Allow specifying tool path/prefix for tests with CROSS_COMPILE.

[flackr]

Summary

CROSS_COMPILE environment variable is a common convention to specify the path and/or prefix to cross compilation tools (e.g. ar, objcopy).

[flackr]

Use consistent immediate expansion of CROSS_COMPILE in AR and OBJCOPY.

[tberghammer]

LGTM

[clayborg]

Looks good.

lldb/trunk/test/make/Makefile.rules

 #----------------------------------------------------------------------
 # Clients fill in the source files to build
 #----------------------------------------------------------------------
 # C_SOURCES := main.c
 # CXX_SOURCES :=
 # OBJC_SOURCES :=
 # OBJCXX_SOURCES :=
 # DYLIB_C_SOURCES :=
 # DYLIB_CXX_SOURCES :=
 #
 # Specifying DYLIB_ONLY has the effect of building dylib only, skipping
 # the building of the a.out executable program.  For example,
 # DYLIB_ONLY := YES
 #
 # Also might be of interest:
 # FRAMEWORK_INCLUDES (Darwin only) :=
-# CFLAGS_EXTRAS +=
+# CFLAGS_EXTRAS :=
 # LD_EXTRAS :=
 # SPLIT_DEBUG_SYMBOLS := YES
+# CROSS_COMPILE :=
 #
 # And test/functionalities/archives/Makefile:
 # MAKE_DSYM := NO
 # ARCHIVE_NAME := libfoo.a
 # ARCHIVE_C_SOURCES := a.c b.c
 
 # Uncomment line below for debugging shell commands
 # SHELL = /bin/sh -x

 
 #----------------------------------------------------------------------
 # Change any build/tool options needed
 #----------------------------------------------------------------------
 ifeq "$(OS)" "Darwin"
   DS := $(shell xcrun -find -toolchain default dsymutil)
   DSFLAGS =
   DSYM = $(EXE).dSYM
-  AR := libtool
+  AR := $(CROSS_COMPILE)libtool
   ARFLAGS := -static -o
 else
+  AR := $(CROSS_COMPILE)ar
   # On non-Apple platforms, -arch becomes -m
   ARCHFLAG := -m
 
   # i386, i686, x86 -> 32
   # amd64, x86_64, x64 -> 64
   ifeq "$(ARCH)" "amd64"
     override ARCH := $(subst amd64,64,$(ARCH))
   endif
cxx_linker_notdir = $(if $(findstring clang,$(1)), \
                               $(subst icc,icpc,$(1)), \
                               $(if $(findstring llvm-gcc,$(1)), \
                                    $(subst llvm-gcc,llvm-g++,$(1)), \
                                    $(if $(findstring gcc,$(1)), \
                                         $(subst gcc,g++,$(1)), \
                                         $(subst cc,c++,$(1))))))
 cxx_linker = $(if $(findstring /,$(1)),$(join $(dir $(1)), $(call cxx_linker_notdir,$(notdir $(1)))),$(call cxx_linker_notdir,$(1)))
 
-OBJCOPY = objcopy
+OBJCOPY := $(CROSS_COMPILE)objcopy
 
 #----------------------------------------------------------------------
 # Windows specific options
 #----------------------------------------------------------------------
 ifeq "$(OS)" "Windows_NT"
   ifneq (,$(findstring clang,$(CC)))
     # Clang for Windows doesn't support C++ Exceptions
     CXXFLAGS += -fno-exceptions