Hi! This series implements the -Wclobbered warning on GIMPLE in place of the old RTL implementation.
This cover letter contains a high-level explanation of what is going on and why. The new implementation itself is in the patch 3. I will post the details in the accompanying blurb. The most obvious benefit of doing it on GIMPLE is making this warning independent of the specific register allocation decisions the RA makes. I.e. if there is a possibility of a different compiler allocating a variable to a register live through the setjmp call, but in the current compilation it got spilled, the existing implementation does not give a warning. So the new implementation strives to indicate as many potential errors in the code as it can, not limited to the problems pertinent to this compilation with this particular compiler. This is in line with e.g. what Tom Lane (of PostgreSQL) expressed interest in seeing [1]. Also, in order to suppress spurious warnings, it is sometimes useful to distinguish paths realizable after the second (and subsequent) returns from setjmp vs. realizable only after the first return (see PR 21161). The new implementation does that using a simple heuristic. All comments are appreciated. Is this OK for trunk? [1] https://bugzilla.redhat.com/show_bug.cgi?id=1185673#c5 Thanks, Vlad
