Introduce gdb_dlhandle_up

This introduces gdb_dlhandle_up, a unique_ptr that can close a
dlopen'd library.  All the functions working with dlopen handles are
updated to use this new type.

I did not try to build this on Windows.

gdb/ChangeLog
2017-04-12  Tom Tromey  <tom@tromey.com>

	* jit.c (struct jit_reader): Declare separately.  Add constructor
	and destructor.  Change type of "handle".
	(loaded_jit_reader): Define separately.
	(jit_reader_load): Update.  New "new".
	(jit_reader_unload_command): Use "delete".
	* gdb-dlfcn.h (struct dlclose_deleter): New.
	(gdb_dlhandle_up): New typedef.
	(gdb_dlopen, gdb_dlsym): Update types.
	(gdb_dlclose): Remove.
	* gdb-dlfcn.c (gdb_dlopen): Return a gdb_dlhandle_up.
	(gdb_dlsym): Change type of "handle".
	(make_cleanup_dlclose): Remove.
	(dlclose_deleter::operator()): Rename from gdb_dlclose.
	* compile/compile-c-support.c (load_libcc): Update.

1 files changed, 13 insertions, 32 deletions

diff --git a/gdb/gdb-dlfcn.c b/gdb/gdb-dlfcn.c
index a11e396c6e..7485a38527 100644
--- a/gdb/gdb-dlfcn.c
+++ b/gdb/gdb-dlfcn.c
@@ -31,27 +31,20 @@
 
 #ifdef NO_SHARED_LIB
 
-void *
+gdb_dlhandle_up
 gdb_dlopen (const char *filename)
 {
   gdb_assert_not_reached ("gdb_dlopen should not be called on this platform.");
 }
 
 void *
-gdb_dlsym (void *handle, const char *symbol)
+gdb_dlsym (const gdb_dlhandle_up &handle, const char *symbol)
 {
   gdb_assert_not_reached ("gdb_dlsym should not be called on this platform.");
 }
 
-struct cleanup *
-make_cleanup_dlclose (void *handle)
-{
-  gdb_assert_not_reached ("make_cleanup_dlclose should not be called on this "
-                          "platform.");
-}
-
-int
-gdb_dlclose (void *handle)
+void
+dlclose_deleter::operator() (void *handle) const
 {
   gdb_assert_not_reached ("gdb_dlclose should not be called on this platform.");
 }
@@ -64,7 +57,7 @@ is_dl_available (void)
 
 #else /* NO_SHARED_LIB */
 
-void *
+gdb_dlhandle_up
 gdb_dlopen (const char *filename)
 {
   void *result;
@@ -74,7 +67,7 @@ gdb_dlopen (const char *filename)
   result = (void *) LoadLibrary (filename);
 #endif
   if (result != NULL)
-    return result;
+    return gdb_dlhandle_up (result);
 
 #ifdef HAVE_DLFCN_H
   error (_("Could not load %s: %s"), filename, dlerror());
@@ -97,37 +90,25 @@ gdb_dlopen (const char *filename)
 }
 
 void *
-gdb_dlsym (void *handle, const char *symbol)
+gdb_dlsym (const gdb_dlhandle_up &handle, const char *symbol)
 {
 #ifdef HAVE_DLFCN_H
-  return dlsym (handle, symbol);
+  return dlsym (handle.get (), symbol);
 #elif __MINGW32__
-  return (void *) GetProcAddress ((HMODULE) handle, symbol);
+  return (void *) GetProcAddress ((HMODULE) handle.get (), symbol);
 #endif
 }
 
-int
-gdb_dlclose (void *handle)
+void
+dlclose_deleter::operator() (void *handle) const
 {
 #ifdef HAVE_DLFCN_H
-  return dlclose (handle);
+  dlclose (handle);
 #elif __MINGW32__
-  return !((int) FreeLibrary ((HMODULE) handle));
+  FreeLibrary ((HMODULE) handle);
 #endif
 }
 
-static void
-do_dlclose_cleanup (void *handle)
-{
-  gdb_dlclose (handle);
-}
-
-struct cleanup *
-make_cleanup_dlclose (void *handle)
-{
-  return make_cleanup (do_dlclose_cleanup, handle);
-}
-
 int
 is_dl_available (void)
 {