+/* __private_extern__ hack required for pre-3.4 gcc versions. */
+#ifndef __private_extern__
+# define __private_extern__ extern
+# include <mach-o/dyld.h>
+# undef __private_extern__
+#else
+# include <mach-o/dyld.h>
+#endif
+#include <mach-o/getsect.h>
+
+/*#define DARWIN_DEBUG*/
+
+const static struct {
+ const char *seg;
+ const char *sect;
+} GC_dyld_sections[] = {
+ { SEG_DATA, SECT_DATA },
+ { SEG_DATA, SECT_BSS },
+ { SEG_DATA, SECT_COMMON }
+};
+
+#ifdef DARWIN_DEBUG
+static const char *GC_dyld_name_for_hdr(const struct GC_MACH_HEADER *hdr) {
+ unsigned long i,c;
+ c = _dyld_image_count();
+ for(i=0;i<c;i++) if(_dyld_get_image_header(i) == hdr)
+ return _dyld_get_image_name(i);
+ return NULL;
+}
+#endif
+
+/* This should never be called by a thread holding the lock */
+static void GC_dyld_image_add(const struct GC_MACH_HEADER *hdr, intptr_t slide)
+{
+ unsigned long start,end,i;
+ const struct GC_MACH_SECTION *sec;
+ if (GC_no_dls) return;
+ for(i=0;i<sizeof(GC_dyld_sections)/sizeof(GC_dyld_sections[0]);i++) {
+# if defined (__LP64__)
+ sec = getsectbynamefromheader_64(
+# else
+ sec = getsectbynamefromheader(
+# endif
+ hdr,GC_dyld_sections[i].seg,GC_dyld_sections[i].sect);
+ if(sec == NULL || sec->size == 0) continue;
+ start = slide + sec->addr;
+ end = start + sec->size;
+# ifdef DARWIN_DEBUG
+ GC_printf4("Adding section at %p-%p (%lu bytes) from image %s\n",
+ start,end,sec->size,GC_dyld_name_for_hdr(hdr));
+# endif
+ GC_add_roots((char*)start,(char*)end);
+ }
+# ifdef DARWIN_DEBUG
+ GC_print_static_roots();
+# endif
+}
+
+/* This should never be called by a thread holding the lock */
+static void GC_dyld_image_remove(const struct GC_MACH_HEADER *hdr,
+ intptr_t slide) {
+ unsigned long start,end,i;
+ const struct GC_MACH_SECTION *sec;
+ for(i=0;i<sizeof(GC_dyld_sections)/sizeof(GC_dyld_sections[0]);i++) {
+# if defined (__LP64__)
+ sec = getsectbynamefromheader_64(
+# else
+ sec = getsectbynamefromheader(
+# endif
+ hdr,GC_dyld_sections[i].seg,GC_dyld_sections[i].sect);
+ if(sec == NULL || sec->size == 0) continue;
+ start = slide + sec->addr;
+ end = start + sec->size;
+# ifdef DARWIN_DEBUG
+ GC_printf4("Removing section at %p-%p (%lu bytes) from image %s\n",
+ start,end,sec->size,GC_dyld_name_for_hdr(hdr));
+# endif
+ GC_remove_roots((char*)start,(char*)end);
+ }
+# ifdef DARWIN_DEBUG
+ GC_print_static_roots();
+# endif
+}
+
+void GC_register_dynamic_libraries() {
+ /* Currently does nothing. The callbacks are setup by GC_init_dyld()
+ The dyld library takes it from there. */
+}
+
+/* The _dyld_* functions have an internal lock so no _dyld functions
+ can be called while the world is stopped without the risk of a deadlock.
+ Because of this we MUST setup callbacks BEFORE we ever stop the world.
+ This should be called BEFORE any thread in created and WITHOUT the
+ allocation lock held. */
+
+void GC_init_dyld() {
+ static GC_bool initialized = FALSE;
+ char *bind_fully_env = NULL;
+
+ if(initialized) return;
+
+# ifdef DARWIN_DEBUG
+ GC_printf0("Registering dyld callbacks...\n");
+# endif
+
+ /* Apple's Documentation:
+ When you call _dyld_register_func_for_add_image, the dynamic linker runtime
+ calls the specified callback (func) once for each of the images that is
+ currently loaded into the program. When a new image is added to the program,
+ your callback is called again with the mach_header for the new image, and the
+ virtual memory slide amount of the new image.
+
+ This WILL properly register already linked libraries and libraries
+ linked in the future
+ */
+
+ _dyld_register_func_for_add_image(GC_dyld_image_add);
+ _dyld_register_func_for_remove_image(GC_dyld_image_remove);
+
+ /* Set this early to avoid reentrancy issues. */
+ initialized = TRUE;
+
+ bind_fully_env = getenv("DYLD_BIND_AT_LAUNCH");
+
+ if (bind_fully_env == NULL) {
+# ifdef DARWIN_DEBUG
+ GC_printf0("Forcing full bind of GC code...\n");
+# endif
+
+ if(!_dyld_bind_fully_image_containing_address((unsigned long*)GC_malloc))
+ GC_abort("_dyld_bind_fully_image_containing_address failed");
+ }
+
+}
+
+#define HAVE_REGISTER_MAIN_STATIC_DATA
+GC_bool GC_register_main_static_data()
+{
+ /* Already done through dyld callbacks */
+ return FALSE;
+}
+
+#endif /* DARWIN */