588051 - Need more compile time or runtime switches to activate code paths

Status: RESOLVED WONTFIX

(Tamarin Graveyard :: Build Config, defect)

Description

[Brent Baker]

The tamarin team is being tasked to push code coverage to 100% function coverage, 80% condition within the VM, however there is code within the VM that requires code changes in order to activate. When this happens the code coverage tools that we are using no longer sees the source file as being the same and only the latest coverage data is used when data is merged together. This will make it impossible for us to have a unified view of code coverage.


Example:
In order to get coverage on MMgc::GC validateDefRef() you need to modify the GC constructor to set validateDefRef(true). This causes a problem when we try and merge coverage data from say a normal "debug-debugger" build of the vm. Since the source file is no longer the same, the merge tool will only keep the most recent coverage data and throw away the rest. So this would mean that MMgc/GC.cpp coverage data will not be a complete view of the coverage of the source.


Reference:
http://www.bullseye.com/help/ref_covmerge.html

NOTES
If covmerge encounters measurements from the same source file with two
different modification times, covmerge discards the older measurements.

Comment 1

[Lars T Hansen]

I guess we can do this within reason, though it tends to introduce complexity and it may introduce slowdowns - it may not be possible to handle every case this way.  (After all we have a lot of compile-time switches too - would it be a valid solution to make validateDefRef a compile-time switch?)

Comment 2

[Trevor Baker]

Adding Dan and Andre for feedback.

Comment 3

[Edwin Smith]

Should this be a tracker with individual bugs for separate problem areas?   If the example in the description is just one of many cases, what are the other cases?

Comment 4

[Trevor Baker]

Please log individual bugs with specific instances of problems where additional testing support is desired.  This is a broad problem statement as written and needs to be more specific.