[PATCH] D144074: [clangd] Hide inlay hints when using a macro as a calling argument that with a param comment

[Nathan Ridge via Phabricator via cfe-commits]

nridge added inline comments.


================
Comment at: clang-tools-extra/clangd/InlayHints.cpp:520
     auto ExprStartLoc = SM.getTopMacroCallerLoc(E->getBeginLoc());
-    auto Decomposed = SM.getDecomposedLoc(ExprStartLoc);
+    auto Decomposed = SM.getDecomposedExpansionLoc(ExprStartLoc);
     if (Decomposed.first != MainFileID)
----------------
I admit I struggle with this spelling/expansion loc stuff. But having spent a bit of time reading the implementations of these functions, would I be correct to say that another, perhaps easier to follow, way to express the same thing would be:

```
auto Decomposed = SM.getDecomposedLoc(SM.getFileLoc(E->getBeginLoc()));
```

?


================
Comment at: clang-tools-extra/clangd/InlayHints.cpp:521
+    auto Decomposed = SM.getDecomposedExpansionLoc(ExprStartLoc);
     if (Decomposed.first != MainFileID)
       return false;
----------------
zyounan wrote:
> stupid question: I was suspicious with this check that when would `Decomposed.first` not being the same as MainFileID? Should the "top-caller" of the macro always be in main file? I didn't find a case that differs, except when `getDecomposedLoc` provides wrong FileID.
I tried adding an assertion in this early-return branch, and it tripped in `ParameterHints.IncludeAtNonGlobalScope`.

The code there is:

```
  Annotations FooInc(R"cpp(
    void bar() { foo(42); }
  )cpp");
  Annotations FooCC(R"cpp(
    struct S {
      void foo(int param);
      #include "foo.inc"
    };
  )cpp");
```

so I guess the decomposed loc there is a file loc, but not in the main file (but rather in `foo.inc`).


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D144074/new/

https://reviews.llvm.org/D144074