[clang] [Clang SA]: add support for mismatched ownership_returns+ownership_takes calls for custom allocation classes (PR #98941)

[Pavel Skripkin via cfe-commits]

================
@@ -103,14 +103,49 @@ using namespace std::placeholders;
 namespace {
 
 // Used to check correspondence between allocators and deallocators.
-enum AllocationFamily {
+enum AllocationFamilyKind {
   AF_None,
   AF_Malloc,
   AF_CXXNew,
   AF_CXXNewArray,
   AF_IfNameIndex,
   AF_Alloca,
-  AF_InnerBuffer
+  AF_InnerBuffer,
+  AF_Custom,
+};
+
+struct AllocationFamily {
+  AllocationFamilyKind Kind;
+  std::optional<StringRef> CustomName;
+
+  explicit AllocationFamily(AllocationFamilyKind kind,
+                            std::optional<StringRef> name = std::nullopt)
+      : Kind(kind), CustomName(name) {
+    assert(kind != AF_Custom || name != std::nullopt);
+
+    // Preseve previous behavior when "malloc" class means AF_Malloc
+    if (Kind == AF_Malloc && CustomName) {
+      if (CustomName.value() == "malloc")
+        CustomName = std::nullopt;
+      else
+        Kind = AF_Custom;
+    }
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pskrgag wrote:

Sorry, I over-engineered things. 

I redo a bit. Now callers pass `AF_Custom` with `customName` set, instead of `AF_Malloc` 

https://github.com/llvm/llvm-project/pull/98941