Replace the use of uname to get the build output.

Using uname has a couple of problems, especially when cross compiling. Instead
check the defines set by the preprocessor to figure the type of binaries it
produces. This improves support for cross compiling as it allows to (1) select
the correct default target and (2) makes it possible to use separate build
folders for different targets.

Change-Id: I69a32904dab97755034f2f0d63f8402309d479d2

2 files changed, 15 insertions, 12 deletions

diff --git a/rbutil/ipodpatcher/Makefile b/rbutil/ipodpatcher/Makefile
index 79fe4c7c03..0b0b404ca2 100644
--- a/rbutil/ipodpatcher/Makefile
+++ b/rbutil/ipodpatcher/Makefile
@@ -27,10 +27,8 @@ BOOTSRC = ipod1g2g.c ipod3g.c ipod4g.c ipodcolor.c ipodmini1g.c \
 CFLAGS += -DWITH_BOOTOBJS
 endif
 
-ifeq ($(findstring Darwin,$(shell uname)),Darwin)
 # additional frameworks to link on on OS X
-LDOPTS += -framework CoreFoundation -framework IOKit
-endif
+LDOPTS_OSX += -framework CoreFoundation -framework IOKit
 
 LIBSOURCES = ipodpatcher.c fat32format.c arc4.c \
              ipodio-posix.c ipodio-win32-scsi.c ipodio-win32.c
diff --git a/rbutil/libtools.make b/rbutil/libtools.make
index 77142355c6..44ed5fef3d 100644
--- a/rbutil/libtools.make
+++ b/rbutil/libtools.make
@@ -25,31 +25,37 @@ TOP := $(dir $(lastword $(MAKEFILE_LIST)))
 # overwrite for releases
 APPVERSION ?= $(shell $(TOP)/../tools/version.sh $(TOP)/..)
 CFLAGS += -DVERSION=\""$(APPVERSION)"\"
-TARGET_DIR ?= $(shell pwd)/
+TARGET_DIR ?= $(abspath .)/
 
+CPPDEFINES=$(shell echo foo | $(CROSS)$(CC) -dM -E -)
 # use POSIX/C99 printf on windows
 CFLAGS += -D__USE_MINGW_ANSI_STDIO=1
 
 BINARY = $(OUTPUT)
 # when building a Windows binary add the correct file suffix
-ifeq ($(findstring CYGWIN,$(shell uname)),CYGWIN)
+ifeq ($(findstring CYGWIN,$(CPPDEFINES)),CYGWIN)
 BINARY = $(OUTPUT).exe
 CFLAGS+=-mno-cygwin
+COMPILETARGET = cygwin
 else
-ifeq ($(findstring MINGW,$(shell uname)),MINGW)
+ifeq ($(findstring MINGW,$(CPPDEFINES)),MINGW)
 BINARY = $(OUTPUT).exe
+COMPILETARGET = mingw
 else
-ifeq ($(findstring mingw,$(CROSS)$(CC)),mingw)
-BINARY = $(OUTPUT).exe
+ifeq ($(findstring APPLE,$(CPPDEFINES)),APPLE)
+COMPILETARGET = darwin
+LDOPTS += $(LDFLAGS_OSX)
+else
+COMPILETARGET = posix
 endif
 endif
 endif
+$(info Compiler creates $(COMPILETARGET) binaries)
 
 NATIVECC ?= gcc
 CC ?= gcc
 # OS X specifics. Needs to consider cross compiling for Windows.
-ifeq ($(findstring Darwin,$(shell uname)),Darwin)
-ifneq ($(findstring mingw,$(CROSS)$(CC)),mingw)
+ifeq ($(findstring APPLE,$(CPPDEFINES)),APPLE)
 # when building libs for OS X build for both i386 and ppc at the same time.
 # This creates fat objects, and ar can only create the archive but not operate
 # on it. As a result the ar call must NOT use the u (update) flag.
@@ -60,10 +66,9 @@ CC ?= gcc-4.0
 CFLAGS += -isysroot /Developer/SDKs/MacOSX10.4u.sdk -mmacosx-version-min=10.4
 NATIVECC ?= gcc-4.0
 endif
-endif
 WINDRES = windres
 
-BUILD_DIR ?= $(TARGET_DIR)build
+BUILD_DIR ?= $(TARGET_DIR)build$(COMPILETARGET)
 OBJDIR = $(abspath $(BUILD_DIR)/$(RBARCH))/
 
 ifdef RBARCH