Fix interfacing with and remaking dynamic objects on MS-Windows.

 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.

1 files changed, 3 insertions, 1 deletions

diff --git a/build_w32.bat b/build_w32.bat
index 27ac3db..43ae6e2 100644
--- a/build_w32.bat
+++ b/build_w32.bat
@@ -290,8 +290,10 @@ set GUILEOBJ=guile.o
 echo on

 gcc -mthreads -Wall -gdwarf-2 -g3 %OPT% %GUILECFLAGS% -I. -I./glob -I./w32/include -DWINDOWS32 -DHAVE_CONFIG_H -c guile.c

 :LinkGCC

+Rem The version NN of libgnumake-NN.dll.a should be bumped whenever

+Rem the API changes in binary-incompatible manner.

 @echo on

-gcc -mthreads -gdwarf-2 -g3 -o gnumake.exe variable.o rule.o remote-stub.o commands.o file.o getloadavg.o default.o signame.o expand.o dir.o main.o getopt1.o %GUILEOBJ% job.o read.o version.o getopt.o arscan.o remake.o misc.o hash.o strcache.o ar.o function.o vpath.o implicit.o loadapi.o load.o glob.o fnmatch.o pathstuff.o posixfcn.o w32_misc.o sub_proc.o w32err.o %GUILELIBS% -lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32 -ladvapi32 -lshell32 -lole32 -loleaut32 -luuid -lodbc32 -lodbccp32

+gcc -mthreads -gdwarf-2 -g3 -o gnumake.exe variable.o rule.o remote-stub.o commands.o file.o getloadavg.o default.o signame.o expand.o dir.o main.o getopt1.o %GUILEOBJ% job.o read.o version.o getopt.o arscan.o remake.o misc.o hash.o strcache.o ar.o function.o vpath.o implicit.o loadapi.o load.o glob.o fnmatch.o pathstuff.o posixfcn.o w32_misc.o sub_proc.o w32err.o %GUILELIBS% -lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32 -ladvapi32 -lshell32 -lole32 -loleaut32 -luuid -lodbc32 -lodbccp32 -Wl,--out-implib=libgnumake-1.dll.a

 @GoTo BuildEnd

 :Usage

 echo Usage: %0 [options] [gcc]