use gcc to compile gcc (there was a weird '-mmacosx-version-min=' issue during gcc compilation with earlier versions)

README.md

@@ -14,11 +14,6 @@ of the [cctools](http://www.opensource.apple.com/tarballs/cctools) (ld, lipo, ..
 
 If you want, then you can build an up-to-date vanilla GCC as well.
 
-### WHAT IS NOT WORKING (YET)? ###
-
-* GCC itself [doesn't build with GCC](https://github.com/tpoechtrager/osxcross/commit/dc8c471),
-  but builds fine when clang is used to build GCC.
-
 ### WHAT CAN I BUILD WITH IT? ###
 
 Basically everything you can build on OS X with clang/gcc should build with this cross toolchain as well.
@@ -46,8 +41,13 @@ That's it. See usage examples below.
 ##### Building GCC: #####
 
 If you want to build GCC as well, then you can do this by running `./build_gcc.sh`.  
-But before you do this, make sure you have got the GCC build depedencies installed on your system,  
-on debian like systems you can run `apt-get install libmpc-dev libmpfr-dev libgmp-dev` to install them.
+But before you do this, make sure you have got the GCC build depedencies installed on your system.  
+
+On debian like systems you can run:
+
+`[sudo] apt-get install gcc g++ zlib1g-dev libmpc-dev libmpfr-dev libgmp-dev`  
+
+to install them.
 
 ### PACKAGING THE SDK: ###
 

build_gcc.sh

@@ -5,6 +5,7 @@ pushd "${0%/*}" &>/dev/null
 unset LIBRARY_PATH
 
 DESC=gcc
+USESYSTEMCOMPILER=1
 source tools/tools.sh
 
 `tools/osxcross_conf.sh`
@@ -108,6 +109,9 @@ fi # have gcc
 
 popd &>/dev/null # build dir
 
+unset USESYSTEMCOMPILER
+source tools/tools.sh
+
 pushd $OSXCROSS_TARGET_DIR/bin &>/dev/null
 
 if [ ! -f i386-apple-$OSXCROSS_TARGET-base-gcc ]; then

tools/tools.sh

@@ -3,8 +3,14 @@
 BASE_DIR=`pwd`
 
 export LC_ALL="C"
-export CC=clang
-export CXX=clang++
+
+if [ -z "$USESYSTEMCOMPILER" ]; then
+  export CC=clang
+  export CXX=clang++
+elif [ -n "$CC" -o -n "$CXX" ]; then
+  echo "CC/CXX should not be set, continuing in 5 seconds..." 1>&2
+  sleep 5
+fi
 
 # enable debug messages
 test -n "$OCDEBUG" && set -x