/*#define DARWIN_DEBUG*/
+/* Writable sections generally available on Darwin. */
STATIC const struct {
- const char *seg;
- const char *sect;
+ const char *seg;
+ const char *sect;
} GC_dyld_sections[] = {
- { SEG_DATA, SECT_DATA },
- { SEG_DATA, SECT_BSS },
- { SEG_DATA, SECT_COMMON }
+ { SEG_DATA, SECT_DATA },
+ /* Used by FSF GCC, but not by OS X system tools, so far. */
+ { SEG_DATA, "__static_data" },
+ { SEG_DATA, SECT_BSS },
+ { SEG_DATA, SECT_COMMON },
+ /* FSF GCC - zero-sized object sections for targets */
+ /*supporting section anchors. */
+ { SEG_DATA, "__zobj_data" },
+ { SEG_DATA, "__zobj_bss" }
};
+/* Additional writable sections: */
+/* GCC on Darwin constructs aligned sections "on demand", where */
+/* the alignment size is embedded in the section name. */
+/* Furthermore, there are distinctions between sections */
+/* containing private vs. public symbols. It also constructs */
+/* sections specifically for zero-sized objects, when the */
+/* target supports section anchors. */
+STATIC const char * GC_dyld_add_sect_fmts[] =
+{
+ "__bss%u",
+ "__pu_bss%u",
+ "__zo_bss%u",
+ "__zo_pu_bss%u",
+ NULL
+};
+
+/* Currently, mach-o will allow up to the max of 2^15 alignment */
+/* in an object file. */
+#ifndef L2_MAX_OFILE_ALIGNMENT
+# define L2_MAX_OFILE_ALIGNMENT 15
+#endif
+
STATIC const char *GC_dyld_name_for_hdr(const struct GC_MACH_HEADER *hdr)
{
unsigned long i, c;
return NULL;
}
-/* 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)
+/* 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;
- const char *name;
- GC_has_static_roots_func callback = GC_has_static_roots;
- DCL_LOCK_STATE;
- if (GC_no_dls) return;
-# ifdef DARWIN_DEBUG
- name = GC_dyld_name_for_hdr(hdr);
-# else
- name = callback != 0 ? GC_dyld_name_for_hdr(hdr) : NULL;
-# endif
- for(i=0;i<sizeof(GC_dyld_sections)/sizeof(GC_dyld_sections[0]);i++) {
- sec = GC_GETSECTBYNAME(hdr, GC_dyld_sections[i].seg,
- GC_dyld_sections[i].sect);
- if(sec == NULL || sec->size < sizeof(word)) continue;
+ unsigned long start, end;
+ int i, j;
+ const struct GC_MACH_SECTION *sec;
+ const char *name;
+ GC_has_static_roots_func callback = GC_has_static_roots;
+ char secnam[16];
+ const char *fmt;
+ DCL_LOCK_STATE;
+
+ if (GC_no_dls) return;
+# ifdef DARWIN_DEBUG
+ name = GC_dyld_name_for_hdr(hdr);
+# else
+ name = callback != 0 ? GC_dyld_name_for_hdr(hdr) : NULL;
+# endif
+ for (i = 0; i < sizeof(GC_dyld_sections)/sizeof(GC_dyld_sections[0]); i++) {
+ sec = GC_GETSECTBYNAME(hdr, GC_dyld_sections[i].seg,
+ GC_dyld_sections[i].sect);
+ if (sec == NULL || sec->size < sizeof(word))
+ continue;
+ start = slide + sec->addr;
+ end = start + sec->size;
+ LOCK();
+ /* The user callback is called holding the lock. */
+ if (callback == 0 || callback(name, (void*)start, (size_t)sec->size)) {
+# ifdef DARWIN_DEBUG
+ GC_log_printf(
+ "Adding section __DATA,%s at %p-%p (%lu bytes) from image %s\n",
+ GC_dyld_sections[i].sect, (void*)start, (void*)end,
+ (unsigned long)sec->size, name);
+# endif
+ GC_add_roots_inner((ptr_t)start, (ptr_t)end, FALSE);
+ }
+ UNLOCK();
+ }
+
+ /* Sections constructed on demand. */
+ for (j = 0; (fmt = GC_dyld_add_sect_fmts[j]) != NULL; j++) {
+ /* Add our manufactured aligned BSS sections. */
+ for (i = 0; i <= L2_MAX_OFILE_ALIGNMENT; i++) {
+ snprintf(secnam, sizeof(secnam), fmt, (unsigned)i);
+ sec = GC_GETSECTBYNAME(hdr, SEG_DATA, secnam);
+ if (sec == NULL || sec->size == 0)
+ continue;
start = slide + sec->addr;
end = start + sec->size;
- LOCK();
- /* The user callback is called holding the lock */
- if (callback == 0 || callback(name, (void*)start, (size_t)sec->size)) {
-# ifdef DARWIN_DEBUG
- GC_log_printf("Adding section at %p-%p (%lu bytes) from image %s\n",
- start, end, sec->size, name);
-# endif
- GC_add_roots_inner((ptr_t)start, (ptr_t)end, FALSE);
- }
- UNLOCK();
+# ifdef DARWIN_DEBUG
+ GC_log_printf("Adding on-demand section __DATA,%s at"
+ " %p-%p (%lu bytes) from image %s\n",
+ secnam, (void*)start, (void*)end,
+ (unsigned long)sec->size, name);
+# endif
+ GC_add_roots((char*)start, (char*)end);
}
-# ifdef DARWIN_DEBUG
- GC_print_static_roots();
-# endif
+ }
+
+# ifdef DARWIN_DEBUG
+ GC_print_static_roots();
+# endif
}
-/* This should never be called by a thread holding the lock */
+/* 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++) {
- sec = GC_GETSECTBYNAME(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;
+ unsigned long start, end;
+ int i, j;
+ const struct GC_MACH_SECTION *sec;
+ char secnam[16];
+ const char *fmt;
+
+ for (i = 0; i < sizeof(GC_dyld_sections)/sizeof(GC_dyld_sections[0]); i++) {
+ sec = GC_GETSECTBYNAME(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_log_printf("Removing section at %p-%p (%lu bytes) from image %s\n",
- start, end, sec->size, GC_dyld_name_for_hdr(hdr));
+ GC_log_printf(
+ "Removing section __DATA,%s at %p-%p (%lu bytes) from image %s\n",
+ GC_dyld_sections[i].sect, (void*)start, (void*)end,
+ (unsigned long)sec->size, GC_dyld_name_for_hdr(hdr));
# endif
- GC_remove_roots((char*)start,(char*)end);
+ GC_remove_roots((char*)start, (char*)end);
+ }
+
+ /* Remove our on-demand sections. */
+ for (j = 0; (fmt = GC_dyld_add_sect_fmts[j]) != NULL; j++) {
+ for (i = 0; i <= L2_MAX_OFILE_ALIGNMENT; i++) {
+ snprintf(secnam, sizeof(secnam), fmt, (unsigned)i);
+ sec = GC_GETSECTBYNAME(hdr, SEG_DATA, secnam);
+ if (sec == NULL || sec->size == 0)
+ continue;
+ start = slide + sec->addr;
+ end = start + sec->size;
+# ifdef DARWIN_DEBUG
+ GC_log_printf("Removing on-demand section __DATA,%s at"
+ " %p-%p (%lu bytes) from image %s\n", secnam,
+ (void*)start, (void*)end, (unsigned long)sec->size,
+ GC_dyld_name_for_hdr(hdr));
+# endif
+ GC_remove_roots((char*)start, (char*)end);
}
-# ifdef DARWIN_DEBUG
- GC_print_static_roots();
-# endif
+ }
+
+# ifdef DARWIN_DEBUG
+ GC_print_static_roots();
+# endif
}
GC_INNER void GC_register_dynamic_libraries(void)
projects / gc / commitdiff