Assertion `false && "Fix conflicts with existing fix!"' failed.

[mikaelholmen]

Bugzilla Link	35408
Version	unspecified
OS	Linux
Attachments	reproducer
CC	@henrickarlsson

Extended Description

clang-tidy foo.c --

on foo.c only containing

a = a && 3;

gives a failed assertion:

Fix conflicts with existing fix! The new replacement overlaps with an existing replacement.
New replacement: /data/repo/llvm-dev2/foo.c: 5:+5:""
Existing replacement: /data/repo/llvm-dev2/foo.c: 6:+2:"&"
clang-tidy: ../tools/clang/tools/extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp:86: virtual void (anonymous namespace)::ClangTidyDiagnosticRenderer::emitCodeContext(clang::FullSourceLoc, DiagnosticsEngine::Level, SmallVectorImplclang::CharSourceRange &, ArrayRefclang::FixItHint): Assertion `false && "Fix conflicts with existing fix!"' failed.
Abort

Changing the input to:

a = a && 1;

avoids the crash and instead we get a bunch of (seemingly correct) warnings.

The crash started appearing with clang-tools-extra commit r284399 2016-10-17:

[clang-tidy] Clean up code after applying replacements.

Summary:
Remove empty namespaces and initializer list commas / colons in
affected ranges. Initial patch: proper options for enabling the cleanup and
specifying the format style are needed.

Reviewers: hokein, ioeric

Subscribers: beanz, mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D24572


git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@284399 91177308-0d34-0410-b5e6-96231b3b80d8

[henrickarlsson]

Problem seem to originate from that we have found two different replacements.

I don't see a need for the assert unless we have actually used the -fix or -fix-error flag. Then you can at least get the diagnostics.

Maybe it's possible to save both solutions and try to resolve the conflict when they are actually applied, and if it can't be resolved, just leave the code untouched. But this is probably a more complex change.

[carlosgalvezp]

No longer reproducible on trunk, closing.
https://godbolt.org/z/Mha6aPa1j

[mikaelholmen]

I think this was fixed by abbe9e2

[clang-tidy] Added command line option `fix-notes`

Added an option to control whether to apply the fixes found in notes attached to clang tidy errors or not.
Diagnostics may contain multiple notes each offering different ways to fix the issue, for that reason the default behaviour should be to not look at fixes found in notes.
Instead offer up all the available fix-its in the output but don't try to apply the first one unless `-fix-notes` is supplied.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D84924