Fix crash on missing register description in SVD file

[aurabindo]

SVDs available for DA1469x from https://www.keil.com/dd2/pack have few registers with missing <description> and this causes svd2rust to crash.

This PR enables to continue with a dummy description and print name of the
problematic register instead of just bailing out.

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @therealprof (or someone else) soon.

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[therealprof]

I haven't looked in detail but maybe we could add the no description text earlier than when generating the output. Oh, and would be great if the no-description description was a bit shorter; no need to be verbose here...

[Disasm]

@therealprof That description field isn't mandatory in SVD spec, so it's ok to get None from svd parser. What do you mean by "earlier" then?

[therealprof]

@Disasm It's a bit unfortunate that we're using the parsed SVD, patch it up and turn it into code all in the same place. Instead it'd be great if we had a pass which used the parsed SVD, checks whether it makes sense, cleans up the odds bits and fills in missing bits so we finally just dump the consistent information into code.

[aurabindo]

@therealprof how about an empty String ("") or do you prefer No description ?

[therealprof]

@therealprof A slight hint would be nice, so "" is not ideal. I'll leave it up to you to figure out what that is, surprise me with a short and descriptive comment. 😉

[aurabindo]

Well that was my version of Slight hint ;) I'll just put "Dummy description" ? Or maybe "Bad SVD" ?

[therealprof]

Well, descriptions are optional so "Bad SVD" would be technically wrong. It should be something which hints to the "problem" at hand, so "Nothing" or just "No description" would work for me. While you are at it, please add a line to the CHANGELOG and rebase the commit.

[therealprof]

Hm, coming to thing of it an empty String would also be acceptable (if Rust accepts that).

[therealprof]

LGTM, thanks!

[therealprof]

bors r+

[bors]

Build succeeded

• continuous-integration/travis-ci/push