LegalizeAdulthood created this revision.
LegalizeAdulthood added a reviewer: alexfh.
LegalizeAdulthood added a subscriber: cfe-commits.

This check looks for `return` statements at the end of a function returning 
`void`:

```
void f()
{
  return;
}
```

becomes

```
void f()
{
}
```


http://reviews.llvm.org/D16259

Files:
  clang-tidy/readability/CMakeLists.txt
  clang-tidy/readability/ReadabilityTidyModule.cpp
  clang-tidy/readability/RedundantReturnCheck.cpp
  clang-tidy/readability/RedundantReturnCheck.h
  docs/clang-tidy/checks/list.rst
  docs/clang-tidy/checks/readability-redundant-return.rst
  test/clang-tidy/readability-redundant-return.cpp

Index: test/clang-tidy/readability-redundant-return.cpp
===================================================================
--- /dev/null
+++ test/clang-tidy/readability-redundant-return.cpp
@@ -0,0 +1,41 @@
+// RUN: %check_clang_tidy %s readability-redundant-return %t
+
+void g(int i);
+void j();
+
+void f()
+{
+  return;
+}
+// CHECK-MESSAGES: :[[@LINE-2]]:3: warning: redundant return statement at the end of void function [readability-redundant-return]
+// CHECK-FIXES: {{^}}void f(){{$}}
+// CHECK-FIXES-NEXT: {{^{$}}
+// CHECK-FIXES-NEXT: {{^ *}$}}
+
+void g()
+{
+  f();
+  return;
+}
+// CHECK-MESSAGES: :[[@LINE-2]]:3: warning: redundant return statement
+// CHECK-FIXES: {{^  }}f();{{$}}
+// CHECK-FIXES-NEXT: {{^ *}$}}
+
+void g(int i)
+{
+  if (i < 0) {
+    return;
+  }
+  if (i < 10) {
+    f();
+  }
+}
+
+int h()
+{
+  return 1;
+}
+
+void j()
+{
+}
Index: docs/clang-tidy/checks/readability-redundant-return.rst
===================================================================
--- /dev/null
+++ docs/clang-tidy/checks/readability-redundant-return.rst
@@ -0,0 +1,7 @@
+.. title:: clang-tidy - readability-redundant-return
+
+readability-redundant-return
+============================
+
+This check looks for procedures (functions returning no value) with return
+statements at the end of the function.  Such return statements are redundant.
Index: docs/clang-tidy/checks/list.rst
===================================================================
--- docs/clang-tidy/checks/list.rst
+++ docs/clang-tidy/checks/list.rst
@@ -76,6 +76,7 @@
    readability-implicit-bool-cast
    readability-inconsistent-declaration-parameter-name
    readability-named-parameter
+   readability-redundant-return
    readability-redundant-smartptr-get
    readability-redundant-string-cstr
    readability-simplify-boolean-expr
Index: clang-tidy/readability/RedundantReturnCheck.h
===================================================================
--- /dev/null
+++ clang-tidy/readability/RedundantReturnCheck.h
@@ -0,0 +1,36 @@
+//===--- RedundantReturnCheck.h - clang-tidy---------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_REDUNDANT_RETURN_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_REDUNDANT_RETURN_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace readability {
+
+/// Eliminates redundant `return` statements at the end of a function that
+/// returns `void`.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/readability-redundant-return.html
+class RedundantReturnCheck : public ClangTidyCheck {
+public:
+  RedundantReturnCheck(StringRef Name, ClangTidyContext *Context)
+      : ClangTidyCheck(Name, Context) {}
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace readability
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_REDUNDANT_RETURN_H
Index: clang-tidy/readability/RedundantReturnCheck.cpp
===================================================================
--- /dev/null
+++ clang-tidy/readability/RedundantReturnCheck.cpp
@@ -0,0 +1,60 @@
+//===--- RedundantReturnCheck.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 "RedundantReturnCheck.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 {
+namespace readability {
+
+void RedundantReturnCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(
+      functionDecl(isDefinition(), returns(asString("void")),
+                   has(compoundStmt(hasAnySubstatement(returnStmt()))))
+          .bind("fn"),
+      this);
+}
+
+void RedundantReturnCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *Fn = Result.Nodes.getNodeAs<FunctionDecl>("fn");
+  if (const auto *Block = dyn_cast<CompoundStmt>(Fn->getBody())) {
+    CompoundStmt::const_reverse_body_iterator last = Block->body_rbegin();
+    if (const auto *Return = dyn_cast<ReturnStmt>(*last)) {
+      CompoundStmt::const_reverse_body_iterator Previous =
+          ++Block->body_rbegin();
+      SourceLocation Start;
+      if (Previous != Block->body_rend()) {
+        Start = Lexer::findLocationAfterToken(
+            dyn_cast<Stmt>(*Previous)->getLocEnd(), tok::semi,
+            *Result.SourceManager, Result.Context->getLangOpts(),
+            /*SkipTrailingWhitespaceAndNewLine=*/true);
+      } else {
+        Start = Return->getLocStart();
+      }
+      auto ReturnRange = CharSourceRange::getCharRange(
+          Start, Lexer::findLocationAfterToken(
+                     Return->getLocEnd(), tok::semi, *Result.SourceManager,
+                     Result.Context->getLangOpts(),
+                     /*SkipTrailingWhitespaceAndNewLine=*/true));
+
+      diag(Return->getLocStart(),
+           "redundant return statement at the end of void function")
+          << FixItHint::CreateRemoval(ReturnRange);
+    }
+  }
+}
+
+} // namespace readability
+} // namespace tidy
+} // namespace clang
Index: clang-tidy/readability/ReadabilityTidyModule.cpp
===================================================================
--- clang-tidy/readability/ReadabilityTidyModule.cpp
+++ clang-tidy/readability/ReadabilityTidyModule.cpp
@@ -18,6 +18,7 @@
 #include "ImplicitBoolCastCheck.h"
 #include "InconsistentDeclarationParameterNameCheck.h"
 #include "NamedParameterCheck.h"
+#include "RedundantReturnCheck.h"
 #include "RedundantSmartptrGetCheck.h"
 #include "RedundantStringCStrCheck.h"
 #include "SimplifyBooleanExprCheck.h"
@@ -44,6 +45,8 @@
         "readability-implicit-bool-cast");
     CheckFactories.registerCheck<InconsistentDeclarationParameterNameCheck>(
         "readability-inconsistent-declaration-parameter-name");
+    CheckFactories.registerCheck<RedundantReturnCheck>(
+        "readability-redundant-return");
     CheckFactories.registerCheck<UniqueptrDeleteReleaseCheck>(
         "readability-uniqueptr-delete-release");
     CheckFactories.registerCheck<readability::NamedParameterCheck>(
Index: clang-tidy/readability/CMakeLists.txt
===================================================================
--- clang-tidy/readability/CMakeLists.txt
+++ clang-tidy/readability/CMakeLists.txt
@@ -11,6 +11,7 @@
   NamedParameterCheck.cpp
   NamespaceCommentCheck.cpp
   ReadabilityTidyModule.cpp
+  RedundantReturnCheck.cpp
   RedundantStringCStrCheck.cpp
   RedundantSmartptrGetCheck.cpp
   SimplifyBooleanExprCheck.cpp
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

Reply via email to