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

llvm-svn: 368147

1 files changed, 120 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaAttr.cpp b/clang/lib/Sema/SemaAttr.cpp
index 8e931884737..e2542edf6ed 100644
--- a/clang/lib/Sema/SemaAttr.cpp
+++ b/clang/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;