[clang-tools-extra] [clang-tidy] Improve integer comparison by matching valid expressions outside implicitCastExpr for use-integer-sign-comparison (PR #144240)

[Baranov Victor via cfe-commits]

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@@ -39,21 +39,23 @@ 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()))));
+
+  const auto IntTypeExpr = expr(HasIntegerType);
 
   const auto ImplicitCastExpr =
-      CastBindName.empty() ? implicitCastExpr(hasSourceExpression(IntTypeExpr))
-                           : implicitCastExpr(hasSourceExpression(IntTypeExpr))
-                                 .bind(CastBindName);
+      implicitCastExpr(hasSourceExpression(IntTypeExpr)).bind(CastBindName);
+
+  const auto ExplicitCastExpr =
+      anyOf(explicitCastExpr(has(ImplicitCastExpr)),
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vbvictor wrote:

This line is excessive, `ignoringImpCasts(explicitCastExpr(has(ImplicitCastExpr)))` must work when there are no `ImpCasts`, then it just becomes `explicitCastExpr(has(ImplicitCastExpr))`.

https://github.com/llvm/llvm-project/pull/144240