https://github.com/nicovank created
https://github.com/llvm/llvm-project/pull/107521
This check will now work out of the box with other containers that have a
`contains` method, such as `folly::F14` or Abseil containers.
It will also work with strings, which are basically just weird containers.
`std::string` and `std::string_view` will have a `contains` method starting with
C++23. `llvm::StringRef` and `folly::StringPiece` are examples of existing
implementations with a `contains` method.
>From d7b62cdcbd48da6c286af7b113ceeadd8a507558 Mon Sep 17 00:00:00 2001
From: Nicolas van Kempen <nvank...@gmail.com>
Date: Fri, 6 Sep 2024 01:18:40 -0400
Subject: [PATCH] [clang-tidy][readability-container-contains] Extend to any
class with contains
This check will now work out of the box with other containers that have a
`contains` method, such as `folly::F14` or Abseil containers.
It will also work with strings, which are basically just weird containers.
`std::string` and `std::string_view` will have a `contains` method starting with
C++23. `llvm::StringRef` and `folly::StringPiece` are examples of existing
implementations with a `contains` method.
---
.../readability/ContainerContainsCheck.cpp | 17 ++++-----
.../readability/ContainerContainsCheck.h | 4 +-
clang-tools-extra/docs/ReleaseNotes.rst | 6 ++-
.../checks/readability/container-contains.rst | 38 +++++++++++--------
.../readability/container-contains.cpp | 37 +++++++++++++-----
5 files changed, 64 insertions(+), 38 deletions(-)
diff --git
a/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.cpp
b/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.cpp
index dbb50a060e5960..9fe5fbae32173a 100644
--- a/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.cpp
@@ -15,26 +15,25 @@ using namespace clang::ast_matchers;
namespace clang::tidy::readability {
void ContainerContainsCheck::registerMatchers(MatchFinder *Finder) {
- const auto SupportedContainers = hasType(
- hasUnqualifiedDesugaredType(recordType(hasDeclaration(cxxRecordDecl(
- hasAnyName("::std::set", "::std::unordered_set", "::std::map",
- "::std::unordered_map", "::std::multiset",
- "::std::unordered_multiset", "::std::multimap",
- "::std::unordered_multimap"))))));
+ const auto HasContainsMethod = hasMethod(cxxMethodDecl(hasName("contains")));
+ const auto ContainerWithContains = hasType(
+
hasUnqualifiedDesugaredType(recordType(hasDeclaration(cxxRecordDecl(anyOf(
+ HasContainsMethod,
hasAnyBase(hasType(hasCanonicalType(hasDeclaration(
+ cxxRecordDecl(HasContainsMethod)))))))))));
const auto CountCall =
- cxxMemberCallExpr(on(SupportedContainers),
+ cxxMemberCallExpr(on(ContainerWithContains),
callee(cxxMethodDecl(hasName("count"))),
argumentCountIs(1))
.bind("call");
const auto FindCall =
- cxxMemberCallExpr(on(SupportedContainers),
+ cxxMemberCallExpr(on(ContainerWithContains),
callee(cxxMethodDecl(hasName("find"))),
argumentCountIs(1))
.bind("call");
- const auto EndCall = cxxMemberCallExpr(on(SupportedContainers),
+ const auto EndCall = cxxMemberCallExpr(on(ContainerWithContains),
callee(cxxMethodDecl(hasName("end"))),
argumentCountIs(0));
diff --git a/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.h
b/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.h
index 2e8276d684cd79..de9fb862f49c7a 100644
--- a/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.h
+++ b/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.h
@@ -24,10 +24,8 @@ class ContainerContainsCheck : public ClangTidyCheck {
: ClangTidyCheck(Name, Context) {}
void registerMatchers(ast_matchers::MatchFinder *Finder) final;
void check(const ast_matchers::MatchFinder::MatchResult &Result) final;
-
-protected:
bool isLanguageVersionSupported(const LangOptions &LO) const final {
- return LO.CPlusPlus20;
+ return LO.CPlusPlus;
}
};
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst
b/clang-tools-extra/docs/ReleaseNotes.rst
index 6999c1ef2ea4b0..ccf7ace1811dc3 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -116,7 +116,11 @@ Changes in existing checks
<clang-tidy/checks/modernize/use-std-print>` check to support replacing
member function calls too.
-- Improved :doc:`readablility-implicit-bool-conversion
+- Improved :doc:`readability-container-contains
+ <clang-tidy/checks/readability/container-contains>` check
+ to let it work on any class that has a `contains` method.
+
+- Improved :doc:`readability-implicit-bool-conversion
<clang-tidy/checks/readability/implicit-bool-conversion>` check
by adding the option `UseUpperCaseLiteralSuffix` to select the
case of the literal suffix in fixes.
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/readability/container-contains.rst
b/clang-tools-extra/docs/clang-tidy/checks/readability/container-contains.rst
index b28daecf7a2cf3..86aac019359ff9 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/readability/container-contains.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/readability/container-contains.rst
@@ -3,23 +3,31 @@
readability-container-contains
==============================
-Finds usages of ``container.count()`` and ``container.find() ==
container.end()`` which should be replaced by a call to the
``container.contains()`` method introduced in C++20.
+Finds usages of ``container.count()`` and
+``container.find() == container.end()`` which should be replaced by a call to
+the ``container.contains()`` method.
-Whether an element is contained inside a container should be checked with
``contains`` instead of ``count``/``find`` because ``contains`` conveys the
intent more clearly. Furthermore, for containers which permit multiple entries
per key (``multimap``, ``multiset``, ...), ``contains`` is more efficient than
``count`` because ``count`` has to do unnecessary additional work.
+Whether an element is contained inside a container should be checked with
+``contains`` instead of ``count``/``find`` because ``contains`` conveys the
+intent more clearly. Furthermore, for containers which permit multiple entries
+per key (``multimap``, ``multiset``, ...), ``contains`` is more efficient than
+``count`` because ``count`` has to do unnecessary additional work.
Examples:
-=========================================== ==============================
-Initial expression Result
-------------------------------------------- ------------------------------
-``myMap.find(x) == myMap.end()`` ``!myMap.contains(x)``
-``myMap.find(x) != myMap.end()`` ``myMap.contains(x)``
-``if (myMap.count(x))`` ``if (myMap.contains(x))``
-``bool exists = myMap.count(x)`` ``bool exists =
myMap.contains(x)``
-``bool exists = myMap.count(x) > 0`` ``bool exists =
myMap.contains(x)``
-``bool exists = myMap.count(x) >= 1`` ``bool exists =
myMap.contains(x)``
-``bool missing = myMap.count(x) == 0`` ``bool missing =
!myMap.contains(x)``
-=========================================== ==============================
+========================================= ==============================
+Initial expression Result
+----------------------------------------- ------------------------------
+``myMap.find(x) == myMap.end()`` ``!myMap.contains(x)``
+``myMap.find(x) != myMap.end()`` ``myMap.contains(x)``
+``if (myMap.count(x))`` ``if (myMap.contains(x))``
+``bool exists = myMap.count(x)`` ``bool exists = myMap.contains(x)``
+``bool exists = myMap.count(x) > 0`` ``bool exists = myMap.contains(x)``
+``bool exists = myMap.count(x) >= 1`` ``bool exists = myMap.contains(x)``
+``bool missing = myMap.count(x) == 0`` ``bool missing =
!myMap.contains(x)``
+========================================= ==============================
-This check applies to ``std::set``, ``std::unordered_set``, ``std::map``,
``std::unordered_map`` and the corresponding multi-key variants.
-It is only active for C++20 and later, as the ``contains`` method was only
added in C++20.
+This check will apply to any class that has a ``contains`` method, notably
+including ``std::set``, ``std::unordered_set``, ``std::map``, and
+``std::unordered_map`` as of C++20, and ``std::string`` and
``std::string_view``
+as of C++23.
diff --git
a/clang-tools-extra/test/clang-tidy/checkers/readability/container-contains.cpp
b/clang-tools-extra/test/clang-tidy/checkers/readability/container-contains.cpp
index 0ecb61b2e7df06..2342b8b38eb883 100644
---
a/clang-tools-extra/test/clang-tidy/checkers/readability/container-contains.cpp
+++
b/clang-tools-extra/test/clang-tidy/checkers/readability/container-contains.cpp
@@ -240,7 +240,7 @@ int testMacroExpansion(std::unordered_set<int> &MySet) {
return 0;
}
-// The following map has the same interface like `std::map`.
+// The following map has the same interface as `std::map`.
template <class Key, class T>
struct CustomMap {
unsigned count(const Key &K) const;
@@ -249,13 +249,30 @@ struct CustomMap {
void *end();
};
-// The clang-tidy check is currently hard-coded against the `std::` containers
-// and hence won't annotate the following instance. We might change this in the
-// future and also detect the following case.
-void *testDifferentCheckTypes(CustomMap<int, int> &MyMap) {
- if (MyMap.count(0))
- // NO-WARNING.
- // CHECK-FIXES: if (MyMap.count(0))
- return nullptr;
- return MyMap.find(2);
+void testDifferentCheckTypes(CustomMap<int, int> &MyMap) {
+ if (MyMap.count(0)) {};
+ // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check
for membership [readability-container-contains]
+ // CHECK-FIXES: if (MyMap.contains(0)) {};
+
+ MyMap.find(0) != MyMap.end();
+ // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check
for membership [readability-container-contains]
+ // CHECK-FIXES: MyMap.contains(0);
+}
+
+struct MySubmap : public CustomMap<int, int> {};
+
+void testSubclass(MySubmap& MyMap) {
+ if (MyMap.count(0)) {};
+ // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check
for membership [readability-container-contains]
+ // CHECK-FIXES: if (MyMap.contains(0)) {};
+}
+
+using UsingMap = CustomMap<int, int>;
+struct MySubmap2 : public UsingMap {};
+using UsingMap2 = MySubmap2;
+
+void testUsing(UsingMap2& MyMap) {
+ if (MyMap.count(0)) {};
+ // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check
for membership [readability-container-contains]
+ // CHECK-FIXES: if (MyMap.contains(0)) {};
}
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