Added check uniqueptr-delete-release to replace "delete x.release()" with "x = nullptr"

Reviewers: alexfh

Differential Revision: http://reviews.llvm.org/D13179

llvm-svn: 250742

1 files changed, 69 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/readability/UniqueptrDeleteReleaseCheck.cpp b/clang-tools-extra/clang-tidy/readability/UniqueptrDeleteReleaseCheck.cpp
new file mode 100644
index 00000000000..8a1ca4c16ce
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/readability/UniqueptrDeleteReleaseCheck.cpp
@@ -0,0 +1,69 @@
+//===--- UniqueptrDeleteReleaseCheck.cpp - clang-tidy----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "UniqueptrDeleteReleaseCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+
+void UniqueptrDeleteReleaseCheck::registerMatchers(MatchFinder *Finder) {
+  auto IsSusbstituted = qualType(anyOf(
+      substTemplateTypeParmType(), hasDescendant(substTemplateTypeParmType())));
+
+  auto UniquePtrWithDefaultDelete = classTemplateSpecializationDecl(
+      hasName("std::unique_ptr"),
+      hasTemplateArgument(1, refersToType(qualType(hasDeclaration(cxxRecordDecl(
+                                 hasName("std::default_delete")))))));
+
+  Finder->addMatcher(
+      cxxDeleteExpr(
+          has(cxxMemberCallExpr(on(expr(hasType(UniquePtrWithDefaultDelete),
+                                        unless(hasType(IsSusbstituted)))
+                                       .bind("uptr")),
+                                callee(cxxMethodDecl(hasName("release"))))))
+          .bind("delete"),
+      this);
+}
+
+void UniqueptrDeleteReleaseCheck::check(
+    const MatchFinder::MatchResult &Result) {
+  const auto *PtrExpr = Result.Nodes.getNodeAs<Expr>("uptr");
+  const auto *DeleteExpr = Result.Nodes.getNodeAs<Expr>("delete");
+
+  if (PtrExpr->getLocStart().isMacroID())
+    return;
+
+  // Ignore dependent types.
+  // It can give us false positives, so we go with false negatives instead to
+  // be safe.
+  if (PtrExpr->getType()->isDependentType())
+    return;
+
+  SourceLocation AfterPtr =
+      Lexer::getLocForEndOfToken(PtrExpr->getLocEnd(), 0, *Result.SourceManager,
+                                 Result.Context->getLangOpts());
+
+  diag(DeleteExpr->getLocStart(),
+       "prefer '= nullptr' to 'delete x.release()' to reset unique_ptr<> "
+       "objects")
+      << FixItHint::CreateRemoval(CharSourceRange::getCharRange(
+             DeleteExpr->getLocStart(), PtrExpr->getLocStart()))
+      << FixItHint::CreateReplacement(
+             CharSourceRange::getTokenRange(AfterPtr, DeleteExpr->getLocEnd()),
+             " = nullptr");
+}
+
+} // namespace tidy
+} // namespace clang
+