just fetch the CRT flag (/MDd) if needed instead.
This has the side-effect of making compiler tests that use self.links
and self.run faster.
This allows the user to specify custom arguments to the compiler to be used
while performing cross-compiler checks. For example, passing a GCC specs file as
c_link_args so that a "prefix" filled with libraries that are to be compiled
against can be found with cc.find_library, or an `-mcpu` c_arg that is required
for compilation.
Also ensure that unix_link_flags_to_native() and unix_compile_flags_to_native()
always return a copy of the original arguments and not a reference to the
original arguments. We never want to modify the original arguments.
This is required for checking for compiler checks that involve linking
to a static library with MSVC. Without this, MSVC errors out since no
CRT is specified.
limits.h is a requirement of the C language and is available with all compilers
and platforms from the last two decades. If limits.h is not available, the
compiler only supports an ancient dialect of C and lots of other things will
break too.
Consolidate the C/C++ compiler sanity checks since the test code is almost
exactly the same, and then use that for the MSVC C/C++ compilers as well. All
these sanity checks had diverged because of the code duplication.
This also fixes an intermittent sanity check failure that I was seeing with
MSVC.
Note: The ObjC/C++ compilers can also probably use the same implementation.
With the change to cc.links to translate unix link flags, this is no
longer needed and is wrong because it hasn't kept-up with the improved
default cc.find_library implementation.
Without any -O options, gcc does not generate properly debuggable code.
> With no -O option at all, some compiler passes that collect information useful
> for debugging do not run at all
gcc recommends -Og, but that isn't supported by clang, so we use -O0
See https://github.com/mesonbuild/meson/pull/509 for more discussion
We now use .links() to detect if a C compiler function is available
or not, that way the user doesn't need to specify all the possible
includes for the check, which simplifies things considerably.
Also detect glibc stub functions that will never work and return
false for them.
Closes#437
Jussi Pakkanen
Nirbheek Chauhan
Zhe Wang
Nirbheek Chauhan
Martin Hostettler
Nicolas Schneider
Tim-Philipp Müller
Hemmo Nieminen