pmt: revert 7f8090b

jni/parted/libgnulib/lib/malloca.c

@@ -1,135 +0,0 @@
-/* Safe automatic memory allocation.
-   Copyright (C) 2003, 2006-2007, 2009-2024 Free Software Foundation, Inc.
-   Written by Bruno Haible <bruno@clisp.org>, 2003, 2018.
-
-   This file is free software: you can redistribute it and/or modify
-   it under the terms of the GNU Lesser General Public License as
-   published by the Free Software Foundation; either version 2.1 of the
-   License, or (at your option) any later version.
-
-   This file is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public License
-   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
-
-#define _GL_USE_STDLIB_ALLOC 1
-#include <config.h>
-
-/* Specification.  */
-#include "malloca.h"
-
-#include <stdckdint.h>
-#if defined __CHERI_PURE_CAPABILITY__
-# include <cheri.h>
-#endif
-
-#include "idx.h"
-
-/* The speed critical point in this file is freea() applied to an alloca()
-   result: it must be fast, to match the speed of alloca().  The speed of
-   mmalloca() and freea() in the other case are not critical, because they
-   are only invoked for big memory sizes.
-   Here we use a bit in the address as an indicator, an idea by Ondřej Bílka.
-   malloca() can return three types of pointers:
-     - Pointers ≡ 0 mod 2*sa_alignment_max come from stack allocation.
-     - Pointers ≡ sa_alignment_max mod 2*sa_alignment_max come from heap
-       allocation.
-     - NULL comes from a failed heap allocation.  */
-
-#if defined __CHERI_PURE_CAPABILITY__
-/* Type for holding the original malloc() result.  */
-typedef uintptr_t small_t;
-#else
-/* Type for holding very small pointer differences.  */
-typedef unsigned char small_t;
-/* Verify that it is wide enough.  */
-static_assert (2 * sa_alignment_max - 1 <= (small_t) -1);
-#endif
-
-void *
-mmalloca (size_t n)
-{
-#if HAVE_ALLOCA
-  /* Allocate one more word, used to determine the address to pass to freea(),
-     and room for the alignment ≡ sa_alignment_max mod 2*sa_alignment_max.  */
-  uintptr_t alignment2_mask = 2 * sa_alignment_max - 1;
-  int plus = sizeof (small_t) + alignment2_mask;
-  idx_t nplus;
-  if (!ckd_add (&nplus, n, plus) && !xalloc_oversized (nplus, 1))
-    {
-      char *mem = (char *) malloc (nplus);
-
-      if (mem != NULL)
-        {
-          uintptr_t umem = (uintptr_t) mem;
-          /* The ckd_add avoids signed integer overflow on
-             theoretical platforms where UINTPTR_MAX <= INT_MAX.  */
-          uintptr_t umemplus;
-          ckd_add (&umemplus, umem, sizeof (small_t) + sa_alignment_max - 1);
-          idx_t offset = (umemplus - umemplus % (2 * sa_alignment_max)
-                          + sa_alignment_max - umem);
-          void *p = mem + offset;
-          /* Here p >= mem + sizeof (small_t),
-             and p <= mem + sizeof (small_t) + 2 * sa_alignment_max - 1
-             hence p + n <= mem + nplus.
-             So, the memory range [p, p+n) lies in the allocated memory range
-             [mem, mem + nplus).  */
-          small_t *sp = p;
-# if defined __CHERI_PURE_CAPABILITY__
-          sp[-1] = umem;
-          p = (char *) cheri_bounds_set ((char *) p - sizeof (small_t),
-                                         sizeof (small_t) + n)
-              + sizeof (small_t);
-# else
-          sp[-1] = offset;
-# endif
-          /* p ≡ sa_alignment_max mod 2*sa_alignment_max.  */
-          return p;
-        }
-    }
-  /* Out of memory.  */
-  return NULL;
-#else
-# if !MALLOC_0_IS_NONNULL
-  if (n == 0)
-    n = 1;
-# endif
-  return malloc (n);
-#endif
-}
-
-#if HAVE_ALLOCA
-void
-freea (void *p)
-{
-  /* Check argument.  */
-  uintptr_t u = (uintptr_t) p;
-  if (u & (sa_alignment_max - 1))
-    {
-      /* p was not the result of a malloca() call.  Invalid argument.  */
-      abort ();
-    }
-  /* Determine whether p was a non-NULL pointer returned by mmalloca().  */
-  if (u & sa_alignment_max)
-    {
-      char *cp = p;
-      small_t *sp = p;
-# if defined __CHERI_PURE_CAPABILITY__
-      void *mem = sp[-1];
-# else
-      void *mem = cp - sp[-1];
-# endif
-      free (mem);
-    }
-}
-#endif
-
-/*
- * Hey Emacs!
- * Local Variables:
- * coding: utf-8
- * End:
- */