gsl::Owner/gsl::Pointer: Add implicit annotations for some std types

Summary:
Hard code gsl::Owner/gsl::Pointer for std types. The paper mentions
some types explicitly. Generally, all containers and their iterators are
covered. For iterators, we cover both the case that they are defined
as an nested class or as an typedef/using. I have started to test this
implementation against some real standard library implementations, namely
libc++ 7.1.0, libc++ 8.0.1rc2, libstdc++ 4.6.4, libstdc++ 4.8.5,
libstdc++ 4.9.4, libstdc++ 5.4.0, libstdc++ 6.5.0, libstdc++ 7.3.0,
libstdc++ 8.3.0 and libstdc++ 9.1.0.

The tests are currently here
  https://github.com/mgehre/llvm-project/blob/lifetime-ci/lifetime-attr-test.sh
  https://github.com/mgehre/llvm-project/blob/lifetime-ci/lifetime-attr-test.cpp
I think due to their dependency on a standard library, they are not a good fit
for clang/test/. Where else could I put them?

Reviewers: gribozavr, xazax.hun

Subscribers: rnkovacs, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64448

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@368147 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/AttrDocs.td b/include/clang/Basic/AttrDocs.td
index 81dec0fdef89d4b358615ac8e5c87b41afe57c2e..0f10d9036937f986da4592ceab51f42e9f64b844 100644 (file)
--- a/include/clang/Basic/AttrDocs.td
+++ b/include/clang/Basic/AttrDocs.td
@@ -4249,7 +4249,7 @@ object of type ``T``:
     int *getInt() { return &value; }
   };
 
-The argument ``T`` is optional and currently ignored.
+The argument ``T`` is optional and is ignored.
 This attribute may be used by analysis tools and has no effect on code
 generation.
 
@@ -4275,7 +4275,7 @@ like pointers to an object of type ``T``:
     int *getInt() { return &valuePointer; }
   };
 
-The argument ``T`` is optional and currently ignored.
+The argument ``T`` is optional and is ignored.
 This attribute may be used by analysis tools and has no effect on code
 generation.
 

diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index a617e71999f9d61435466b56efc2ea24b4876c77..4be2e5cdb96c639de01d335da66b80765038991c 100644 (file)
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -6116,6 +6116,17 @@ public:
       ClassTemplateSpecializationDecl *BaseTemplateSpec,
       SourceLocation BaseLoc);
 
+  /// Add gsl::Pointer attribute to std::container::iterator
+  /// \param ND The declaration that introduces the name
+  /// std::container::iterator. \param UnderlyingRecord The record named by ND.
+  void inferGslPointerAttribute(NamedDecl *ND, CXXRecordDecl *UnderlyingRecord);
+
+  /// Add [[gsl::Owner]] and [[gsl::Pointer]] attributes for std:: types.
+  void inferGslOwnerPointerAttribute(CXXRecordDecl *Record);
+
+  /// Add [[gsl::Pointer]] attributes for std:: types.
+  void inferGslPointerAttribute(TypedefNameDecl *TD);
+
   void CheckCompletedCXXClass(CXXRecordDecl *Record);
 
   /// Check that the C++ class annoated with "trivial_abi" satisfies all the

diff --git a/lib/Sema/SemaAttr.cpp b/lib/Sema/SemaAttr.cpp
index 8e9318847373d20e4b8862cd25d7ae1903574f75..e2542edf6ed5072228e6fccd6568d83871f10e39 100644 (file)
--- a/lib/Sema/SemaAttr.cpp
+++ b/lib/Sema/SemaAttr.cpp
@@ -85,6 +85,126 @@ void Sema::AddMsStructLayoutForRecord(RecordDecl *RD) {
         MSVtorDispAttr::CreateImplicit(Context, VtorDispStack.CurrentValue));
 }
 
+template <typename Attribute>
+static void addGslOwnerPointerAttributeIfNotExisting(ASTContext &Context,
+                                                     CXXRecordDecl *Record) {
+  CXXRecordDecl *Canonical = Record->getCanonicalDecl();
+  if (Canonical->hasAttr<OwnerAttr>() || Canonical->hasAttr<PointerAttr>())
+    return;
+
+  Canonical->addAttr(::new (Context) Attribute(SourceRange{}, Context,
+                                               /*DerefType*/ nullptr,
+                                               /*Spelling=*/0));
+}
+
+void Sema::inferGslPointerAttribute(NamedDecl *ND,
+                                    CXXRecordDecl *UnderlyingRecord) {
+  if (!UnderlyingRecord)
+    return;
+
+  const auto *Parent = dyn_cast<CXXRecordDecl>(ND->getDeclContext());
+  if (!Parent)
+    return;
+
+  static llvm::StringSet<> Containers{
+      "array",
+      "basic_string",
+      "deque",
+      "forward_list",
+      "vector",
+      "list",
+      "map",
+      "multiset",
+      "multimap",
+      "priority_queue",
+      "queue",
+      "set",
+      "stack",
+      "unordered_set",
+      "unordered_map",
+      "unordered_multiset",
+      "unordered_multimap",
+  };
+
+  static llvm::StringSet<> Iterators{"iterator", "const_iterator",
+                                     "reverse_iterator",
+                                     "const_reverse_iterator"};
+
+  if (Parent->isInStdNamespace() && Iterators.count(ND->getName()) &&
+      Containers.count(Parent->getName()))
+    addGslOwnerPointerAttributeIfNotExisting<PointerAttr>(Context,
+                                                          UnderlyingRecord);
+}
+
+void Sema::inferGslPointerAttribute(TypedefNameDecl *TD) {
+
+  QualType Canonical = TD->getUnderlyingType().getCanonicalType();
+
+  CXXRecordDecl *RD = Canonical->getAsCXXRecordDecl();
+  if (!RD) {
+    if (auto *TST =
+            dyn_cast<TemplateSpecializationType>(Canonical.getTypePtr())) {
+
+      RD = dyn_cast_or_null<CXXRecordDecl>(
+          TST->getTemplateName().getAsTemplateDecl()->getTemplatedDecl());
+    }
+  }
+
+  inferGslPointerAttribute(TD, RD);
+}
+
+void Sema::inferGslOwnerPointerAttribute(CXXRecordDecl *Record) {
+  static llvm::StringSet<> StdOwners{
+      "any",
+      "array",
+      "basic_regex",
+      "basic_string",
+      "deque",
+      "forward_list",
+      "vector",
+      "list",
+      "map",
+      "multiset",
+      "multimap",
+      "optional",
+      "priority_queue",
+      "queue",
+      "set",
+      "stack",
+      "unique_ptr",
+      "unordered_set",
+      "unordered_map",
+      "unordered_multiset",
+      "unordered_multimap",
+      "variant",
+  };
+  static llvm::StringSet<> StdPointers{
+      "basic_string_view",
+      "reference_wrapper",
+      "regex_iterator",
+  };
+
+  if (!Record->getIdentifier())
+    return;
+
+  // Handle classes that directly appear in std namespace.
+  if (Record->isInStdNamespace()) {
+    CXXRecordDecl *Canonical = Record->getCanonicalDecl();
+    if (Canonical->hasAttr<OwnerAttr>() || Canonical->hasAttr<PointerAttr>())
+      return;
+
+    if (StdOwners.count(Record->getName()))
+      addGslOwnerPointerAttributeIfNotExisting<OwnerAttr>(Context, Record);
+    else if (StdPointers.count(Record->getName()))
+      addGslOwnerPointerAttributeIfNotExisting<PointerAttr>(Context, Record);
+
+    return;
+  }
+
+  // Handle nested classes that could be a gsl::Pointer.
+  inferGslPointerAttribute(Record, Record);
+}
+
 void Sema::ActOnPragmaOptionsAlign(PragmaOptionsAlignKind Kind,
                                    SourceLocation PragmaLoc) {
   PragmaMsStackAction Action = Sema::PSK_Reset;

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 74c6316da6a1aee392f96866a2d0a39a8b55b0ad..4df0bc12d523dbe7dfaf1f121e73abe760a2a75c 100644 (file)
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -5858,6 +5858,8 @@ Sema::ActOnTypedefNameDecl(Scope *S, DeclContext *DC, TypedefNameDecl *NewTD,
   if (!Previous.empty()) {
     Redeclaration = true;
     MergeTypedefNameDecl(S, NewTD, Previous);
+  } else {
+    inferGslPointerAttribute(NewTD);
   }
 
   if (ShadowedDecl && !Redeclaration)
@@ -15131,6 +15133,9 @@ CreateNewDecl:
   if (PrevDecl)
     mergeDeclAttributes(New, PrevDecl);
 
+  if (auto *CXXRD = dyn_cast<CXXRecordDecl>(New))
+    inferGslOwnerPointerAttribute(CXXRD);
+
   // If there's a #pragma GCC visibility in scope, set the visibility of this
   // record.
   AddPushedVisibilityAttribute(New);

diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 3212281cc34d2d1ee8555dd6ba13699b43b60f53..3df74edf2f9a202c4ddc2d9b81436adc05fff3a6 100644 (file)
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -1690,6 +1690,7 @@ DeclResult Sema::CheckClassTemplate(
     mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl());
 
   AddPushedVisibilityAttribute(NewClass);
+  inferGslOwnerPointerAttribute(NewClass);
 
   if (TUK != TUK_Friend) {
     // Per C++ [basic.scope.temp]p2, skip the template parameter scopes.

diff --git a/test/SemaCXX/attr-gsl-owner-pointer-std.cpp b/test/SemaCXX/attr-gsl-owner-pointer-std.cpp
new file mode 100644 (file)
index 0000000..29675c2
--- /dev/null
+++ b/test/SemaCXX/attr-gsl-owner-pointer-std.cpp
@@ -0,0 +1,129 @@
+// RUN: %clang_cc1 -ast-dump %s | \
+// RUN: FileCheck --implicit-check-not OwnerAttr --implicit-check-not PointerAttr %s
+
+// Test attribute inference for types in the standard library.
+namespace std {
+// Attributes are inferred for a (complete) class.
+class any {
+  // CHECK: CXXRecordDecl {{.*}} any
+  // CHECK: OwnerAttr {{.*}}
+};
+
+// Attributes are inferred for instantiations of a complete template.
+template <typename T>
+class vector {
+public:
+  class iterator {};
+  // CHECK: ClassTemplateDecl {{.*}} vector
+  // CHECK: OwnerAttr {{.*}}
+  // CHECK: CXXRecordDecl {{.*}} iterator
+  // CHECK: PointerAttr {{.*}}
+  // CHECK: ClassTemplateSpecializationDecl {{.*}} vector
+  // CHECK: TemplateArgument type 'int'
+  // CHECK: OwnerAttr
+  // CHECK: CXXRecordDecl {{.*}} iterator
+  // CHECK: PointerAttr {{.*}}
+};
+static_assert(sizeof(vector<int>), "");           // Force instantiation.
+static_assert(sizeof(vector<int>::iterator), ""); // Force instantiation.
+
+// If std::container::iterator is a using declaration, attributes are inferred
+// for the underlying class.
+template <typename T>
+class __set_iterator {};
+// CHECK: ClassTemplateDecl {{.*}} __set_iterator
+// CHECK: PointerAttr
+// CHECK: ClassTemplateSpecializationDecl {{.*}} __set_iterator
+// CHECK: TemplateArgument type 'int'
+// CHECK: PointerAttr
+
+template <typename T>
+class set {
+  // CHECK: ClassTemplateDecl {{.*}} set
+  // CHECK: OwnerAttr {{.*}}
+  // CHECK: ClassTemplateSpecializationDecl {{.*}} set
+  // CHECK: OwnerAttr {{.*}}
+public:
+  using iterator = __set_iterator<T>;
+};
+static_assert(sizeof(set<int>::iterator), ""); // Force instantiation.
+
+// If std::container::iterator is a typedef, attributes are inferred for the
+// underlying class.
+template <typename T>
+class __map_iterator {};
+// CHECK: ClassTemplateDecl {{.*}} __map_iterator
+// CHECK: PointerAttr
+// CHECK: ClassTemplateSpecializationDecl {{.*}} __map_iterator
+// CHECK: TemplateArgument type 'int'
+// CHECK: PointerAttr
+
+template <typename T>
+class map {
+  // CHECK: ClassTemplateDecl {{.*}} map
+  // CHECK: OwnerAttr {{.*}}
+  // CHECK: ClassTemplateSpecializationDecl {{.*}} map
+  // CHECK: OwnerAttr {{.*}}
+public:
+  typedef __map_iterator<T> iterator;
+};
+static_assert(sizeof(map<int>::iterator), ""); // Force instantiation.
+
+// Inline namespaces are ignored when checking if
+// the class lives in the std namespace.
+inline namespace inlinens {
+template <typename T>
+class __unordered_map_iterator {};
+// CHECK: ClassTemplateDecl {{.*}} __unordered_map_iterator
+// CHECK: PointerAttr
+// CHECK: ClassTemplateSpecializationDecl {{.*}} __unordered_map_iterator
+// CHECK: TemplateArgument type 'int'
+// CHECK: PointerAttr
+
+template <typename T>
+class unordered_map {
+  // CHECK: ClassTemplateDecl {{.*}} unordered_map
+  // CHECK: OwnerAttr {{.*}}
+  // CHECK: ClassTemplateSpecializationDecl {{.*}} unordered_map
+  // CHECK: OwnerAttr {{.*}}
+public:
+  typedef __unordered_map_iterator<T> iterator;
+};
+static_assert(sizeof(unordered_map<int>::iterator), ""); // Force instantiation.
+} // namespace inlinens
+
+// std::list has an implicit gsl::Owner attribute,
+// but explicit attributes take precedence.
+template <typename T>
+class [[gsl::Pointer]] list{};
+// CHECK: ClassTemplateDecl {{.*}} list
+// CHECK: PointerAttr {{.*}}
+// CHECK: ClassTemplateSpecializationDecl {{.*}} list
+// CHECK: PointerAttr {{.*}}
+
+static_assert(sizeof(list<int>), ""); // Force instantiation.
+
+// Forward declared template (Owner).
+template <
+    class CharT,
+    class Traits>
+class basic_regex;
+// CHECK: ClassTemplateDecl {{.*}} basic_regex
+// CHECK: OwnerAttr {{.*}}
+
+// Forward declared template (Pointer).
+template <class T>
+class reference_wrapper;
+// CHECK: ClassTemplateDecl {{.*}} reference_wrapper
+// CHECK: PointerAttr {{.*}}
+
+class some_unknown_type;
+// CHECK: CXXRecordDecl {{.*}} some_unknown_type
+
+} // namespace std
+
+namespace user {
+// If a class is not in the std namespace, we don't infer the attributes.
+class any {
+};
+} // namespace user