Specify output explicitly for the .c.o compile rule

Specify output explicitly for the .c.o compile rule

The current Makefile.in does not specify the output file name even though upper
level Makefile assumes that the output filename is crt0.o. However, breaks when
the compiler does not use .o extension for object files. Newer Automake is
already using explicit output, but since Newlib does not currently build with
newer Autoconf/Automake versions, we need to override the rule manually.

BUG= none
TEST= toolchain_build_pnacl.py
R=mcgrathr@chromium.org

Committed: https://git.chromium.org/gitweb?p=native_client/nacl-newlib.git;a=commit;h=3b7c4ddb17a22f463043363e18adabe0b325c5b6

[Petr Hosek, 2015-09-29 23:37:22]

phosek@chromium.org changed reviewers:
+ dschuff@chromium.org, mcgrathr@chromium.org

[Petr Hosek, 2015-10-07 21:58:51]

Ping, alternatively I could just add rule for crt0.o to
newlib/libc/sys/nacl/Makefile.{am,in} if that's the preferred solution.

[Roland McGrath, 2015-10-07 22:13:23]

All the makefile changes are pretty horrific.
If you can tackle this in a fashion that does not involve such horrors, and
ideally that touches fewer upstream files, that would be better.

https://chromiumcodereview.appspot.com/1377003003/diff/1/newlib/Makefile.am
File newlib/Makefile.am (right):

https://chromiumcodereview.appspot.com/1377003003/diff/1/newlib/Makefile.am#n...
newlib/Makefile.am:90: toollib_DATA = $(wildcard $(CRT0)) $(CRT1)
This is horrible in multiple ways.

https://chromiumcodereview.appspot.com/1377003003/diff/1/newlib/Makefile.am#n...
newlib/Makefile.am:180: crt0.o: $(wildcard $(CRT0_DIR)$(CRT0))
Also horrible.

[Petr Hosek, 2015-10-09 18:54:33]

How about this version?

[Roland McGrath, 2015-10-09 20:42:19]

LGTM with comment

https://codereview.chromium.org/1377003003/diff/20001/newlib/libc/sys/nacl/Ma...
File newlib/libc/sys/nacl/Makefile.am (right):

https://codereview.chromium.org/1377003003/diff/20001/newlib/libc/sys/nacl/Ma...
newlib/libc/sys/nacl/Makefile.am:15: .c.o:
Put the explanation in a comment here rather than in the log message.

[Petr Hosek, 2015-10-15 18:39:59]

https://chromiumcodereview.appspot.com/1377003003/diff/20001/newlib/libc/sys/...
File newlib/libc/sys/nacl/Makefile.am (right):

https://chromiumcodereview.appspot.com/1377003003/diff/20001/newlib/libc/sys/...
newlib/libc/sys/nacl/Makefile.am:15: .c.o:
On 2015/10/09 20:42:19, Roland McGrath wrote:
> Put the explanation in a comment here rather than in the log message.

Done.

[Petr Hosek, 2015-10-17 22:48:35]

Committed patchset #3 (id:40001) manually as
3b7c4ddb17a22f463043363e18adabe0b325c5b6 (presubmit successful).