Make header strings customizable via the environment

If no header string is specified in write_(min_)config() or
write_autoconf(), use the values of the environment variables
KCONFIG_CONFIG_HEADER and KCONFIG_AUTOHEADER_HEADER, respectively, if
set. KCONFIG_AUTOHEADER_HEADER is consistent with KCONFIG_AUTOHEADER
(the header path), which will be added soon.

Using environment variables avoids having to add separate flags to each
tool that writes configuration files or headers.

Like for $prefix and $CONFIG_, store the values of the environment
variables when the Kconfig instance is created, and expose them via
Kconfig.config_header and Kconfig.header_header. This if flexible and
avoids gotchas when working with multiple Kconfig instances.

Also remove the old default header and make the default no header. Less
advertising, but it felt a bit silly to add workarounds to keep it.

Came up in https://github.com/ulfalizer/Kconfiglib/pull/80.

1 files changed, 7 insertions, 0 deletions

diff --git a/genconfig.py b/genconfig.py
index bb3e6ff..96124c5 100755
--- a/genconfig.py
+++ b/genconfig.py
@@ -20,6 +20,13 @@ might save work depending on your build setup.
 
 By default, the configuration is generated from '.config'. A different
 configuration file can be passed in the KCONFIG_CONFIG environment variable.
+
+A custom header string can be inserted at the beginning of generated
+configuration and header files by setting the KCONFIG_CONFIG_HEADER and
+KCONFIG_AUTOHEADER_HEADER environment variables, respectively (this also works
+for other scripts). The string is not automatically made a comment (this is by
+design, to allow anything to be added), and no trailing newline is added, so
+add '/* */', '#', and newlines as appropriate.
 """
 import argparse
 import os