Merge #19548: fuzz: add missing overrides to signature_checker

c0f09c2 fuzz: add missing overrides to signature_checker (Jon Atack)

Pull request description:

  These functions in `fuzz/signature_checker.cpp` override virtual member functions and should be marked `override` instead of `virtual`, which is for introducing a new virtual function. The overridden virtual functions are in `script/interpreter.h:151/156/161`.

  Also, per MarcoFalke suggestion, add missing parentheses in `fuzz/scriptnum_ops.cpp` and remove useless `unsigned int >= 0` conditional in `fuzz/script.cpp`.

  These changes fix 5 compile warnings in gcc 10 and 3 in clang 11/12.

ACKs for top commit:
  vasild:
    ACK c0f09c2
  MarcoFalke:
    review ACK c0f09c2

Tree-SHA512: 76ce73ec577c1f23cf8646c31d44dcd6c6303732c47187d041a8921d0d24a50163989a375352ebc221abf2ac337bc0902149be46b6f9eebc071d2f364c407f71

Author: fanquake

src/test/fuzz/script.cpp

@@ -48,7 +48,7 @@ void test_one_input(const std::vector<uint8_t>& buffer)
     if (CompressScript(script, compressed)) {
         const unsigned int size = compressed[0];
         compressed.erase(compressed.begin());
-        assert(size >= 0 && size <= 5);
+        assert(size <= 5);
         CScript decompressed_script;
         const bool ok = DecompressScript(decompressed_script, size, compressed);
         assert(ok);

src/test/fuzz/scriptnum_ops.cpp

@@ -33,7 +33,7 @@ void test_one_input(const std::vector<uint8_t>& buffer)
         case 0: {
             const int64_t i = fuzzed_data_provider.ConsumeIntegral<int64_t>();
             assert((script_num == i) != (script_num != i));
-            assert((script_num <= i) != script_num > i);
+            assert((script_num <= i) != (script_num > i));
             assert((script_num >= i) != (script_num < i));
             // Avoid signed integer overflow:
             // script/script.h:264:93: runtime error: signed integer overflow: -2261405121394637306 + -9223372036854775802 cannot be represented in type 'long'

src/test/fuzz/signature_checker.cpp

@@ -28,17 +28,17 @@ class FuzzedSignatureChecker : public BaseSignatureChecker
     {
     }
 
-    virtual bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode, SigVersion sigversion) const
+    bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode, SigVersion sigversion) const override
     {
         return m_fuzzed_data_provider.ConsumeBool();
     }
 
-    virtual bool CheckLockTime(const CScriptNum& nLockTime) const
+    bool CheckLockTime(const CScriptNum& nLockTime) const override
     {
         return m_fuzzed_data_provider.ConsumeBool();
     }
 
-    virtual bool CheckSequence(const CScriptNum& nSequence) const
+    bool CheckSequence(const CScriptNum& nSequence) const override
     {
         return m_fuzzed_data_provider.ConsumeBool();
     }