On Tiger, automatically apply the -fno-PIE workaround/hack (see previous commit); also, check that --host-c*-compiler options have been specified

README.md

@@ -82,10 +82,9 @@ the build directory. All the commands are in `toolchain/bin`, so you might want
 to add that to your `PATH`.
 
 If you're building this on a PowerMac running Mac OS X 10.4, tell the build script
-to use the gcc you've installed via tigerbrew, and set an environment variable to work around
-a problem caused by GCC's build system:
+to use the gcc you've installed via tigerbrew:
 
-    gcc_cv_c_no_fpie=no ../Retro68/build-toolchain.bash --host-cxx-compiler=g++-5 --host-c-compiler=gcc-5
+    ../Retro68/build-toolchain.bash --host-cxx-compiler=g++-5 --host-c-compiler=gcc-5
 
 ### Build options and recompiling
 

build-toolchain.bash

@@ -93,6 +93,7 @@ if [ $BUILD_PPC != false ]; then
 	ARCHS="$ARCHS powerpc"
 fi
 
+
 ##################### Sanity checks
 
 if [ `pwd -P` == "$SRC" ]; then
@@ -124,6 +125,26 @@ if [ $SKIP_THIRDPARTY != false ]; then
 	fi
 fi
 
+### Running on a Power Mac (tested with 10.4 Tiger)
+
+if [ "`uname -m`" = "Power Macintosh" ]; then
+		# The default compiler won't work, 
+		# check whether the compiler has been explictly specified
+		# on the command line
+	if [ $SKIP_THIRDPARTY = false ]; then
+		if [ -z "$HOST_CXX_COMPILER" -o -z "$HOST_C_COMPILER" ]; then
+			echo "**** Apple's version of GCC on Power Macs is too old."
+			echo "**** Please explicitly specify the C and C++ compilers"
+			echo "**** using the --host-c-compiler and --host-cxx-compiler options."
+			echo "**** You can install a usable compiler using tigerbrew."
+			exit 1
+		fi
+	fi
+
+		# work around a problem with building gcc-7 with homebrew's gcc-5
+	export gcc_cv_c_no_fpie=no
+fi
+
 ##################### Locate and check Interfaces & Libraries
 
 if [ -d "$SRC/CIncludes" -o -d "$SRC/RIncludes" ]; then