config/functions: add local-cc flag for building with local build-host cc

This is needed for host packages built in very early stages,
before host-cc (which typically uses ccache) is available.

Set CC/CXX to LOCAL_CC/CXX in this case.

Signed-off-by: Matthias Reichl <hias@horus.com>

config/functions

@@ -492,8 +492,13 @@ setup_toolchain() {
     host:*|bootstrap:*)
       export DESTIMAGE="host"
       export AWK="gawk"
-      export CC="$TOOLCHAIN/bin/host-gcc"
-      export CXX="$TOOLCHAIN/bin/host-g++"
+      if [ "$1" = "host" ] && flag_enabled "local-cc" "no"; then
+        export CC="${LOCAL_CC}"
+        export CXX="${LOCAL_CXX}"
+      else
+        export CC="$TOOLCHAIN/bin/host-gcc"
+        export CXX="$TOOLCHAIN/bin/host-g++"
+      fi
       export CPP="cpp"
       export LD="ld"
       export AS="as"

packages/readme.md

@@ -132,6 +132,7 @@ Set the variable `PKG_BUILD_FLAGS` in the `package.mk` to enable/disable the sin
 | parallel | enabled  | all | `make` or `ninja` builds with multiple threads/processes (or not) |
 | strip    | enabled  | target | strips executables (or not) |
 | sysroot  | enabled  | target | installs the package to the sysroot folder (or not) |
+| local-cc | disabled | host | use compiler from buildhost instead of host-gcc/g++ in toolchain |
 
 ###### Example
 ```