llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang-tidy Author: Congcong Cai (HerrCai0907) <details> <summary>Changes</summary> Fixes: #<!-- -->84480 We assuem assignemnt at most of time, operator overloading means the value is assigned to the other variable, then clang-tidy should suppress warning even if this operator overloading match the regex. --- Full diff: https://github.com/llvm/llvm-project/pull/84489.diff 3 Files Affected: - (modified) clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp (+14-10) - (modified) clang-tools-extra/docs/ReleaseNotes.rst (+2-2) - (added) clang-tools-extra/test/clang-tidy/checkers/bugprone/unused-return-value-avoid-assignment.cpp (+31) ``````````diff diff --git a/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp index 1252b2f23805a1..2167d381c42b03 100644 --- a/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp +++ b/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp @@ -11,6 +11,7 @@ #include "../utils/OptionsUtils.h" #include "clang/AST/ASTContext.h" #include "clang/ASTMatchers/ASTMatchFinder.h" +#include "clang/ASTMatchers/ASTMatchers.h" using namespace clang::ast_matchers; using namespace clang::ast_matchers::internal; @@ -157,16 +158,19 @@ void UnusedReturnValueCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) { } void UnusedReturnValueCheck::registerMatchers(MatchFinder *Finder) { - auto MatchedDirectCallExpr = - expr(callExpr(callee(functionDecl( - // Don't match void overloads of checked functions. - unless(returns(voidType())), - anyOf(isInstantiatedFrom(matchers::matchesAnyListedName( - CheckedFunctions)), - returns(hasCanonicalType(hasDeclaration( - namedDecl(matchers::matchesAnyListedName( - CheckedReturnTypes))))))))) - .bind("match")); + auto MatchedDirectCallExpr = expr( + callExpr(callee(functionDecl( + // Don't match void overloads of checked functions. + unless(returns(voidType())), + // Don't match copy or move assignment operator. + unless(cxxMethodDecl(anyOf(isCopyAssignmentOperator(), + isMoveAssignmentOperator()))), + anyOf(isInstantiatedFrom( + matchers::matchesAnyListedName(CheckedFunctions)), + returns(hasCanonicalType(hasDeclaration( + namedDecl(matchers::matchesAnyListedName( + CheckedReturnTypes))))))))) + .bind("match")); auto CheckCastToVoid = AllowCastToVoid ? castExpr(unless(hasCastKind(CK_ToVoid))) : castExpr(); diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst index b5f025ce467a15..c7121fe07e0ad3 100644 --- a/clang-tools-extra/docs/ReleaseNotes.rst +++ b/clang-tools-extra/docs/ReleaseNotes.rst @@ -152,9 +152,9 @@ Changes in existing checks - Improved :doc:`bugprone-unused-return-value <clang-tidy/checks/bugprone/unused-return-value>` check by updating the - parameter `CheckedFunctions` to support regexp and avoiding false postive for + parameter `CheckedFunctions` to support regexp, avoiding false positive for function with the same prefix as the default argument, e.g. ``std::unique_ptr`` - and ``std::unique``. + and ``std::unique``, avoiding false positive for assignment operator overloading. - Improved :doc:`bugprone-use-after-move <clang-tidy/checks/bugprone/use-after-move>` check to also handle diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/unused-return-value-avoid-assignment.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/unused-return-value-avoid-assignment.cpp new file mode 100644 index 00000000000000..8bd3c30e71b51a --- /dev/null +++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/unused-return-value-avoid-assignment.cpp @@ -0,0 +1,31 @@ +// RUN: %check_clang_tidy %s bugprone-unused-return-value %t \ +// RUN: -config='{CheckOptions: \ +// RUN: {bugprone-unused-return-value.CheckedFunctions: "::*"}}' \ +// RUN: -- + +struct S { + S(){}; + S(S const &); + S(S &&); + S &operator=(S const &); + S &operator=(S &&); +}; + +S returnValue(); +S const &returnRef(); + +void bar() { + returnValue(); + // CHECK-MESSAGES: [[@LINE-1]]:3: warning: the value returned by this function should not be disregarded; neglecting it may lead to errors + + S a{}; + a = returnValue(); + // CHECK-NOT: [[@LINE-1]]:3: warning + a.operator=(returnValue()); + // CHECK-NOT: [[@LINE-1]]:3: warning + + a = returnRef(); + // CHECK-NOT: [[@LINE-1]]:3: warning + a.operator=(returnRef()); + // CHECK-NOT: [[@LINE-1]]:3: warning +} `````````` </details> https://github.com/llvm/llvm-project/pull/84489 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
