Commit 4a1507b8 authored by Paul Eggert's avatar Paul Eggert

pure_alloc returns cleared memory

* src/alloc.c (pure_alloc): Clear any heap-allocated storage.
This is simpler than auditing all the callers to make sure
they don’t assume pure memory is cleared memory, and the
performance implication is nonexistent except when Emacs
is misconfigured.  Also, add an assertion to catch
caller misuse when pure space is exhausted.
parent 51f5c194
...@@ -5086,7 +5086,13 @@ valid_lisp_object_p (Lisp_Object obj) ...@@ -5086,7 +5086,13 @@ valid_lisp_object_p (Lisp_Object obj)
/* Allocate room for SIZE bytes from pure Lisp storage and return a /* Allocate room for SIZE bytes from pure Lisp storage and return a
pointer to it. TYPE is the Lisp type for which the memory is pointer to it. TYPE is the Lisp type for which the memory is
allocated. TYPE < 0 means it's not used for a Lisp object, allocated. TYPE < 0 means it's not used for a Lisp object,
and that the result should have an alignment of -TYPE. */ and that the result should have an alignment of -TYPE.
The bytes are initially zero.
If pure space is exhausted, allocate space from the heap. This is
merely an expedient to let Emacs warn that pure space was exhausted
and that Emacs should be rebuilt with a larger pure space. */
static void * static void *
pure_alloc (size_t size, int type) pure_alloc (size_t size, int type)
...@@ -5119,8 +5125,10 @@ pure_alloc (size_t size, int type) ...@@ -5119,8 +5125,10 @@ pure_alloc (size_t size, int type)
/* Don't allocate a large amount here, /* Don't allocate a large amount here,
because it might get mmap'd and then its address because it might get mmap'd and then its address
might not be usable. */ might not be usable. */
purebeg = xmalloc (10000); int small_amount = 10000;
pure_size = 10000; eassert (size <= small_amount - LISP_ALIGNMENT);
purebeg = xzalloc (small_amount);
pure_size = small_amount;
pure_bytes_used_before_overflow += pure_bytes_used - size; pure_bytes_used_before_overflow += pure_bytes_used - size;
pure_bytes_used = 0; pure_bytes_used = 0;
pure_bytes_used_lisp = pure_bytes_used_non_lisp = 0; pure_bytes_used_lisp = pure_bytes_used_non_lisp = 0;
......
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