LegalizeAdulthood updated this revision to Diff 45110.
LegalizeAdulthood added a comment.
Extend this check to handle redundant `continue` statements in loop bodies.
With this extension, I'm wondering if the check should be renamed
redundant-control-flow instead of redundant-return.
Comments?
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 +1,68 @@
+// 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() {{{$}}
+// CHECK-FIXES-NEXT: {{^ *}$}}
+
+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() {
+}
+
+void k() {
+ for (int i = 0; i < 10; ++i) {
+ continue;
+ }
+}
+// CHECK-MESSAGES: :[[@LINE-3]]:5: warning: redundant continue statement
+// CHECK-FIXES: {{^}} for (int i = 0; i < 10; ++i) {{{$}}
+// CHECK-FIXES-NEXT: {{^ *}$}}
+
+void m() {
+ int i = 0;
+ do {
+ ++i;
+ continue;
+ } while (i < 10);
+}
+// CHECK-MESSAGES: :[[@LINE-3]]:5: warning: redundant continue statement
+// CHECK-FIXES: {{^ do {$}}
+// CHECK-FIXES-NEXT: {{^}} ++i;{{$}}
+// CHECK-FIXES-NEXT: {{^ *}}} while (i < 10);{{$}}
+
+void p() {
+ int i = 0;
+ while (i < 10) {
+ ++i;
+ continue;
+ }
+}
+// CHECK-MESSAGES: :[[@LINE-3]]:5: warning: redundant continue statement
+// CHECK-FIXES: {{^}} while (i < 10) {{{$}}
+// CHECK-FIXES-NEXT: {{^}} ++i;{{$}}
+// CHECK-FIXES-NEXT: {{^ *}$}}
Index: docs/clang-tidy/checks/readability-redundant-return.rst
===================================================================
--- /dev/null
+++ docs/clang-tidy/checks/readability-redundant-return.rst
@@ -0,0 +1,10 @@
+.. 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.
+
+Loop statements (`for`, `while`, `do while`) are checked for redundant
+`continue` statements at the end of the loop body.
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 +1,47 @@
+//===--- 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`.
+///
+/// Eliminates redundant `continue` statements at the end of a loop body.
+///
+/// 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;
+
+private:
+ void
+ checkRedundantReturn(const ast_matchers::MatchFinder::MatchResult &Result,
+ const FunctionDecl *Fn);
+
+ void
+ checkRedundantContinue(const ast_matchers::MatchFinder::MatchResult &Result,
+ const CompoundStmt *Block);
+};
+
+} // 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 +1,106 @@
+//===--- 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);
+ auto CompoundContinue = has(compoundStmt(hasAnySubstatement(continueStmt())));
+ Finder->addMatcher(forStmt(CompoundContinue).bind("for"), this);
+ Finder->addMatcher(whileStmt(CompoundContinue).bind("while"), this);
+ Finder->addMatcher(doStmt(CompoundContinue).bind("do"), this);
+}
+
+void RedundantReturnCheck::check(const MatchFinder::MatchResult &Result) {
+ if (const auto *Fn = Result.Nodes.getNodeAs<FunctionDecl>("fn")) {
+ checkRedundantReturn(Result, Fn);
+ } else if (const auto *For = Result.Nodes.getNodeAs<ForStmt>("for")) {
+ checkRedundantContinue(Result, dyn_cast<CompoundStmt>(For->getBody()));
+ } else if (const auto *While = Result.Nodes.getNodeAs<WhileStmt>("while")) {
+ checkRedundantContinue(Result, dyn_cast<CompoundStmt>(While->getBody()));
+ } else if (const auto *Do = Result.Nodes.getNodeAs<DoStmt>("do")) {
+ checkRedundantContinue(Result, dyn_cast<CompoundStmt>(Do->getBody()));
+ }
+}
+
+void RedundantReturnCheck::checkRedundantReturn(
+ const MatchFinder::MatchResult &Result, const 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);
+ }
+ }
+}
+
+void RedundantReturnCheck::checkRedundantContinue(
+ const ast_matchers::MatchFinder::MatchResult &Result,
+ const CompoundStmt *Block) {
+ if (Block) {
+ CompoundStmt::const_reverse_body_iterator last = Block->body_rbegin();
+ if (const auto *Continue = dyn_cast<ContinueStmt>(*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 = Continue->getLocStart();
+ }
+ auto ContinueRange = CharSourceRange::getCharRange(
+ Start, Lexer::findLocationAfterToken(
+ Continue->getLocEnd(), tok::semi, *Result.SourceManager,
+ Result.Context->getLangOpts(),
+ /*SkipTrailingWhitespaceAndNewLine=*/true));
+
+ diag(Continue->getLocStart(),
+ "redundant continue statement at the end of for statement")
+ << FixItHint::CreateRemoval(ContinueRange);
+ }
+ }
+}
+
+} // 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
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