[clang-tools-extra] [clang-tidy] Support find for string-like classes in readability-container-contains (PR #157243)

[Baranov Victor via cfe-commits]

================
@@ -9,47 +9,43 @@
 #include "ContainerContainsCheck.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
 
 using namespace clang::ast_matchers;
 
 namespace clang::tidy::readability {
 void ContainerContainsCheck::registerMatchers(MatchFinder *Finder) {
-  const auto HasContainsMatchingParamType = hasMethod(
-      cxxMethodDecl(isConst(), parameterCountIs(1), returns(booleanType()),
-                    hasName("contains"), unless(isDeleted()), isPublic(),
-                    hasParameter(0, hasType(hasUnqualifiedDesugaredType(
-                                        equalsBoundNode("parameterType"))))));
+  const auto Literal0 = integerLiteral(equals(0));
+  const auto Literal1 = integerLiteral(equals(1));
+
+  const auto ClassWithContains = cxxRecordDecl(
+      hasMethod(cxxMethodDecl(isConst(), parameterCountIs(1), isPublic(),
+                              unless(isDeleted()), returns(booleanType()),
+                              hasAnyName("contains", "Contains"))
+                    .bind("contains_fun")));
 
   const auto CountCall =
-      cxxMemberCallExpr(
-          argumentCountIs(1),
-          callee(cxxMethodDecl(
-              hasName("count"),
-              hasParameter(0, hasType(hasUnqualifiedDesugaredType(
-                                  type().bind("parameterType")))),
-              ofClass(cxxRecordDecl(HasContainsMatchingParamType)))))
+      cxxMemberCallExpr(argumentCountIs(1),
+                        callee(cxxMethodDecl(hasAnyName("count", "Count"),
+                                             ofClass(ClassWithContains))))
           .bind("call");
 
   const auto FindCall =
-      cxxMemberCallExpr(
-          argumentCountIs(1),
-          callee(cxxMethodDecl(
-              hasName("find"),
-              hasParameter(0, hasType(hasUnqualifiedDesugaredType(
-                                  type().bind("parameterType")))),
-              ofClass(cxxRecordDecl(HasContainsMatchingParamType)))))
+      // Either one argument, or assume the second argument is the position to
+      // start searching from.
+      cxxMemberCallExpr(anyOf(argumentCountIs(1),
+                              cxxMemberCallExpr(argumentCountIs(2),
+                                                hasArgument(1, Literal0))),
----------------
vbvictor wrote:

It's strange that we write `cxxMemberCallExpr` two times. Is it possible to write:
```cpp
cxxMemberCallExpr(
  anyOf(
     argumentCountIs(1),
     allOf(
         argumentCountIs(2),
         hasArgument(1, Literal0)
     )
  )
)
```

https://github.com/llvm/llvm-project/pull/157243