Add attributions so printf like functions can have their arguments checked.

Add attributions so printf like functions can have their arguments checked.

This change also corrects some misuses of format strings and format
arguments that discovered by the compiler checks.

Committed: https://code.google.com/p/dart/source/detail?r=11912

[cshapiro, 2012-08-25 04:03:08]

I believe the size of this change is, in part, a reflection of the overuse of
intptr_t.  For example, the basic block numbers in the compiler could just as
easily be an int instead of an intptr_t.  Similarly, the class id could easily
be an int (or int32_t) instead of an intptr_t.

I believe it is important to add the format attributes but I have no strong
convictions about submitting this change as-is.  I would pleased to hold off
pending changes in the compiler, class id, etc. to eliminate the need for so
many "PRI(mumble)PTR" format control substrings.

[turnidge, 2012-08-26 03:34:54]

Hi Carl,

I looked over the changes and didn't see any errors.  I'll let Ivan and Siva
comment on what they think of the new format specifiers.  I'll just say that,
although it is ugly, it makes me feel happier having the compiler check our
printf args for us.

There are a few other printf-style functions not in the CL.  For example,
Api::NewError in dart_api_impl.h seems to be not in the CL.  Also, there are a
couple of printf-style functions in dart_api.h, but I'm not sure that there is
any nice portable way to drop the annotation into that file.

Todd

[cshapiro, 2012-08-28 04:31:01]

I have fixed Api::NewError and added PRINTF_ATTRIBUTE to some other functions.

Per our off-line conversation, I would like to submit a 2nd change which adds
the printf checks to dart_api.h as there are probably a lot of callers in bin
which will need to be fixed up.  One Jupiterian code review at a time...

[turnidge, 2012-08-28 18:18:56]

lgtm for turndige.

Took a look again.  Still fine.  Thanks for new additions.

[Ivan Posva, 2012-08-28 23:46:43]

Carl,

I like the checking of arguments, but we should discuss alternatives to reduce
the string formatting overhead. I have no good solutions in mind, but hopefully
we find something that works better than PRIxPTR and friends.

-Ivan

[cshapiro, 2012-08-29 00:26:03]

Hi Ivan,

I think the only way to reduce the amount of format string overhead is to make
more pervasive use of int.  There are a lot of places where we are using
intptr_t when we do not need the additional dynamic range. As an example, I
think the basic block numbers in the compiler could be converted to an int as it
is unlikely that 1) one will ever have more than 2 billion basic blocks and 2)
the number of basic blocks needs to scale with the pointer width of a machine.

Would you like me to hold off on committing pending that discussion?  Just let
me know how you would like this to go.

Carl