[clang-tools-extra] [clang-tidy] Add check hicpp-ignored-remove-result (PR #73119)
Björn Svensson via cfe-commits
cfe-commits at lists.llvm.org
Tue Dec 5 14:41:34 PST 2023
https://github.com/bjosv updated https://github.com/llvm/llvm-project/pull/73119
>From 91cf412abcfd231ab399c3e44c6a9bc14109537c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Svensson?= <bjorn.a.svensson at est.tech>
Date: Tue, 21 Nov 2023 23:30:07 +0100
Subject: [PATCH 1/3] [clang-tidy] Add check hicpp-ignored-remove-result
This check implements the rule 17.5.1 of the HICPP standard
which states:
- Do not ignore the result of std::remove, std::remove_if or std::unique
The mutating algorithms std::remove, std::remove_if and both overloads of
std::unique operate by swapping or moving elements of the range they are
operating over. On completion, they return an iterator to the last valid element.
In the majority of cases the correct behavior is to use this result as the
first operand in a call to std::erase.
Suppressing issues by casting to `void` is enabled by default, but can be
disabled by setting `AllowCastToVoid` option to `false`.
---
.../clang-tidy/hicpp/HICPPTidyModule.cpp | 20 ++++++++
clang-tools-extra/docs/ReleaseNotes.rst | 4 ++
.../checks/hicpp/ignored-remove-result.rst | 20 ++++++++
.../docs/clang-tidy/checks/list.rst | 1 +
.../checkers/hicpp/ignored-remove-result.cpp | 47 +++++++++++++++++++
5 files changed, 92 insertions(+)
create mode 100644 clang-tools-extra/docs/clang-tidy/checks/hicpp/ignored-remove-result.rst
create mode 100644 clang-tools-extra/test/clang-tidy/checkers/hicpp/ignored-remove-result.cpp
diff --git a/clang-tools-extra/clang-tidy/hicpp/HICPPTidyModule.cpp b/clang-tools-extra/clang-tidy/hicpp/HICPPTidyModule.cpp
index 3749796877120e..09d15ccab3f29c 100644
--- a/clang-tools-extra/clang-tidy/hicpp/HICPPTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/hicpp/HICPPTidyModule.cpp
@@ -10,6 +10,7 @@
#include "../ClangTidyModule.h"
#include "../ClangTidyModuleRegistry.h"
#include "../bugprone/UndelegatedConstructorCheck.h"
+#include "../bugprone/UnusedReturnValueCheck.h"
#include "../bugprone/UseAfterMoveCheck.h"
#include "../cppcoreguidelines/AvoidGotoCheck.h"
#include "../cppcoreguidelines/NoMallocCheck.h"
@@ -41,6 +42,15 @@
#include "NoAssemblerCheck.h"
#include "SignedBitwiseCheck.h"
+namespace {
+
+// Checked functions for hicpp-ignored-remove-result.
+const llvm::StringRef CheckedFunctions = "::std::remove;"
+ "::std::remove_if;"
+ "::std::unique;";
+
+} // namespace
+
namespace clang::tidy {
namespace hicpp {
@@ -64,6 +74,8 @@ class HICPPModule : public ClangTidyModule {
"hicpp-explicit-conversions");
CheckFactories.registerCheck<readability::FunctionSizeCheck>(
"hicpp-function-size");
+ CheckFactories.registerCheck<bugprone::UnusedReturnValueCheck>(
+ "hicpp-ignored-remove-result");
CheckFactories.registerCheck<readability::NamedParameterCheck>(
"hicpp-named-parameter");
CheckFactories.registerCheck<bugprone::UseAfterMoveCheck>(
@@ -107,6 +119,14 @@ class HICPPModule : public ClangTidyModule {
CheckFactories.registerCheck<cppcoreguidelines::ProTypeVarargCheck>(
"hicpp-vararg");
}
+
+ ClangTidyOptions getModuleOptions() override {
+ ClangTidyOptions Options;
+ ClangTidyOptions::OptionMap &Opts = Options.CheckOptions;
+ Opts["hicpp-ignored-remove-result.CheckedFunctions"] = CheckedFunctions;
+ Opts["hicpp-ignored-remove-result.AllowCastToVoid"] = "true";
+ return Options;
+ }
};
// Register the HICPPModule using this statically initialized variable.
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 6d5f49dc062545..c940025df1c63c 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -205,6 +205,10 @@ New check aliases
<clang-tidy/checks/cppcoreguidelines/macro-to-enum>` to :doc:`modernize-macro-to-enum
<clang-tidy/checks/modernize/macro-to-enum>` was added.
+- New alias :doc:`hicpp-ignored-remove-result
+ <clang-tidy/checks/hicpp/ignored-remove-result>` to :doc:`bugprone-unused-return-value
+ <clang-tidy/checks/bugprone/unused-return-value>` was added.
+
Changes in existing checks
^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang-tools-extra/docs/clang-tidy/checks/hicpp/ignored-remove-result.rst b/clang-tools-extra/docs/clang-tidy/checks/hicpp/ignored-remove-result.rst
new file mode 100644
index 00000000000000..4b6188b886db12
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/hicpp/ignored-remove-result.rst
@@ -0,0 +1,20 @@
+.. title:: clang-tidy - hicpp-ignored-remove-result
+
+hicpp-ignored-remove-result
+===========================
+
+Ensure that the result of ``std::remove``, ``std::remove_if`` and ``std::unique``
+are not ignored according to
+`rule 17.5.1 <https://www.perforce.com/resources/qac/high-integrity-cpp-coding-standard/standard-library>`_.
+
+The mutating algorithms ``std::remove``, ``std::remove_if`` and both overloads
+of ``std::unique`` operate by swapping or moving elements of the range they are
+operating over. On completion, they return an iterator to the last valid
+element. In the majority of cases the correct behavior is to use this result as
+the first operand in a call to std::erase.
+
+This check is an alias of check :doc:`bugprone-unused-return-value <../bugprone/unused-return-value>`
+with a fixed set of functions.
+
+Suppressing issues by casting to ``void`` is enabled by default and can be
+disabled by setting `AllowCastToVoid` option to ``false``.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index 6f987ba1672e3f..417513b2f2aaa3 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -226,6 +226,7 @@ Clang-Tidy Checks
:doc:`google-runtime-operator <google/runtime-operator>`,
:doc:`google-upgrade-googletest-case <google/upgrade-googletest-case>`, "Yes"
:doc:`hicpp-exception-baseclass <hicpp/exception-baseclass>`,
+ :doc:`hicpp-ignored-remove-result <hicpp/ignored-remove-result>`,
:doc:`hicpp-multiway-paths-covered <hicpp/multiway-paths-covered>`,
:doc:`hicpp-no-assembler <hicpp/no-assembler>`,
:doc:`hicpp-signed-bitwise <hicpp/signed-bitwise>`,
diff --git a/clang-tools-extra/test/clang-tidy/checkers/hicpp/ignored-remove-result.cpp b/clang-tools-extra/test/clang-tidy/checkers/hicpp/ignored-remove-result.cpp
new file mode 100644
index 00000000000000..86deb96216a687
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/hicpp/ignored-remove-result.cpp
@@ -0,0 +1,47 @@
+// RUN: %check_clang_tidy %s hicpp-ignored-remove-result %t
+
+namespace std {
+
+template <typename ForwardIt, typename T>
+ForwardIt remove(ForwardIt, ForwardIt, const T &);
+
+template <typename ForwardIt, typename UnaryPredicate>
+ForwardIt remove_if(ForwardIt, ForwardIt, UnaryPredicate);
+
+template <typename ForwardIt>
+ForwardIt unique(ForwardIt, ForwardIt);
+
+template <class InputIt, class T>
+InputIt find(InputIt, InputIt, const T&);
+
+} // namespace std
+
+void warning() {
+ std::remove(nullptr, nullptr, 1);
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: the value returned by this function should not be disregarded; neglecting it may lead to errors
+ // CHECK-MESSAGES: [[@LINE-2]]:3: note: cast the expression to void to silence this warning
+
+ std::remove_if(nullptr, nullptr, nullptr);
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: the value returned by this function should not be disregarded; neglecting it may lead to errors
+ // CHECK-MESSAGES: [[@LINE-2]]:3: note: cast the expression to void to silence this warning
+
+ std::unique(nullptr, nullptr);
+ // CHECK-MESSAGES: [[@LINE-1]]:3: warning: the value returned by this function should not be disregarded; neglecting it may lead to errors
+ // CHECK-MESSAGES: [[@LINE-2]]:3: note: cast the expression to void to silence this warning
+}
+
+void noWarning() {
+
+ auto RemoveRetval = std::remove(nullptr, nullptr, 1);
+
+ auto RemoveIfRetval = std::remove_if(nullptr, nullptr, nullptr);
+
+ auto UniqueRetval = std::unique(nullptr, nullptr);
+
+ // cast to void should allow ignoring the return value
+ (void)std::remove(nullptr, nullptr, 1);
+
+ // no warning on std::find since the checker overrides
+ // bugprone-unused-return-value's checked functions.
+ std::find(nullptr, nullptr, 1);
+}
>From 46179bdf862a531f45b44f03de0803cec089e9b8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Svensson?= <bjorn.a.svensson at est.tech>
Date: Thu, 23 Nov 2023 09:49:00 +0100
Subject: [PATCH 2/3] fixup: missing double back-ticks in docs
---
.../docs/clang-tidy/checks/hicpp/ignored-remove-result.rst | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang-tools-extra/docs/clang-tidy/checks/hicpp/ignored-remove-result.rst b/clang-tools-extra/docs/clang-tidy/checks/hicpp/ignored-remove-result.rst
index 4b6188b886db12..ff1d25d31f52c7 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/hicpp/ignored-remove-result.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/hicpp/ignored-remove-result.rst
@@ -11,7 +11,7 @@ The mutating algorithms ``std::remove``, ``std::remove_if`` and both overloads
of ``std::unique`` operate by swapping or moving elements of the range they are
operating over. On completion, they return an iterator to the last valid
element. In the majority of cases the correct behavior is to use this result as
-the first operand in a call to std::erase.
+the first operand in a call to ``std::erase``.
This check is an alias of check :doc:`bugprone-unused-return-value <../bugprone/unused-return-value>`
with a fixed set of functions.
>From c1e05d10c6c68935b7f5894900492fa0f29aaea0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Svensson?= <bjorn.a.svensson at est.tech>
Date: Thu, 23 Nov 2023 17:56:05 +0100
Subject: [PATCH 3/3] fixup: implement as own check (using add_new_check.py)
---
.../bugprone/UnusedReturnValueCheck.cpp | 5 ++++
.../bugprone/UnusedReturnValueCheck.h | 6 ++--
.../clang-tidy/hicpp/CMakeLists.txt | 1 +
.../clang-tidy/hicpp/HICPPTidyModule.cpp | 23 ++-------------
.../hicpp/IgnoredRemoveResultCheck.cpp | 28 ++++++++++++++++++
.../hicpp/IgnoredRemoveResultCheck.h | 29 +++++++++++++++++++
clang-tools-extra/docs/ReleaseNotes.rst | 10 ++++---
.../checks/hicpp/ignored-remove-result.rst | 3 --
.../checkers/hicpp/ignored-remove-result.cpp | 29 +++++++++++++++----
9 files changed, 100 insertions(+), 34 deletions(-)
create mode 100644 clang-tools-extra/clang-tidy/hicpp/IgnoredRemoveResultCheck.cpp
create mode 100644 clang-tools-extra/clang-tidy/hicpp/IgnoredRemoveResultCheck.h
diff --git a/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp
index 6bc9f2dd367dcb..a79e5d62eb48e3 100644
--- a/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp
@@ -133,6 +133,11 @@ UnusedReturnValueCheck::UnusedReturnValueCheck(llvm::StringRef Name,
"::boost::system::error_code"))),
AllowCastToVoid(Options.get("AllowCastToVoid", false)) {}
+UnusedReturnValueCheck::UnusedReturnValueCheck(llvm::StringRef Name,
+ ClangTidyContext *Context,
+ std::string CheckedFunctions)
+ : ClangTidyCheck(Name, Context), CheckedFunctions(CheckedFunctions) {}
+
void UnusedReturnValueCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
Options.store(Opts, "CheckedFunctions", CheckedFunctions);
Options.store(Opts, "CheckedReturnTypes",
diff --git a/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.h b/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.h
index b4356f8379fdc8..ca5181f438a2d0 100644
--- a/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.h
+++ b/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.h
@@ -28,10 +28,12 @@ class UnusedReturnValueCheck : public ClangTidyCheck {
return TK_IgnoreUnlessSpelledInSource;
}
-private:
+protected:
+ UnusedReturnValueCheck(StringRef Name, ClangTidyContext *Context,
+ std::string CheckedFunctions);
std::string CheckedFunctions;
const std::vector<StringRef> CheckedReturnTypes;
- const bool AllowCastToVoid;
+ bool AllowCastToVoid;
};
} // namespace clang::tidy::bugprone
diff --git a/clang-tools-extra/clang-tidy/hicpp/CMakeLists.txt b/clang-tools-extra/clang-tidy/hicpp/CMakeLists.txt
index d12ca275d39647..132fbaccccf8a9 100644
--- a/clang-tools-extra/clang-tidy/hicpp/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/hicpp/CMakeLists.txt
@@ -6,6 +6,7 @@ set(LLVM_LINK_COMPONENTS
add_clang_library(clangTidyHICPPModule
ExceptionBaseclassCheck.cpp
HICPPTidyModule.cpp
+ IgnoredRemoveResultCheck.cpp
MultiwayPathsCoveredCheck.cpp
NoAssemblerCheck.cpp
SignedBitwiseCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/hicpp/HICPPTidyModule.cpp b/clang-tools-extra/clang-tidy/hicpp/HICPPTidyModule.cpp
index 09d15ccab3f29c..daa9f398a740ed 100644
--- a/clang-tools-extra/clang-tidy/hicpp/HICPPTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/hicpp/HICPPTidyModule.cpp
@@ -10,7 +10,6 @@
#include "../ClangTidyModule.h"
#include "../ClangTidyModuleRegistry.h"
#include "../bugprone/UndelegatedConstructorCheck.h"
-#include "../bugprone/UnusedReturnValueCheck.h"
#include "../bugprone/UseAfterMoveCheck.h"
#include "../cppcoreguidelines/AvoidGotoCheck.h"
#include "../cppcoreguidelines/NoMallocCheck.h"
@@ -38,19 +37,11 @@
#include "../readability/NamedParameterCheck.h"
#include "../readability/UppercaseLiteralSuffixCheck.h"
#include "ExceptionBaseclassCheck.h"
+#include "IgnoredRemoveResultCheck.h"
#include "MultiwayPathsCoveredCheck.h"
#include "NoAssemblerCheck.h"
#include "SignedBitwiseCheck.h"
-namespace {
-
-// Checked functions for hicpp-ignored-remove-result.
-const llvm::StringRef CheckedFunctions = "::std::remove;"
- "::std::remove_if;"
- "::std::unique;";
-
-} // namespace
-
namespace clang::tidy {
namespace hicpp {
@@ -67,6 +58,8 @@ class HICPPModule : public ClangTidyModule {
"hicpp-deprecated-headers");
CheckFactories.registerCheck<ExceptionBaseclassCheck>(
"hicpp-exception-baseclass");
+ CheckFactories.registerCheck<IgnoredRemoveResultCheck>(
+ "hicpp-ignored-remove-result");
CheckFactories.registerCheck<MultiwayPathsCoveredCheck>(
"hicpp-multiway-paths-covered");
CheckFactories.registerCheck<SignedBitwiseCheck>("hicpp-signed-bitwise");
@@ -74,8 +67,6 @@ class HICPPModule : public ClangTidyModule {
"hicpp-explicit-conversions");
CheckFactories.registerCheck<readability::FunctionSizeCheck>(
"hicpp-function-size");
- CheckFactories.registerCheck<bugprone::UnusedReturnValueCheck>(
- "hicpp-ignored-remove-result");
CheckFactories.registerCheck<readability::NamedParameterCheck>(
"hicpp-named-parameter");
CheckFactories.registerCheck<bugprone::UseAfterMoveCheck>(
@@ -119,14 +110,6 @@ class HICPPModule : public ClangTidyModule {
CheckFactories.registerCheck<cppcoreguidelines::ProTypeVarargCheck>(
"hicpp-vararg");
}
-
- ClangTidyOptions getModuleOptions() override {
- ClangTidyOptions Options;
- ClangTidyOptions::OptionMap &Opts = Options.CheckOptions;
- Opts["hicpp-ignored-remove-result.CheckedFunctions"] = CheckedFunctions;
- Opts["hicpp-ignored-remove-result.AllowCastToVoid"] = "true";
- return Options;
- }
};
// Register the HICPPModule using this statically initialized variable.
diff --git a/clang-tools-extra/clang-tidy/hicpp/IgnoredRemoveResultCheck.cpp b/clang-tools-extra/clang-tidy/hicpp/IgnoredRemoveResultCheck.cpp
new file mode 100644
index 00000000000000..d154c42c432f34
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/hicpp/IgnoredRemoveResultCheck.cpp
@@ -0,0 +1,28 @@
+//===--- IgnoredRemoveResultCheck.cpp - clang-tidy ------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "IgnoredRemoveResultCheck.h"
+
+namespace clang::tidy::hicpp {
+
+IgnoredRemoveResultCheck::IgnoredRemoveResultCheck(llvm::StringRef Name,
+ ClangTidyContext *Context)
+ : UnusedReturnValueCheck(Name, Context,
+ "::std::remove;"
+ "::std::remove_if;"
+ "::std::unique;") {
+ // The constructor for ClangTidyCheck needs to have been called
+ // before we can access options via Options.get().
+ AllowCastToVoid = Options.get("AllowCastToVoid", true);
+}
+
+void IgnoredRemoveResultCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+ Options.store(Opts, "AllowCastToVoid", AllowCastToVoid);
+}
+
+} // namespace clang::tidy::hicpp
diff --git a/clang-tools-extra/clang-tidy/hicpp/IgnoredRemoveResultCheck.h b/clang-tools-extra/clang-tidy/hicpp/IgnoredRemoveResultCheck.h
new file mode 100644
index 00000000000000..48354c34a8581a
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/hicpp/IgnoredRemoveResultCheck.h
@@ -0,0 +1,29 @@
+//===--- IgnoredRemoveResultCheck.h - clang-tidy ----------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_HICPP_IGNOREDREMOVERESULTCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_HICPP_IGNOREDREMOVERESULTCHECK_H
+
+#include "../bugprone/UnusedReturnValueCheck.h"
+
+namespace clang::tidy::hicpp {
+
+/// Ensure that the result of std::remove, std::remove_if and std::unique
+/// are not ignored according to rule 17.5.1.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/hicpp/ignored-remove-result.html
+class IgnoredRemoveResultCheck : public bugprone::UnusedReturnValueCheck {
+public:
+ IgnoredRemoveResultCheck(StringRef Name, ClangTidyContext *Context);
+ void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+};
+
+} // namespace clang::tidy::hicpp
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_HICPP_IGNOREDREMOVERESULTCHECK_H
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index c940025df1c63c..268040415d5e01 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -174,6 +174,12 @@ New checks
Flags coroutines that suspend while a lock guard is in scope at the
suspension point.
+- New :doc:`hicpp-ignored-remove-result
+ <clang-tidy/checks/hicpp/ignored-remove-result>` check.
+
+ Ensure that the result of ``std::remove``, ``std::remove_if`` and
+ ``std::unique`` are not ignored according to rule 17.5.1.
+
- New :doc:`misc-coroutine-hostile-raii
<clang-tidy/checks/misc/coroutine-hostile-raii>` check.
@@ -205,10 +211,6 @@ New check aliases
<clang-tidy/checks/cppcoreguidelines/macro-to-enum>` to :doc:`modernize-macro-to-enum
<clang-tidy/checks/modernize/macro-to-enum>` was added.
-- New alias :doc:`hicpp-ignored-remove-result
- <clang-tidy/checks/hicpp/ignored-remove-result>` to :doc:`bugprone-unused-return-value
- <clang-tidy/checks/bugprone/unused-return-value>` was added.
-
Changes in existing checks
^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang-tools-extra/docs/clang-tidy/checks/hicpp/ignored-remove-result.rst b/clang-tools-extra/docs/clang-tidy/checks/hicpp/ignored-remove-result.rst
index ff1d25d31f52c7..62533f54f28a89 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/hicpp/ignored-remove-result.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/hicpp/ignored-remove-result.rst
@@ -13,8 +13,5 @@ operating over. On completion, they return an iterator to the last valid
element. In the majority of cases the correct behavior is to use this result as
the first operand in a call to ``std::erase``.
-This check is an alias of check :doc:`bugprone-unused-return-value <../bugprone/unused-return-value>`
-with a fixed set of functions.
-
Suppressing issues by casting to ``void`` is enabled by default and can be
disabled by setting `AllowCastToVoid` option to ``false``.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/hicpp/ignored-remove-result.cpp b/clang-tools-extra/test/clang-tidy/checkers/hicpp/ignored-remove-result.cpp
index 86deb96216a687..b068f085909893 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/hicpp/ignored-remove-result.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/hicpp/ignored-remove-result.cpp
@@ -1,4 +1,5 @@
// RUN: %check_clang_tidy %s hicpp-ignored-remove-result %t
+// RUN: %check_clang_tidy -check-suffixes=NOCAST %s hicpp-ignored-remove-result %t -- -config='{CheckOptions: {hicpp-ignored-remove-result.AllowCastToVoid: false}}'
namespace std {
@@ -14,20 +15,36 @@ ForwardIt unique(ForwardIt, ForwardIt);
template <class InputIt, class T>
InputIt find(InputIt, InputIt, const T&);
+class error_code {
+};
+
} // namespace std
+std::error_code errorFunc() {
+ return std::error_code();
+}
+
void warning() {
std::remove(nullptr, nullptr, 1);
// CHECK-MESSAGES: [[@LINE-1]]:3: warning: the value returned by this function should not be disregarded; neglecting it may lead to errors
// CHECK-MESSAGES: [[@LINE-2]]:3: note: cast the expression to void to silence this warning
+ // CHECK-MESSAGES-NOCAST: [[@LINE-3]]:3: warning: the value returned by this function should not be disregarded; neglecting it may lead to errors
std::remove_if(nullptr, nullptr, nullptr);
// CHECK-MESSAGES: [[@LINE-1]]:3: warning: the value returned by this function should not be disregarded; neglecting it may lead to errors
// CHECK-MESSAGES: [[@LINE-2]]:3: note: cast the expression to void to silence this warning
+ // CHECK-MESSAGES-NOCAST: [[@LINE-3]]:3: warning: the value returned by this function should not be disregarded; neglecting it may lead to errors
std::unique(nullptr, nullptr);
// CHECK-MESSAGES: [[@LINE-1]]:3: warning: the value returned by this function should not be disregarded; neglecting it may lead to errors
// CHECK-MESSAGES: [[@LINE-2]]:3: note: cast the expression to void to silence this warning
+ // CHECK-MESSAGES-NOCAST: [[@LINE-3]]:3: warning: the value returned by this function should not be disregarded; neglecting it may lead to errors
+}
+
+void optionalWarning() {
+ // No warning unless AllowCastToVoid=false
+ (void)std::remove(nullptr, nullptr, 1);
+ // CHECK-MESSAGES-NOCAST: [[@LINE-1]]:9: warning: the value returned by this function should not be disregarded; neglecting it may lead to errors
}
void noWarning() {
@@ -38,10 +55,12 @@ void noWarning() {
auto UniqueRetval = std::unique(nullptr, nullptr);
- // cast to void should allow ignoring the return value
- (void)std::remove(nullptr, nullptr, 1);
-
- // no warning on std::find since the checker overrides
- // bugprone-unused-return-value's checked functions.
+ // Verify that other checks in the baseclass are not used.
+ // - no warning on std::find since the checker overrides
+ // bugprone-unused-return-value's checked functions.
std::find(nullptr, nullptr, 1);
+ // - no warning on return types since the checker disable
+ // bugprone-unused-return-value's checked return types.
+ errorFunc();
+ (void) errorFunc();
}
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