[clang] [APINotes] Diagnose invalid Where.Parameters selectors (PR #209408)

[Gábor Horváth via cfe-commits]

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@@ -0,0 +1,99 @@
+//===--- SemaAPINotesInternal.h - API Notes Sema Internals ------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_LIB_SEMA_SEMAAPINOTESINTERNAL_H
+#define LLVM_CLANG_LIB_SEMA_SEMAAPINOTESINTERNAL_H
+
+#include "clang/APINotes/Types.h"
+#include "clang/Basic/SourceLocation.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/STLFunctionalExtras.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include <string>
+#include <utility>
+
+namespace clang {
+class Sema;
+struct APINotesParameterSelectorCandidates;
+namespace api_notes {
+class APINotesReader;
+} // namespace api_notes
+
+/// Source name and location for a declaration seen by Sema.
+struct APINotesSelectorDiagnosticName {
+  SourceLocation Loc;
+  std::string Name;
+};
+
+/// Tracks exact Where.Parameters selectors from one API notes reader.
+///
+/// Sema marks selectors as used when a visible declaration matches them. It
+/// also records broad/name-only declarations seen in the translation unit, so
+/// end-of-TU diagnostics can warn about exact selectors for known names that
+/// were never matched.
+struct APINotesSelectorDiagnosticReaderState {
+  /// Exact Where.Parameters selector keys stored by API notes. The bool is
+  /// true once Sema sees a declaration matching the exact selector.
+  llvm::DenseMap<api_notes::APINotesFunctionSelectorKey, bool> SelectorUsed;
+
+  /// Maps broad/name-only keys to a declaration location/name used for
+  /// diagnostics.
+  llvm::DenseMap<api_notes::APINotesFunctionSelectorKey,
+                 APINotesSelectorDiagnosticName>
+      SeenNames;
+
+  void addSelector(const api_notes::APINotesFunctionSelectorKey &Key) {
+    SelectorUsed.try_emplace(Key, false);
+  }
+
+  void
+  addSelectors(llvm::SmallVectorImpl<api_notes::APINotesFunctionSelectorKey>
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Xazax-hun wrote:

This only reads the vector, could take an `ArrayRef` by value instead.

https://github.com/llvm/llvm-project/pull/209408