allows any character in the variable name #1086
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BIL and Core Theory variable literals can contain only a specific set of valid characters. Thus approach doesn't play nice with various manglers and non-C languages as well as contradicts with our own tradition as we generally tend to allow any character in variables, see our Knowledge variables for example (and which are used underneath the hood of CT and BIL variables). One of the real-world examples where bap fails is the new C++ code with lambdas, that uses `#` for anonymous variables. In this proposal we allow any string (including the empty one) to be used as a variable name. First of all, we escape any non-printable or whitespace characters. We also escape '.' as we use it for variable versioning. Next, if a prospective variable name starts from a digit, is empty, or starts with `$` or `#` (which we use to encode de-bruijin style variables) we prefix them with `_`. Note, that escaping whitespaces and non-printable characters is really not necessary, but helps with the textual representation of the variable name, in case if we hit one.
gitoleg
approved these changes
Mar 26, 2020
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BIL and Core Theory variable literals can contain only a specific
set of valid characters. This approach doesn't play nice with various
manglers and non-C languages as well as contradicts with our own
tradition as we generally tend to allow any character in variables,
see our Knowledge variables for example (and which are used underneath
the hood of CT and BIL variables).
One of the real-world examples where bap fails is the new C++ code
with lambdas, that uses
#for anonymous variables.In this proposal we allow any string (including the empty one) to be
used as a variable name. First of all, we escape any non-printable or
whitespace characters. We also escape '.' as we use it for variable
versioning. Next, if a prospective variable name starts from a digit,
is empty, or starts with
$or#(which we use to encode de-Bruijnstyle variables) we prefix them with
_.Note, that escaping whitespaces and non-printable characters is really
not necessary, but helps with the textual representation of the
the variable name, in case, if we hit one.