Fix matching of regex patterns lacking a right-anchor:

[zcutlip]

• This addresses issue #310
• ctags sometimes omits the right-anchor ('$') from its regexes
• This seems to happen with C macros
• Split ex_command into the pattern, sans right-anchor plus:
  • an optional '$' anchor is there was one to start with
• Return a tuple: (pattern, optional_anchor)
• When later searching for the pattern, add the anchor or empty string back on

[stephenfin]

I haven't touched this for quite some time and no longer use it myself, therefore I'm unable to test this :( I'd be willing to blindly merge it but how well tested is it?

[zcutlip]

Not terribly well tested. I tried it out on some fairly complex open source kernel code, but that's about it. Do you have a set of tests or some sort of testing process I can do?

[stephenfin]

Not particularly. There are some unit tests but I'm not sure how applicable they are. If you've been using this for some time, that's probably good enough testing

[anatol]

@zcutlip thank you for fixing the issue.

I see more things with C code and incorrect regexps. For example a bunch of functions in Linux tree are not properly CTagged. e.g. jumping to arch_local_irq_restore does not work. Looking at tags file I see

arch_local_irq_restore  arch/x86/include/asm/irqflags.h /^static inline notrace void arch_local_irq_restore(unsigned long flags)$/;"    f       typeref:typename:notrace void   signature:(unsigned long flags)
arch_local_irq_restore  arch/x86/include/asm/paravirt.h /^static inline notrace void arch_local_irq_restore(unsigned long f)$/;"        f       typeref:typename:notrace void   signature:(unsigned long f)
arch_local_irq_restore  include/asm-generic/irqflags.h  /^void arch_local_irq_restore(unsigned long flags);$/;" p       typeref:typename:void   signature:(unsigned long flags)

I wonder if parethesis in the regexp should be escaped. But as it is harder to change CTgas behavior maybe the plugin should workaround the pproblem?