diff options
Diffstat (limited to 'doc/make.texi')
| -rw-r--r-- | doc/make.texi | 78 |
1 files changed, 71 insertions, 7 deletions
diff --git a/doc/make.texi b/doc/make.texi index 2e76e900..57c13077 100644 --- a/doc/make.texi +++ b/doc/make.texi @@ -11990,7 +11990,7 @@ If the load succeeds @code{make} will invoke an initializing function. If @var{symbol-name} is provided, it will be used as the name of the initializing function. -If no @var{symbol-name} is provided, the initializing function name is created +If @var{symbol-name} is not provided, the initializing function name is created by taking the base file name of @var{object-file}, up to the first character which is not a valid symbol name character (alphanumerics and underscores are valid symbol name characters). To this prefix will be appended the suffix @@ -12030,6 +12030,31 @@ an error, you can use the @code{-load} directive instead of @code{load}. GNU to load. The failed object is not added to the @code{.LOADED} variable, which can then be consulted to determine if the load was successful. +@subsubheading Unloading Objects +@cindex unloading objects +@cindex unload function for loaded objects + +When GNU Make needs to unload a loaded object, either because it is exiting or +because the loaded object has been rebuilt, it will invoke an unload function. +The unload function name is created by taking the base file name of the object +file, up to the first character which is not a valid symbol name character +(alphanumerics and underscores are valid symbol name characters), then +appending the suffix @code{_gmk_unload}. + +If that function exists it will be called using the signature: + +@example +void <name>_gmk_unload (void); +@end example + +If the function does not exist, it will not be called. + +Note that only one unload function may be defined per loaded object, +regardless of how many different setup methods are provided in that loaded +object. If your loaded object provides multiple setup methods that require +unload support it's up to you to coordinate which setups have been invoked in +the unload function. + @node Initializing Functions, Remaking Loaded Objects, load Directive, Loading Objects @subsection Initializing Functions @cindex loaded object initializing function @@ -12275,8 +12300,16 @@ take a prefix as an argument. First we can write the function in a file int plugin_is_GPL_compatible; -char * -gen_tmpfile(const char *nm, int argc, char **argv) +struct tmpfile @{ + struct tmpfile *next; + char *name; +@}; +static struct tmpfile *files = NULL; +@end group + +@group +static char * +gen_tmpfile(const char *nm, unsigned int argc, char **argv) @{ int fd; @@ -12290,6 +12323,11 @@ gen_tmpfile(const char *nm, int argc, char **argv) fd = mkstemp(buf); if (fd >= 0) @{ + struct tmpfile *new = malloc (sizeof (struct tmpfile)); + new->name = strdup (buf); + new->next = files; + files = new; + /* Don't leak the file descriptor. */ close (fd); return buf; @@ -12300,7 +12338,9 @@ gen_tmpfile(const char *nm, int argc, char **argv) gmk_free (buf); return NULL; @} +@end group +@group int mk_temp_gmk_setup (unsigned int abi, const gmk_floc *floc) @{ @@ -12311,6 +12351,23 @@ mk_temp_gmk_setup (unsigned int abi, const gmk_floc *floc) return 1; @} @end group + +@group +void +mk_temp_gmk_close () +@{ + while (files) + @{ + struct tmpfile *f = files; + files = f->next; + printf ("mk_temp removing %s\n", f->name); + remove (f->name); + free (f->name); + free (f); + @} + printf ("mk_temp plugin closed\n"); +@} +@end group @end example Next, we will write a @file{Makefile} that can build this shared object, load @@ -12320,8 +12377,9 @@ it, and use it: @group all: @@echo Temporary file: $(mk-temp tmpfile.) + @@echo Temporary file: $(mk-temp tmpfile.) -load mk_temp.so +-load mk_temp.so mk_temp.so: mk_temp.c $(CC) -shared -fPIC -o $@@ $< @@ -12332,7 +12390,7 @@ On MS-Windows, due to peculiarities of how shared objects are produced, the compiler needs to scan the @dfn{import library} produced when building @code{make}, typically called @file{libgnumake-@var{version}.dll.a}, where @var{version} is the version of the load object API. So the recipe to produce -a shared object will look on Windows like this (assuming the API version is +a shared object will look like this on Windows (assuming the API version is 1): @example @@ -12345,10 +12403,16 @@ mk_temp.dll: mk_temp.c Now when you run @code{make} you'll see something like: @example +@group $ make -mk_temp abi 1 plugin loaded from Makefile:4 cc -shared -fPIC -o mk_temp.so mk_temp.c -Temporary filename: tmpfile.A7JEwd +mk_temp abi 1 plugin loaded from Makefile:5 +Temporary file: tmpfile.OYkGMT +Temporary file: tmpfile.sYsJO0 +mk_temp removing tmpfile.sYsJO0 +mk_temp removing tmpfile.OYkGMT +mk_temp plugin closed +@end group @end example @node Integrating make, Features, Extending make, Top |