From 23092ca9bac2b0569ce800dab5c428e1378b6017 Mon Sep 17 00:00:00 2001 From: Matthias Gehre Date: Wed, 7 Aug 2019 10:45:36 +0000 Subject: [PATCH] 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 --- clang/include/clang/Basic/AttrDocs.td | 4 +- clang/include/clang/Sema/Sema.h | 11 ++ clang/lib/Sema/SemaAttr.cpp | 120 ++++++++++++++++++++ clang/lib/Sema/SemaDecl.cpp | 5 + clang/lib/Sema/SemaTemplate.cpp | 1 + clang/test/SemaCXX/attr-gsl-owner-pointer-std.cpp | 129 ++++++++++++++++++++++ 6 files changed, 268 insertions(+), 2 deletions(-) create mode 100644 clang/test/SemaCXX/attr-gsl-owner-pointer-std.cpp diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td index 81dec0f..0f10d90 100644 --- a/clang/include/clang/Basic/AttrDocs.td +++ b/clang/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/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h index a617e71..4be2e5c 100644 --- a/clang/include/clang/Sema/Sema.h +++ b/clang/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/clang/lib/Sema/SemaAttr.cpp b/clang/lib/Sema/SemaAttr.cpp index 8e93188..e2542ed 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 +static void addGslOwnerPointerAttributeIfNotExisting(ASTContext &Context, + CXXRecordDecl *Record) { + CXXRecordDecl *Canonical = Record->getCanonicalDecl(); + if (Canonical->hasAttr() || Canonical->hasAttr()) + 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(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(Context, + UnderlyingRecord); +} + +void Sema::inferGslPointerAttribute(TypedefNameDecl *TD) { + + QualType Canonical = TD->getUnderlyingType().getCanonicalType(); + + CXXRecordDecl *RD = Canonical->getAsCXXRecordDecl(); + if (!RD) { + if (auto *TST = + dyn_cast(Canonical.getTypePtr())) { + + RD = dyn_cast_or_null( + 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() || Canonical->hasAttr()) + return; + + if (StdOwners.count(Record->getName())) + addGslOwnerPointerAttributeIfNotExisting(Context, Record); + else if (StdPointers.count(Record->getName())) + addGslOwnerPointerAttributeIfNotExisting(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/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp index 74c6316..4df0bc1 100644 --- a/clang/lib/Sema/SemaDecl.cpp +++ b/clang/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(New)) + inferGslOwnerPointerAttribute(CXXRD); + // If there's a #pragma GCC visibility in scope, set the visibility of this // record. AddPushedVisibilityAttribute(New); diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp index 3212281..3df74ed 100644 --- a/clang/lib/Sema/SemaTemplate.cpp +++ b/clang/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/clang/test/SemaCXX/attr-gsl-owner-pointer-std.cpp b/clang/test/SemaCXX/attr-gsl-owner-pointer-std.cpp new file mode 100644 index 0000000..29675c2 --- /dev/null +++ b/clang/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 +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), ""); // Force instantiation. +static_assert(sizeof(vector::iterator), ""); // Force instantiation. + +// If std::container::iterator is a using declaration, attributes are inferred +// for the underlying class. +template +class __set_iterator {}; +// CHECK: ClassTemplateDecl {{.*}} __set_iterator +// CHECK: PointerAttr +// CHECK: ClassTemplateSpecializationDecl {{.*}} __set_iterator +// CHECK: TemplateArgument type 'int' +// CHECK: PointerAttr + +template +class set { + // CHECK: ClassTemplateDecl {{.*}} set + // CHECK: OwnerAttr {{.*}} + // CHECK: ClassTemplateSpecializationDecl {{.*}} set + // CHECK: OwnerAttr {{.*}} +public: + using iterator = __set_iterator; +}; +static_assert(sizeof(set::iterator), ""); // Force instantiation. + +// If std::container::iterator is a typedef, attributes are inferred for the +// underlying class. +template +class __map_iterator {}; +// CHECK: ClassTemplateDecl {{.*}} __map_iterator +// CHECK: PointerAttr +// CHECK: ClassTemplateSpecializationDecl {{.*}} __map_iterator +// CHECK: TemplateArgument type 'int' +// CHECK: PointerAttr + +template +class map { + // CHECK: ClassTemplateDecl {{.*}} map + // CHECK: OwnerAttr {{.*}} + // CHECK: ClassTemplateSpecializationDecl {{.*}} map + // CHECK: OwnerAttr {{.*}} +public: + typedef __map_iterator iterator; +}; +static_assert(sizeof(map::iterator), ""); // Force instantiation. + +// Inline namespaces are ignored when checking if +// the class lives in the std namespace. +inline namespace inlinens { +template +class __unordered_map_iterator {}; +// CHECK: ClassTemplateDecl {{.*}} __unordered_map_iterator +// CHECK: PointerAttr +// CHECK: ClassTemplateSpecializationDecl {{.*}} __unordered_map_iterator +// CHECK: TemplateArgument type 'int' +// CHECK: PointerAttr + +template +class unordered_map { + // CHECK: ClassTemplateDecl {{.*}} unordered_map + // CHECK: OwnerAttr {{.*}} + // CHECK: ClassTemplateSpecializationDecl {{.*}} unordered_map + // CHECK: OwnerAttr {{.*}} +public: + typedef __unordered_map_iterator iterator; +}; +static_assert(sizeof(unordered_map::iterator), ""); // Force instantiation. +} // namespace inlinens + +// std::list has an implicit gsl::Owner attribute, +// but explicit attributes take precedence. +template +class [[gsl::Pointer]] list{}; +// CHECK: ClassTemplateDecl {{.*}} list +// CHECK: PointerAttr {{.*}} +// CHECK: ClassTemplateSpecializationDecl {{.*}} list +// CHECK: PointerAttr {{.*}} + +static_assert(sizeof(list), ""); // 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 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 -- 2.7.4