[clang] [clang] Avoid printing overly large integer/_BitInt numbers in static assertion failure diagnostics #71675 (PR #145053)

[Timm Baeder via cfe-commits]

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@@ -17575,7 +17576,21 @@ static bool ConvertAPValueToString(const APValue &V, QualType T,
           break;
         }
       }
-      V.getInt().toString(Str);
+
+      llvm::APSInt vInt = V.getInt();
+      if (llvm::APSInt::compareValues(
+              vInt, llvm::APSInt::getUnsigned(
+                        std::numeric_limits<uint64_t>::max())) >= 0 ||
+          vInt < std::numeric_limits<int64_t>::min()) {
+        // The value of cutSize is not special, it is just a number of
+        // characters that gives us enough info without losing readability
+        const int cutSize = 20;
+        vInt.toString(Str, 16);
+        Str.erase(Str.begin() + cutSize, Str.end() - cutSize);
----------------
tbaederr wrote:

I don't really know how this is supposed to work. We need to know what to display _without_ printing the value to a string at all, because THAT is what's breaking our neck. The simplest solution would be to just check the value (or even `getActiveBits()`?) and if that is larger than some arbitrary value (you can just check that printing the note doesn't take longer than, say, 3 seconds), we simply skip the note altogether.

https://github.com/llvm/llvm-project/pull/145053