Filter certain compile-time options into -DATF_BUILD_*

[ngie]

Summary

Filter certain compile-time options into -DATF_BUILD_*

Items filtered through are:

• Constant defines (-D)
• Include flags (-I)
• Linker flags (-L)
• Optimization level (-O)
• Warnings / linker flags (-W)
• Preprocessor options (-f)

This fixes the scenario hit by the Jenkins job where it's infecting
the build with --sysroot, etc options from the Jenkins build in the
tests.

MFC after: 2 weeks
Reported by: Jenkins
Sponsored by: EMC / Isilon Storage Division

[jmmv]

I think this is fine. I just wonder if we should just zero out the parameters instead, or hardcode them to known values. I can't imagine a well-behaving compiler that wouldn't correctly build the test programs just with a call to ${CC} and no explicit flags.

lib/atf/libatf-c/Makefile

33 ↗

(On Diff #19807)

While you are doing this, could you rename these variables to ATF_BUILD_*? It's weird they are prefixed just with an underscore.

Maybe just inline the values down below where the -D are defined.

[ngie]

In D7702#159902, @jmmv wrote:

I think this is fine. I just wonder if we should just zero out the parameters instead, or hardcode them to known values. I can't imagine a well-behaving compiler that wouldn't correctly build the test programs just with a call to ${CC} and no explicit flags.

It's a double edged sword depending on what you're trying to test..

User options specified - great for users because they know it's more likely to build if the options matched. Hard for maintainers though to debug.

User options omitted - great for maintainers because the failure "surface area" is lower, but it'll likely end up with support questions when a user specified "unexpected" compile-time flags.

lib/atf/libatf-c/Makefile

33 ↗

(On Diff #19807)

I can't inline the values below as I would be assigning a non-immediate (expanded) value to a non-immediate value, but I can definitely add a prefix.