[Xen-changelog] [xen-3.4-testing] Fix Makefile targets that generate several files at once

["Xen patchbot-3.4-testing" <patchbot-3.4-testing@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1268158194 0
# Node ID 0489c4f40f243deb206cc24ff19390cd770533d0
# Parent  351b79a183c91c061e92550019f0eee106f270f8
Fix Makefile targets that generate several files at once

In a few places in the tree the Makefiles have constructs like this:
   one_file another_file:
       $(COMMAND_WHICH_GENERATES_BOTH_AT_ONCE)
This is wrong, because make will run _two copies_ of the same command
at once.  This generally causes races and hard-to-reproduce build
failures.

Notably, `make -j4' at the top level will build stubdom libxc twice
simultaneously!

In this patch we replace the occurrences of this construct with the
correct idiom:
   one_file: another_file
   another_file:
       $(COMMAND_WHICH_GENERATES_BOTH_AT_ONCE)

Signed-off-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
xen-unstable changeset:   21003:8f98581c2dd1
xen-unstable date:        Fri Mar 05 14:40:19 2010 +0000
---
 stubdom/Makefile                  |    4 +++-
 tools/xenstat/libxenstat/Makefile |    6 ++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff -r 351b79a183c9 -r 0489c4f40f24 stubdom/Makefile
--- a/stubdom/Makefile  Tue Mar 09 18:08:57 2010 +0000
+++ b/stubdom/Makefile  Tue Mar 09 18:09:54 2010 +0000
@@ -224,8 +224,10 @@ TARGETS_MINIOS=$(addprefix mini-os-$(XEN
 
 .PHONY: libxc
 libxc: libxc-$(XEN_TARGET_ARCH)/libxenctrl.a 
libxc-$(XEN_TARGET_ARCH)/libxenguest.a
-libxc-$(XEN_TARGET_ARCH)/libxenctrl.a libxc-$(XEN_TARGET_ARCH)/libxenguest.a:: 
cross-zlib
+libxc-$(XEN_TARGET_ARCH)/libxenctrl.a: cross-zlib
        CPPFLAGS="$(TARGET_CPPFLAGS)" CFLAGS="$(TARGET_CFLAGS)" $(MAKE) -C 
libxc-$(XEN_TARGET_ARCH)
+
+ libxc-$(XEN_TARGET_ARCH)/libxenguest.a: libxc-$(XEN_TARGET_ARCH)/libxenctrl.a
 
 #######
 # ioemu
diff -r 351b79a183c9 -r 0489c4f40f24 tools/xenstat/libxenstat/Makefile
--- a/tools/xenstat/libxenstat/Makefile Tue Mar 09 18:08:57 2010 +0000
+++ b/tools/xenstat/libxenstat/Makefile Tue Mar 09 18:09:54 2010 +0000
@@ -107,7 +107,8 @@ SWIG_FLAGS=-module xenstat -Isrc
 # Python bindings
 PYTHON_VERSION=2.3
 PYTHON_FLAGS=-I/usr/include/python$(PYTHON_VERSION) -lpython$(PYTHON_VERSION)
-$(PYSRC) $(PYMOD): bindings/swig/xenstat.i
+$(PYMOD): $(PYSRC)
+$(PYSRC): bindings/swig/xenstat.i
        swig -python $(SWIG_FLAGS) -outdir $(@D) -o $(PYSRC) $<
 
 $(PYLIB): $(PYSRC)
@@ -128,7 +129,8 @@ endif
 
 # Perl bindings
 PERL_FLAGS=`perl -MConfig -e 'print "$$Config{ccflags} 
-I$$Config{archlib}/CORE";'`
-$(PERLSRC) $(PERLMOD): bindings/swig/xenstat.i
+$(PERLMOD): $(PERLSRC)
+$(PERLSRC): bindings/swig/xenstat.i
        swig -perl $(SWIG_FLAGS) -outdir $(@D) -o $(PERLSRC) $<
 
 $(PERLLIB): $(PERLSRC)

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