[PATCH/RFA]: New configure option disabling target optimization

[Corinna Vinschen <vinschen at redhat dot com>]

Hi,


when building newlib, there's a statement in configure.host which always
adds some sort of optimization to NEWLIB_CFLAGS.  Maybe I'm just dense,
but I haven't found a way to disable the generation of the optimization
flags using configure or make, without having to enter a new
NEWLIB_CFLAGS value, which in turn requires to enter the full rat tail
of target specific options.  For Cygwin, this means for instance:

  make NEWLIB_CFLAGS='-DHAVE_OPENDIR -DHAVE_RENAME -DSIGNAL_PROVIDED -D_COMPILING_NEWLIB -DHAVE_BLKSIZE -DHAVE_FCNTL -DMALLOC_PROVIDED -fno-builtin'

That's pretty cumbersome.  I'm constantly building the Cygwin/newlib
source tree for debuggging using `CFLAGS=-g', and for debugging any
optimization is just in the way.

Therefore I'd like to propose a patch to add a configure option to
disable this automatic optimization option in configure.host.  Would
something like this be ok to apply, or is there already some easier way
to accomplish the same which I just didn't notice?


Thanks,
Corinna


	* acinclude.m4: Add --disable-target-optimization option.
	* configure.host: Skip target optimization setting if
	--disable-target-optimization has been specified.


Index: acinclude.m4
===================================================================
RCS file: /cvs/src/src/newlib/acinclude.m4,v
retrieving revision 1.29
diff -u -p -r1.29 acinclude.m4
--- acinclude.m4	22 Dec 2008 19:45:40 -0000	1.29
+++ acinclude.m4	20 Oct 2009 10:05:02 -0000
@@ -20,6 +20,17 @@ AC_ARG_ENABLE(multilib,
   *)   AC_MSG_ERROR(bad value ${enableval} for multilib option) ;;
  esac], [multilib=yes])dnl
 
+dnl Support --disable-target-optimization
+AC_ARG_ENABLE(target-optimization,
+[  --disable-target-optimization disable automatic optimization support],
+[if test "${target_optimization+set}" != set; then
+  case "${enableval}" in
+    yes) target_optimization=yes ;;
+    no)  target_optimization=no ;;
+    *)   AC_MSG_ERROR(bad value ${enableval} for target-optimization option) ;;
+  esac
+ fi], [target_optimization=${target_optimization}])dnl
+
 dnl Support --enable-target-optspace
 AC_ARG_ENABLE(target-optspace,
 [  --enable-target-optspace  optimize for space],
Index: configure.host
===================================================================
RCS file: /cvs/src/src/newlib/configure.host,v
retrieving revision 1.110
diff -u -p -r1.110 configure.host
--- configure.host	8 Oct 2009 16:44:09 -0000	1.110
+++ configure.host	20 Oct 2009 10:05:02 -0000
@@ -72,17 +72,20 @@ aext=a
 oext=o
 lpfx="lib_a-"
 
-case "${target_optspace}:${host}" in
-  yes:*)
-    newlib_cflags="${newlib_cflags} -Os"
-    ;;
-  :m32r-* | :d10v-* | :d30v-* | :avr-* | :m32c-* )
-    newlib_cflags="${newlib_cflags} -Os"
-    ;;
-  no:* | :*)
-    newlib_cflags="${newlib_cflags} -O2"
-    ;;
-esac
+if [ "${target_optimization}" != "no" ]
+then
+  case "${target_optspace}:${host}" in
+    yes:*)
+      newlib_cflags="${newlib_cflags} -Os"
+      ;;
+    :m32r-* | :d10v-* | :d30v-* | :avr-* | :m32c-* )
+      newlib_cflags="${newlib_cflags} -Os"
+      ;;
+    no:* | :*)
+      newlib_cflags="${newlib_cflags} -O2"
+      ;;
+  esac
+fi
 
 # Get the source directories to use for the CPU type.
 # machine_dir should supply CPU dependent routines, such as setjmp.

-- 
Corinna Vinschen
Cygwin Project Co-Leader
Red Hat