Clean up memory allocation and unexec support on MS-Windows

* src/w32heap.c (report_temacs_memory_usage): Condition on
!CANNOT_DUMP, in addition to ENABLE_CHECKING.
(init_heap): Accept an argument, which tells us what heap
allocation method to use.
(DUMPED_HEAP_SIZE) [CANNOT_DUMP]: Define to a small value, as
we don't use dumped_data[] in this case.
* src/w32heap.h (init_heap): Adjust prototype.
<using_dynamic_heap>: Remove declaration.
* src/emacs.c (main) [WINDOWSNT]: Determine heap allocation
method based on whether we are in temacs and whether unexec
will be used to dump Emacs.  Pass the heap allocation method
to init_heap, which is now called after parsing the
--temacs=METHOD option.
* src/unexw32.c (unexec): Don't fiddle with using_dynamic_heap.
<using_dynamic_heap>: Remove definition.
* src/w32proc.c (malloc_before_init, realloc_before_init)
(free_before_init): New functions, to catch memory allocation
before heap allocation method is set up.

1 files changed, 34 insertions, 3 deletions

diff --git a/src/w32proc.c b/src/w32proc.c
index a5d08f60117..05e6c46b336 100644
--- a/src/w32proc.c
+++ b/src/w32proc.c
@@ -81,6 +81,36 @@ static sigset_t sig_mask;
 
 static CRITICAL_SECTION crit_sig;
 
+/* Catch memory allocation before the heap allocation scheme is set
+   up.  These functions should never be called, unless code is added
+   early on in 'main' that runs before init_heap is called.  */
+_Noreturn void * malloc_before_init (size_t);
+_Noreturn void * realloc_before_init (void *, size_t);
+_Noreturn void   free_before_init (void *);
+
+_Noreturn void *
+malloc_before_init (size_t size)
+{
+  fprintf (stderr,
+	   "error: 'malloc' called before setting up heap allocation; exiting.\n");
+  exit (-1);
+}
+
+_Noreturn void *
+realloc_before_init (void *ptr, size_t size)
+{
+  fprintf (stderr,
+	   "error: 'realloc' called before setting up heap allocation; exiting.\n");
+  exit (-1);
+}
+
+_Noreturn void
+free_before_init (void *ptr)
+{
+  fprintf (stderr,
+	   "error: 'free' called before setting up heap allocation; exiting.\n");
+  exit (-1);
+}
 
 extern BOOL ctrl_c_handler (unsigned long type);
 
@@ -110,12 +140,13 @@ _start (void)
     DebugBreak ();
 #endif
 
+  the_malloc_fn = malloc_before_init;
+  the_realloc_fn = realloc_before_init;
+  the_free_fn = free_before_init;
+
   /* Cache system info, e.g., the NT page size.  */
   cache_system_info ();
 
-  /* Grab our malloc arena space now, before CRT starts up. */
-  init_heap ();
-
   /* This prevents ctrl-c's in shells running while we're suspended from
      having us exit.  */
   SetConsoleCtrlHandler ((PHANDLER_ROUTINE) ctrl_c_handler, TRUE);