Make {load,write}_config(filename=None) implement the standard behavior

Make the previously obligatory 'filename' argument to load_config() and
write_config() default to None, and have that implement the behavior
you'd usually want: read/write either KCONFIG_CONFIG or ".config" if
unset, and read the 'option defconfig_list' configuration file if
KCONFIG_CONFIG/".config" doesn't exist.

For load_config(), filename=None also allows the configuration file to
be missing without raising an error. load_config() returns True if a
local configuration file was loaded, which is useful to check in the
menuconfig (if no local configuration file exists, we always want to
prompt for saving the configuration when exiting).

Also add a 'verbose' argument (default True) to load_config() and
read_config() that makes them print which files were read/written in
filename=None mode.

Also generalize olddefconfig.py and oldconfig.py to not require there to
already be a local configuration file. This was a bit silly for
olddefconfig.py in particular.

Remove the examples/defconfig.py script. It's a duplicate of
olddefconfig.py.

3 files changed, 6 insertions, 29 deletions

diff --git a/examples/allnoconfig_walk.py b/examples/allnoconfig_walk.py
index 227effd..5abc80c 100644
--- a/examples/allnoconfig_walk.py
+++ b/examples/allnoconfig_walk.py
@@ -61,4 +61,4 @@ while True:
     if not changed:
         break
 
-kconf.write_config(".config")
+kconf.write_config()
diff --git a/examples/defconfig.py b/examples/defconfig.py
deleted file mode 100644
index c9cc7c6..0000000
--- a/examples/defconfig.py
+++ /dev/null
@@ -1,23 +0,0 @@
-# Works like entering "make menuconfig" and immediately saving and exiting
-#
-# Usage:
-#
-#   $ make [ARCH=<arch>] scriptconfig SCRIPT=Kconfiglib/examples/allyesconfig.py
-
-import os
-import sys
-
-import kconfiglib
-
-
-kconf = kconfiglib.Kconfig(sys.argv[1])
-
-if os.path.exists(".config"):
-    print("using existing .config")
-    kconf.load_config(".config")
-elif kconf.defconfig_filename is not None:
-    print("using " + kconf.defconfig_filename)
-    kconf.load_config(kconf.defconfig_filename)
-
-kconf.write_config(".config")
-print("configuration written to .config")
diff --git a/examples/defconfig_oldconfig.py b/examples/defconfig_oldconfig.py
index 0b24e1d..98f97a0 100644
--- a/examples/defconfig_oldconfig.py
+++ b/examples/defconfig_oldconfig.py
@@ -21,19 +21,19 @@ kconf = kconfiglib.Kconfig(sys.argv[1])
 
 # Mirrors defconfig
 kconf.load_config("arch/x86/configs/x86_64_defconfig")
-kconf.write_config(".config")
+kconf.write_config()
 
 # Mirrors the first oldconfig
-kconf.load_config(".config")
+kconf.load_config()
 kconf.syms["ETHERNET"].set_value(0)
-kconf.write_config(".config")
+kconf.write_config()
 
 # Mirrors the second oldconfig
-kconf.load_config(".config")
+kconf.load_config()
 kconf.syms["ETHERNET"].set_value(2)
 for s in kconf.unique_defined_syms:
     if s.user_value is None and 0 in s.assignable:
         s.set_value(0)
 
 # Write the final configuration
-kconf.write_config(".config")
+kconf.write_config()