Attribute tablegen now understands that attribute arguments can be optional. This allows for automated checking of the number of arguments expected vs number of arguments given for attributes. Greatly reduces the amount of manual checking required.

llvm-svn: 190368

Author: AaronBallman

clang/include/clang/Basic/Attr.td

@@ -42,39 +42,40 @@ def NonBitField : SubsetSubject<Field, "non-bit field",
                                 [{!S->isBitField()}]>;
 
 // A single argument to an attribute
-class Argument<string name> {
+class Argument<string name, bit optional> {
   string Name = name;
+  bit Optional = optional;
 }
 
-class BoolArgument<string name> : Argument<name>;
-class IdentifierArgument<string name> : Argument<name>;
-class IntArgument<string name> : Argument<name>;
-class StringArgument<string name> : Argument<name>;
-class ExprArgument<string name> : Argument<name>;
-class FunctionArgument<string name> : Argument<name>;
-class TypeArgument<string name> : Argument<name>;
-class UnsignedArgument<string name> : Argument<name>;
-class SourceLocArgument<string name> : Argument<name>;
-class VariadicUnsignedArgument<string name> : Argument<name>;
-class VariadicExprArgument<string name> : Argument<name>;
+class BoolArgument<string name, bit opt = 0> : Argument<name, opt>;
+class IdentifierArgument<string name, bit opt = 0> : Argument<name, opt>;
+class IntArgument<string name, bit opt = 0> : Argument<name, opt>;
+class StringArgument<string name, bit opt = 0> : Argument<name, opt>;
+class ExprArgument<string name, bit opt = 0> : Argument<name, opt>;
+class FunctionArgument<string name, bit opt = 0> : Argument<name, opt>;
+class TypeArgument<string name, bit opt = 0> : Argument<name, opt>;
+class UnsignedArgument<string name, bit opt = 0> : Argument<name, opt>;
+class SourceLocArgument<string name, bit opt = 0> : Argument<name, opt>;
+class VariadicUnsignedArgument<string name> : Argument<name, 1>;
+class VariadicExprArgument<string name> : Argument<name, 1>;
 
 // A version of the form major.minor[.subminor].
-class VersionArgument<string name> : Argument<name>;
+class VersionArgument<string name, bit opt = 0> : Argument<name, opt>;
 
 // This one's a doozy, so it gets its own special type
 // It can be an unsigned integer, or a type. Either can
 // be dependent.
-class AlignedArgument<string name> : Argument<name>;
+class AlignedArgument<string name, bit opt = 0> : Argument<name, opt>;
 
 // An integer argument with a default value
-class DefaultIntArgument<string name, int default> : IntArgument<name> {
+class DefaultIntArgument<string name, int default> : IntArgument<name, 1> {
   int Default = default;
 }
 
 // This argument is more complex, it includes the enumerator type name,
 // a list of strings to accept, and a list of enumerators to map them to.
 class EnumArgument<string name, string type, list<string> values,
-                         list<string> enums> : Argument<name> {
+                   list<string> enums, bit opt = 0> : Argument<name, opt> {
   string Type = type;
   list<string> Values = values;
   list<string> Enums = enums;
@@ -122,6 +123,10 @@ class Attr {
   bit Ignored = 0;
   // Set to true if each of the spellings is a distinct attribute.
   bit DistinctSpellings = 0;
+  // Set to true if the attribute's parsing does not match its semantic
+  // content. Eg) It parses 3 args, but semantically takes 4 args.  Opts out of
+  // common attribute error checking.
+  bit HasCustomParsing = 0;
   // Any additional text that should be included verbatim in the class.
   code AdditionalMembers = [{}];
 }
@@ -168,7 +173,7 @@ def Aligned : InheritableAttr {
   let Spellings = [GNU<"aligned">, Declspec<"align">, CXX11<"gnu", "aligned">,
                    Keyword<"alignas">, Keyword<"_Alignas">];
   let Subjects = [NonBitField, NormalVar, Tag];
-  let Args = [AlignedArgument<"Alignment">];
+  let Args = [AlignedArgument<"Alignment", 1>];
   let Accessors = [Accessor<"isGNU", [GNU<"aligned">, CXX11<"gnu","aligned">]>,
                    Accessor<"isC11", [Keyword<"_Alignas">]>,
                    Accessor<"isAlignas", [Keyword<"alignas">,
@@ -223,6 +228,7 @@ def Availability : InheritableAttr {
              .Case("macosx", "OS X")
              .Default(llvm::StringRef());
 } }];
+  let HasCustomParsing = 1;
 }
 
 def Blocks : InheritableAttr {
@@ -296,7 +302,7 @@ def Const : InheritableAttr {
 
 def Constructor : InheritableAttr {
   let Spellings = [GNU<"constructor">, CXX11<"gnu", "constructor">];
-  let Args = [IntArgument<"Priority">];
+  let Args = [IntArgument<"Priority", 1>];
 }
 
 def CUDAConstant : InheritableAttr {
@@ -346,12 +352,12 @@ def OpenCLImageAccess : Attr {
 
 def Deprecated : InheritableAttr {
   let Spellings = [GNU<"deprecated">, CXX11<"gnu", "deprecated">];
-  let Args = [StringArgument<"Message">];
+  let Args = [StringArgument<"Message", 1>];
 }
 
 def Destructor : InheritableAttr {
   let Spellings = [GNU<"destructor">, CXX11<"gnu", "destructor">];
-  let Args = [IntArgument<"Priority">];
+  let Args = [IntArgument<"Priority", 1>];
 }
 
 def ExtVectorType : Attr {
@@ -409,7 +415,7 @@ def IBOutlet : InheritableAttr {
 
 def IBOutletCollection : InheritableAttr {
   let Spellings = [GNU<"iboutletcollection">];
-  let Args = [TypeArgument<"Interface">, SourceLocArgument<"InterfaceLoc">];
+  let Args = [TypeArgument<"Interface", 1>, SourceLocArgument<"InterfaceLoc">];
 }
 
 def Malloc : InheritableAttr {
@@ -513,7 +519,7 @@ def NoThrow : InheritableAttr {
 def NSBridged : InheritableAttr {
   let Spellings = [GNU<"ns_bridged">];
   let Subjects = [Record];
-  let Args = [IdentifierArgument<"BridgedType">];
+  let Args = [IdentifierArgument<"BridgedType", 1>];
 }
 
 def NSReturnsRetained : InheritableAttr {
@@ -678,7 +684,7 @@ def TransparentUnion : InheritableAttr {
 
 def Unavailable : InheritableAttr {
   let Spellings = [GNU<"unavailable">];
-  let Args = [StringArgument<"Message">];
+  let Args = [StringArgument<"Message", 1>];
 }
 
 def ArcWeakrefUnavailable : InheritableAttr {
@@ -724,6 +730,7 @@ def VectorSize : TypeAttr {
 def VecTypeHint : InheritableAttr {
   let Spellings = [GNU<"vec_type_hint">];
   let Args = [TypeArgument<"TypeHint">, SourceLocArgument<"TypeLoc">];
+  let HasCustomParsing = 1;
 }
 
 def Visibility : InheritableAttr {
@@ -768,6 +775,8 @@ def WeakImport : InheritableAttr {
 
 def WeakRef : InheritableAttr {
   let Spellings = [GNU<"weakref">, CXX11<"gnu", "weakref">];
+  // A WeakRef that has an argument is treated as being an AliasAttr
+  let Args = [StringArgument<"Aliasee", 1>];
 }
 
 def X86ForceAlignArgPointer : InheritableAttr, TargetSpecificAttr {
@@ -969,6 +978,7 @@ def ArgumentWithTypeTag : InheritableAttr {
               UnsignedArgument<"TypeTagIdx">,
               BoolArgument<"IsPointer">];
   let Subjects = [Function];
+  let HasCustomParsing = 1;
 }
 
 def TypeTagForDatatype : InheritableAttr {
@@ -978,6 +988,7 @@ def TypeTagForDatatype : InheritableAttr {
               BoolArgument<"LayoutCompatible">,
               BoolArgument<"MustBeNull">];
   let Subjects = [Var];
+  let HasCustomParsing = 1;
 }
 
 // Microsoft-related attributes

clang/include/clang/Sema/AttributeList.h

@@ -463,6 +463,10 @@ class AttributeList { // TODO: This should really be called ParsedAttribute
   /// defined in Attr.td. This index is used by an attribute
   /// to pretty print itself.
   unsigned getAttributeSpellingListIndex() const;
+
+  bool hasCustomParsing() const;
+  unsigned getMinArgs() const;
+  unsigned getMaxArgs() const;
 };
 
 /// A factory, from which one makes pools, from which one creates

clang/include/clang/Sema/CMakeLists.txt

@@ -17,3 +17,8 @@ clang_tablegen(AttrSpellingListIndex.inc -gen-clang-attr-spelling-index
   -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
   SOURCE ../Basic/Attr.td
   TARGET ClangAttrSpellingListIndex)
+
+clang_tablegen(AttrParsedAttrImpl.inc -gen-clang-attr-parsed-attr-impl
+  -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
+  SOURCE ../Basic/Attr.td
+  TARGET ClangAttrParsedAttrImpl)

clang/lib/Sema/AttributeList.cpp

@@ -145,3 +145,28 @@ unsigned AttributeList::getAttributeSpellingListIndex() const {
 
 }
 
+struct ParsedAttrInfo {
+  unsigned NumArgs : 4;
+  unsigned OptArgs : 4;
+  unsigned HasCustomParsing : 1;
+};
+
+namespace {
+  #include "clang/Sema/AttrParsedAttrImpl.inc"
+}
+
+const ParsedAttrInfo& getInfo(const AttributeList& A) {
+  return AttrInfoMap[A.getKind()];
+}
+
+unsigned AttributeList::getMinArgs() const {
+  return getInfo(*this).NumArgs;
+}
+
+unsigned AttributeList::getMaxArgs() const {
+  return getMinArgs() + getInfo(*this).OptArgs;
+}
+
+bool AttributeList::hasCustomParsing() const {
+  return getInfo(*this).HasCustomParsing;
+}

clang/lib/Sema/CMakeLists.txt

@@ -60,6 +60,7 @@ add_dependencies(clangSema
   ClangAttrList
   ClangAttrParsedAttrList
   ClangAttrParsedAttrKinds
+  ClangAttrParsedAttrImpl
   ClangAttrSpellingListIndex
   ClangAttrTemplateInstantiate
   ClangCommentNodes