-cov does not account for inline conditionals

[dlangBugzillaToGithub]

Andrei Alexandrescu (@andralex) reported this on 2014-09-23T15:24:26Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=13524

CC List

• yebblies

Description

Executing code with -cov does not account for things like:

auto x = condition ? fun() : gun();

If condition is always the same, one of the function calls isn't covered, and cov does not detect that. Writing the condition on 2-3 lines does work, but coverage analysis shouldn't require code reformatting.

(Same goes about the arguably less frequent

if (condition) fun(); else gun();

and other constructs that cram several statements on one line.)

Thoughts on how we could fix that? One idea for output is to write "000:nnn" instead of the customary "0000000", where nnn is the column number (999 for overflow).

Would this be doable?

[dlangBugzillaToGithub]

yebblies commented on 2014-11-04T09:52:52Z

(In reply to Andrei Alexandrescu from comment #0)
> 
> If condition is always the same, one of the function calls isn't covered,
> and cov does not detect that. Writing the condition on 2-3 lines does work,
> but coverage analysis shouldn't require code reformatting.
> 

It does require reformatting, because dmd's coverage is line-based.  I would expect an expression-based coverage implementation to be much more complicated, both in output format and internal implementation.