[NFCI][cfi] Refactor into 'SanitizerInfoFromCFICheckKind' (#140117)

This refactors existing code into a 'SanitizerInfoFromCFICheckKind'
helper function. This will be useful in future work to annotate CFI
checks with debug info
(#139809).

Author: thurstond

clang/lib/CodeGen/CGClass.cpp

@@ -2784,6 +2784,29 @@ void CodeGenFunction::EmitTypeMetadataCodeForVCall(const CXXRecordDecl *RD,
   }
 }
 
+/// Converts the CFITypeCheckKind into SanitizerKind::SanitizerOrdinal and
+/// llvm::SanitizerStatKind.
+static std::pair<SanitizerKind::SanitizerOrdinal, llvm::SanitizerStatKind>
+SanitizerInfoFromCFICheckKind(CodeGenFunction::CFITypeCheckKind TCK) {
+  switch (TCK) {
+  case CodeGenFunction::CFITCK_VCall:
+    return std::make_pair(SanitizerKind::SO_CFIVCall, llvm::SanStat_CFI_VCall);
+  case CodeGenFunction::CFITCK_NVCall:
+    return std::make_pair(SanitizerKind::SO_CFINVCall,
+                          llvm::SanStat_CFI_NVCall);
+  case CodeGenFunction::CFITCK_DerivedCast:
+    return std::make_pair(SanitizerKind::SO_CFIDerivedCast,
+                          llvm::SanStat_CFI_DerivedCast);
+  case CodeGenFunction::CFITCK_UnrelatedCast:
+    return std::make_pair(SanitizerKind::SO_CFIUnrelatedCast,
+                          llvm::SanStat_CFI_UnrelatedCast);
+  case CodeGenFunction::CFITCK_ICall:
+  case CodeGenFunction::CFITCK_NVMFCall:
+  case CodeGenFunction::CFITCK_VMFCall:
+    llvm_unreachable("unexpected sanitizer kind");
+  }
+}
+
 void CodeGenFunction::EmitVTablePtrCheckForCall(const CXXRecordDecl *RD,
                                                 llvm::Value *VTable,
                                                 CFITypeCheckKind TCK,
@@ -2847,30 +2870,7 @@ void CodeGenFunction::EmitVTablePtrCheck(const CXXRecordDecl *RD,
       !CGM.HasHiddenLTOVisibility(RD))
     return;
 
-  SanitizerKind::SanitizerOrdinal M;
-  llvm::SanitizerStatKind SSK;
-  switch (TCK) {
-  case CFITCK_VCall:
-    M = SanitizerKind::SO_CFIVCall;
-    SSK = llvm::SanStat_CFI_VCall;
-    break;
-  case CFITCK_NVCall:
-    M = SanitizerKind::SO_CFINVCall;
-    SSK = llvm::SanStat_CFI_NVCall;
-    break;
-  case CFITCK_DerivedCast:
-    M = SanitizerKind::SO_CFIDerivedCast;
-    SSK = llvm::SanStat_CFI_DerivedCast;
-    break;
-  case CFITCK_UnrelatedCast:
-    M = SanitizerKind::SO_CFIUnrelatedCast;
-    SSK = llvm::SanStat_CFI_UnrelatedCast;
-    break;
-  case CFITCK_ICall:
-  case CFITCK_NVMFCall:
-  case CFITCK_VMFCall:
-    llvm_unreachable("unexpected sanitizer kind");
-  }
+  auto [M, SSK] = SanitizerInfoFromCFICheckKind(TCK);
 
   std::string TypeName = RD->getQualifiedNameAsString();
   if (getContext().getNoSanitizeList().containsType(