import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

build/autoconf/alloc.m4

@@ -0,0 +1,51 @@
+dnl This Source Code Form is subject to the terms of the Mozilla Public
+dnl License, v. 2.0. If a copy of the MPL was not distributed with this
+dnl file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+dnl Check for the existence of various allocation headers/functions
+AC_DEFUN([MOZ_CHECK_ALLOCATOR],[
+
+MALLOC_HEADERS="malloc.h malloc_np.h malloc/malloc.h sys/malloc.h"
+MALLOC_H=
+
+for file in $MALLOC_HEADERS; do
+  MOZ_CHECK_HEADER($file, [MALLOC_H=$file])
+  if test "$MALLOC_H" != ""; then
+    AC_DEFINE_UNQUOTED(MALLOC_H, <$MALLOC_H>)
+    break
+  fi
+done
+
+AC_CHECK_FUNCS(strndup posix_memalign memalign)
+
+AC_CHECK_FUNCS(malloc_usable_size)
+MALLOC_USABLE_SIZE_CONST_PTR=const
+if test -n "$HAVE_MALLOC_H"; then
+  AC_MSG_CHECKING([whether malloc_usable_size definition can use const argument])
+  AC_TRY_COMPILE([#include <malloc.h>
+                  #include <stddef.h>
+                  size_t malloc_usable_size(const void *ptr);],
+                  [return malloc_usable_size(0);],
+                  AC_MSG_RESULT([yes]),
+                  AC_MSG_RESULT([no])
+                  MALLOC_USABLE_SIZE_CONST_PTR=)
+fi
+AC_DEFINE_UNQUOTED([MALLOC_USABLE_SIZE_CONST_PTR],[$MALLOC_USABLE_SIZE_CONST_PTR])
+
+
+dnl In newer bionic headers, valloc is built but not defined,
+dnl so we check more carefully here.
+AC_MSG_CHECKING([for valloc in malloc.h])
+AC_EGREP_HEADER(valloc, malloc.h,
+                AC_DEFINE(HAVE_VALLOC)
+                AC_MSG_RESULT([yes]),
+                AC_MSG_RESULT([no]))
+
+AC_MSG_CHECKING([for valloc in unistd.h])
+AC_EGREP_HEADER(valloc, unistd.h,
+                AC_DEFINE(HAVE_VALLOC)
+                AC_MSG_RESULT([yes]),
+                AC_MSG_RESULT([no]))
+
+
+])