[clang-tools-extra] [clang-tidy] Add a new check 'performance-string-view-conversions' (PR #174288)

[Zinovy Nis via cfe-commits]

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+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "RedundantStringViewConversionsCheck.h"
+#include "clang/AST/Expr.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::bugprone {
+
+static auto getStringTypeMatcher(StringRef CharType) {
+  return hasCanonicalType(hasDeclaration(cxxRecordDecl(hasName(CharType))));
+}
+
+void RedundantStringViewConversionsCheck::registerMatchers(
+    MatchFinder *Finder) {
+  const auto IsStdString = getStringTypeMatcher("::std::basic_string");
+  const auto IsStdStringView = getStringTypeMatcher("::std::basic_string_view");
+
+  const auto ImplicitlyConvertibleToStringView =
+      expr(anyOf(hasType(IsStdStringView), stringLiteral(),
+                 hasType(pointerType(pointee(isAnyCharacter())))))
+          .bind("originalStringView");
+
+  Finder->addMatcher(
+      callExpr(forEachArgumentWithParam(
+          expr(hasType(IsStdStringView),
+               hasDescendant(
+                   cxxFunctionalCastExpr(
+                       hasType(IsStdString),
+                       hasDescendant(cxxConstructExpr(
+                           hasType(IsStdString),
+                           hasArgument(0,
+                                       ignoringImplicit(
+                                           ImplicitlyConvertibleToStringView)),
+                           unless(hasDeclaration(
+                               cxxConstructorDecl(isCopyConstructor()))),
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irishrover wrote:

Done!

https://github.com/llvm/llvm-project/pull/174288