Function Passes can leave dangling pointers in CallGraph

[llvmbot]

Bugzilla Link	4029
Resolution	DUPLICATE
Resolved on	Sep 01, 2009 01:31
Version	unspecified
OS	Linux
Depends On	#3973
Attachments	Debugging patch that fires an assertion if the callgraph contains deleted instructions
Reporter	LLVM Bugzilla Contributor
CC	@lattner

Extended Description

The test Analysis/GlobalsModRef/purecse.ll runs opt -globalsmodref-aa -gvn -instcombine. The callgraph constructed for globalsmodref-aa is not destroyed
before gvn is run. Similarly, the test Transforms/CondProp/2007-08-01-InvalidRead.ll runs opt -inline -tailduplicate -condprop -simplifycfg, and
the callgraph constructed for -inline is not destroyed before simplifycfg is
run. This is in spite of the fact that gvn/simplifycfg neither require nor
preserve the callgraph.

Spotted using the attached debugging patch (which would be good to commit
one day). My guess is that this is essentially the same problem as #3973 .

[llvmbot]

*** Bug llvm/llvm-bugzilla-archive#4835 has been marked as a duplicate of this bug. ***

[llvmbot]

Note that llvm/llvm-bugzilla-archive#4835 (a duplicate) has an independent and more recent patch to make
callgraph use an asserting VH. It also has a different suggestion on how to
solve this PR.

[lattner]

Testing a patch for this.

[lattner]

*** This bug has been marked as a duplicate of bug #3973 ***

[llvmbot]

mentioned in issue llvm/llvm-bugzilla-archive#4835