Revert "[clang-tidy] Add portability-std-allocator-const check"

This reverts commit 73da7eed8f.
Breaks check-clang-tools on Windows, see comment on
https://reviews.llvm.org/D123655

clang-tools-extra/clang-tidy/portability/CMakeLists.txt

@@ -7,7 +7,6 @@ add_clang_library(clangTidyPortabilityModule
   PortabilityTidyModule.cpp
   RestrictSystemIncludesCheck.cpp
   SIMDIntrinsicsCheck.cpp
-  StdAllocatorConstCheck.cpp
 
   LINK_LIBS
   clangTidy

clang-tools-extra/clang-tidy/portability/PortabilityTidyModule.cpp

@@ -11,7 +11,6 @@
 #include "../ClangTidyModuleRegistry.h"
 #include "RestrictSystemIncludesCheck.h"
 #include "SIMDIntrinsicsCheck.h"
-#include "StdAllocatorConstCheck.h"
 
 namespace clang {
 namespace tidy {
@@ -24,8 +23,6 @@ public:
         "portability-restrict-system-includes");
     CheckFactories.registerCheck<SIMDIntrinsicsCheck>(
         "portability-simd-intrinsics");
-    CheckFactories.registerCheck<StdAllocatorConstCheck>(
-        "portability-std-allocator-const");
   }
 };
 

clang-tools-extra/clang-tidy/portability/StdAllocatorConstCheck.cpp

@@ -1,71 +0,0 @@
-//===-- StdAllocatorConstCheck.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 "StdAllocatorConstCheck.h"
-#include "clang/ASTMatchers/ASTMatchFinder.h"
-
-using namespace clang::ast_matchers;
-
-namespace clang {
-namespace tidy {
-namespace portability {
-
-void StdAllocatorConstCheck::registerMatchers(MatchFinder *Finder) {
-  // Match std::allocator<const T>.
-  auto allocatorConst =
-      recordType(hasDeclaration(classTemplateSpecializationDecl(
-          hasName("::std::allocator"),
-          hasTemplateArgument(0, refersToType(qualType(isConstQualified()))))));
-
-  auto hasContainerName =
-      hasAnyName("::std::vector", "::std::deque", "::std::list",
-                 "::std::multiset", "::std::set", "::std::unordered_multiset",
-                 "::std::unordered_set", "::absl::flat_hash_set");
-
-  // Match `std::vector<const T> var;` and other common containers like deque,
-  // list, and absl::flat_hash_set. Containers like queue and stack use deque
-  // but do not directly use std::allocator as a template argument, so they
-  // aren't caught.
-  Finder->addMatcher(
-      typeLoc(
-          templateSpecializationTypeLoc(),
-          loc(hasUnqualifiedDesugaredType(anyOf(
-              recordType(hasDeclaration(classTemplateSpecializationDecl(
-                  hasContainerName,
-                  anyOf(
-                      hasTemplateArgument(1, refersToType(allocatorConst)),
-                      hasTemplateArgument(2, refersToType(allocatorConst)),
-                      hasTemplateArgument(3, refersToType(allocatorConst)))))),
-              // Match std::vector<const dependent>
-              templateSpecializationType(
-                  templateArgumentCountIs(1),
-                  hasTemplateArgument(
-                      0, refersToType(qualType(isConstQualified()))),
-                  hasDeclaration(namedDecl(hasContainerName)))))))
-          .bind("type_loc"),
-      this);
-}
-
-void StdAllocatorConstCheck::check(const MatchFinder::MatchResult &Result) {
-  const auto *T = Result.Nodes.getNodeAs<TypeLoc>("type_loc");
-  if (!T)
-    return;
-  // Exclude TypeLoc matches in STL headers.
-  if (isSystem(Result.Context->getSourceManager().getFileCharacteristic(
-          T->getBeginLoc())))
-    return;
-
-  diag(T->getBeginLoc(),
-       "container using std::allocator<const T> is a deprecated libc++ "
-       "extension; remove const for compatibility with other standard "
-       "libraries");
-}
-
-} // namespace portability
-} // namespace tidy
-} // namespace clang

clang-tools-extra/clang-tidy/portability/StdAllocatorConstCheck.h

@@ -1,37 +0,0 @@
-//===--- StdAllocatorConstT.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_PORTABILITY_STDALLOCATORCONSTCHECK_H
-#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PORTABILITY_STDALLOCATORCONSTCHECK_H
-
-#include "../ClangTidyCheck.h"
-
-namespace clang {
-namespace tidy {
-namespace portability {
-
-/// Report use of ``std::vector<const T>`` (and similar containers of const
-/// elements). These are not allowed in standard C++ due to undefined
-/// ``std::allocator<const T>``. They do not compile with libstdc++ or MSVC.
-///
-/// For the user-facing documentation see:
-/// http://clang.llvm.org/extra/clang-tidy/checks/portability-std-allocator-const.html
-class StdAllocatorConstCheck : public ClangTidyCheck {
-public:
-  StdAllocatorConstCheck(StringRef Name, ClangTidyContext *Context)
-      : ClangTidyCheck(Name, Context) {}
-
-  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
-  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
-};
-
-} // namespace portability
-} // namespace tidy
-} // namespace clang
-
-#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PORTABILITY_STDALLOCATORCONSTCHECK_H

clang-tools-extra/docs/ReleaseNotes.rst

@@ -117,14 +117,6 @@ New checks
 
   Replaces groups of adjacent macros with an unscoped anonymous enum.
 
-- New :doc:`portability-std-allocator-const <clang-tidy/checks/portability-std-allocator-const>` check.
-
-  Report use of ``std::vector<const T>`` (and similar containers of const
-  elements). These are not allowed in standard C++ due to undefined
-  ``std::allocator<const T>``. They do not compile with libstdc++ or MSVC.
-  Future libc++ will remove the extension (`D120996
-  <https://reviews.llvm.org/D120996>`).
-
 New check aliases
 ^^^^^^^^^^^^^^^^^
 

clang-tools-extra/docs/clang-tidy/checks/list.rst

@@ -289,7 +289,6 @@ Clang-Tidy Checks
    `performance-unnecessary-value-param <performance-unnecessary-value-param.html>`_, "Yes"
    `portability-restrict-system-includes <portability-restrict-system-includes.html>`_, "Yes"
    `portability-simd-intrinsics <portability-simd-intrinsics.html>`_,
-   `portability-std-allocator-const <portability-std-allocator-const.html>`_,
    `readability-avoid-const-params-in-decls <readability-avoid-const-params-in-decls.html>`_, "Yes"
    `readability-braces-around-statements <readability-braces-around-statements.html>`_, "Yes"
    `readability-const-return-type <readability-const-return-type.html>`_, "Yes"

clang-tools-extra/docs/clang-tidy/checks/portability-std-allocator-const.rst

@@ -1,31 +0,0 @@
-.. title:: clang-tidy - portability-std-allocator-const
-
-portability-std-allocator-const
-===============================
-
-Report use of ``std::vector<const T>`` (and similar containers of const
-elements). These are not allowed in standard C++, and should usually be
-``std::vector<T>`` instead."
-
-Per C++ ``[allocator.requirements.general]``: "T is any cv-unqualified object
-type", ``std::allocator<const T>`` is undefined. Many standard containers use
-``std::allocator`` by default and therefore their ``const T`` instantiations are
-undefined.
-
-libc++ defines ``std::allocator<const T>`` as an extension which will be removed
-in the future.
-
-libstdc++ and MSVC do not support ``std::allocator<const T>``:
-
-.. code:: c++
-
-  // libstdc++ has a better diagnostic since https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48101
-  std::deque<const int> deque; // error: static assertion failed: std::deque must have a non-const, non-volatile value_type
-  std::set<const int> set; // error: static assertion failed: std::set must have a non-const, non-volatile value_type
-  std::vector<int* const> vector; // error: static assertion failed: std::vector must have a non-const, non-volatile value_type
-
-  // MSVC
-  // error C2338: static_assert failed: 'The C++ Standard forbids containers of const elements because allocator<const T> is ill-formed.'
-
-Code bases only compiled with libc++ may accrue such undefined usage. This
-check finds such code and prevents backsliding while clean-up is ongoing.

clang-tools-extra/test/clang-tidy/checkers/portability-std-allocator-const.cpp

@@ -1,94 +0,0 @@
-// RUN: %check_clang_tidy -std=c++11-or-later %s portability-std-allocator-const %t --
-
-namespace std {
-typedef unsigned size_t;
-
-template <class T>
-class allocator {};
-template <class T>
-class hash {};
-template <class T>
-class equal_to {};
-template <class T>
-class less {};
-
-template <class T, class A = std::allocator<T>>
-class deque {};
-template <class T, class A = std::allocator<T>>
-class forward_list {};
-template <class T, class A = std::allocator<T>>
-class list {};
-template <class T, class A = std::allocator<T>>
-class vector {};
-
-template <class K, class C = std::less<K>, class A = std::allocator<K>>
-class multiset {};
-template <class K, class C = std::less<K>, class A = std::allocator<K>>
-class set {};
-template <class K, class H = std::hash<K>, class Eq = std::equal_to<K>, class A = std::allocator<K>>
-class unordered_multiset {};
-template <class K, class H = std::hash<K>, class Eq = std::equal_to<K>, class A = std::allocator<K>>
-class unordered_set {};
-
-template <class T, class C = std::deque<T>>
-class stack {};
-} // namespace std
-
-namespace absl {
-template <class K, class H = std::hash<K>, class Eq = std::equal_to<K>, class A = std::allocator<K>>
-class flat_hash_set {};
-} // namespace absl
-
-template <class T>
-class allocator {};
-
-void simple(const std::vector<const char> &v, std::deque<const short> *d) {
-  // CHECK-MESSAGES: [[#@LINE-1]]:24: warning: container using std::allocator<const T> is a deprecated libc++ extension; remove const for compatibility with other standard libraries
-  // CHECK-MESSAGES: [[#@LINE-2]]:52: warning: container
-  std::list<const long> l;
-  // CHECK-MESSAGES: [[#@LINE-1]]:8: warning: container
-
-  std::multiset<int *const> ms;
-  // CHECK-MESSAGES: [[#@LINE-1]]:8: warning: container
-  std::set<const std::hash<int>> s;
-  // CHECK-MESSAGES: [[#@LINE-1]]:8: warning: container
-  std::unordered_multiset<int *const> ums;
-  // CHECK-MESSAGES: [[#@LINE-1]]:8: warning: container
-  std::unordered_set<const int> us;
-  // CHECK-MESSAGES: [[#@LINE-1]]:8: warning: container
-
-  absl::flat_hash_set<const int> fhs;
-  // CHECK-MESSAGES: [[#@LINE-1]]:9: warning: container
-
-  using my_vector = std::vector<const int>;
-  // CHECK-MESSAGES: [[#@LINE-1]]:26: warning: container
-  my_vector v1;
-  using my_vector2 = my_vector;
-
-  std::vector<int> neg1;
-  std::vector<const int *> neg2;                     // not const T
-  std::vector<const int, allocator<const int>> neg3; // not use std::allocator<const T>
-  std::allocator<const int> a;                       // not caught, but rare
-  std::forward_list<const int> forward;              // not caught, but rare
-  std::stack<const int> stack;                       // not caught, but rare
-}
-
-template <class T>
-void temp1() {
-  std::vector<const T> v;
-  // CHECK-MESSAGES: [[#@LINE-1]]:8: warning: container
-
-  std::vector<T> neg1;
-  std::forward_list<const T> neg2;
-}
-void use_temp1() { temp1<int>(); }
-
-template <class T>
-void temp2() {
-  // Match std::vector<const dependent> for the uninstantiated temp2.
-  std::vector<const T> v;
-  // CHECK-MESSAGES: [[#@LINE-1]]:8: warning: container
-
-  std::vector<T> neg1;
-  std::forward_list<const T> neg2;
-}