* output.c (error, fatal, message): Take an extra argument specifying
how many bytes are used by the formatted arguments.
(get_buffer): New function that allocates the requested buffer size.
Remove msc_vsnprintf(), vfmtconcat(), and fmtconcat() as unneeded.
* makeint.h: Declare various helper macros for generating output.
* *.c: Change all error(), fatal(), message() calls to use the macros,
or pass the extra length argument directly.
This pointer is almost never needed, and it increases the size of the filedef
struct for all files (of which there are a huge number for large builds).
Instead keep a bit field marking whether the file is a loaded object and if so
call a new function to unload it. In load.c we keep a simple linked list of
loaded objects (of which there will be very few typically) and their dlopen()
pointers.
load.c (load_object, load_file): Accept an additional argument
DLP and return in it a pointer that can be used to unload the
dynamic object.
read.c (eval): Call load_file with an additional argument, and
record the pointer returned there in the 'struct file' object of
dynamic objects in that object's 'struct file'.
commands.c (execute_file_commands): Unload dynamic objects
before remaking them, to avoid failure to remake if the OS doesn't
allow overwriting objects that are in use.
filedef.h (struct file): New member dlopen_ptr.
gnumake.h (GMK_EXPORT): Define to dllexport/dllimport
decorations for Windows and to nothing on other platforms.
(gmk_eval, gmk_expand, gmk_add_function): Add GMK_EXPORT qualifier
to prototypes.
makeint.h (MAIN): Define before including gnumake.h, to give
correct dllexport decorations to exported functions.
(load_file): Adjust prototype.
loadapi.c: Don't include gnumake.h, since makeint.h already
includes it, and takes care of defining MAIN before doing so.
build_w32.bat (LinkGCC): Produce an import library for functions
exported by Make for loadable dynamic objects.
w32/compat/posixfcn.c (dlclose): New function.
w32/include/dlfcn.h (dlclose): Add prototype.
scripts/features/load: Fix signatures of testload_gmk_setup and
explicit_setup, to bring them in line with the documentation.
w32/include/dlfcn.h: New file.
w32/compat/posixfcn.c: Include dlfcn.h.
(dlopen, dlerror, dlsym) [MAKE_LOAD]: New functions, in support of
dynamic loading.
config.h.W32.template (MAKE_LOAD): Define.
load.c (load_object) [HAVE_DOS_PATHS]: Support backslashes and
drive letters in file names of dynamic objects.
It should be sufficient, now, to write a new version of the load_object()
function. That function won't be called unless we really want to load, so all
checking and parsing is taken care of before that.
Provide a simple API for loaded objects to interact with GNU make. I still
won't guarantee that this API won't change but it's much closer to something
that's supported and provides easy-to-use interfaces with a public header
file.
