bitbake: ConfHandler: Allow the '@' character in variable flag names

This patch enables the usage of the '@' character in variable flag
names.

One use case of variable flags is to assign the network namespaces of
some systemd services/targets to configure other parts of the build
process of some system. The filenames of systemd services/targets might
contain the '@' character if they are template unit files that can take
in a single parameter/argument and be instanced multiple times, as
indicated by systemd's official manual page.

The '@' character is disallowed as the first character in a variable
flag name. Imposing more restrictions on the first character is a
compromise to make parsing easier and to allow for more options in the
future to extend the syntax.

This patch is successfully verified by creating a custom BitBake recipe
that sets and unsets the value of a variable flag with the '@' character
in its name and ensuring that no ParseError is being thrown. Regression
tests have also been added to `bb.parse`.

`bin/bitbake-selftest` has also been successfully executed and all tests
passed.

(Bitbake rev: 00f9ab2cacfbd2a63b6b4959cf5401babae7e32a)

Signed-off-by: James Raphael Tiovalen <jamestiotio@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/bitbake/lib/bb/parse/parse_py/ConfHandler.py b/bitbake/lib/bb/parse/parse_py/ConfHandler.py
index 3076067287..05c627ec8b 100644
--- a/bitbake/lib/bb/parse/parse_py/ConfHandler.py
+++ b/bitbake/lib/bb/parse/parse_py/ConfHandler.py
@@ -21,7 +21,7 @@ __config_regexp__  = re.compile( r"""
     ^
     (?P<exp>export\s+)?
     (?P<var>[a-zA-Z0-9\-_+.${}/~:]+?)
-    (\[(?P<flag>[a-zA-Z0-9\-_+.]+)\])?
+    (\[(?P<flag>[a-zA-Z0-9\-_+.][a-zA-Z0-9\-_+.@]+)\])?
 
     \s* (
         (?P<colon>:=) |
@@ -45,7 +45,7 @@ __include_regexp__ = re.compile( r"include\s+(.+)" )
 __require_regexp__ = re.compile( r"require\s+(.+)" )
 __export_regexp__ = re.compile( r"export\s+([a-zA-Z0-9\-_+.${}/~]+)$" )
 __unset_regexp__ = re.compile( r"unset\s+([a-zA-Z0-9\-_+.${}/~]+)$" )
-__unset_flag_regexp__ = re.compile( r"unset\s+([a-zA-Z0-9\-_+.${}/~]+)\[([a-zA-Z0-9\-_+.]+)\]$" )
+__unset_flag_regexp__ = re.compile( r"unset\s+([a-zA-Z0-9\-_+.${}/~]+)\[([a-zA-Z0-9\-_+.][a-zA-Z0-9\-_+.@]+)\]$" )
 __addpylib_regexp__      = re.compile(r"addpylib\s+(.+)\s+(.+)" )
 
 def init(data):