Index: clang-tidy/bugprone/BugproneTidyModule.cpp =================================================================== --- clang-tidy/bugprone/BugproneTidyModule.cpp +++ clang-tidy/bugprone/BugproneTidyModule.cpp @@ -40,6 +40,7 @@ #include "SuspiciousSemicolonCheck.h" #include "SuspiciousStringCompareCheck.h" #include "SwappedArgumentsCheck.h" +#include "TerminatingContinueCheck.h" #include "ThrowKeywordMissingCheck.h" #include "UndefinedMemoryManipulationCheck.h" #include "UndelegatedConstructorCheck.h" @@ -115,6 +116,8 @@ "bugprone-suspicious-string-compare"); CheckFactories.registerCheck( "bugprone-swapped-arguments"); + CheckFactories.registerCheck( + "bugprone-terminating-continue"); CheckFactories.registerCheck( "bugprone-throw-keyword-missing"); CheckFactories.registerCheck( Index: clang-tidy/bugprone/CMakeLists.txt =================================================================== --- clang-tidy/bugprone/CMakeLists.txt +++ clang-tidy/bugprone/CMakeLists.txt @@ -32,6 +32,7 @@ SuspiciousSemicolonCheck.cpp SuspiciousStringCompareCheck.cpp SwappedArgumentsCheck.cpp + TerminatingContinueCheck.cpp ThrowKeywordMissingCheck.cpp UndefinedMemoryManipulationCheck.cpp UndelegatedConstructorCheck.cpp Index: clang-tidy/bugprone/TerminatingContinueCheck.h =================================================================== --- /dev/null +++ clang-tidy/bugprone/TerminatingContinueCheck.h @@ -0,0 +1,36 @@ +//===--- TerminatingContinueCheck.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_BUGPRONE_TERMINATINGCONTINUECHECK_H +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_TERMINATINGCONTINUECHECK_H + +#include "../ClangTidy.h" + +namespace clang { +namespace tidy { +namespace bugprone { + +/// Checks if a 'continue' statement terminates the loop (i.e. the loop has +/// a condition which always evaluates to false). +/// +/// For the user-facing documentation see: +/// http://clang.llvm.org/extra/clang-tidy/checks/bugprone-terminating-continue.html +class TerminatingContinueCheck : public ClangTidyCheck { +public: + TerminatingContinueCheck(StringRef Name, ClangTidyContext *Context) + : ClangTidyCheck(Name, Context) {} + void registerMatchers(ast_matchers::MatchFinder *Finder) override; + void check(const ast_matchers::MatchFinder::MatchResult &Result) override; +}; + +} // namespace bugprone +} // namespace tidy +} // namespace clang + +#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_TERMINATINGCONTINUECHECK_H Index: clang-tidy/bugprone/TerminatingContinueCheck.cpp =================================================================== --- /dev/null +++ clang-tidy/bugprone/TerminatingContinueCheck.cpp @@ -0,0 +1,49 @@ +//===--- TerminatingContinueCheck.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 "TerminatingContinueCheck.h" +#include "clang/AST/ASTContext.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" +#include "clang/Lex/Lexer.h" +#include "clang/Tooling/FixIt.h" + +using namespace clang::ast_matchers; + +namespace clang { +namespace tidy { +namespace bugprone { + +void TerminatingContinueCheck::registerMatchers(MatchFinder *Finder) { + const auto doWithFalse = + doStmt(hasCondition(ignoringImpCasts( + anyOf(cxxBoolLiteral(equals(false)), integerLiteral(equals(0)), + cxxNullPtrLiteralExpr(), gnuNullExpr()))), + equalsBoundNode("closestLoop")); + + Finder->addMatcher( + continueStmt(hasAncestor(stmt(anyOf(forStmt(), whileStmt(), + cxxForRangeStmt(), doStmt())) + .bind("closestLoop")), + hasAncestor(doWithFalse)) + .bind("continue"), + this); +} + +void TerminatingContinueCheck::check(const MatchFinder::MatchResult &Result) { + const auto *ContStmt = Result.Nodes.getNodeAs("continue"); + + auto Diag = + diag(ContStmt->getLocStart(), + "'continue' in loop with false condition is equivalent to 'break'") + << tooling::fixit::createReplacement(*ContStmt, "break"); +} + +} // namespace bugprone +} // namespace tidy +} // namespace clang Index: docs/ReleaseNotes.rst =================================================================== --- docs/ReleaseNotes.rst +++ docs/ReleaseNotes.rst @@ -130,6 +130,11 @@ Warns or suggests alternatives if SIMD intrinsics are used which can be replaced by ``std::experimental::simd`` operations. +- New :doc:`bugprone-terminating-continue + ` check + + Checks if a ``continue`` statement terminates the loop. + - New :doc:`zircon-temporary-objects ` check Index: docs/clang-tidy/checks/bugprone-terminating-continue.rst =================================================================== --- /dev/null +++ docs/clang-tidy/checks/bugprone-terminating-continue.rst @@ -0,0 +1,17 @@ +.. title:: clang-tidy - bugprone-terminating-continue + +bugprone-terminating-continue +============================= + +Detects `do while` loops with a condition always evaluating to false that +have a `continue` statement, as this `continue` terminates the loop +effectively. + +.. code-block:: c++ + + void f() { + do { + // some code + continue; // terminating continue + // some other code + } while(false); Index: docs/clang-tidy/checks/list.rst =================================================================== --- docs/clang-tidy/checks/list.rst +++ docs/clang-tidy/checks/list.rst @@ -48,6 +48,7 @@ bugprone-suspicious-semicolon bugprone-suspicious-string-compare bugprone-swapped-arguments + bugprone-terminating-continue bugprone-throw-keyword-missing bugprone-undefined-memory-manipulation bugprone-undelegated-constructor Index: test/clang-tidy/bugprone-terminating-continue.cpp =================================================================== --- /dev/null +++ test/clang-tidy/bugprone-terminating-continue.cpp @@ -0,0 +1,65 @@ +// RUN: %check_clang_tidy %s bugprone-terminating-continue %t + +void f() { + do { + continue; + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: 'continue' in loop with false condition is equivalent to 'break' [bugprone-terminating-continue] + // CHECK-FIXES: break; + } while(false); + + do { + continue; + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: 'continue' in loop with false condition is equivalent to 'break' [bugprone-terminating-continue] + // CHECK-FIXES: break; + } while(0); + + do { + continue; + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: 'continue' in loop with false condition is equivalent to 'break' [bugprone-terminating-continue] + // CHECK-FIXES: break; + } while(nullptr); + + do { + continue; + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: 'continue' in loop with false condition is equivalent to 'break' [bugprone-terminating-continue] + // CHECK-FIXES: break; + } while(__null); + + + do { + int x = 1; + if (x > 0) continue; + // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: 'continue' in loop with false condition is equivalent to 'break' [bugprone-terminating-continue] + // CHECK-FIXES: if (x > 0) break; + } while (false); +} + +void g() { + do { + do { + continue; + int x = 1; + } while (1 == 1); + } while (false); + + do { + for (int i = 0; i < 1; ++i) { + continue; + int x = 1; + } + } while (false); + + do { + while (true) { + continue; + int x = 1; + } + } while (false); + + int v[] = {1,2,3,34}; + do { + for (int n : v) { + if (n>2) continue; + } + } while (false); +}