[llvm] [BOLT] Gadget scanner: refactor analysis of RET instructions (PR #131897)

[Anatoly Trosinenko via llvm-commits]

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@@ -199,19 +199,34 @@ struct Report {
   virtual void generateReport(raw_ostream &OS,
                               const BinaryContext &BC) const = 0;
 
+  virtual const ArrayRef<MCPhysReg> getAffectedRegisters() const { return {}; }
+  virtual void
+  setOverwritingInstrs(const std::vector<MCInstReference> &Instrs) {}
+
   void printBasicInfo(raw_ostream &OS, const BinaryContext &BC,
                       StringRef IssueKind) const;
 };
 
 struct GadgetReport : public Report {
   const GadgetKind &Kind;
+  SmallVector<MCPhysReg> AffectedRegisters;
   std::vector<MCInstReference> OverwritingInstrs;
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atrosinenko wrote:

Kept these fields vectors (but both are `SmallVector`s now), added comments. With `SmallVector` one could return `SmallVectorImpl &` without hard-coding the size parameter or even return `ArrayRef` (which handles `std::vector` as well), but there doesn't seem to be similar option for `SmallSet`.

https://github.com/llvm/llvm-project/pull/131897