kbuild: New 'cc-fullversion' macro

Prints a six-digit string including the GCC patchlevel.  Also fix
the 'usage' comment for cc-version.
Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/Kbuild.include

@@ -100,9 +100,14 @@ cc-option-align = $(subst -functions=0,,\
 	$(call cc-option,-falign-functions=0,-malign-functions=0))
 
 # cc-version
-# Usage gcc-ver := $(call cc-version,$(CC))
+# Usage gcc-ver := $(call cc-version)
 cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
 
+# cc-fullversion
+# Usage gcc-ver := $(call cc-fullversion)
+cc-fullversion = $(shell $(CONFIG_SHELL) \
+	$(srctree)/scripts/gcc-version.sh -p $(CC))
+
 # cc-ifversion
 # Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
 cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3))

scripts/gcc-version.sh

 #!/bin/sh
 #
-# gcc-version gcc-command
+# gcc-version [-p] gcc-command
 #
 # Prints the gcc version of `gcc-command' in a canonical 4-digit form
 # such as `0295' for gcc-2.95, `0303' for gcc-3.3, etc.
 #
+# With the -p option, prints the patchlevel as well, for example `029503' for
+# gcc-2.95.3, `030301' for gcc-3.3.1, etc.
+#
+
+if [ $1 = "-p" ] ; then with_patchlevel=1; shift; fi
 
 compiler="$*"
 
 MAJOR=$(echo __GNUC__ | $compiler -E -xc - | tail -n 1)
 MINOR=$(echo __GNUC_MINOR__ | $compiler -E -xc - | tail -n 1)
-printf "%02d%02d\\n" $MAJOR $MINOR
-
+if [ "x$with_patchlevel" != "x" ] ; then
+	PATCHLEVEL=$(echo __GNUC_PATCHLEVEL__ | $compiler -E -xc - | tail -n 1)
+	printf "%02d%02d%02d\\n" $MAJOR $MINOR $PATCHLEVEL
+else
+	printf "%02d%02d\\n" $MAJOR $MINOR
+fi