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

[Donát Nagy 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);
+        };
+
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NagyDonat wrote:

Yes, that's a good point about eager stringification.

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