[clang-tools-extra] [clangd] Harden incomingCalls() against possible misinterpretation of a range as pertaining to the wrong file (PR #111616)

[Haojian Wu via cfe-commits]

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@@ -2292,9 +2289,26 @@ incomingCalls(const CallHierarchyItem &Item, const SymbolIndex *Index) {
   Index->lookup(ContainerLookup, [&](const Symbol &Caller) {
     auto It = CallsIn.find(Caller.ID);
     assert(It != CallsIn.end());
-    if (auto CHI = symbolToCallHierarchyItem(Caller, Item.uri.file()))
+    if (auto CHI = symbolToCallHierarchyItem(Caller, Item.uri.file())) {
+      SymbolLocation CallerLoc =
+          Caller.Definition ? Caller.Definition : Caller.CanonicalDeclaration;
+      std::vector<Range> FromRanges;
+      for (const SymbolLocation &L : It->second) {
+        if (StringRef{L.FileURI} != StringRef{CallerLoc.FileURI}) {
+          elog("incomingCalls: call location not in same file as caller, this "
----------------
hokein wrote:

I think this case is possible.

```
// t.h
#pragma  once
#define abc2 void test4() {

// t.cc
#include "./t.h"

void func();

abc 
  func();
}
```

calling call-hierarchy for `func()`.

https://github.com/llvm/llvm-project/pull/111616