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Make setInitializer() assert that the entire initializer is usable.
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Authored by arnt on Apr 12 2019, 6:42 AM.



Until now, it was possible to set an initilizer for e.g. a struct that
contained a global constant from some other module. The verifier would
complain, but the verifier's complaint doesn't point very accurately at
the problem.

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arnt created this revision.Apr 12 2019, 6:42 AM
Herald added a project: Restricted Project. · View Herald TranscriptApr 12 2019, 6:42 AM
arnt added a comment.Apr 12 2019, 6:43 AM

I picked reviewers by taking the last two people who changed the file, hope you don't mind.

You probably want to wrap that entire function into #ifndef NDEBUG


The style is usually

for(int I = 0, N = V->getNumOperands(); I != N; ++I)
  assertThatAllGlobalsAreIn(V->getOperand(--n), Correct);

well, s/--n/n/

arnt updated this revision to Diff 194876.Apr 12 2019, 7:17 AM

updated following comments from lebedev.ri; thanks

arnt marked 2 inline comments as done.May 14 2019, 5:15 AM


arnt updated this revision to Diff 206821.Jun 27 2019, 4:12 AM

Rebased to this morning's LLVM.

No changes were necessary.

arnt added a reviewer: pete.Jun 27 2019, 4:19 AM

pete: I took the liberty of adding you as reviewer since you made the most recent change to that function. 2015-06-02. Not exactly yesterday.

efriedma added inline comments.Jun 27 2019, 6:58 PM

Please clang-format this.

Can you check for ConstantAggregate here, instead of checking ConstantStruct and ConstantArray separately? Would it also make sense to check for ConstantExpr?

Can you use a for-range loop here? (for (auto *Op : V->operands()))

arnt updated this revision to Diff 207257.Jul 1 2019, 3:24 AM

Add unit test, plus some nonfunctional changes.

arnt marked 2 inline comments as done.Jul 1 2019, 3:29 AM

I like colon-for.


Oooh, I can call constants() now. Someone has added that. (Might be a while ago, this isn't exactly new code. ;-)

I changed it to test ConstantAggregate, and added a passing unit test involving ConstantExpr.

efriedma added inline comments.Jul 1 2019, 11:28 AM

Are you sure this actually does what you want? ConstantExpr::get() does basic constant folding.

arnt updated this revision to Diff 211433.Jul 24 2019, 12:23 AM
arnt marked an inline comment as done.

best take care of self-referential initialisers.

arnt updated this revision to Diff 211434.Jul 24 2019, 12:48 AM
arnt marked 2 inline comments as done.

More conservative testing, as half-suggested by efriedma.

I don't think you actually need a recursion guard; you only recurse on ConstantAggregates, and they can't refer to themselves circularly. But maybe it's a good idea anyway to avoid exponential compile-time in certain edge cases.


This test *still* isn't testing what you want; verification fails due to the other global variable.