Add flag to specify an alternative to std::forward #138755
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Since std::forward is nothing more than a cast, part of STL and not the language itself, it's easy to provide a custom implementation if one wishes not to include the entirety of <utility>. Added flag (ForwardFunction) provides a way to continue using this essential check even with the custom implementation of forwarding.
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@llvm/pr-subscribers-clang-tidy @llvm/pr-subscribers-clang-tools-extra Author: Dimitrije Dobrota (DimitrijeDobrota) ChangesSince std::forward is nothing more than a cast, part of STL and not the language itself, it's easy to provide a custom implementation if one wishes not to include the entirety of <utility>. Added flag (ForwardFunction) provides a way to continue using this essential check even with the custom implementation of forwarding. Since Full diff: https://github.com/llvm/llvm-project/pull/138755.diff 4 Files Affected:
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/MissingStdForwardCheck.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/MissingStdForwardCheck.cpp
index bbb35228ce47f..c90966413de69 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/MissingStdForwardCheck.cpp
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/MissingStdForwardCheck.cpp
@@ -124,7 +124,7 @@ void MissingStdForwardCheck::registerMatchers(MatchFinder *Finder) {
equalsBoundNode("param"), equalsBoundNode("var")))))),
CapturedInLambda)),
callee(unresolvedLookupExpr(hasAnyDeclaration(
- namedDecl(hasUnderlyingDecl(hasName("::std::forward")))))),
+ namedDecl(hasUnderlyingDecl(hasName(ForwardFunction)))))),
unless(anyOf(hasAncestor(typeLoc()),
hasAncestor(expr(hasUnevaluatedContext())))));
@@ -153,4 +153,13 @@ void MissingStdForwardCheck::check(const MatchFinder::MatchResult &Result) {
<< Param;
}
+MissingStdForwardCheck::MissingStdForwardCheck(StringRef Name,
+ ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context),
+ ForwardFunction(Options.get("ForwardFunction", "::std::forward")) {}
+
+void MissingStdForwardCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+ Options.store(Opts, "ForwardFunction", ForwardFunction);
+}
+
} // namespace clang::tidy::cppcoreguidelines
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/MissingStdForwardCheck.h b/clang-tools-extra/clang-tidy/cppcoreguidelines/MissingStdForwardCheck.h
index 5995ad588855e..f833b8031f8af 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/MissingStdForwardCheck.h
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/MissingStdForwardCheck.h
@@ -21,8 +21,7 @@ namespace clang::tidy::cppcoreguidelines {
/// http://clang.llvm.org/extra/clang-tidy/checks/cppcoreguidelines/missing-std-forward.html
class MissingStdForwardCheck : public ClangTidyCheck {
public:
- MissingStdForwardCheck(StringRef Name, ClangTidyContext *Context)
- : ClangTidyCheck(Name, Context) {}
+ MissingStdForwardCheck(StringRef Name, ClangTidyContext *Context);
void registerMatchers(ast_matchers::MatchFinder *Finder) override;
void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
@@ -31,6 +30,10 @@ class MissingStdForwardCheck : public ClangTidyCheck {
std::optional<TraversalKind> getCheckTraversalKind() const override {
return TK_IgnoreUnlessSpelledInSource;
}
+ void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+
+private:
+ const StringRef ForwardFunction;
};
} // namespace clang::tidy::cppcoreguidelines
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 579fca54924d5..9c71d651af75f 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -219,6 +219,10 @@ Changes in existing checks
tolerating fix-it breaking compilation when functions is used as pointers
to avoid matching usage of functions within the current compilation unit.
+- Improved :doc:`cppcoreguidelines-missing-std-forward
+ <clang-tidy/checks/cppcoreguidelines/missing-std-forward>` check by adding a
+ flag to specify the function used for forwarding instead of ``std::forward``.
+
Removed checks
^^^^^^^^^^^^^^
diff --git a/clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines/missing-std-forward.rst b/clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines/missing-std-forward.rst
index 0c311b59a5d5a..d6cc1e53f768d 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines/missing-std-forward.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines/missing-std-forward.rst
@@ -35,6 +35,14 @@ Example:
f(1, 2); // Incorrect - may not invoke the desired qualified function operator
}
+Options
+-------
+
+.. option:: ForwardFunction
+
+ Specify the function used for forwarding.
+ Default is `::std::forward`.
+
This check implements `F.19
<http://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Rf-forward>`_
from the C++ Core Guidelines.
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| @@ -219,6 +219,10 @@ Changes in existing checks | |||
| tolerating fix-it breaking compilation when functions is used as pointers | |||
| to avoid matching usage of functions within the current compilation unit. | |||
|
|
|||
| - Improved :doc:`cppcoreguidelines-missing-std-forward | |||
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Please keep alphabetical order (by check name) in this list.
Since std::forward is nothing more than a cast, part of STL and not the language itself, it's easy to provide a custom implementation if one wishes not to include the entirety of .
Added flag (ForwardFunction) provides a way to continue using this essential check even with the custom implementation of forwarding.
Since
::are specified beforestd::forward, I am not entirely sure whether it would be required for the custom function. In my testing it worked both with and without::.