text: /* 
   * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
   * Copyright (c) 1991-1995 by Xerox Corporation.  All rights reserved.
   * Copyright 1996-1999 by Silicon Graphics.  All rights reserved.
   * Copyright 1999 by Hewlett-Packard Company.  All rights reserved.
   *
   * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
   *
   * Permission is hereby granted to use or copy this program
   * for any purpose,  provided the above notices are retained on all copies.
   * Permission to modify the code and to distribute modified code is granted,
   * provided the above notices are retained, and a notice that the code was
   * modified is included with the above copyright notice.
   */
  
  /*
   * Note that this defines a large number of tuning hooks, which can
   * safely be ignored in nearly all cases.  For normal use it suffices
   * to call only GC_MALLOC and perhaps GC_REALLOC.
   * For better performance, also look at GC_MALLOC_ATOMIC, and
   * GC_enable_incremental.  If you need an action to be performed
   * immediately before an object is collected, look at GC_register_finalizer.
   * If you are using Solaris threads, look at the end of this file.
   * Everything else is best ignored unless you encounter performance
   * problems.
   */
   
  #ifndef _GC_H
  
  # define _GC_H
  
  # include "gc_config_macros.h"
  
  # if defined(__STDC__) || defined(__cplusplus) || defined(_AIX)
  #   define GC_PROTO(args) args
      typedef void * GC_PTR;
  #   define GC_CONST const
  # else
  #   define GC_PROTO(args) ()
      typedef char * GC_PTR;
  #   define GC_CONST
  #  endif
  
  # ifdef __cplusplus
      extern "C" {
  # endif
  
  
  /* Define word and signed_word to be unsigned and signed types of the 	*/
  /* size as char * or void *.  There seems to be no way to do this	*/
  /* even semi-portably.  The following is probably no better/worse 	*/
  /* than almost anything else.						*/
  /* The ANSI standard suggests that size_t and ptr_diff_t might be 	*/
  /* better choices.  But those had incorrect definitions on some older	*/
  /* systems.  Notably "typedef int size_t" is WRONG.			*/
  #ifndef _WIN64
    typedef unsigned long GC_word;
    typedef long GC_signed_word;
  #else
    /* Win64 isn't really supported yet, but this is the first step. And	*/
    /* it might cause error messages to show up in more plausible places.	*/
    /* This needs basetsd.h, which is included by windows.h.	 	*/
    typedef unsigned __int64 GC_word;
    typedef __int64 GC_signed_word;
  #endif
  
  /* Public read-only variables */
  
  GC_API GC_word GC_gc_no;/* Counter incremented per collection.  	*/
  			/* Includes empty GCs at startup.		*/
  
  GC_API int GC_parallel;	/* GC is parallelized for performance on	*/
  			/* multiprocessors.  Currently set only		*/
  			/* implicitly if collector is built with	*/
  			/* -DPARALLEL_MARK and if either:		*/
  			/*  Env variable GC_NPROC is set to > 1, or	*/
  			/*  GC_NPROC is not set and this is an MP.	*/
  			/* If GC_parallel is set, incremental		*/
  			/* collection is only partially functional,	*/
  			/* and may not be desirable.			*/
  			
  
  /* Public R/W variables */
  
  GC_API GC_PTR (*GC_oom_fn) GC_PROTO((size_t bytes_requested));
  			/* When there is insufficient memory to satisfy */
  			/* an allocation request, we return		*/
  			/* (*GC_oom_fn)().  By default this just	*/
  			/* returns 0.					*/
  			/* If it returns, it must return 0 or a valid	*/
  			/* pointer to a previously allocated heap 	*/
  			/* object.					*/
  
  typedef enum {
  	GC_EVENT_START,
  	GC_EVENT_MARK_START,
  	GC_EVENT_MARK_END,
  	GC_EVENT_RECLAIM_START,
  	GC_EVENT_RECLAIM_END,
  	GC_EVENT_END,
  	GC_EVENT_PRE_STOP_WORLD,
  	GC_EVENT_POST_STOP_WORLD,
  	GC_EVENT_PRE_START_WORLD,
  	GC_EVENT_POST_START_WORLD
  } GCEventType;
  
  GC_API void (*GC_notify_event) GC_PROTO((GCEventType event_type));
  			/* Invoked at specific points during every collection.
  			 */
  			 
  GC_API void (*GC_on_heap_resize) GC_PROTO((size_t new_size));
  			/* Invoked when the heap grows or shrinks        */
  
  GC_API int GC_find_leak;
  			/* Do not actually garbage collect, but simply	*/
  			/* report inaccessible memory that was not	*/
  			/* deallocated with GC_free.  Initial value	*/
  			/* is determined by FIND_LEAK macro.		*/
  
  GC_API int GC_all_interior_pointers;
  			/* Arrange for pointers to object interiors to	*/
  			/* be recognized as valid.  May not be changed	*/
  			/* after GC initialization.			*/
  			/* Initial value is determined by 		*/
  			/* -DALL_INTERIOR_POINTERS.			*/
  			/* Unless DONT_ADD_BYTE_AT_END is defined, this	*/
  			/* also affects whether sizes are increased by	*/
  			/* at least a byte to allow "off the end"	*/
  			/* pointer recognition.				*/
  			/* MUST BE 0 or 1.				*/
  
  GC_API int GC_quiet;	/* Disable statistics output.  Only matters if	*/
  			/* collector has been compiled with statistics	*/
  			/* enabled.  This involves a performance cost,	*/
  			/* and is thus not the default.			*/
  
  GC_API int GC_finalize_on_demand;
  			/* If nonzero, finalizers will only be run in 	*/
  			/* response to an explicit GC_invoke_finalizers	*/
  			/* call.  The default is determined by whether	*/
  			/* the FINALIZE_ON_DEMAND macro is defined	*/
  			/* when the collector is built.			*/
  
  GC_API int GC_java_finalization;
  			/* Mark objects reachable from finalizable 	*/
  			/* objects in a separate postpass.  This makes	*/
  			/* it a bit safer to use non-topologically-	*/
  			/* ordered finalization.  Default value is	*/
  			/* determined by JAVA_FINALIZATION macro.	*/
  
  GC_API void (* GC_finalizer_notifier)(void);
  			/* Invoked by the collector when there are 	*/
  			/* objects to be finalized.  Invoked at most	*/
  			/* once per GC cycle.  Never invoked unless 	*/
  			/* GC_finalize_on_demand is set.		*/
  			/* Typically this will notify a finalization	*/
  			/* thread, which will call GC_invoke_finalizers */
  			/* in response.					*/
  
  GC_API int GC_dont_gc;	/* != 0 ==> Dont collect.  In versions 6.2a1+,	*/
  			/* this overrides explicit GC_gcollect() calls.	*/
  			/* Used as a counter, so that nested enabling	*/
  			/* and disabling work correctly.  Should	*/
  			/* normally be updated with GC_enable() and	*/
  			/* GC_disable() calls.				*/
  			/* Direct assignment to GC_dont_gc is 		*/
  			/* deprecated.					*/
  
  GC_API int GC_dont_expand;
  			/* Dont expand heap unless explicitly requested */
  			/* or forced to.				*/
  
  GC_API int GC_use_entire_heap;
  		/* Causes the nonincremental collector to use the	*/
  		/* entire heap before collecting.  This was the only 	*/
  		/* option for GC versions < 5.0.  This sometimes	*/
  		/* results in more large block fragmentation, since	*/
  		/* very larg blocks will tend to get broken up		*/
  		/* during each GC cycle.  It is likely to result in a	*/
  		/* larger working set, but lower collection		*/
  		/* frequencies, and hence fewer instructions executed	*/
  		/* in the collector.					*/
  
  GC_API int GC_full_freq;    /* Number of partial collections between	*/
  			    /* full collections.  Matters only if	*/
  			    /* GC_incremental is set.			*/
  			    /* Full collections are also triggered if	*/
  			    /* the collector detects a substantial	*/
  			    /* increase in the number of in-use heap	*/
  			    /* blocks.  Values in the tens are now	*/
  			    /* perfectly reasonable, unlike for		*/
  			    /* earlier GC versions.			*/
  			
  GC_API GC_word GC_non_gc_bytes;
  			/* Bytes not considered candidates for collection. */
  			/* Used only to control scheduling of collections. */
  			/* Updated by GC_malloc_uncollectable and GC_free. */
  			/* Wizards only.				   */
  
  GC_API int GC_no_dls;
  			/* Don't register dynamic library data segments. */
  			/* Wizards only.  Should be used only if the	 */
  			/* application explicitly registers all roots.	 */
  			/* In Microsoft Windows environments, this will	 */
  			/* usually also prevent registration of the	 */
  			/* main data segment as part of the root set.	 */
  
  GC_API GC_word GC_free_space_divisor;
  			/* We try to make sure that we allocate at 	*/
  			/* least N/GC_free_space_divisor bytes between	*/
  			/* collections, where N is the heap size plus	*/
  			/* a rough estimate of the root set size.	*/
  			/* Initially, GC_free_space_divisor = 3.	*/
  			/* Increasing its value will use less space	*/
  			/* but more collection time.  Decreasing it	*/
  			/* will appreciably decrease collection time	*/
  			/* at the expense of space.			*/
  			/* GC_free_space_divisor = 1 will effectively	*/
  			/* disable collections.				*/
  
  GC_API GC_word GC_max_retries;
  			/* The maximum number of GCs attempted before	*/
  			/* reporting out of memory after heap		*/
  			/* expansion fails.  Initially 0.		*/
  			
  
  GC_API char *GC_stackbottom;	/* Cool end of user stack.		*/
  				/* May be set in the client prior to	*/
  				/* calling any GC_ routines.  This	*/
  				/* avoids some overhead, and 		*/
  				/* potentially some signals that can 	*/
  				/* confuse debuggers.  Otherwise the	*/
  				/* collector attempts to set it 	*/
  				/* automatically.			*/
  				/* For multithreaded code, this is the	*/
  				/* cold end of the stack for the	*/
  				/* primordial thread.			*/	
  				
  GC_API int GC_dont_precollect;  /* Don't collect as part of 		*/
  				/* initialization.  Should be set only	*/
  				/* if the client wants a chance to	*/
  				/* manually initialize the root set	*/
  				/* before the first collection.		*/
  				/* Interferes with blacklisting.	*/
  				/* Wizards only.			*/
  
  GC_API unsigned long GC_time_limit;
  				/* If incremental collection is enabled, */
  				/* We try to terminate collections	 */
  				/* after this many milliseconds.  Not a	 */
  				/* hard time bound.  Setting this to 	 */
  				/* GC_TIME_UNLIMITED will essentially	 */
  				/* disable incremental collection while  */
  				/* leaving generational collection	 */
  				/* enabled.	 			 */
  #	define GC_TIME_UNLIMITED 999999
  				/* Setting GC_time_limit to this value	 */
  				/* will disable the "pause time exceeded"*/
  				/* tests.				 */
  
  /* Public procedures */
  
  /* Initialize the collector.  This is only required when using thread-local
   * allocation, since unlike the regular allocation routines, GC_local_malloc
   * is not self-initializing.  If you use GC_local_malloc you should arrange
   * to call this somehow (e.g. from a constructor) before doing any allocation.
   * For win32 threads, it needs to be called explicitly.
   */
  GC_API void GC_init GC_PROTO((void));
  
  /*
   * general purpose allocation routines, with roughly malloc calling conv.
   * The atomic versions promise that no relevant pointers are contained
   * in the object.  The nonatomic versions guarantee that the new object
   * is cleared.  GC_malloc_stubborn promises that no changes to the object
   * will occur after GC_end_stubborn_change has been called on the
   * result of GC_malloc_stubborn. GC_malloc_uncollectable allocates an object
   * that is scanned for pointers to collectable objects, but is not itself
   * collectable.  The object is scanned even if it does not appear to
   * be reachable.  GC_malloc_uncollectable and GC_free called on the resulting
   * object implicitly update GC_non_gc_bytes appropriately.
   *
   * Note that the GC_malloc_stubborn support is stubbed out by default
   * starting in 6.0.  GC_malloc_stubborn is an alias for GC_malloc unless
   * the collector is built with STUBBORN_ALLOC defined.
   */
  GC_API GC_PTR GC_malloc GC_PROTO((size_t size_in_bytes));
  GC_API GC_PTR GC_malloc_atomic GC_PROTO((size_t size_in_bytes));
  GC_API GC_PTR GC_malloc_uncollectable GC_PROTO((size_t size_in_bytes));
  GC_API GC_PTR GC_malloc_stubborn GC_PROTO((size_t size_in_bytes));
  
  /* The following is only defined if the library has been suitably	*/
  /* compiled:								*/
  GC_API GC_PTR GC_malloc_atomic_uncollectable GC_PROTO((size_t size_in_bytes));
  
  /* Explicitly deallocate an object.  Dangerous if used incorrectly.     */
  /* Requires a pointer to the base of an object.				*/
  /* If the argument is stubborn, it should not be changeable when freed. */
  /* An object should not be enable for finalization when it is 		*/
  /* explicitly deallocated.						*/
  /* GC_free(0) is a no-op, as required by ANSI C for free.		*/
  GC_API void GC_free GC_PROTO((GC_PTR object_addr));
  
  /*
   * Stubborn objects may be changed only if the collector is explicitly informed.
   * The collector is implicitly informed of coming change when such
   * an object is first allocated.  The following routines inform the
   * collector that an object will no longer be changed, or that it will
   * once again be changed.  Only nonNIL pointer stores into the object
   * are considered to be changes.  The argument to GC_end_stubborn_change
   * must be exacly the value returned by GC_malloc_stubborn or passed to
   * GC_change_stubborn.  (In the second case it may be an interior pointer
   * within 512 bytes of the beginning of the objects.)
   * There is a performance penalty for allowing more than
   * one stubborn object to be changed at once, but it is acceptable to
   * do so.  The same applies to dropping stubborn objects that are still
   * changeable.
   */
  GC_API void GC_change_stubborn GC_PROTO((GC_PTR));
  GC_API void GC_end_stubborn_change GC_PROTO((GC_PTR));
  
  /* Return a pointer to the base (lowest address) of an object given	*/
  /* a pointer to a location within the object.				*/
  /* I.e. map an interior pointer to the corresponding bas pointer.	*/
  /* Note that with debugging allocation, this returns a pointer to the	*/
  /* actual base of the object, i.e. the debug information, not to	*/
  /* the base of the user object.						*/
  /* Return 0 if displaced_pointer doesn't point to within a valid	*/
  /* object.								*/
  /* Note that a deallocated object in the garbage collected heap		*/
  /* may be considered valid, even if it has been deallocated with	*/
  /* GC_free.  								*/
  GC_API GC_PTR GC_base GC_PROTO((GC_PTR displaced_pointer));
  
  /* Given a pointer to the base of an object, return its size in bytes.	*/
  /* The returned size may be slightly larger than what was originally	*/
  /* requested.								*/
  GC_API size_t GC_size GC_PROTO((GC_PTR object_addr));
  
  /* For compatibility with C library.  This is occasionally faster than	*/
  /* a malloc followed by a bcopy.  But if you rely on that, either here	*/
  /* or with the standard C library, your code is broken.  In my		*/
  /* opinion, it shouldn't have been invented, but now we're stuck. -HB	*/
  /* The resulting object has the same kind as the original.		*/
  /* If the argument is stubborn, the result will have changes enabled.	*/
  /* It is an error to have changes enabled for the original object.	*/
  /* Follows ANSI comventions for NULL old_object.			*/
  GC_API GC_PTR GC_realloc
  	GC_PROTO((GC_PTR old_object, size_t new_size_in_bytes));
  				   
  /* Explicitly increase the heap size.	*/
  /* Returns 0 on failure, 1 on success.  */
  GC_API int GC_expand_hp GC_PROTO((size_t number_of_bytes));
  
  /* Limit the heap size to n bytes.  Useful when you're debugging, 	*/
  /* especially on systems that don't handle running out of memory well.	*/
  /* n == 0 ==> unbounded.  This is the default.				*/
  GC_API void GC_set_max_heap_size GC_PROTO((GC_word n));
  
  /* Inform the collector that a certain section of statically allocated	*/
  /* memory contains no pointers to garbage collected memory.  Thus it 	*/
  /* need not be scanned.  This is sometimes important if the application */
  /* maps large read/write files into the address space, which could be	*/
  /* mistaken for dynamic library data segments on some systems.		*/
  GC_API void GC_exclude_static_roots GC_PROTO((GC_PTR start, GC_PTR finish));
  
  /* Clear the set of root segments.  Wizards only. */
  GC_API void GC_clear_roots GC_PROTO((void));
  
  /* Add a root segment.  Wizards only. */
  GC_API void GC_add_roots GC_PROTO((char * low_address,
  				   char * high_address_plus_1));
  
  /* Remove a root segment.  Wizards only. */
  GC_API void GC_remove_roots GC_PROTO((char * low_address, 
      char * high_address_plus_1));
  
  /* Add a displacement to the set of those considered valid by the	*/
  /* collector.  GC_register_displacement(n) means that if p was returned */
  /* by GC_malloc, then (char *)p + n will be considered to be a valid	*/
  /* pointer to p.  N must be small and less than the size of p.		*/
  /* (All pointers to the interior of objects from the stack are		*/
  /* considered valid in any case.  This applies to heap objects and	*/
  /* static data.)							*/
  /* Preferably, this should be called before any other GC procedures.	*/
  /* Calling it later adds to the probability of excess memory		*/
  /* retention.								*/
  /* This is a no-op if the collector has recognition of			*/
  /* arbitrary interior pointers enabled, which is now the default.	*/
  GC_API void GC_register_displacement GC_PROTO((GC_word n));
  
  /* The following version should be used if any debugging allocation is	*/
  /* being done.								*/
  GC_API void GC_debug_register_displacement GC_PROTO((GC_word n));
  
  /* Explicitly trigger a full, world-stop collection. 	*/
  GC_API void GC_gcollect GC_PROTO((void));
  
  /* Trigger a full world-stopped collection.  Abort the collection if 	*/
  /* and when stop_func returns a nonzero value.  Stop_func will be 	*/
  /* called frequently, and should be reasonably fast.  This works even	*/
  /* if virtual dirty bits, and hence incremental collection is not 	*/
  /* available for this architecture.  Collections can be aborted faster	*/
  /* than normal pause times for incremental collection.  However,	*/
  /* aborted collections do no useful work; the next collection needs	*/
  /* to start from the beginning.						*/
  /* Return 0 if the collection was aborted, 1 if it succeeded.		*/
  typedef int (* GC_stop_func) GC_PROTO((void));
  GC_API int GC_try_to_collect GC_PROTO((GC_stop_func stop_func));
  
  /* Return the number of bytes in the heap.  Excludes collector private	*/
  /* data structures.  Includes empty blocks and fragmentation loss.	*/
  /* Includes some pages that were allocated but never written.		*/
  GC_API size_t GC_get_heap_size GC_PROTO((void));
  
  /* Return a lower bound on the number of free bytes in the heap.	*/
  GC_API size_t GC_get_free_bytes GC_PROTO((void));
  
  /* Return the number of bytes allocated since the last collection.	*/
  GC_API size_t GC_get_bytes_since_gc GC_PROTO((void));
  
  /* Return the total number of bytes allocated in this process.		*/
  /* Never decreases, except due to wrapping.				*/
  GC_API size_t GC_get_total_bytes GC_PROTO((void));
  
  /* Return the signal used by the gc to suspend threads on posix platforms. */
  /* Return -1 otherwise. */
  int GC_get_suspend_signal GC_PROTO((void));
  
  /* Disable garbage collection.  Even GC_gcollect calls will be 		*/
  /* ineffective.								*/
  GC_API void GC_disable GC_PROTO((void));
  
  /* Reenable garbage collection.  GC_disable() and GC_enable() calls 	*/
  /* nest.  Garbage collection is enabled if the number of calls to both	*/
  /* both functions is equal.						*/
  GC_API void GC_enable GC_PROTO((void));
  
  /* Enable incremental/generational collection.	*/
  /* Not advisable unless dirty bits are 		*/
  /* available or most heap objects are		*/
  /* pointerfree(atomic) or immutable.		*/
  /* Don't use in leak finding mode.		*/
  /* Ignored if GC_dont_gc is true.		*/
  /* Only the generational piece of this is	*/
  /* functional if GC_parallel is TRUE		*/
  /* or if GC_time_limit is GC_TIME_UNLIMITED.	*/
  /* Causes GC_local_gcj_malloc() to revert to	*/
  /* locked allocation.  Must be called 		*/
  /* before any GC_local_gcj_malloc() calls.	*/
  GC_API void GC_enable_incremental GC_PROTO((void));
  
  /* Does incremental mode write-protect pages?  Returns zero or	*/
  /* more of the following, or'ed together:			*/
  #define GC_PROTECTS_POINTER_HEAP  1 /* May protect non-atomic objs.	*/
  #define GC_PROTECTS_PTRFREE_HEAP  2
  #define GC_PROTECTS_STATIC_DATA   4 /* Curently never.			*/
  #define GC_PROTECTS_STACK	  8 /* Probably impractical.		*/
  
  #define GC_PROTECTS_NONE 0
  GC_API int GC_incremental_protection_needs GC_PROTO((void));
  
  /* Perform some garbage collection work, if appropriate.	*/
  /* Return 0 if there is no more work to be done.		*/
  /* Typically performs an amount of work corresponding roughly	*/
  /* to marking from one page.  May do more work if further	*/
  /* progress requires it, e.g. if incremental collection is	*/
  /* disabled.  It is reasonable to call this in a wait loop	*/
  /* until it returns 0.						*/
  GC_API int GC_collect_a_little GC_PROTO((void));
  
  /* Allocate an object of size lb bytes.  The client guarantees that	*/
  /* as long as the object is live, it will be referenced by a pointer	*/
  /* that points to somewhere within the first 256 bytes of the object.	*/
  /* (This should normally be declared volatile to prevent the compiler	*/
  /* from invalidating this assertion.)  This routine is only useful	*/
  /* if a large array is being allocated.  It reduces the chance of 	*/
  /* accidentally retaining such an array as a result of scanning an	*/
  /* integer that happens to be an address inside the array.  (Actually,	*/
  /* it reduces the chance of the allocator not finding space for such	*/
  /* an array, since it will try hard to avoid introducing such a false	*/
  /* reference.)  On a SunOS 4.X or MS Windows system this is recommended */
  /* for arrays likely to be larger than 100K or so.  For other systems,	*/
  /* or if the collector is not configured to recognize all interior	*/
  /* pointers, the threshold is normally much higher.			*/
  GC_API GC_PTR GC_malloc_ignore_off_page GC_PROTO((size_t lb));
  GC_API GC_PTR GC_malloc_atomic_ignore_off_page GC_PROTO((size_t lb));
  
  #if defined(__sgi) && !defined(__GNUC__) && _COMPILER_VERSION >= 720
  #   define GC_ADD_CALLER
  #   define GC_RETURN_ADDR (GC_word)__return_address
  #endif
  
  #ifdef __linux__
  # include <features.h>
  # if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1 || __GLIBC__ > 2) \
       && !defined(__ia64__)
  #   ifndef GC_HAVE_BUILTIN_BACKTRACE
  #     define GC_HAVE_BUILTIN_BACKTRACE
  #   endif
  # endif
  # if defined(__i386__) || defined(__x86_64__)
  #   define GC_CAN_SAVE_CALL_STACKS
  # endif
  #endif
  
  #if defined(GC_HAVE_BUILTIN_BACKTRACE) && !defined(GC_CAN_SAVE_CALL_STACKS)
  # define GC_CAN_SAVE_CALL_STACKS
  #endif
  
  #if defined(__sparc__)
  #   define GC_CAN_SAVE_CALL_STACKS
  #endif
  
  /* If we're on an a platform on which we can't save call stacks, but	*/
  /* gcc is normally used, we go ahead and define GC_ADD_CALLER.  	*/
  /* We make this decision independent of whether gcc is actually being	*/
  /* used, in order to keep the interface consistent, and allow mixing	*/
  /* of compilers.							*/
  /* This may also be desirable if it is possible but expensive to	*/
  /* retrieve the call chain.						*/
  #if (defined(__linux__) || defined(__NetBSD__) || defined(__OpenBSD__) \
       || defined(__FreeBSD__)) & !defined(GC_CAN_SAVE_CALL_STACKS)
  # define GC_ADD_CALLER
  # if __GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95) 
      /* gcc knows how to retrieve return address, but we don't know */
      /* how to generate call stacks.				   */
  #   define GC_RETURN_ADDR (GC_word)__builtin_return_address(0)
  # else
      /* Just pass 0 for gcc compatibility. */
  #   define GC_RETURN_ADDR 0
  # endif
  #endif
  
  #ifdef GC_ADD_CALLER
  #  define GC_EXTRAS GC_RETURN_ADDR, __FILE__, __LINE__
  #  define GC_EXTRA_PARAMS GC_word ra, GC_CONST char * s, int i
  #else
  #  define GC_EXTRAS __FILE__, __LINE__
  #  define GC_EXTRA_PARAMS GC_CONST char * s, int i
  #endif
  
  /* Debugging (annotated) allocation.  GC_gcollect will check 		*/
  /* objects allocated in this way for overwrites, etc.			*/
  GC_API GC_PTR GC_debug_malloc
  	GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
  GC_API GC_PTR GC_debug_malloc_atomic
  	GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
  GC_API GC_PTR GC_debug_malloc_uncollectable
  	GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
  GC_API GC_PTR GC_debug_malloc_stubborn
  	GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
  GC_API GC_PTR GC_debug_malloc_ignore_off_page
  	GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
  GC_API GC_PTR GC_debug_malloc_atomic_ignore_off_page
  	GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
  GC_API void GC_debug_free GC_PROTO((GC_PTR object_addr));
  GC_API GC_PTR GC_debug_realloc
  	GC_PROTO((GC_PTR old_object, size_t new_size_in_bytes,
    		  GC_EXTRA_PARAMS));
  GC_API void GC_debug_change_stubborn GC_PROTO((GC_PTR));
  GC_API void GC_debug_end_stubborn_change GC_PROTO((GC_PTR));
  
  /* Routines that allocate objects with debug information (like the 	*/
  /* above), but just fill in dummy file and line number information.	*/
  /* Thus they can serve as drop-in malloc/realloc replacements.  This	*/
  /* can be useful for two reasons:  					*/
  /* 1) It allows the collector to be built with DBG_HDRS_ALL defined	*/
  /*    even if some allocation calls come from 3rd party libraries	*/
  /*    that can't be recompiled.						*/
  /* 2) On some platforms, the file and line information is redundant,	*/
  /*    since it can be reconstructed from a stack trace.  On such	*/
  /*    platforms it may be more convenient not to recompile, e.g. for	*/
  /*    leak detection.  This can be accomplished by instructing the	*/
  /*    linker to replace malloc/realloc with these.			*/
  GC_API GC_PTR GC_debug_malloc_replacement GC_PROTO((size_t size_in_bytes));
  GC_API GC_PTR GC_debug_realloc_replacement
  	      GC_PROTO((GC_PTR object_addr, size_t size_in_bytes));
    			 	 
  # ifdef GC_DEBUG
  #   define GC_MALLOC(sz) GC_debug_malloc(sz, GC_EXTRAS)
  #   define GC_MALLOC_ATOMIC(sz) GC_debug_malloc_atomic(sz, GC_EXTRAS)
  #   define GC_MALLOC_UNCOLLECTABLE(sz) \
  			GC_debug_malloc_uncollectable(sz, GC_EXTRAS)
  #   define GC_MALLOC_IGNORE_OFF_PAGE(sz) \
  			GC_debug_malloc_ignore_off_page(sz, GC_EXTRAS)
  #   define GC_MALLOC_ATOMIC_IGNORE_OFF_PAGE(sz) \
  			GC_debug_malloc_atomic_ignore_off_page(sz, GC_EXTRAS)
  #   define GC_REALLOC(old, sz) GC_debug_realloc(old, sz, GC_EXTRAS)
  #   define GC_FREE(p) GC_debug_free(p)
  #   define GC_REGISTER_FINALIZER(p, f, d, of, od) \
  	GC_debug_register_finalizer(p, f, d, of, od)
  #   define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \
  	GC_debug_register_finalizer_ignore_self(p, f, d, of, od)
  #   define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \
  	GC_debug_register_finalizer_no_order(p, f, d, of, od)
  #   define GC_MALLOC_STUBBORN(sz) GC_debug_malloc_stubborn(sz, GC_EXTRAS);
  #   define GC_CHANGE_STUBBORN(p) GC_debug_change_stubborn(p)
  #   define GC_END_STUBBORN_CHANGE(p) GC_debug_end_stubborn_change(p)
  #   define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \
  	GC_general_register_disappearing_link(link, GC_base(obj))
  #   define GC_REGISTER_LONG_LINK(link, obj) \
  	GC_register_long_link(link, GC_base(obj))
  #   define GC_REGISTER_DISPLACEMENT(n) GC_debug_register_displacement(n)
  # else
  #   define GC_MALLOC(sz) GC_malloc(sz)
  #   define GC_MALLOC_ATOMIC(sz) GC_malloc_atomic(sz)
  #   define GC_MALLOC_UNCOLLECTABLE(sz) GC_malloc_uncollectable(sz)
  #   define GC_MALLOC_IGNORE_OFF_PAGE(sz) \
  			GC_malloc_ignore_off_page(sz)
  #   define GC_MALLOC_ATOMIC_IGNORE_OFF_PAGE(sz) \
  			GC_malloc_atomic_ignore_off_page(sz)
  #   define GC_REALLOC(old, sz) GC_realloc(old, sz)
  #   define GC_FREE(p) GC_free(p)
  #   define GC_REGISTER_FINALIZER(p, f, d, of, od) \
  	GC_register_finalizer(p, f, d, of, od)
  #   define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \
  	GC_register_finalizer_ignore_self(p, f, d, of, od)
  #   define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \
  	GC_register_finalizer_no_order(p, f, d, of, od)
  #   define GC_MALLOC_STUBBORN(sz) GC_malloc_stubborn(sz)
  #   define GC_CHANGE_STUBBORN(p) GC_change_stubborn(p)
  #   define GC_END_STUBBORN_CHANGE(p) GC_end_stubborn_change(p)
  #   define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \
  	GC_general_register_disappearing_link(link, obj)
  #   define GC_REGISTER_LONG_LINK(link, obj) \
  	GC_register_long_link(link, obj)
  #   define GC_REGISTER_DISPLACEMENT(n) GC_register_displacement(n)
  # endif
  /* The following are included because they are often convenient, and	*/
  /* reduce the chance for a misspecifed size argument.  But calls may	*/
  /* expand to something syntactically incorrect if t is a complicated	*/
  /* type expression.  							*/
  # define GC_NEW(t) (t *)GC_MALLOC(sizeof (t))
  # define GC_NEW_ATOMIC(t) (t *)GC_MALLOC_ATOMIC(sizeof (t))
  # define GC_NEW_STUBBORN(t) (t *)GC_MALLOC_STUBBORN(sizeof (t))
  # define GC_NEW_UNCOLLECTABLE(t) (t *)GC_MALLOC_UNCOLLECTABLE(sizeof (t))
  
  /* Finalization.  Some of these primitives are grossly unsafe.		*/
  /* The idea is to make them both cheap, and sufficient to build		*/
  /* a safer layer, closer to Modula-3, Java, or PCedar finalization.	*/
  /* The interface represents my conclusions from a long discussion	*/
  /* with Alan Demers, Dan Greene, Carl Hauser, Barry Hayes, 		*/
  /* Christian Jacobi, and Russ Atkinson.  It's not perfect, and		*/
  /* probably nobody else agrees with it.	    Hans-J. Boehm  3/13/92	*/
  typedef void (*GC_finalization_proc)
    	GC_PROTO((GC_PTR obj, GC_PTR client_data));
  
  GC_API void GC_register_finalizer
      	GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
  		  GC_finalization_proc *ofn, GC_PTR *ocd));
  GC_API void GC_debug_register_finalizer
      	GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
  		  GC_finalization_proc *ofn, GC_PTR *ocd));
  	/* When obj is no longer accessible, invoke		*/
  	/* (*fn)(obj, cd).  If a and b are inaccessible, and	*/
  	/* a points to b (after disappearing links have been	*/
  	/* made to disappear), then only a will be		*/
  	/* finalized.  (If this does not create any new		*/
  	/* pointers to b, then b will be finalized after the	*/
  	/* next collection.)  Any finalizable object that	*/
  	/* is reachable from itself by following one or more	*/
  	/* pointers will not be finalized (or collected).	*/
  	/* Thus cycles involving finalizable objects should	*/
  	/* be avoided, or broken by disappearing links.		*/
  	/* All but the last finalizer registered for an object  */
  	/* is ignored.						*/
  	/* Finalization may be removed by passing 0 as fn.	*/
  	/* Finalizers are implicitly unregistered just before   */
  	/* they are invoked.					*/
  	/* The old finalizer and client data are stored in	*/
  	/* *ofn and *ocd.					*/ 
  	/* Fn is never invoked on an accessible object,		*/
  	/* provided hidden pointers are converted to real 	*/
  	/* pointers only if the allocation lock is held, and	*/
  	/* such conversions are not performed by finalization	*/
  	/* routines.						*/
  	/* If GC_register_finalizer is aborted as a result of	*/
  	/* a signal, the object may be left with no		*/
  	/* finalization, even if neither the old nor new	*/
  	/* finalizer were NULL.					*/
  	/* Obj should be the nonNULL starting address of an 	*/
  	/* object allocated by GC_malloc or friends.		*/
  	/* Note that any garbage collectable object referenced	*/
  	/* by cd will be considered accessible until the	*/
  	/* finalizer is invoked.				*/
  
  /* Another versions of the above follow.  It ignores		*/
  /* self-cycles, i.e. pointers from a finalizable object to	*/
  /* itself.  There is a stylistic argument that this is wrong,	*/
  /* but it's unavoidable for C++, since the compiler may		*/
  /* silently introduce these.  It's also benign in that specific	*/
  /* case.  And it helps if finalizable objects are split to	*/
  /* avoid cycles.						*/
  /* Note that cd will still be viewed as accessible, even if it	*/
  /* refers to the object itself.					*/
  GC_API void GC_register_finalizer_ignore_self
  	GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
  		  GC_finalization_proc *ofn, GC_PTR *ocd));
  GC_API void GC_debug_register_finalizer_ignore_self
  	GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
  		  GC_finalization_proc *ofn, GC_PTR *ocd));
  
  /* Another version of the above.  It ignores all cycles.        */
  /* It should probably only be used by Java implementations.     */
  /* Note that cd will still be viewed as accessible, even if it	*/
  /* refers to the object itself.					*/
  GC_API void GC_register_finalizer_no_order
  	GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
  		  GC_finalization_proc *ofn, GC_PTR *ocd));
  GC_API void GC_debug_register_finalizer_no_order
  	GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
  		  GC_finalization_proc *ofn, GC_PTR *ocd));
  
  
  /* The following routine may be used to break cycles between	*/
  /* finalizable objects, thus causing cyclic finalizable		*/
  /* objects to be finalized in the correct order.  Standard	*/
  /* use involves calling GC_register_disappearing_link(&p),	*/
  /* where p is a pointer that is not followed by finalization	*/
  /* code, and should not be considered in determining 		*/
  /* finalization order.						*/
  GC_API int GC_register_disappearing_link GC_PROTO((GC_PTR * /* link */));
  	/* Link should point to a field of a heap allocated 	*/
  	/* object obj.  *link will be cleared when obj is	*/
  	/* found to be inaccessible.  This happens BEFORE any	*/
  	/* finalization code is invoked, and BEFORE any		*/
  	/* decisions about finalization order are made.		*/
  	/* This is useful in telling the finalizer that 	*/
  	/* some pointers are not essential for proper		*/
  	/* finalization.  This may avoid finalization cycles.	*/
  	/* Note that obj may be resurrected by another		*/
  	/* finalizer, and thus the clearing of *link may	*/
  	/* be visible to non-finalization code.  		*/
  	/* There's an argument that an arbitrary action should  */
  	/* be allowed here, instead of just clearing a pointer. */
  	/* But this causes problems if that action alters, or 	*/
  	/* examines connectivity.				*/
  	/* Returns 1 if link was already registered, 0		*/
  	/* otherwise.						*/
  	/* Only exists for backward compatibility.  See below:	*/
  	
  GC_API int GC_general_register_disappearing_link
  	GC_PROTO((GC_PTR * /* link */, GC_PTR obj));
  	/* A slight generalization of the above. *link is	*/
  	/* cleared when obj first becomes inaccessible.  This	*/
  	/* can be used to implement weak pointers easily and	*/
  	/* safely. Typically link will point to a location	*/
  	/* holding a disguised pointer to obj.  (A pointer 	*/
  	/* inside an "atomic" object is effectively  		*/
  	/* disguised.)   In this way soft			*/
  	/* pointers are broken before any object		*/
  	/* reachable from them are finalized.  Each link	*/
  	/* May be registered only once, i.e. with one obj	*/
  	/* value.  This was added after a long email discussion */
  	/* with John Ellis.					*/
  	/* Obj must be a pointer to the first word of an object */
  	/* we allocated.  It is unsafe to explicitly deallocate */
  	/* the object containing link.  Explicitly deallocating */
  	/* obj may or may not cause link to eventually be	*/
  	/* cleared.						*/
  GC_API int GC_unregister_disappearing_link GC_PROTO((GC_PTR * /* link */));
  	/* Returns 0 if link was not actually registered.	*/
  	/* Undoes a registration by either of the above two	*/
  	/* routines.						*/
  
  GC_API int GC_register_long_link GC_PROTO((GC_PTR * /* link */, GC_PTR obj));
  GC_API int GC_unregister_long_link GC_PROTO((GC_PTR * /* link */));
  
  /* Returns !=0  if GC_invoke_finalizers has something to do. 		*/
  GC_API int GC_should_invoke_finalizers GC_PROTO((void));
  
  GC_API int GC_invoke_finalizers GC_PROTO((void));
  	/* Run finalizers for all objects that are ready to	*/
  	/* be finalized.  Return the number of finalizers	*/
  	/* that were run.  Normally this is also called		*/
  	/* implicitly during some allocations.	If		*/
  	/* GC-finalize_on_demand is nonzero, it must be called	*/
  	/* explicitly.						*/
  
  /* GC_set_warn_proc can be used to redirect or filter warning messages.	*/
  /* p may not be a NULL pointer.						*/
  typedef void (*GC_warn_proc) GC_PROTO((char *msg, GC_word arg));
  GC_API GC_warn_proc GC_set_warn_proc GC_PROTO((GC_warn_proc p));
      /* Returns old warning procedure.	*/
  
  GC_API GC_word GC_set_free_space_divisor GC_PROTO((GC_word value));
      /* Set free_space_divisor.  See above for definition.	*/
      /* Returns old value.					*/
  	
  /* The following is intended to be used by a higher level	*/
  /* (e.g. Java-like) finalization facility.  It is expected	*/
  /* that finalization code will arrange for hidden pointers to	*/
  /* disappear.  Otherwise objects can be accessed after they	*/
  /* have been collected.						*/
  /* Note that putting pointers in atomic objects or in 		*/
  /* nonpointer slots of "typed" objects is equivalent to 	*/
  /* disguising them in this way, and may have other advantages.	*/
  # if defined(I_HIDE_POINTERS) || defined(GC_I_HIDE_POINTERS)
      typedef GC_word GC_hidden_pointer;
  #   define HIDE_POINTER(p) (~(GC_hidden_pointer)(p))
  #   define REVEAL_POINTER(p) ((GC_PTR)(HIDE_POINTER(p)))
      /* Converting a hidden pointer to a real pointer requires verifying	*/
      /* that the object still exists.  This involves acquiring the  	*/
      /* allocator lock to avoid a race with the collector.		*/
  # endif /* I_HIDE_POINTERS */
  
  typedef GC_PTR (*GC_fn_type) GC_PROTO((GC_PTR client_data));
  GC_API GC_PTR GC_call_with_alloc_lock
          	GC_PROTO((GC_fn_type fn, GC_PTR client_data));
  
  /* The following routines are primarily intended for use with a 	*/
  /* preprocessor which inserts calls to check C pointer arithmetic.	*/
  /* They indicate failure by invoking the corresponding _print_proc.	*/
  
  /* Check that p and q point to the same object.  		*/
  /* Fail conspicuously if they don't.				*/
  /* Returns the first argument.  				*/
  /* Succeeds if neither p nor q points to the heap.		*/
  /* May succeed if both p and q point to between heap objects.	*/
  GC_API GC_PTR GC_same_obj GC_PROTO((GC_PTR p, GC_PTR q));
  
  /* Checked pointer pre- and post- increment operations.  Note that	*/
  /* the second argument is in units of bytes, not multiples of the	*/
  /* object size.  This should either be invoked from a macro, or the	*/
  /* call should be automatically generated.				*/
  GC_API GC_PTR GC_pre_incr GC_PROTO((GC_PTR *p, size_t how_much));
  GC_API GC_PTR GC_post_incr GC_PROTO((GC_PTR *p, size_t how_much));
  
  /* Check that p is visible						*/
  /* to the collector as a possibly pointer containing location.		*/
  /* If it isn't fail conspicuously.					*/
  /* Returns the argument in all cases.  May erroneously succeed		*/
  /* in hard cases.  (This is intended for debugging use with		*/
  /* untyped allocations.  The idea is that it should be possible, though	*/
  /* slow, to add such a call to all indirect pointer stores.)		*/
  /* Currently useless for multithreaded worlds.				*/
  GC_API GC_PTR GC_is_visible GC_PROTO((GC_PTR p));
  
  /* Check that if p is a pointer to a heap page, then it points to	*/
  /* a valid displacement within a heap object.				*/
  /* Fail conspicuously if this property does not hold.			*/
  /* Uninteresting with GC_all_interior_pointers.				*/
  /* Always returns its argument.						*/
  GC_API GC_PTR GC_is_valid_displacement GC_PROTO((GC_PTR	p));
  
  /* Returns 1 if the calling thread is registered with the GC, 0 otherwise */
  GC_API int GC_thread_is_registered GC_PROTO((void));
  
  /* Notify the collector about the stack and the altstack of the current thread */
  /* STACK/STACK_SIZE is used to determine the stack dimensions when a thread is
   * suspended while it is on an altstack.
   */
  GC_API void GC_register_altstack GC_PROTO((void *stack, int stack_size, void *altstack, int altstack_size));
  
  /* Safer, but slow, pointer addition.  Probably useful mainly with 	*/
  /* a preprocessor.  Useful only for heap pointers.			*/
  #ifdef GC_DEBUG
  #   define GC_PTR_ADD3(x, n, type_of_result) \
  	((type_of_result)GC_same_obj((x)+(n), (x)))
  #   define GC_PRE_INCR3(x, n, type_of_result) \
  	((type_of_result)GC_pre_incr(&(x), (n)*sizeof(*x))
  #   define GC_POST_INCR2(x, type_of_result) \
  	((type_of_result)GC_post_incr(&(x), sizeof(*x))
  #   ifdef __GNUC__
  #       define GC_PTR_ADD(x, n) \
  	    GC_PTR_ADD3(x, n, typeof(x))
  #       define GC_PRE_INCR(x, n) \
  	    GC_PRE_INCR3(x, n, typeof(x))
  #       define GC_POST_INCR(x, n) \
  	    GC_POST_INCR3(x, typeof(x))
  #   else
  	/* We can't do this right without typeof, which ANSI	*/
  	/* decided was not sufficiently useful.  Repeatedly	*/
  	/* mentioning the arguments seems too dangerous to be	*/
  	/* useful.  So does not casting the result.		*/
  #   	define GC_PTR_ADD(x, n) ((x)+(n))
  #   endif
  #else	/* !GC_DEBUG */
  #   define GC_PTR_ADD3(x, n, type_of_result) ((x)+(n))
  #   define GC_PTR_ADD(x, n) ((x)+(n))
  #   define GC_PRE_INCR3(x, n, type_of_result) ((x) += (n))
  #   define GC_PRE_INCR(x, n) ((x) += (n))
  #   define GC_POST_INCR2(x, n, type_of_result) ((x)++)
  #   define GC_POST_INCR(x, n) ((x)++)
  #endif
  
  /* Safer assignment of a pointer to a nonstack location.	*/
  #ifdef GC_DEBUG
  # if defined(__STDC__) || defined(_AIX)
  #   define GC_PTR_STORE(p, q) \
  	(*(void **)GC_is_visible(p) = GC_is_valid_displacement(q))
  # else
  #   define GC_PTR_STORE(p, q) \
  	(*(char **)GC_is_visible(p) = GC_is_valid_displacement(q))
  # endif
  #else /* !GC_DEBUG */
  #   define GC_PTR_STORE(p, q) *((p) = (q))
  #endif
  
  /* Functions called to report pointer checking errors */
  GC_API void (*GC_same_obj_print_proc) GC_PROTO((GC_PTR p, GC_PTR q));
  
  GC_API void (*GC_is_valid_displacement_print_proc)
  	GC_PROTO((GC_PTR p));
  
  GC_API void (*GC_is_visible_print_proc)
  	GC_PROTO((GC_PTR p));
  
  /* For pthread support, we generally need to intercept a number of 	*/
  /* thread library calls.  We do that here by macro defining them.	*/
  
  #if !defined(GC_USE_LD_WRAP) && \
      (defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS) || defined(GC_DARWIN_THREADS) || defined(GC_MACOSX_THREADS))
  #if defined(_IN_LIBGC) || defined(USE_INCLUDED_LIBGC)
  # include "gc_pthread_redirects.h"
  #else
  # include <gc/gc_pthread_redirects.h>
  #endif
  #endif
  
  # if defined(PCR) || defined(GC_SOLARIS_THREADS) || \
       defined(GC_PTHREADS) || defined(GC_WIN32_THREADS)
     	/* Any flavor of threads except SRC_M3.	*/
  /* This returns a list of objects, linked through their first		*/
  /* word.  Its use can greatly reduce lock contention problems, since	*/
  /* the allocation lock can be acquired and released many fewer times.	*/
  /* lb must be large enough to hold the pointer field.			*/
  /* It is used internally by gc_local_alloc.h, which provides a simpler	*/
  /* programming interface on Linux.					*/
  GC_PTR GC_malloc_many(size_t lb);
  #define GC_NEXT(p) (*(GC_PTR *)(p)) 	/* Retrieve the next element	*/
  					/* in returned list.		*/
  extern void GC_thr_init(void);	/* Needed for Solaris/X86	*/
  
  #endif /* THREADS && !SRC_M3 */
  
  #if defined(GC_WIN32_THREADS) && !defined(__CYGWIN32__) && !defined(__CYGWIN__)
  # include <windows.h>
  
     BOOL WINAPI GC_DllMain(HINSTANCE inst, ULONG reason, LPVOID reserved);
  
    /*
     * All threads must be created using GC_CreateThread, so that they will be
     * recorded in the thread table.  For backwards compatibility, this is not
     * technically true if the GC is built as a dynamic library, since it can
     * and does then use DllMain to keep track of thread creations.  But new code
     * should be built to call GC_CreateThread.
     */
     GC_API HANDLE WINAPI GC_CreateThread(
        LPSECURITY_ATTRIBUTES lpThreadAttributes,
        DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress,
        LPVOID lpParameter, DWORD dwCreationFlags, LPDWORD lpThreadId );
  
  # if defined(_WIN32_WCE)
    /*
     * win32_threads.c implements the real WinMain, which will start a new thread
     * to call GC_WinMain after initializing the garbage collector.
     */
    int WINAPI GC_WinMain(
        HINSTANCE hInstance,
        HINSTANCE hPrevInstance,
        LPWSTR lpCmdLine,
        int nCmdShow );
  
  #  ifndef GC_BUILD
  #    define WinMain GC_WinMain
  #    define CreateThread GC_CreateThread
  #  endif
  # endif /* defined(_WIN32_WCE) */
  
  #endif /* defined(GC_WIN32_THREADS)  && !cygwin */
  
   /*
    * Fully portable code should call GC_INIT() from the main program
    * before making any other GC_ calls.  On most platforms this is a
    * no-op and the collector self-initializes.  But a number of platforms
    * make that too hard.
    */
  #if (defined(sparc) || defined(__sparc)) && defined(sun)
      /*
       * If you are planning on putting
       * the collector in a SunOS 5 dynamic library, you need to call GC_INIT()
       * from the statically loaded program section.
       * This circumvents a Solaris 2.X (X<=4) linker bug.
       */
  #   define GC_INIT() { extern end, etext; \
  		       GC_noop(&end, &etext); }
  #else
  # if defined(__CYGWIN32__) || defined (_AIX)
      /*
       * Similarly gnu-win32 DLLs need explicit initialization from
       * the main program, as does AIX.
       */
  #   ifdef __CYGWIN32__
        extern int _data_start__[];
        extern int _data_end__[];
        extern int _bss_start__[];
        extern int _bss_end__[];
  #     define GC_MAX(x,y) ((x) > (y) ? (x) : (y))
  #     define GC_MIN(x,y) ((x) < (y) ? (x) : (y))
  #     define GC_DATASTART ((GC_PTR) GC_MIN(_data_start__, _bss_start__))
  #     define GC_DATAEND	 ((GC_PTR) GC_MAX(_data_end__, _bss_end__))
  #     ifdef GC_DLL
  #       define GC_INIT() { GC_add_roots(GC_DATASTART, GC_DATAEND); }
  #     else
  #       define GC_INIT()
  #     endif
  #   endif
  #   if defined(_AIX)
        extern int _data[], _end[];
  #     define GC_DATASTART ((GC_PTR)((ulong)_data))
  #     define GC_DATAEND ((GC_PTR)((ulong)_end))
  #     define GC_INIT() { GC_add_roots(GC_DATASTART, GC_DATAEND); }
  #   endif
  # else
  #  if defined(__APPLE__) && defined(__MACH__) || defined(GC_WIN32_THREADS)
  #   define GC_INIT() { GC_init(); }
  #  else
  #   define GC_INIT()
  #  endif /* !__MACH && !GC_WIN32_THREADS */
  # endif /* !AIX && !cygwin */
  #endif /* !sparc */
  
  #if !defined(_WIN32_WCE) \
      && ((defined(_MSDOS) || defined(_MSC_VER)) && (_M_IX86 >= 300) \
          || defined(_WIN32) && !defined(__CYGWIN32__) && !defined(__CYGWIN__))
    /* win32S may not free all resources on process exit.  */
    /* This explicitly deallocates the heap.		 */
      GC_API void GC_win32_free_heap ();
  #endif
  
  #if ( defined(_AMIGA) && !defined(GC_AMIGA_MAKINGLIB) )
    /* Allocation really goes through GC_amiga_allocwrapper_do */
  # include "gc_amiga_redirects.h"
  #endif
  
  #if defined(GC_REDIRECT_TO_LOCAL) && !defined(GC_LOCAL_ALLOC_H)
  #  include  "gc_local_alloc.h"
  #endif
  
  #ifdef __cplusplus
      }  /* end of extern "C" */
  #endif
  
  #endif /* _GC_H */
  