[ft-devel] configure option to disable mmap()

[suzuki toshiya]

Dear Werner,

During the benchmark tests, sometimes I build FreeType2
library without mmap() on GNU/Linux, to guess the situation
in legacy or embedded systems without mmap() functions
that the slower standard I/O is used.

At present, configure script always uses mmap() if it is
found, so I added an option "--disable-mmap" to ignore it.
Although this is only for developers who want to make
irregular configuration, is it meaningful to merger in
official source code?

diff --git a/builds/unix/configure.raw b/builds/unix/configure.raw
index a58d20c..2b071f8 100644
--- a/builds/unix/configure.raw
+++ b/builds/unix/configure.raw
@@ -189,8 +189,14 @@ CPPFLAGS="${orig_CPPFLAGS}"

 # Here we check whether we can use our mmap file component.

-AC_FUNC_MMAP
-if test "$ac_cv_func_mmap_fixed_mapped" != yes; then
+AC_ARG_ENABLE([mmap],
+  AS_HELP_STRING([--disable-mmap],
+                 [do not check mmap() and do not use]),
+  [enable_mmap="no"],[enable_mmap="yes"])
+if test "x${enable_mmap}" != "xno"; then
+  AC_FUNC_MMAP
+fi
+if test "x${enable_mmap}" = "xno" -o "$ac_cv_func_mmap_fixed_mapped" != "yes" 
; then
   FTSYS_SRC='$(BASE_DIR)/ftsystem.c'
 else
   FTSYS_SRC='$(BUILD_DIR)/ftsystem.c'