[PATCH v3 7/7] compiler-gcc: improve version error

[Nick Desaulniers]

As Kees suggests, doing so provides developers with two useful pieces of
information:
- The kernel build was attempting to use GCC.
  (Maybe they accidentally poked the wrong configs in a CI.)
- They need 4.9 or better.
  ("Upgrade to what version?" doesn't need to be dug out of documentation,
   headers, etc.)

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Miguel Ojeda <miguel.ojeda.sandonis@xxxxxxxxx>
Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Reviewed-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>
Suggested-by: Kees Cook <keescook@xxxxxxxxxxxx>
Tested-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>
Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
---
 include/linux/compiler-gcc.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 7a3769040d7d..d1e3c6896b71 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -12,7 +12,7 @@
 
 /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145 */
 #if GCC_VERSION < 40900
-# error Sorry, your compiler is too old - please upgrade it.
+# error Sorry, your version of GCC is too old - please use 4.9 or newer.
 #endif
 
 /* Optimization barrier */
-- 
2.28.0.402.g5ffc5be6b7-goog