[clang] [analyzer][NFC] Make RegionStore dumps deterministic (PR #115615)

[Balazs Benics via cfe-commits]

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@@ -232,27 +233,86 @@ class RegionBindingsRef : public llvm::ImmutableMapRef<const MemRegion *,
 
   void printJson(raw_ostream &Out, const char *NL = "\n",
                  unsigned int Space = 0, bool IsDot = false) const {
-    for (iterator I = begin(), E = end(); I != E; ++I) {
-      // TODO: We might need a .printJson for I.getKey() as well.
+    using namespace llvm;
+    DenseMap<const MemRegion *, std::string> StringifyCache;
+    auto ToString = [&StringifyCache](const MemRegion *R) {
+      auto [Place, Inserted] = StringifyCache.try_emplace(R);
+      if (!Inserted)
+        return Place->second;
+      std::string Res;
+      raw_string_ostream OS(Res);
+      OS << R;
+      Place->second = Res;
+      return Res;
+    };
+
+    using Cluster =
+        std::pair<const MemRegion *, ImmutableMap<BindingKey, SVal>>;
+    using Binding = std::pair<BindingKey, SVal>;
+
+    const auto MemSpaceBeforeRegionName = [&ToString](const Cluster *L,
+                                                      const Cluster *R) {
+      if (isa<MemSpaceRegion>(L->first) && !isa<MemSpaceRegion>(R->first))
+        return true;
+      if (!isa<MemSpaceRegion>(L->first) && isa<MemSpaceRegion>(R->first))
+        return false;
+      return ToString(L->first) < ToString(R->first);
+    };
+
+    const auto SymbolicBeforeOffset = [&ToString](const BindingKey &L,
+                                                  const BindingKey &R) {
+      if (L.hasSymbolicOffset() && !R.hasSymbolicOffset())
+        return true;
+      if (!L.hasSymbolicOffset() && R.hasSymbolicOffset())
+        return false;
+      if (L.hasSymbolicOffset() && R.hasSymbolicOffset())
+        return ToString(L.getRegion()) < ToString(R.getRegion());
+      return L.getOffset() < R.getOffset();
+    };
+
+    const auto DefaultBindingBeforeDirectBindings =
+        [&SymbolicBeforeOffset](const Binding *LPtr, const Binding *RPtr) {
+          const BindingKey &L = LPtr->first;
+          const BindingKey &R = RPtr->first;
+          if (L.isDefault() && !R.isDefault())
+            return true;
+          if (!L.isDefault() && R.isDefault())
+            return false;
+          assert(L.isDefault() == R.isDefault());
+          return SymbolicBeforeOffset(L, R);
+        };
+
----------------
steakhal wrote:

Good idea. One minor remark is that with using this tuple technique, the stringifications would happen eagerly instead of lazily, but this is dump code, so it shouldn't matter. Thanks for the suggestion!

https://github.com/llvm/llvm-project/pull/115615