dyn_load.c

Boost provides free peer-reviewed portable C++ source libraries. We emphasize libraries that work

    size_t regioninfosize = sizeof(regioninfo);
    size_t regionreturnsize;

  /* Obtain id of this process */
    mypid = ldr_my_process();
  
  /* For each module */
    while (TRUE) {

      /* Get the next (first) module */
        status = ldr_next_module(mypid, &moduleid);

      /* Any more modules? */
        if (moduleid == LDR_NULL_MODULE)
            break;    /* No more modules */

      /* Check status AFTER checking moduleid because */
      /* of a bug in the non-shared ldr_next_module stub */
        if (status != 0 ) {
            GC_printf("dynamic_load: status = %d\n", status);
            {
                extern char *sys_errlist[];
                extern int sys_nerr;
                extern int errno;
                if (errno <= sys_nerr) {
                    GC_printf("dynamic_load: %s\n", sys_errlist[errno]);
               } else {
                    GC_printf("dynamic_load: %d\n", errno);
                }
        }
            ABORT("ldr_next_module failed");
         }

      /* Get the module information */
        status = ldr_inq_module(mypid, moduleid, &moduleinfo,
                                moduleinfosize, &modulereturnsize); 
        if (status != 0 )
            ABORT("ldr_inq_module failed");

      /* is module for the main program (i.e. nonshared portion)? */
          if (moduleinfo.lmi_flags & LDR_MAIN)
              continue;    /* skip the main module */

#     ifdef DL_VERBOSE
          GC_printf("---Module---\n");
          GC_printf("Module ID            = %16ld\n", moduleinfo.lmi_modid);
          GC_printf("Count of regions     = %16d\n", moduleinfo.lmi_nregion);
          GC_printf("flags for module     = %16lx\n", moduleinfo.lmi_flags); 
          GC_printf("pathname of module   = \"%s\"\n", moduleinfo.lmi_name);
#     endif

      /* For each region in this module */
        for (region = 0; region < moduleinfo.lmi_nregion; region++) {

          /* Get the region information */
            status = ldr_inq_region(mypid, moduleid, region, &regioninfo,
                                    regioninfosize, &regionreturnsize);
            if (status != 0 )
                ABORT("ldr_inq_region failed");

          /* only process writable (data) regions */
            if (! (regioninfo.lri_prot & LDR_W))
                continue;

#         ifdef DL_VERBOSE
              GC_printf("--- Region ---\n");
              GC_printf("Region number    = %16ld\n",
              	        regioninfo.lri_region_no);
              GC_printf("Protection flags = %016x\n",  regioninfo.lri_prot);
              GC_printf("Virtual address  = %16p\n",   regioninfo.lri_vaddr);
              GC_printf("Mapped address   = %16p\n",   regioninfo.lri_mapaddr);
              GC_printf("Region size      = %16ld\n",  regioninfo.lri_size);
              GC_printf("Region name      = \"%s\"\n", regioninfo.lri_name);
#         endif

          /* register region as a garbage collection root */
            GC_add_roots_inner (
                (char *)regioninfo.lri_mapaddr,
                (char *)regioninfo.lri_mapaddr + regioninfo.lri_size,
                TRUE);

        }
    }
}
#endif

#if defined(HPUX)

#include <errno.h>
#include <dl.h>

extern char *sys_errlist[];
extern int sys_nerr;

void GC_register_dynamic_libraries()
{
  int status;
  int index = 1; /* Ordinal position in shared library search list */
  struct shl_descriptor *shl_desc; /* Shared library info, see dl.h */

  /* For each dynamic library loaded */
    while (TRUE) {

      /* Get info about next shared library */
        status = shl_get(index, &shl_desc);

      /* Check if this is the end of the list or if some error occured */
        if (status != 0) {
#	 ifdef GC_HPUX_THREADS
	   /* I've seen errno values of 0.  The man page is not clear	*/
	   /* as to whether errno should get set on a -1 return.	*/
	   break;
#	 else
          if (errno == EINVAL) {
              break; /* Moved past end of shared library list --> finished */
          } else {
              if (errno <= sys_nerr) {
                    GC_printf("dynamic_load: %s\n", sys_errlist[errno]);
              } else {
                    GC_printf("dynamic_load: %d\n", errno);
	      }
              ABORT("shl_get failed");
          }
#	 endif
        }

#     ifdef DL_VERBOSE
          GC_printf("---Shared library---\n");
          GC_printf("\tfilename        = \"%s\"\n", shl_desc->filename);
          GC_printf("\tindex           = %d\n", index);
          GC_printf("\thandle          = %08x\n",
					(unsigned long) shl_desc->handle);
          GC_printf("\ttext seg. start = %08x\n", shl_desc->tstart);
          GC_printf("\ttext seg. end   = %08x\n", shl_desc->tend);
          GC_printf("\tdata seg. start = %08x\n", shl_desc->dstart);
          GC_printf("\tdata seg. end   = %08x\n", shl_desc->dend);
          GC_printf("\tref. count      = %lu\n", shl_desc->ref_count);
#     endif

      /* register shared library's data segment as a garbage collection root */
        GC_add_roots_inner((char *) shl_desc->dstart,
			   (char *) shl_desc->dend, TRUE);

        index++;
    }
}
#endif /* HPUX */

#ifdef AIX
#pragma alloca
#include <sys/ldr.h>
#include <sys/errno.h>
void GC_register_dynamic_libraries()
{
	int len;
	char *ldibuf;
	int ldibuflen;
	struct ld_info *ldi;

	ldibuf = alloca(ldibuflen = 8192);

	while ( (len = loadquery(L_GETINFO,ldibuf,ldibuflen)) < 0) {
		if (errno != ENOMEM) {
			ABORT("loadquery failed");
		}
		ldibuf = alloca(ldibuflen *= 2);
	}

	ldi = (struct ld_info *)ldibuf;
	while (ldi) {
		len = ldi->ldinfo_next;
		GC_add_roots_inner(
				ldi->ldinfo_dataorg,
				(ptr_t)(unsigned long)ldi->ldinfo_dataorg
			        + ldi->ldinfo_datasize,
				TRUE);
		ldi = len ? (struct ld_info *)((char *)ldi + len) : 0;
	}
}
#endif /* AIX */

#ifdef DARWIN

/* __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_printf("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_printf("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_printf("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_printf("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 */

#else /* !DYNAMIC_LOADING */

#ifdef PCR

#   include "il/PCR_IL.h"
#   include "th/PCR_ThCtl.h"
#   include "mm/PCR_MM.h"

void GC_register_dynamic_libraries()
{
    /* Add new static data areas of dynamically loaded modules.	*/
        {
          PCR_IL_LoadedFile * p = PCR_IL_GetLastLoadedFile();
          PCR_IL_LoadedSegment * q;
          
          /* Skip uncommited files */
          while (p != NIL && !(p -> lf_commitPoint)) {
              /* The loading of this file has not yet been committed	*/
              /* Hence its description could be inconsistent.  		*/
              /* Furthermore, it hasn't yet been run.  Hence its data	*/
              /* segments can't possibly reference heap allocated	*/
              /* objects.						*/
              p = p -> lf_prev;
          }
          for (; p != NIL; p = p -> lf_prev) {
            for (q = p -> lf_ls; q != NIL; q = q -> ls_next) {
              if ((q -> ls_flags & PCR_IL_SegFlags_Traced_MASK)
                  == PCR_IL_SegFlags_Traced_on) {
                GC_add_roots_inner
                	((char *)(q -> ls_addr), 
                	 (char *)(q -> ls_addr) + q -> ls_bytes,
                	 TRUE);
              }
            }
          }
        }
}


#else /* !PCR */

void GC_register_dynamic_libraries(){}

int GC_no_dynamic_loading;

#endif /* !PCR */

#endif /* !DYNAMIC_LOADING */

#ifndef HAVE_REGISTER_MAIN_STATIC_DATA

/* Do we need to separately register the main static data segment? */
GC_bool GC_register_main_static_data()
{
  return TRUE;
}

/* Register a routine to filter dynamic library registration.  */
void
GC_register_has_static_roots_callback
  (int (*callback)(const char *, void *, size_t)) {
  GC_has_static_roots = callback;
}

#endif /* HAVE_REGISTER_MAIN_STATIC_DATA */