Clean up kernel Makefile patch and add new targets

Add two new targets:

 - 'make kmenuconfig' runs the menuconfig interface

 - 'make dumpvarsconfig' lists all referenced environment variables
   together with their values (assuming they used the preprocessor
   syntax)

Remove the 'kconfiglibtestconfig' target, which is no longer used.

Also clean up the target definitions. The joys of ancient code.

1 files changed, 25 insertions, 8 deletions

diff --git a/kconfiglib.py b/kconfiglib.py
index 770614a..c0746ec 100644
--- a/kconfiglib.py
+++ b/kconfiglib.py
@@ -44,6 +44,13 @@ The targets added by the Makefile patch are described in the following
 sections.
 
 
+make kmenuconfig
+----------------
+
+This target runs the curses menuconfig interface with Python 3 (Python 2 is
+currently not supported for the menuconfig).
+
+
 make [ARCH=<arch>] iscriptconfig
 --------------------------------
 
@@ -75,12 +82,23 @@ argument, if given.
 See the examples/ subdirectory for example scripts.
 
 
+make dumpvarsconfig
+-------------------
+
+This target prints a list of all environment variables referenced from the
+Kconfig files, together with their values. See the
+Kconfiglib/examples/dumpvars.py script.
+
+Only environment variables that are referenced via the Kconfig preprocessor
+$(FOO) syntax are included. The preprocessor was added in Linux 4.18.
+
+
 Using Kconfiglib without the Makefile targets
 =============================================
 
 The make targets are only needed to pick up environment variables exported from
 the Kbuild makefiles and referenced inside Kconfig files, via e.g.
-'source "arch/$(SRCARCH)/Kconfig" and '$(shell,...)'.
+'source "arch/$(SRCARCH)/Kconfig" and commands run via '$(shell,...)'.
 
 These variables are referenced as of writing (Linux 4.18), together with sample
 values:
@@ -94,6 +112,12 @@ values:
   HOSTCXX          (g++)
   CC_VERSION_TEXT  (gcc (Ubuntu 7.3.0-16ubuntu3) 7.3.0)
 
+Older kernels only reference ARCH, SRCARCH, and KERNELVERSION.
+
+If your kernel is recent enough (4.18+), you can get a list of referenced
+environment variables via 'make dumpvarsconfig' (see above). Note that this
+command is added by the Makefile patch.
+
 To run Kconfiglib without the Makefile patch, set the environment variables
 manually:
 
@@ -104,13 +128,6 @@ manually:
 Search the top-level Makefile for "Additional ARCH settings" to see other
 possibilities for ARCH and SRCARCH.
 
-To see a list of all referenced environment variables together with their
-values, run this code from e.g. 'make iscriptconfig':
-
-  import os
-  for var in kconf.env_vars:
-      print(var, os.environ[var])
-
 
 Intro to symbol values
 ======================