[clang-tidy] Give readability-redundant-string-init a customizable list of string types to fix

Summary:
This patch adds a feature requested in https://reviews.llvm.org/D69238 to enable `readability-redundant-string-init` to take a list of strings to apply the fix to rather than hard-coding `basic_string`. It adds a `StringNames` option of semicolon-delimited names of string classes to which to apply this fix. Tests ensure this works with test class out::TestString as well as std::string and std::wstring as before. It should be applicable to llvm::StringRef, QString, etc.

Reviewers: MyDeveloperDay, aaron.ballman, hokein, alexfh, JonasToth, gribozavr2

Patch by: poelmanc

Subscribers: gribozavr2, xazax.hun, Eugene.Zelenko, cfe-commits

Tags: #clang-tools-extra, #clang

Differential Revision: https://reviews.llvm.org/D69548

1 files changed, 34 insertions, 9 deletions

diff --git a/clang-tools-extra/clang-tidy/readability/RedundantStringInitCheck.cpp b/clang-tools-extra/clang-tidy/readability/RedundantStringInitCheck.cpp
index a140e17fabf..6bf0edb7231 100644
--- a/clang-tools-extra/clang-tidy/readability/RedundantStringInitCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/RedundantStringInitCheck.cpp
@@ -8,6 +8,7 @@
 
 #include "RedundantStringInitCheck.h"
 #include "../utils/Matchers.h"
+#include "../utils/OptionsUtils.h"
 #include "clang/ASTMatchers/ASTMatchers.h"
 
 using namespace clang::ast_matchers;
@@ -17,19 +18,43 @@ namespace clang {
 namespace tidy {
 namespace readability {
 
+const char DefaultStringNames[] = "::std::basic_string";
+
+RedundantStringInitCheck::RedundantStringInitCheck(StringRef Name,
+                                                   ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      StringNames(utils::options::parseStringList(
+          Options.get("StringNames", DefaultStringNames))) {}
+
+void RedundantStringInitCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "StringNames", DefaultStringNames);
+}
+
 void RedundantStringInitCheck::registerMatchers(MatchFinder *Finder) {
   if (!getLangOpts().CPlusPlus)
     return;
+  const auto hasStringTypeName = hasAnyName(
+      SmallVector<StringRef, 3>(StringNames.begin(), StringNames.end()));
+
+  // Version of StringNames with namespaces removed
+  std::vector<std::string> stringNamesNoNamespace;
+  for (const std::string &name : StringNames) {
+    std::string::size_type colonPos = name.rfind(':');
+    stringNamesNoNamespace.push_back(
+        name.substr(colonPos == std::string::npos ? 0 : colonPos + 1));
+  }
+  const auto hasStringCtorName = hasAnyName(SmallVector<StringRef, 3>(
+      stringNamesNoNamespace.begin(), stringNamesNoNamespace.end()));
 
   // Match string constructor.
-  const auto StringConstructorExpr = expr(anyOf(
-      cxxConstructExpr(argumentCountIs(1),
-                       hasDeclaration(cxxMethodDecl(hasName("basic_string")))),
-      // If present, the second argument is the alloc object which must not
-      // be present explicitly.
-      cxxConstructExpr(argumentCountIs(2),
-                       hasDeclaration(cxxMethodDecl(hasName("basic_string"))),
-                       hasArgument(1, cxxDefaultArgExpr()))));
+  const auto StringConstructorExpr = expr(
+      anyOf(cxxConstructExpr(argumentCountIs(1),
+                             hasDeclaration(cxxMethodDecl(hasStringCtorName))),
+            // If present, the second argument is the alloc object which must
+            // not be present explicitly.
+            cxxConstructExpr(argumentCountIs(2),
+                             hasDeclaration(cxxMethodDecl(hasStringCtorName)),
+                             hasArgument(1, cxxDefaultArgExpr()))));
 
   // Match a string constructor expression with an empty string literal.
   const auto EmptyStringCtorExpr = cxxConstructExpr(
@@ -48,7 +73,7 @@ void RedundantStringInitCheck::registerMatchers(MatchFinder *Finder) {
       namedDecl(
           varDecl(
               hasType(hasUnqualifiedDesugaredType(recordType(
-                  hasDeclaration(cxxRecordDecl(hasName("basic_string")))))),
+                  hasDeclaration(cxxRecordDecl(hasStringTypeName))))),
               hasInitializer(expr(ignoringImplicit(anyOf(
                   EmptyStringCtorExpr, EmptyStringCtorExprWithTemporaries)))))
               .bind("vardecl"),