[clang] Warn when unique objects might be duplicated in shared libraries (PR #117622)

[Hans Wennborg via cfe-commits]

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@@ -13386,6 +13386,62 @@ void Sema::checkNonTrivialCUnion(QualType QT, SourceLocation Loc,
         .visit(QT, nullptr, false);
 }
 
+bool Sema::GloballyUniqueObjectMightBeAccidentallyDuplicated(
+    const VarDecl *dcl) {
+  if (!dcl || !getLangOpts().CPlusPlus)
+    return false;
+
+  // If an object is defined in a source file, its definition can't get
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zmodem wrote:

At this point it's not clear that we're looking at a definition, so maybe move this check below the "is this a definition" check below?

https://github.com/llvm/llvm-project/pull/117622