[PATCH] D57883: [clang-tidy] refactor ExceptionAnalyzer further to give ternary answer

[Roman Lebedev via Phabricator via cfe-commits]

lebedev.ri accepted this revision.
lebedev.ri added a comment.
This revision is now accepted and ready to land.

Sorry for the reviews, i'm really stalling it seems..

This looks like a straight-forward change, but i'm not sure i'm familiar enough with ExceptionAnalyzer to fully properly review this..
As far as i can tell, this is ok. Perhaps @baloghadamsoftware will have other remarks.

In D57883#1402023 <https://reviews.llvm.org/D57883#1402023>, @baloghadamsoftware wrote:

> If I understand it correctly, this is more of an infrastructure improvement than check enhancement. It looks like a nice and clean code. Where do we expect to use this new behavior? In the current check or in the upcoming "modernize" check?


It's for D57108 <https://reviews.llvm.org/D57108>, i'we guessed that such ternary answer will be required there.



================
Comment at: clang-tidy/utils/ExceptionAnalyzer.h:218
   llvm::StringSet<> IgnoredExceptions;
-  llvm::DenseMap<const FunctionDecl *, bool> FunctionCache;
+  std::map<const FunctionDecl *, ExceptionInfo> FunctionCache;
 };
----------------
JonasToth wrote:
> lebedev.ri wrote:
> > Why can't `llvm::DenseMap` continue to be used?
> I would need to add traits for `ExceptionInfo` to work with `DenseMap`. So i went this way :)
> From the docs `DenseMap` shall map small types (like ptr-ptr) but the `ExceptionInfo` has the set of types as `SmallSet<Type*, 8>`, so not sure if that is actually a good fit.
Good point.


================
Comment at: clang-tidy/utils/ExceptionAnalyzer.h:26-31
+  enum class State : std::int8_t {
+    Throwing,    ///< The function can definitly throw given an AST.
+    NotThrowing, ///< This function can not throw, given an AST.
+    Unknown,     ///< This can happen for extern functions without available
+                 ///< definition.
+  };
----------------
Since this is later used in a bit field, it might be better to be explicit 
```
  enum class State : std::int8_t {
    Throwing = 0,    ///< The function can definitly throw given an AST.
    NotThrowing = 1, ///< This function can not throw, given an AST.
    Unknown = 2,     ///< This can happen for extern functions without available
                 ///< definition.
  };
```
and indeed, only 2 bits needed.


Repository:
  rCTE Clang Tools Extra

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  https://reviews.llvm.org/D57883/new/

https://reviews.llvm.org/D57883