diff --git a/configure.ac b/configure.ac
index cd3a9bc3daf..ef6ddc66d4d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1589,6 +1589,7 @@ fi
 
 dnl checks for header files
 AC_CHECK_HEADERS_ONCE(
+  malloc.h
   sys/systeminfo.h
   sys/sysinfo.h
   coff.h pty.h
diff --git a/src/alloc.c b/src/alloc.c
index 617148e85e5..039b7285e39 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -59,6 +59,10 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "dosfns.h"		/* For dos_memory_info.  */
 #endif
 
+#ifdef HAVE_MALLOC_H
+# include <malloc.h>
+#endif
+
 #if (defined ENABLE_CHECKING			\
      && defined HAVE_VALGRIND_VALGRIND_H	\
      && !defined USE_VALGRIND)
@@ -107,8 +111,6 @@ my_heap_start (void)
 
 #ifdef DOUG_LEA_MALLOC
 
-#include <malloc.h>
-
 /* Specify maximum number of areas to mmap.  It would be nice to use a
    value that explicitly means "no limit".  */
 
diff --git a/src/conf_post.h b/src/conf_post.h
index 9f4becdfd7c..c5eec5acb6d 100644
--- a/src/conf_post.h
+++ b/src/conf_post.h
@@ -99,7 +99,6 @@ typedef bool bool_bf;
 #ifdef emacs
 #define malloc hybrid_malloc
 #define realloc hybrid_realloc
-#define calloc hybrid_calloc
 #define aligned_alloc hybrid_aligned_alloc
 #define free hybrid_free
 #endif
diff --git a/src/emacs.c b/src/emacs.c
index 7cfc91ee9e0..de770a6d7f5 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -134,8 +134,6 @@ bool might_dump;
 extern void unexec_init_emacs_zone (void);
 #endif
 
-extern void malloc_enable_thread (void);
-
 /* If true, Emacs should not attempt to use a window-specific code,
    but instead should use the virtual terminal under which it was started.  */
 bool inhibit_window_system;
diff --git a/src/gmalloc.c b/src/gmalloc.c
index 4fd324686ba..4feff83a2d1 100644
--- a/src/gmalloc.c
+++ b/src/gmalloc.c
@@ -25,6 +25,7 @@ License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 #define USE_PTHREAD
 #endif
 
+#include <stddef.h>
 #include <string.h>
 #include <limits.h>
 #include <stdint.h>
@@ -38,6 +39,26 @@ License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 #include <w32heap.h>	/* for sbrk */
 #endif
 
+#ifdef emacs
+# include "lisp.h"
+#endif
+
+#ifdef HAVE_MALLOC_H
+# if 4 < __GNUC__ + (2 <= __GNUC_MINOR__)
+#  pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+# endif
+# include <malloc.h>
+#endif
+#ifndef __MALLOC_HOOK_VOLATILE
+# define __MALLOC_HOOK_VOLATILE volatile
+#endif
+#ifndef HAVE_MALLOC_H
+extern void (*__MALLOC_HOOK_VOLATILE __after_morecore_hook) (void);
+extern void (*__MALLOC_HOOK_VOLATILE __malloc_initialize_hook) (void);
+extern void *(*__morecore) (ptrdiff_t);
+extern void *__default_morecore (ptrdiff_t);
+#endif
+
 /* If HYBRID_MALLOC is defined, then temacs will use malloc,
    realloc... as defined in this file (and renamed gmalloc,
    grealloc... via the macros that follow).  The dumped emacs,
@@ -58,9 +79,10 @@ License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 #undef free
 #define malloc gmalloc
 #define realloc grealloc
-#define calloc gcalloc
+#define calloc do_not_call_me /* Emacs never calls calloc.  */
 #define aligned_alloc galigned_alloc
 #define free gfree
+#define malloc_info gmalloc_info
 
 #ifdef HYBRID_MALLOC
 # include "sheap.h"
@@ -77,15 +99,6 @@ extern "C"
 {
 #endif
 
-#include <stddef.h>
-
-/* Underlying allocation function; successive calls should
-   return contiguous pieces of memory.  */
-extern void *(*__morecore) (ptrdiff_t size);
-
-/* Default value of `__morecore'.  */
-extern void *__default_morecore (ptrdiff_t size);
-
 #ifdef HYBRID_MALLOC
 #define extern static
 #endif
@@ -95,9 +108,7 @@ extern void *malloc (size_t size) ATTRIBUTE_MALLOC_SIZE ((1));
 /* Re-allocate the previously allocated block
    in ptr, making the new block SIZE bytes long.  */
 extern void *realloc (void *ptr, size_t size) ATTRIBUTE_ALLOC_SIZE ((2));
-/* Allocate NMEMB elements of SIZE bytes each, all initialized to 0.  */
-extern void *calloc (size_t nmemb, size_t size) ATTRIBUTE_MALLOC_SIZE ((1,2));
-/* Free a block allocated by `malloc', `realloc' or `calloc'.  */
+/* Free a block.  */
 extern void free (void *ptr);
 
 /* Allocate SIZE bytes allocated to ALIGNMENT bytes.  */
@@ -107,11 +118,6 @@ extern void *memalign (size_t, size_t);
 extern int posix_memalign (void **, size_t, size_t);
 #endif
 
-#ifdef USE_PTHREAD
-/* Set up mutexes and make malloc etc. thread-safe.  */
-extern void malloc_enable_thread (void);
-#endif
-
 /* The allocator divides the heap into blocks of fixed size; large
    requests receive one or more whole blocks, and small requests
    receive a fragment of a block.  Fragment sizes are powers of two,
@@ -243,26 +249,11 @@ extern int _malloc_thread_enabled_p;
 #define UNLOCK_ALIGNED_BLOCKS()
 #endif
 
-/* If not NULL, this function is called after each time
-   `__morecore' is called to increase the data size.  */
-extern void (*__after_morecore_hook) (void);
-
-/* Number of extra blocks to get each time we ask for more core.
-   This reduces the frequency of calling `(*__morecore)'.  */
-extern size_t __malloc_extra_blocks;
-
 /* Nonzero if `malloc' has been called and done its initialization.  */
 extern int __malloc_initialized;
 /* Function called to initialize malloc data structures.  */
 extern int __malloc_initialize (void);
 
-/* Hooks for debugging versions.  */
-extern void (*__malloc_initialize_hook) (void);
-extern void (*__free_hook) (void *ptr);
-extern void *(*__malloc_hook) (size_t size);
-extern void *(*__realloc_hook) (void *ptr, size_t size);
-extern void *(*__memalign_hook) (size_t size, size_t alignment);
-
 #ifdef GC_MCHECK
 
 /* Return values for `mprobe': these are the kinds of inconsistencies that
@@ -304,9 +295,6 @@ struct mstats
 /* Pick up the current statistics. */
 extern struct mstats mstats (void);
 
-/* Call WARNFUN with a warning message when memory usage is high.  */
-extern void memory_warnings (void *start, void (*warnfun) (const char *));
-
 #endif
 
 #undef extern
@@ -337,13 +325,11 @@ License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <errno.h>
 
-void *(*__morecore) (ptrdiff_t size) = __default_morecore;
+/* Debugging hook for 'malloc'.  */
+static void *(*__MALLOC_HOOK_VOLATILE gmalloc_hook) (size_t);
 
 #ifndef HYBRID_MALLOC
 
-/* Debugging hook for `malloc'.  */
-void *(*__malloc_hook) (size_t size);
-
 /* Pointer to the base of the first block.  */
 char *_heapbase;
 
@@ -368,10 +354,9 @@ size_t _bytes_free;
 /* Are you experienced?  */
 int __malloc_initialized;
 
-size_t __malloc_extra_blocks;
-
-void (*__malloc_initialize_hook) (void);
-void (*__after_morecore_hook) (void);
+void (*__MALLOC_HOOK_VOLATILE __malloc_initialize_hook) (void);
+void (*__MALLOC_HOOK_VOLATILE __after_morecore_hook) (void);
+void *(*__morecore) (ptrdiff_t);
 
 #else
 
@@ -379,6 +364,13 @@ static struct list _fraghead[BLOCKLOG];
 
 #endif /* HYBRID_MALLOC */
 
+/* Number of extra blocks to get each time we ask for more core.
+   This reduces the frequency of calling `(*__morecore)'.  */
+#if defined DOUG_LEA_MALLOC || defined HYBRID_MALLOC || defined SYSTEM_MALLOC
+static
+#endif
+size_t __malloc_extra_blocks;
+
 /* Number of info entries.  */
 static size_t heapsize;
 
@@ -935,15 +927,15 @@ malloc (size_t size)
   if (!__malloc_initialized && !__malloc_initialize ())
     return NULL;
 
-  /* Copy the value of __malloc_hook to an automatic variable in case
-     __malloc_hook is modified in another thread between its
+  /* Copy the value of gmalloc_hook to an automatic variable in case
+     gmalloc_hook is modified in another thread between its
      NULL-check and the use.
 
      Note: Strictly speaking, this is not a right solution.  We should
      use mutexes to access non-read-only variables that are shared
      among multiple threads.  We just leave it for compatibility with
-     glibc malloc (i.e., assignments to __malloc_hook) for now.  */
-  hook = __malloc_hook;
+     glibc malloc (i.e., assignments to gmalloc_hook) for now.  */
+  hook = gmalloc_hook;
   return (hook != NULL ? *hook : _malloc_internal) (size);
 }
 
@@ -995,10 +987,10 @@ License along with this library.  If not, see <http://www.gnu.org/licenses/>.
    The author may be reached (Email) at the address mike@ai.mit.edu,
    or (US mail) as Mike Haertel c/o Free Software Foundation.  */
 
+/* Debugging hook for free.  */
+static void (*__MALLOC_HOOK_VOLATILE gfree_hook) (void *);
 
 #ifndef HYBRID_MALLOC
-/* Debugging hook for free.  */
-void (*__free_hook) (void *__ptr);
 
 /* List of blocks allocated by aligned_alloc.  */
 struct alignlist *_aligned_blocks = NULL;
@@ -1251,7 +1243,7 @@ _free_internal_nolock (void *ptr)
 }
 
 /* Return memory to the heap.
-   Like `free' but don't call a __free_hook if there is one.  */
+   Like 'free' but don't call a hook if there is one.  */
 void
 _free_internal (void *ptr)
 {
@@ -1265,7 +1257,7 @@ _free_internal (void *ptr)
 void
 free (void *ptr)
 {
-  void (*hook) (void *) = __free_hook;
+  void (*hook) (void *) = gfree_hook;
 
   if (hook != NULL)
     (*hook) (ptr);
@@ -1309,10 +1301,8 @@ License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 #define min(a, b) ((a) < (b) ? (a) : (b))
 #endif
 
-#ifndef HYBRID_MALLOC
 /* Debugging hook for realloc.  */
-void *(*__realloc_hook) (void *ptr, size_t size);
-#endif
+static void *(*grealloc_hook) (void *, size_t);
 
 /* Resize the given region to the new size, returning a pointer
    to the (possibly moved) region.  This is optimized for speed;
@@ -1456,7 +1446,7 @@ realloc (void *ptr, size_t size)
   if (!__malloc_initialized && !__malloc_initialize ())
     return NULL;
 
-  hook = __realloc_hook;
+  hook = grealloc_hook;
   return (hook != NULL ? *hook : _realloc_internal) (ptr, size);
 }
 /* Copyright (C) 1991, 1992, 1994 Free Software Foundation, Inc.
@@ -1479,6 +1469,7 @@ License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 
 /* Allocate an array of NMEMB elements each SIZE bytes long.
    The entire array is initialized to zeros.  */
+#ifndef calloc
 void *
 calloc (size_t nmemb, size_t size)
 {
@@ -1496,6 +1487,7 @@ calloc (size_t nmemb, size_t size)
     return memset (result, 0, bytes);
   return result;
 }
+#endif
 /* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
 This file is part of the GNU C Library.
 
@@ -1541,6 +1533,9 @@ __default_morecore (ptrdiff_t increment)
     return NULL;
   return result;
 }
+
+void *(*__morecore) (ptrdiff_t) = __default_morecore;
+
 /* Copyright (C) 1991, 92, 93, 94, 95, 96 Free Software Foundation, Inc.
 
 This library is free software; you can redistribute it and/or
@@ -1556,19 +1551,11 @@ General Public License for more details.
 You should have received a copy of the GNU General Public
 License along with this library.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#ifndef HYBRID_MALLOC
-void *(*__memalign_hook) (size_t size, size_t alignment);
-#endif
-
 void *
 aligned_alloc (size_t alignment, size_t size)
 {
   void *result;
   size_t adj, lastadj;
-  void *(*hook) (size_t, size_t) = __memalign_hook;
-
-  if (hook)
-    return (*hook) (alignment, size);
 
   /* Allocate a block with enough extra space to pad the block with up to
      (ALIGNMENT - 1) bytes if necessary.  */
@@ -1731,7 +1718,6 @@ valloc (size_t size)
 /* Declare system malloc and friends.  */
 extern void *malloc (size_t size);
 extern void *realloc (void *ptr, size_t size);
-extern void *calloc (size_t nmemb, size_t size);
 extern void free (void *ptr);
 #ifdef HAVE_ALIGNED_ALLOC
 extern void *aligned_alloc (size_t alignment, size_t size);
@@ -1750,14 +1736,6 @@ hybrid_malloc (size_t size)
   return gmalloc (size);
 }
 
-void *
-hybrid_calloc (size_t nmemb, size_t size)
-{
-  if (DUMPED)
-    return calloc (nmemb, size);
-  return gcalloc (nmemb, size);
-}
-
 void
 hybrid_free (void *ptr)
 {
@@ -1947,9 +1925,9 @@ freehook (void *ptr)
   else
     hdr = NULL;
 
-  __free_hook = old_free_hook;
+  gfree_hook = old_free_hook;
   free (hdr);
-  __free_hook = freehook;
+  gfree_hook = freehook;
 }
 
 static void *
@@ -1957,9 +1935,9 @@ mallochook (size_t size)
 {
   struct hdr *hdr;
 
-  __malloc_hook = old_malloc_hook;
+  gmalloc_hook = old_malloc_hook;
   hdr = malloc (sizeof *hdr + size + 1);
-  __malloc_hook = mallochook;
+  gmalloc_hook = mallochook;
   if (hdr == NULL)
     return NULL;
 
@@ -1985,13 +1963,13 @@ reallochook (void *ptr, size_t size)
 	memset ((char *) ptr + size, FREEFLOOD, osize - size);
     }
 
-  __free_hook = old_free_hook;
-  __malloc_hook = old_malloc_hook;
-  __realloc_hook = old_realloc_hook;
+  gfree_hook = old_free_hook;
+  gmalloc_hook = old_malloc_hook;
+  grealloc_hook = old_realloc_hook;
   hdr = realloc (hdr, sizeof *hdr + size + 1);
-  __free_hook = freehook;
-  __malloc_hook = mallochook;
-  __realloc_hook = reallochook;
+  gfree_hook = freehook;
+  gmalloc_hook = mallochook;
+  grealloc_hook = reallochook;
   if (hdr == NULL)
     return NULL;
 
@@ -2048,12 +2026,12 @@ mcheck (void (*func) (enum mcheck_status))
   /* These hooks may not be safely inserted if malloc is already in use.  */
   if (!__malloc_initialized && !mcheck_used)
     {
-      old_free_hook = __free_hook;
-      __free_hook = freehook;
-      old_malloc_hook = __malloc_hook;
-      __malloc_hook = mallochook;
-      old_realloc_hook = __realloc_hook;
-      __realloc_hook = reallochook;
+      old_free_hook = gfree_hook;
+      gfree_hook = freehook;
+      old_malloc_hook = gmalloc_hook;
+      gmalloc_hook = mallochook;
+      old_realloc_hook = grealloc_hook;
+      grealloc_hook = reallochook;
       mcheck_used = 1;
     }
 
diff --git a/src/lisp.h b/src/lisp.h
index 3c8e3ddb137..4f4ec2c5fcc 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3769,6 +3769,12 @@ extern void check_cons_list (void);
 INLINE void (check_cons_list) (void) { lisp_h_check_cons_list (); }
 #endif
 
+#if !defined DOUG_LEA_MALLOC && !defined HYBRID_MALLOC && !defined SYSTEM_MALLOC
+/* Defined in gmalloc.c.  */
+extern size_t __malloc_extra_blocks;
+#endif
+extern void malloc_enable_thread (void);
+
 #ifdef REL_ALLOC
 /* Defined in ralloc.c.  */
 extern void *r_alloc (void **, size_t) ATTRIBUTE_ALLOC_SIZE ((2));
diff --git a/src/ralloc.c b/src/ralloc.c
index 12d2fa9ab50..d1a9e01652e 100644
--- a/src/ralloc.c
+++ b/src/ralloc.c
@@ -22,31 +22,15 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    rather than all of them.  This means allowing for a possible
    hole between the first bloc and the end of malloc storage.  */
 
-#ifdef emacs
-
 #include <config.h>
 
-#include "lisp.h"		/* Needed for VALBITS.  */
-#include "blockinput.h"
-
-#include <unistd.h>
-
-#ifdef DOUG_LEA_MALLOC
-#define M_TOP_PAD           -2
-extern int mallopt (int, int);
-#else /* not DOUG_LEA_MALLOC */
-#if !defined SYSTEM_MALLOC && !defined HYBRID_MALLOC
-extern size_t __malloc_extra_blocks;
-#endif /* not SYSTEM_MALLOC and not HYBRID_MALLOC */
-#endif /* not DOUG_LEA_MALLOC */
-
-#else /* not emacs */
-
 #include <stddef.h>
-#include <malloc.h>
-
-#endif	/* not emacs */
 
+#ifdef emacs
+# include "lisp.h"
+# include "blockinput.h"
+# include <unistd.h>
+#endif
 
 #include "getpagesize.h"
 
@@ -95,7 +79,9 @@ static int extra_bytes;
 /* The hook `malloc' uses for the function which gets more space
    from the system.  */
 
-#if !defined SYSTEM_MALLOC && !defined HYBRID_MALLOC
+#ifdef HAVE_MALLOC_H
+# include <malloc.h>
+#else
 extern void *(*__morecore) (ptrdiff_t);
 #endif
 
diff --git a/src/vm-limit.c b/src/vm-limit.c
index 0c6dbddc4f2..42f04708f94 100644
--- a/src/vm-limit.c
+++ b/src/vm-limit.c
@@ -51,9 +51,16 @@ char data_start[1] = { 1 };
 # endif
 #endif
 
-/* From gmalloc.c.  */
-extern void (* __after_morecore_hook) (void);
+#ifdef HAVE_MALLOC_H
+# include <malloc.h>
+#endif
+#ifndef __MALLOC_HOOK_VOLATILE
+# define __MALLOC_HOOK_VOLATILE volatile
+#endif
+#ifndef HAVE_MALLOC_H
 extern void *(*__morecore) (ptrdiff_t);
+extern void (*__MALLOC_HOOK_VOLATILE __after_morecore_hook) (void);
+#endif
 
 /* From ralloc.c.  */
 #ifdef REL_ALLOC