Fix PowerPC compiler macros in Darwin Makefile.arch

Author: AliceLR

arch/darwin/Makefile.arch

@@ -5,6 +5,7 @@
 ALL_ARCH        = arm64 arm64e i686 x86_64 x86_64h ppc ppc64
 
 # Override these to match the compiler(s) being used.
+# For x86 and ARM, assume clang is being used by default.
 ifeq (${XCODE_3},1)
 ARM64_CC        ?= unsupported-architecture
 ARM64E_CC       ?= unsupported-architecture
@@ -13,17 +14,23 @@ X86_CC          ?= i686-apple-darwin10-gcc-4.2.1
 X86_CXX         ?= i686-apple-darwin10-g++-4.2.1
 X86_64_CC       ?= ${X86_CC} -m64
 X86_64_CXX      ?= ${X86_CXX} -m64
-PPC_CC          ?= powerpc-apple-darwin10-gcc-4.0.1
-PPC_CXX         ?= powerpc-apple-darwin10-g++-4.0.1
-PPC64_CC        ?= powerpc-apple-darwin10-gcc-4.2.1 -m64
-PPC64_CXX       ?= powerpc-apple-darwin10-g++-4.2.1 -m64
 STDLIB          ?=
 else
 ARM64_CFLAGS    ?= -arch arm64
 ARM64E_CFLAGS   ?= -arch arm64e
 X86_CFLAGS      ?= -arch i686
 X86_64_CFLAGS   ?= -arch x86_64
 X86_64H_CFLAGS  ?= -arch x86_64h
+endif
+
+# For PowerPC, assume the Xcode 3 compilers are being used by default.
+XCODE_3_PPC     ?= 1
+ifeq (${XCODE_3_PPC},1)
+PPC_CC          ?= powerpc-apple-darwin10-gcc-4.0.1
+PPC_CXX         ?= powerpc-apple-darwin10-g++-4.0.1
+PPC64_CC        ?= powerpc-apple-darwin10-gcc-4.2.1 -m64
+PPC64_CXX       ?= powerpc-apple-darwin10-g++-4.2.1 -m64
+else
 PPC_CC          ?= powerpc-apple-darwin10-gcc
 PPC_CXX         ?= powerpc-apple-darwin10-g++
 PPC64_CC        ?= powerpc64-apple-darwin10-gcc
@@ -68,14 +75,14 @@ endif
 ifeq (${ARCH},ppc)
 CC      := $(or ${PPC_CC},${CC}) ${PPC_CFLAGS}
 CXX     := $(or ${PPC_CXX},${CXX}) ${PPC_CFLAGS}
-STDLIB  ?= libstdc++
+SYSROOT ?= /Developer/SDKs/MacOSX10.4u.sdk
 MINVER  ?= 10.4
 endif
 
 ifeq (${ARCH},ppc64)
 CC      := $(or ${PPC64_CC},${CC}) ${PPC64_CFLAGS}
 CXX     := $(or ${PPC64_CXX},${CXX}) ${PPC64_CFLAGS}
-STDLIB  ?= libstdc++
+SYSROOT ?= /Developer/SDKs/MacOSX10.4u.sdk
 MINVER  ?= 10.4
 endif
 
@@ -87,3 +94,8 @@ endif
 
 CC      += -mmacosx-version-min=${MINVER}
 CXX     += -mmacosx-version-min=${MINVER}
+
+ifneq (${SYSROOT},)
+CC      += -isysroot "${SYSROOT}"
+CXX     += -isysroot "${SYSROOT}"
+endif