[clang] nonblocking/nonallocating attributes: 2nd pass caller/callee analysis (PR #99656)

[via cfe-commits]

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@@ -15074,6 +15012,106 @@ class Sema final : public SemaBase {
   std::string getFixItZeroLiteralForType(QualType T, SourceLocation Loc) const;
 
   ///@}
+
+  //
+  //
+  // -------------------------------------------------------------------------
+  //
+  //
+
+  /// \name Function Effects
+  /// Implementations are in SemaFunctionEffects.cpp
+  ///@{
+public:
+  struct FunctionEffectDiff {
+    enum class Kind { Added, Removed, ConditionMismatch };
+
+    FunctionEffect::Kind EffectKind;
+    Kind DiffKind;
+    FunctionEffectWithCondition Old; // invalid when Kind is Added.
+    FunctionEffectWithCondition New; // invalid when Kind is Removed.
+
+    StringRef effectName() const {
+      if (Old.Effect.kind() != FunctionEffect::Kind::None)
+        return Old.Effect.name();
+      return New.Effect.name();
+    }
+
+    /// Describes the result of effects differing between a base class's virtual
+    /// method and an overriding method in a subclass.
+    enum class OverrideResult {
+      NoAction,
+      Warn,
+      Merge // Merge missing effect from base to derived.
+    };
+
+    /// Return true if adding or removing the effect as part of a type
+    /// conversion should generate a diagnostic.
+    bool shouldDiagnoseConversion(QualType SrcType,
+                                  const FunctionEffectsRef &SrcFX,
+                                  QualType DstType,
+                                  const FunctionEffectsRef &DstFX) const;
+
+    /// Return true if adding or removing the effect in a redeclaration should
+    /// generate a diagnostic.
+    bool shouldDiagnoseRedeclaration(const FunctionDecl &OldFunction,
+                                     const FunctionEffectsRef &OldFX,
+                                     const FunctionDecl &NewFunction,
+                                     const FunctionEffectsRef &NewFX) const;
+
+    /// Return true if adding or removing the effect in a C++ virtual method
+    /// override should generate a diagnostic.
+    OverrideResult shouldDiagnoseMethodOverride(
+        const CXXMethodDecl &OldMethod, const FunctionEffectsRef &OldFX,
+        const CXXMethodDecl &NewMethod, const FunctionEffectsRef &NewFX) const;
+  };
+
+  struct FunctionEffectDifferences : public SmallVector<FunctionEffectDiff> {
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Sirraide wrote:

Maybe calling this `FunctionEffectDiffVector` would make it more obvious what the purpose of this is.

https://github.com/llvm/llvm-project/pull/99656