dtrace/tests: compile D sources at runtime on test target

[siva]

Summary

Previously, we would precompile D test dependencies using the
host's dtrace, which unconditionally outputs ELF files in the
host's format. This breaks the cross-compile build with errors
like the following:

dtrace: failed to link script: incorrect ELF machine type for
object file: tst.usdt.pieo

• usdt.o ---
• Failed target: usdt.o

This patch moves compilation to runtime for all C-based testcases
that have a dependent D source file.

[markj]

This is fine I guess, but ideally dtrace would support cross-compilation. It'd take some work though: to start, dt_link.c would need some notion of a target platform where today it uses ifdefs. I don't object to your approach though, if it solves some immediate problem.

cddl/usr.sbin/dtrace/tests/tools/dtest.sh

59

There should be some comment explaining what this is doing, and why.

cddl/usr.sbin/dtrace/tests/tools/genmakefiles.sh

70

Can't we just set this to ${TFILES} ${CFILES} in each makefile? That should make the diff smaller.

[siva]

v2

[siva]

cddl/usr.sbin/dtrace/tests/tools/dtest.sh

59

Hope this is sufficient. Yeah I'd like to get the tests running on all archs first, this is just a short term fix.

cddl/usr.sbin/dtrace/tests/tools/genmakefiles.sh

70

Good idea, thanks!