[PATCH] D123352: [analyzer] Add FixItHint to `nullability.NullReturnedFromNonnull` and `nullability.NullableReturnedFromNonnull`

[Moshe via Phabricator via cfe-commits]

MosheBerman planned changes to this revision.
MosheBerman added a comment.

Thanks for all the thoughtful and fantastic feedback!



================
Comment at: clang/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp:592-602
+  // If we're inside of an NS_ASSUME, then the sourceRange will end before the
+  // asterisk.
+  const auto CanonicalTypeSize = CanonicalTypeStr.size();
+  const bool IsInsideOfAssume =
+      NullabilityLoc == RetTypeLoc.getSourceRange().getBegin().getLocWithOffset(
+                            CanonicalTypeSize - 1);
+
----------------
steakhal wrote:
> Uh, this is really ugly. I don't believe this is the preferred way of detecting this. @NoQ WDYT?
> Uh, this is really ugly.

It is really ugly. And a more correct implementation would probably handle some of the edge cases highlighted in the diff summary. It’s on me - being a n00b at llvm stuff. 

By “_this_” do you mean `IsInsideOfAssume` or `UseSyntaxSugar` in general?

> I don't believe this is the preferred way of detecting this. @NoQ WDYT?

I tried `isMacroExpansion` for assume nonnull, passing the end loc of the return type without success. 

A colleague suggested [SourceManager::isMacroBodyExpansion](https://clang.llvm.org/doxygen/classclang_1_1SourceManager.html#a04eadd011628b7c4cd3304712c8c221c). I’ll look at it again later today. 

Thank you so much for your patience and direction with reviews as I work on this. I really appreciate you making time for me!


================
Comment at: clang/test/Analysis/nullability-fixits.mm:5-10
+// RUN: %clang_cc1 -analyze \
+
+// RUN: -Wno-nonnull \
+// RUN: -analyzer-checker=core,nullability.NullableReturnedFromNonnull,nullability.NullReturnedFromNonnull \
+// RUN: -fdiagnostics-parseable-fixits %s 2>%t
+// RUN: cat %t | FileCheck %s -check-prefix=CHECK-FIXIT-DISABLED-IMPLICIT
----------------
steakhal wrote:
> Why don't you use the `%clang_analyze_cc1 ...` form instead or even better the `%check_analyzer_fixit` tool-subst pattern?
> See the `clang/test/Analysis/dead-stores.c` as an example.
That’s a good call out. I looked at that exact test and was having trouble testing. Instead, I implemented the RUN commands from the most basic invocation I could find. 

I’m happy to update the tests that verify that fixits are emitted. For the one that checks that fixits are applied, is there a better way? The `-verify` flag doesn’t do that, from what I saw in the docs. 


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D123352/new/

https://reviews.llvm.org/D123352