* feat: allow identifiers in string concatenations
Resolves errors in strings of the form:
("failed in line %" PRIdLINENR)
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Co-authored-by: Lewis Russell <lewis6991@gmail.com>
According to cppreference, identifiers are `(XID_Start | '_')
XID_Continue*`, which is the case as of C++23 and C2x. I have confirmed
this myself with the drafts of C++23 and C2x.
https://en.cppreference.com/w/cpp/language/identifiers
Clang indeed implements identifiers as `(XID_Start | '_') XID_Continue*`
in C++ mode and C2x mode, with a slight extension to the character set
to include some extra math characters:
231992d9b8/clang/lib/Lex/Lexer.cpp (L1517-L1530)
This also lets it bind to _any_ statement, which is necessary for some
c++ attributes that can attach to the statement in if, while, and
do/while statements.
* Add support for C23 attributes
https://en.cppreference.com/w/c/language/attributes
* Use wrapper for statements with attributes to reduce state machine size
* Missed a couple _declarators that needed attributes directly after
* Use annotated_declarator for declarators that have attributes immediately following them
* Give field and type declarators the same attribute treatment
* Parse expressions in preprocessor #if statement
* Make preproc_expression look like a normal expression
* Hide the wrapper rules
* Alias the rulres to match their corresponding expression rule
* Handle line continuations as extra tokens