cc-wrapper merge fixes

pkgs/build-support/cc-wrapper/setup-hook-stdinc.sh

@@ -0,0 +1,44 @@
+# This is an alternate setup hook for gcc-wrapper that uses the -I flag to
+# add include search paths instead of -isystem. We need this for some packages
+# because -isystem can change the search order specified by prior -I flags.
+# Changing the search order can point gcc to the wrong package's headers.
+# The -I flag will never change the order of prior flags.
+
+export NIX_CC=@out@
+
+addCVars () {
+    if [ -d $1/include ]; then
+        export NIX_CFLAGS_COMPILE+=" -I $1/include"
+    fi
+
+    if [ -d $1/lib64 -a ! -L $1/lib64 ]; then
+        export NIX_LDFLAGS+=" -L$1/lib64"
+    fi
+
+    if [ -d $1/lib ]; then
+        export NIX_LDFLAGS+=" -L$1/lib"
+    fi
+}
+
+envHooks+=(addCVars)
+
+# Note: these come *after* $out in the PATH (see setup.sh).
+
+if [ -n "@gcc@" ]; then
+    addToSearchPath PATH @gcc@/bin
+fi
+
+if [ -n "@binutils@" ]; then
+    addToSearchPath PATH @binutils@/bin
+fi
+
+if [ -n "@libc@" ]; then
+    addToSearchPath PATH @libc@/bin
+fi
+
+if [ -n "@coreutils@" ]; then
+    addToSearchPath PATH @coreutils@/bin
+fi
+
+export CC=gcc
+export CXX=g++