[PATCH] D84600: [Analyzer] Support note tags for smart ptr checker

Sun Aug 9 11:34:21 PDT 2020

NoQ added inline comments.

================
Comment at: clang/test/Analysis/smart-ptr-text-output.cpp:79
+
+// TODO: Enabale this test when "std::swap" is modeled seperately.
+void derefOnStdSwappedNullPtr() {
----------------
vrnithinkumar wrote:
> vrnithinkumar wrote:
> > NoQ wrote:
> > > Instead of commenting out tests, i recommend testing the incorrect behavior (with a FIXME comment telling us why it's incorrect). This way we'll be notified when the test is fixed, accidentally or intentionally, and also generally that's more testing for everybody.
> > I have commented out this since right now `std::swap` is using `unique_ptr.swap`.
> > So note tag for std::swap is added in header file  `system-header-simulator-cxx.h`
> > eg:
> > `system-header-simulator-cxx.h Line 978: Swapped null smart pointer 'PNull' with smart pointer 'P'`
> - Is it okay to add a expected-note on `system-header-simulator-cxx.h`?
Aha, i see.

It's obviously not ok because the header is included by multiple tests but only some tests will have the note show up.

The usual solution is to put the expected-note comment in the current test file but make it refer to the header. Here's doc from https://clang.llvm.org/doxygen/classclang_1_1VerifyDiagnosticConsumer.html:
> If the diagnostic is generated in a separate file, for example in a shared header file, it may be beneficial to be able to declare the file in which the diagnostic will appear, rather than placing the expected-* directive in the actual file itself. This can be done using the following syntax:
> ```// expected-error at path/include.h:15 {{error message}}```

It still is a bit of a problem that you have to hardcode the line number (so everybody who modifies the header above your note will have to update your test) but that's not a big deal.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D84600/new/

https://reviews.llvm.org/D84600