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
On MSVC, shared libraries only export symbols that have been explicitly exported
either as part of the symbol prototype or via a module definitions file.
On compilers other than MSVC, all symbols are exported in the shared library by
default and the format for the list of symbols to export is different, so this
is only used with the VisualStudio compiler.
The module defs file path can either be relative to the current source directory
or an absolute path using meson.source_root() + '/some/path'
Nirbheek Chauhan