gcc-plugins: Add support for plugin subdirectories

This adds support for building more complex gcc plugins that live in a
subdirectory instead of just in a single source file.

Reported-by: PaX Team <pageexec@freemail.hu>
Signed-off-by: Emese Revfy <re.emese@gmail.com>
[kees: clarified commit message]
Signed-off-by: Kees Cook <keescook@chromium.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins
index ffb928b9c74b..61f0e6db909b 100644
--- a/scripts/Makefile.gcc-plugins
+++ b/scripts/Makefile.gcc-plugins
@@ -21,7 +21,7 @@ ifdef CONFIG_GCC_PLUGINS
 
   GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y))
 
-  export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN SANCOV_PLUGIN
+  export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR SANCOV_PLUGIN
 
   ifneq ($(PLUGINCC),)
     # SANCOV_PLUGIN can be only in CFLAGS_KCOV because avoid duplication.
@@ -30,6 +30,7 @@ ifdef CONFIG_GCC_PLUGINS
 
   KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS)
   GCC_PLUGIN := $(gcc-plugin-y)
+  GCC_PLUGIN_SUBDIR := $(gcc-plugin-subdir-y)
 endif
 
 # If plugins aren't supported, abort the build before hard-to-read compiler