Add #pragma clang attribute

The new '#pragma clang attribute' directive can be used to apply attributes to
multiple declarations. An attribute must satisfy the following conditions to
be supported by the pragma:
- It must have a subject list that's defined in the TableGen file.
- It must be documented.
- It must not be late parsed.
- It must have a GNU/C++11 spelling.

Differential Revision: https://reviews.llvm.org/D30009


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@300539 91177308-0d34-0410-b5e6-96231b3b80d8

11 files changed, 275 insertions, 1 deletions

diff --git a/include/clang/Basic/Attr.td b/include/clang/Basic/Attr.td
index c5d2c7fc61..bf62408db2 100644
--- a/include/clang/Basic/Attr.td
+++ b/include/clang/Basic/Attr.td
@@ -248,6 +248,8 @@ def COnly : LangOpt<"CPlusPlus", 1>;
 def CPlusPlus : LangOpt<"CPlusPlus">;
 def OpenCL : LangOpt<"OpenCL">;
 def RenderScript : LangOpt<"RenderScript">;
+def ObjC : LangOpt<"ObjC1">;
+def BlocksSupported : LangOpt<"Blocks">;
 
 // Defines targets for target-specific attributes. The list of strings should
 // specify architectures for which the target applies, based off the ArchType
@@ -270,6 +272,102 @@ def TargetMicrosoftCXXABI : TargetArch<["x86", "x86_64", "arm", "thumb"]> {
   let CXXABIs = ["Microsoft"];
 }
 
+// Attribute subject match rules that are used for #pragma clang attribute.
+//
+// A instance of AttrSubjectMatcherRule represents an individual match rule.
+// An individual match rule can correspond to a number of different attribute
+// subjects, e.g. "record" matching rule corresponds to the Record and
+// CXXRecord attribute subjects.
+//
+// Match rules are used in the subject list of the #pragma clang attribute.
+// Match rules can have sub-match rules that are instances of
+// AttrSubjectMatcherSubRule. A sub-match rule can correspond to a number
+// of different attribute subjects, and it can have a negated spelling as well.
+// For example, "variable(unless(is_parameter))" matching rule corresponds to
+// the NonParmVar attribute subject.
+class AttrSubjectMatcherSubRule<string name, list<AttrSubject> subjects,
+                                bit negated = 0> {
+  string Name = name;
+  list<AttrSubject> Subjects = subjects;
+  bit Negated = negated;
+  // Lists language options, one of which is required to be true for the
+  // attribute to be applicable. If empty, the language options are taken
+  // from the parent matcher rule.
+  list<LangOpt> LangOpts = [];
+}
+class AttrSubjectMatcherRule<string name, list<AttrSubject> subjects,
+                             list<AttrSubjectMatcherSubRule> subrules = []> {
+  string Name = name;
+  list<AttrSubject> Subjects = subjects;
+  list<AttrSubjectMatcherSubRule> Constraints = subrules;
+  // Lists language options, one of which is required to be true for the
+  // attribute to be applicable. If empty, no language options are required.
+  list<LangOpt> LangOpts = [];
+}
+
+// function(is_member)
+def SubRuleForCXXMethod : AttrSubjectMatcherSubRule<"is_member", [CXXMethod]> {
+  let LangOpts = [CPlusPlus];
+}
+def SubjectMatcherForFunction : AttrSubjectMatcherRule<"function", [Function], [
+  SubRuleForCXXMethod
+]>;
+// hasType is abstract, it should be used with one of the sub-rules.
+def SubjectMatcherForType : AttrSubjectMatcherRule<"hasType", [], [
+  AttrSubjectMatcherSubRule<"functionType", [FunctionLike]>
+
+  // FIXME: There's a matcher ambiguity with objc methods and blocks since
+  // functionType excludes them but functionProtoType includes them.
+  // AttrSubjectMatcherSubRule<"functionProtoType", [HasFunctionProto]>
+]>;
+def SubjectMatcherForTypedef : AttrSubjectMatcherRule<"type_alias",
+                                                      [TypedefName]>;
+def SubjectMatcherForRecord : AttrSubjectMatcherRule<"record", [Record,
+                                                                CXXRecord], [
+  // unless(is_union)
+  AttrSubjectMatcherSubRule<"is_union", [Struct], 1>
+]>;
+def SubjectMatcherForEnum : AttrSubjectMatcherRule<"enum", [Enum]>;
+def SubjectMatcherForEnumConstant : AttrSubjectMatcherRule<"enum_constant",
+                                                           [EnumConstant]>;
+def SubjectMatcherForVar : AttrSubjectMatcherRule<"variable", [Var], [
+  AttrSubjectMatcherSubRule<"is_thread_local", [TLSVar]>,
+  AttrSubjectMatcherSubRule<"is_global", [GlobalVar]>,
+  AttrSubjectMatcherSubRule<"is_parameter", [ParmVar]>,
+  // unless(is_parameter)
+  AttrSubjectMatcherSubRule<"is_parameter", [NonParmVar], 1>
+]>;
+def SubjectMatcherForField : AttrSubjectMatcherRule<"field", [Field]>;
+def SubjectMatcherForNamespace : AttrSubjectMatcherRule<"namespace",
+                                                        [Namespace]> {
+  let LangOpts = [CPlusPlus];
+}
+def SubjectMatcherForObjCInterface : AttrSubjectMatcherRule<"objc_interface",
+                                                            [ObjCInterface]> {
+  let LangOpts = [ObjC];
+}
+def SubjectMatcherForObjCProtocol : AttrSubjectMatcherRule<"objc_protocol",
+                                                           [ObjCProtocol]> {
+  let LangOpts = [ObjC];
+}
+def SubjectMatcherForObjCCategory : AttrSubjectMatcherRule<"objc_category",
+                                                           [ObjCCategory]> {
+  let LangOpts = [ObjC];
+}
+def SubjectMatcherForObjCMethod : AttrSubjectMatcherRule<"objc_method",
+                                                         [ObjCMethod], [
+  AttrSubjectMatcherSubRule<"is_instance", [ObjCInstanceMethod]>
+]> {
+  let LangOpts = [ObjC];
+}
+def SubjectMatcherForObjCProperty : AttrSubjectMatcherRule<"objc_property",
+                                                           [ObjCProperty]> {
+  let LangOpts = [ObjC];
+}
+def SubjectMatcherForBlock : AttrSubjectMatcherRule<"block", [Block]> {
+  let LangOpts = [BlocksSupported];
+}
+
 class Attr {
   // The various ways in which an attribute can be spelled in source
   list<Spelling> Spellings;
@@ -305,6 +403,14 @@ class Attr {
   // Set to true if this attribute meaningful when applied to or inherited 
   // in a class template definition.
   bit MeaningfulToClassTemplateDefinition = 0;
+  // Set to true if this attribute can be used with '#pragma clang attribute'.
+  // By default, when this value is false, an attribute is supported by the
+  // '#pragma clang attribute' only when:
+  // - It has documentation.
+  // - It has a subject list whose subjects can be represented using subject
+  //   match rules.
+  // - It has GNU/CXX11 spelling and doesn't require delayed parsing.
+  bit ForcePragmaAttributeSupport = 0;
   // Lists language options, one of which is required to be true for the
   // attribute to be applicable. If empty, no language options are required.
   list<LangOpt> LangOpts = [];
@@ -478,6 +584,9 @@ def AnalyzerNoReturn : InheritableAttr {
 def Annotate : InheritableParamAttr {
   let Spellings = [GNU<"annotate">];
   let Args = [StringArgument<"Annotation">];
+  // Ensure that the annotate attribute can be used with
+  // '#pragma clang attribute' even though it has no subject list.
+  let ForcePragmaAttributeSupport = 1;
   let Documentation = [Undocumented];
 }
 
diff --git a/include/clang/Basic/AttrSubjectMatchRules.h b/include/clang/Basic/AttrSubjectMatchRules.h
new file mode 100644
index 0000000000..955f495ad6
--- /dev/null
+++ b/include/clang/Basic/AttrSubjectMatchRules.h
@@ -0,0 +1,46 @@
+//===-- AttrSubjectMatchRules.h - Attribute subject match rules -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_BASIC_ATTR_SUBJECT_MATCH_RULES_H
+#define LLVM_CLANG_BASIC_ATTR_SUBJECT_MATCH_RULES_H
+
+#include "clang/Basic/SourceLocation.h"
+#include "llvm/ADT/DenseMap.h"
+
+namespace clang {
+namespace attr {
+
+/// \brief A list of all the recognized kinds of attributes.
+enum SubjectMatchRule {
+#define ATTR_MATCH_RULE(X, Spelling, IsAbstract) X,
+#include "clang/Basic/AttrSubMatchRulesList.inc"
+};
+
+const char *getSubjectMatchRuleSpelling(SubjectMatchRule Rule);
+
+using ParsedSubjectMatchRuleSet = llvm::DenseMap<SubjectMatchRule, SourceRange>;
+
+} // end namespace attr
+} // end namespace clang
+
+namespace llvm {
+
+template <>
+struct DenseMapInfo<clang::attr::SubjectMatchRule> : DenseMapInfo<int> {
+  static inline clang::attr::SubjectMatchRule getEmptyKey() {
+    return (clang::attr::SubjectMatchRule)DenseMapInfo<int>::getEmptyKey();
+  }
+  static inline clang::attr::SubjectMatchRule getTombstoneKey() {
+    return (clang::attr::SubjectMatchRule)DenseMapInfo<int>::getTombstoneKey();
+  }
+};
+
+} // end namespace llvm
+
+#endif
diff --git a/include/clang/Basic/CMakeLists.txt b/include/clang/Basic/CMakeLists.txt
index e4929b5b52..3e0fb8728c 100644
--- a/include/clang/Basic/CMakeLists.txt
+++ b/include/clang/Basic/CMakeLists.txt
@@ -28,6 +28,11 @@ clang_tablegen(AttrList.inc -gen-clang-attr-list
   SOURCE Attr.td
   TARGET ClangAttrList)
 
+clang_tablegen(AttrSubMatchRulesList.inc -gen-clang-attr-subject-match-rule-list
+  -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
+  SOURCE Attr.td
+  TARGET ClangAttrSubjectMatchRuleList)
+
 clang_tablegen(AttrHasAttributeImpl.inc -gen-clang-attr-has-attribute-impl
   -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
   SOURCE Attr.td
diff --git a/include/clang/Basic/DiagnosticGroups.td b/include/clang/Basic/DiagnosticGroups.td
index 4bcf3be0a8..4cde1c81fd 100644
--- a/include/clang/Basic/DiagnosticGroups.td
+++ b/include/clang/Basic/DiagnosticGroups.td
@@ -461,7 +461,9 @@ def Uninitialized  : DiagGroup<"uninitialized", [UninitializedSometimes,
 def IgnoredPragmaIntrinsic : DiagGroup<"ignored-pragma-intrinsic">;
 def UnknownPragmas : DiagGroup<"unknown-pragmas">;
 def IgnoredPragmas : DiagGroup<"ignored-pragmas", [IgnoredPragmaIntrinsic]>;
-def Pragmas : DiagGroup<"pragmas", [UnknownPragmas, IgnoredPragmas]>;
+def PragmaClangAttribute : DiagGroup<"pragma-clang-attribute">;
+def Pragmas : DiagGroup<"pragmas", [UnknownPragmas, IgnoredPragmas,
+                                    PragmaClangAttribute]>;
 def UnknownWarningOption : DiagGroup<"unknown-warning-option">;
 def NSobjectAttribute : DiagGroup<"NSObject-attribute">;
 def IndependentClassAttribute : DiagGroup<"IndependentClass-attribute">;
diff --git a/include/clang/Basic/DiagnosticParseKinds.td b/include/clang/Basic/DiagnosticParseKinds.td
index aebf8a9f35..d95e43c10c 100644
--- a/include/clang/Basic/DiagnosticParseKinds.td
+++ b/include/clang/Basic/DiagnosticParseKinds.td
@@ -979,6 +979,43 @@ def err_pragma_optimize_invalid_argument : Error<
   "expected 'on' or 'off'">;
 def err_pragma_optimize_extra_argument : Error<
   "unexpected extra argument '%0' to '#pragma clang optimize'">;
+// - #pragma clang attribute
+def err_pragma_attribute_expected_push_pop : Error<
+  "expected 'push' or 'pop' after '#pragma clang attribute'">;
+def err_pragma_attribute_invalid_argument : Error<
+  "unexpected argument '%0' to '#pragma clang attribute'; "
+  "expected 'push' or 'pop'">;
+def err_pragma_attribute_expected_attribute : Error<
+  "expected an attribute after '('">;
+def err_pragma_attribute_expected_attribute_name : Error<
+  "expected identifier that represents an attribute name">;
+def err_pragma_attribute_extra_tokens_after_attribute : Error<
+  "extra tokens after attribute in a '#pragma clang attribute push'">;
+def err_pragma_attribute_unsupported_attribute : Error<
+  "attribute %0 is not supported by '#pragma clang attribute'">;
+def err_pragma_attribute_multiple_attributes : Error<
+  "more than one attribute specified in '#pragma clang attribute push'">;
+def err_pragma_attribute_expected_attribute_syntax : Error<
+  "expected an attribute that is specified using the GNU, C++11 or '__declspec'"
+  " syntax">;
+def note_pragma_attribute_use_attribute_kw : Note<"use the GNU '__attribute__' "
+  "syntax">;
+def err_pragma_attribute_invalid_subject_set_specifier : Error<
+  "expected attribute subject set specifier 'apply_to'">;
+def err_pragma_attribute_expected_subject_identifier : Error<
+  "expected an identifier that corresponds to an attribute subject rule">;
+def err_pragma_attribute_unknown_subject_rule : Error<
+  "unknown attribute subject rule '%0'">;
+def err_pragma_attribute_expected_subject_sub_identifier : Error<
+  "expected an identifier that corresponds to an attribute subject matcher "
+  "sub-rule; '%0' matcher %select{does not support sub-rules|supports the "
+  "following sub-rules: %2|}1">;
+def err_pragma_attribute_unknown_subject_sub_rule : Error<
+  "%select{invalid use of|unknown}2 attribute subject matcher sub-rule '%0'; "
+  "'%1' matcher %select{does not support sub-rules|supports the following "
+  "sub-rules: %3}2">;
+def err_pragma_attribute_duplicate_subject : Error<
+  "duplicate attribute subject matcher '%0'">;
 
 def err_opencl_unroll_hint_on_non_loop : Error<
   "OpenCL only supports 'opencl_unroll_hint' attribute on for, while, and do statements">;
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 8afe61645a..3912a85491 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -750,6 +750,25 @@ def err_pragma_loop_compatibility : Error<
 def err_pragma_loop_precedes_nonloop : Error<
   "expected a for, while, or do-while loop to follow '%0'">;
 
+def err_pragma_attribute_matcher_subrule_contradicts_rule : Error<
+  "redundant attribute subject matcher sub-rule '%0'; '%1' already matches "
+  "those declarations">;
+def err_pragma_attribute_matcher_negated_subrule_contradicts_subrule : Error<
+  "negated attribute subject matcher sub-rule '%0' contradicts sub-rule '%1'">;
+def err_pragma_attribute_invalid_matchers : Error<
+  "attribute %0 can't be applied to %1">;
+def err_pragma_attribute_stack_mismatch : Error<
+  "'#pragma clang attribute pop' with no matching '#pragma clang attribute push'">;
+def warn_pragma_attribute_unused : Warning<
+  "unused attribute %0 in '#pragma clang attribute push' region">,
+  InGroup<PragmaClangAttribute>;
+def note_pragma_attribute_region_ends_here : Note<
+  "'#pragma clang attribute push' regions ends here">;
+def err_pragma_attribute_no_pop_eof : Error<"unterminated "
+  "'#pragma clang attribute push' at end of file">;
+def note_pragma_attribute_applied_decl_here : Note<
+  "when applied to this declaration">;
+
 /// Objective-C parser diagnostics
 def err_duplicate_class_def : Error<
   "duplicate interface definition for class %0">;
diff --git a/include/clang/Basic/TokenKinds.def b/include/clang/Basic/TokenKinds.def
index 48e0c33f0e..968b203a38 100644
--- a/include/clang/Basic/TokenKinds.def
+++ b/include/clang/Basic/TokenKinds.def
@@ -790,6 +790,9 @@ ANNOTATION(pragma_loop_hint)
 
 ANNOTATION(pragma_fp)
 
+// Annotation for the attribute pragma directives - #pragma clang attribute ...
+ANNOTATION(pragma_attribute)
+
 // Annotations for module import translated from #include etc.
 ANNOTATION(module_include)
 ANNOTATION(module_begin)
diff --git a/include/clang/Parse/CMakeLists.txt b/include/clang/Parse/CMakeLists.txt
index ec75f7b96b..2cc7e54b3b 100644
--- a/include/clang/Parse/CMakeLists.txt
+++ b/include/clang/Parse/CMakeLists.txt
@@ -2,3 +2,9 @@ clang_tablegen(AttrParserStringSwitches.inc -gen-clang-attr-parser-string-switch
   -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
   SOURCE ../Basic/Attr.td
   TARGET ClangAttrParserStringSwitches)
+
+clang_tablegen(AttrSubMatchRulesParserStringSwitches.inc
+  -gen-clang-attr-subject-match-rules-parser-string-switches
+  -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
+  SOURCE ../Basic/Attr.td
+  TARGET ClangAttrSubMatchRulesParserStringSwitches)
diff --git a/include/clang/Parse/Parser.h b/include/clang/Parse/Parser.h
index 5f4e5fb4b2..8d0935dec1 100644
--- a/include/clang/Parse/Parser.h
+++ b/include/clang/Parse/Parser.h
@@ -184,6 +184,7 @@ class Parser : public CodeCompletionHandler {
   std::unique_ptr<PragmaHandler> UnrollHintHandler;
   std::unique_ptr<PragmaHandler> NoUnrollHintHandler;
   std::unique_ptr<PragmaHandler> FPHandler;
+  std::unique_ptr<PragmaHandler> AttributePragmaHandler;
 
   std::unique_ptr<CommentHandler> CommentSemaHandler;
 
@@ -565,6 +566,12 @@ private:
   /// #pragma clang loop and #pragma unroll.
   bool HandlePragmaLoopHint(LoopHint &Hint);
 
+  bool ParsePragmaAttributeSubjectMatchRuleSet(
+      attr::ParsedSubjectMatchRuleSet &SubjectMatchRules,
+      SourceLocation &AnyLoc, SourceLocation &LastMatchRuleEndLoc);
+
+  void HandlePragmaAttribute();
+
   /// GetLookAheadToken - This peeks ahead N tokens and returns that token
   /// without consuming any tokens.  LookAhead(0) returns 'Tok', LookAhead(1)
   /// returns the token after Tok, etc.
diff --git a/include/clang/Sema/AttributeList.h b/include/clang/Sema/AttributeList.h
index 7c1678086c..f3b042c9ce 100644
--- a/include/clang/Sema/AttributeList.h
+++ b/include/clang/Sema/AttributeList.h
@@ -15,6 +15,7 @@
 #ifndef LLVM_CLANG_SEMA_ATTRIBUTELIST_H
 #define LLVM_CLANG_SEMA_ATTRIBUTELIST_H
 
+#include "clang/Basic/AttrSubjectMatchRules.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/VersionTuple.h"
@@ -509,9 +510,14 @@ public:
   unsigned getMaxArgs() const;
   bool hasVariadicArg() const;
   bool diagnoseAppertainsTo(class Sema &S, const Decl *D) const;
+  bool appliesToDecl(const Decl *D, attr::SubjectMatchRule MatchRule) const;
+  void getMatchRules(const LangOptions &LangOpts,
+                     SmallVectorImpl<std::pair<attr::SubjectMatchRule, bool>>
+                         &MatchRules) const;
   bool diagnoseLangOpts(class Sema &S) const;
   bool existsInTarget(const TargetInfo &Target) const;
   bool isKnownToGCC() const;
+  bool isSupportedByPragmaAttribute() const;
 
   /// \brief If the parsed attribute has a semantic equivalent, and it would
   /// have a semantic Spelling enumeration (due to having semantically-distinct
@@ -774,6 +780,8 @@ public:
   void clear() { list = nullptr; pool.clear(); }
   AttributeList *getList() const { return list; }
 
+  void clearListOnly() { list = nullptr; }
+
   /// Returns a reference to the attribute list.  Try not to introduce
   /// dependencies on this method, it may not be long-lived.
   AttributeList *&getListRef() { return list; }
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 5a3cdfb77c..bd68842c9f 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -437,6 +437,20 @@ public:
   /// VisContext - Manages the stack for \#pragma GCC visibility.
   void *VisContext; // Really a "PragmaVisStack*"
 
+  /// \brief This represents the stack of attributes that were pushed by
+  /// \#pragma clang attribute.
+  struct PragmaAttributeEntry {
+    SourceLocation Loc;
+    AttributeList *Attribute;
+    SmallVector<attr::SubjectMatchRule, 4> MatchRules;
+    bool IsUsed;
+  };
+  SmallVector<PragmaAttributeEntry, 2> PragmaAttributeStack;
+
+  /// \brief The declaration that is currently receiving an attribute from the
+  /// #pragma attribute stack.
+  const Decl *PragmaAttributeCurrentTargetDecl;
+
   /// \brief This represents the last location of a "#pragma clang optimize off"
   /// directive if such a directive has not been closed by an "on" yet. If
   /// optimizations are currently "on", this is set to an invalid location.
@@ -7206,9 +7220,13 @@ public:
       PrintInstantiationStack();
       LastEmittedCodeSynthesisContextDepth = CodeSynthesisContexts.size();
     }
+    if (PragmaAttributeCurrentTargetDecl)
+      PrintPragmaAttributeInstantiationPoint();
   }
   void PrintInstantiationStack();
 
+  void PrintPragmaAttributeInstantiationPoint();
+
   /// \brief Determines whether we are currently in a context where
   /// template argument substitution failures are not considered
   /// errors.
@@ -8152,6 +8170,20 @@ public:
   /// the appropriate attribute.
   void AddCFAuditedAttribute(Decl *D);
 
+  /// \brief Called on well-formed '\#pragma clang attribute push'.
+  void ActOnPragmaAttributePush(AttributeList &Attribute,
+                                SourceLocation PragmaLoc,
+                                attr::ParsedSubjectMatchRuleSet Rules);
+
+  /// \brief Called on well-formed '\#pragma clang attribute pop'.
+  void ActOnPragmaAttributePop(SourceLocation PragmaLoc);
+
+  /// \brief Adds the attributes that have been specified using the
+  /// '\#pragma clang attribute push' directives to the given declaration.
+  void AddPragmaAttributes(Scope *S, Decl *D);
+
+  void DiagnoseUnterminatedPragmaAttribute();
+
   /// \brief Called on well formed \#pragma clang optimize.
   void ActOnPragmaOptimize(bool On, SourceLocation PragmaLoc);