[clang-tidy] Improve integer comparison by matching valid expressions outside implicitCastExpr

Author: RiverDave

clang-tools-extra/clang-tidy/modernize/UseIntegerSignComparisonCheck.cpp

@@ -39,9 +39,11 @@ intCastExpression(bool IsSigned,
   // std::cmp_{} functions trigger a compile-time error if either LHS or RHS
   // is a non-integer type, char, enum or bool
   // (unsigned char/ signed char are Ok and can be used).
-  auto IntTypeExpr = expr(hasType(hasCanonicalType(qualType(
+  const auto HasIntegerType = hasType(hasCanonicalType(qualType(
       isInteger(), IsSigned ? isSignedInteger() : isUnsignedInteger(),
-      unless(isActualChar()), unless(booleanType()), unless(enumType())))));
+      unless(isActualChar()), unless(booleanType()), unless(enumType()))));
+
+  auto IntTypeExpr = expr(HasIntegerType);
 
   const auto ImplicitCastExpr =
       CastBindName.empty() ? implicitCastExpr(hasSourceExpression(IntTypeExpr))
@@ -52,8 +54,14 @@ intCastExpression(bool IsSigned,
   const auto StaticCastExpr = cxxStaticCastExpr(has(ImplicitCastExpr));
   const auto FunctionalCastExpr = cxxFunctionalCastExpr(has(ImplicitCastExpr));
 
+  // Match function calls or variable references not directly wrapped by an
+  // implicit cast
+  const auto CallIntExpr = CastBindName.empty()
+                               ? callExpr(HasIntegerType)
+                               : callExpr(HasIntegerType).bind(CastBindName);
+
   return expr(anyOf(ImplicitCastExpr, CStyleCastExpr, StaticCastExpr,
-                    FunctionalCastExpr));
+                    FunctionalCastExpr, CallIntExpr));
 }
 
 static StringRef parseOpCode(BinaryOperator::Opcode Code) {

clang-tools-extra/docs/ReleaseNotes.rst

@@ -197,6 +197,10 @@ Changes in existing checks
   <clang-tidy/checks/modernize/use-designated-initializers>` check by avoiding
   diagnosing designated initializers for ``std::array`` initializations.
 
+- Improved :doc:`modernize-use-integer-sign-comparison
+  <clang-tidy/checks/modernize/use-integer-sign-comparison>` check by matching
+  valid integer expressions not directly wrapped around an implicit cast.
+
 - Improved :doc:`modernize-use-ranges
   <clang-tidy/checks/modernize/use-ranges>` check by updating suppress 
   warnings logic for ``nullptr`` in ``std::find``.

clang-tools-extra/test/clang-tidy/checkers/modernize/use-integer-sign-comparison.cpp

@@ -121,3 +121,29 @@ int AllComparisons() {
 
     return 0;
 }
+
+namespace PR127471 {
+    int getSignedValue();
+    unsigned int getUnsignedValue();
+
+    void callExprTest() {
+
+        if (getSignedValue() < getUnsignedValue())
+            return;
+// CHECK-MESSAGES: :[[@LINE-2]]:13: warning: comparison between 'signed' and 'unsigned' integers [modernize-use-integer-sign-comparison]
+// CHECK-FIXES:  if (std::cmp_less(getSignedValue() , getUnsignedValue()))
+
+        int sVar = 0;
+        if (getUnsignedValue() > sVar)
+            return;
+// CHECK-MESSAGES: :[[@LINE-2]]:13: warning: comparison between 'signed' and 'unsigned' integers [modernize-use-integer-sign-comparison]
+// CHECK-FIXES: if (std::cmp_greater(getUnsignedValue() , sVar))
+
+        unsigned int uVar = 0;
+        if (getSignedValue() > uVar)
+            return;
+// CHECK-MESSAGES: :[[@LINE-2]]:13: warning: comparison between 'signed' and 'unsigned' integers [modernize-use-integer-sign-comparison]
+// CHECK-FIXES: if (std::cmp_greater(getSignedValue() , uVar))
+
+    }
+} // namespace PR127471