Expose AttributeSetNode, use it to provide aggregate getter for attribute in the C API.

[deadalnix]

Summary

See D19181 for context.

[whitequark]

Aggregate getters LGTM

[deadalnix]

Rebase and fix conflicts

[bkramer]

Exposing the guts of the attribute implementation is really ugly. Why can't this be supported through AttributeSet?

[deadalnix]

@bkramer AttributeSet simply doesn't provide the required infos here. I'm open to alternative way to expose these (that's why I wanted your feedback here). Do you have a suggestion ?

[deadalnix]

Add CallSite support

[deadalnix]

Ping ?

[deadalnix]

Move AttributeSetNode.h for include to lib so that it is not exposed anymore.

[deadalnix]

@whitequark , @bkramer don't wanted to expose AttributeSetNode so I moved it back to lib .

[whitequark]

@deadalnix, So, no aggregate getters at all? That's unacceptable.

[deadalnix]

Aggregate getters are exposed. AttributeSetNode isn't, as per @bkramer 's request (it was in the initial diff).

[bkramer]

Sorry for dropping the ball here. All I wanted is that AttributeSetNode doesn't become part of the public API, i.e. being in a header in include/llvm. Patch is fine now. I know it's annoying but I would've approved this with the latest change if you pinged me again after that.

[deadalnix]

Good to see everyone got what they wanted. Sorry for the screw up on my side, I forgot that @whitequark accepted the diff a while ago and assumed someone accepted the newer revision when I saw it was green. I apologize.

include/llvm-c/Core.h

  * Add an attribute to a function.
  *
  * @see llvm::Function::addAttribute()
  */
 void LLVMAddFunctionAttr(LLVMValueRef Fn, LLVMAttribute PA);
 
 void LLVMAddAttributeAtIndex(LLVMValueRef F, LLVMAttributeIndex Idx,
                              LLVMAttributeRef A);
+unsigned LLVMGetAttributeCountAtIndex(LLVMValueRef F, LLVMAttributeIndex Idx);
+void LLVMGetAttributesAtIndex(LLVMValueRef F, LLVMAttributeIndex Idx,
+                              LLVMAttributeRef *Attrs);
 LLVMAttributeRef LLVMGetEnumAttributeAtIndex(LLVMValueRef F,
                                              LLVMAttributeIndex Idx,
                                              unsigned KindID);
 LLVMAttributeRef LLVMGetStringAttributeAtIndex(LLVMValueRef F,
                                                LLVMAttributeIndex Idx,
                                                const char *K, unsigned KLen);
 void LLVMRemoveEnumAttributeAtIndex(LLVMValueRef F, LLVMAttributeIndex Idx,
                                     unsigned KindID);

 void LLVMAddInstrAttribute(LLVMValueRef Instr, unsigned index, LLVMAttribute);
 void LLVMRemoveInstrAttribute(LLVMValueRef Instr, unsigned index,
                               LLVMAttribute);
 void LLVMSetInstrParamAlignment(LLVMValueRef Instr, unsigned index,
                                 unsigned Align);
 
 void LLVMAddCallSiteAttribute(LLVMValueRef C, LLVMAttributeIndex Idx,
                               LLVMAttributeRef A);
+unsigned LLVMGetCallSiteAttributeCount(LLVMValueRef C, LLVMAttributeIndex Idx);
+void LLVMGetCallSiteAttributes(LLVMValueRef C, LLVMAttributeIndex Idx,
+                               LLVMAttributeRef *Attrs);
 LLVMAttributeRef LLVMGetCallSiteEnumAttribute(LLVMValueRef C,
                                               LLVMAttributeIndex Idx,
                                               unsigned KindID);
 LLVMAttributeRef LLVMGetCallSiteStringAttribute(LLVMValueRef C,
                                                 LLVMAttributeIndex Idx,
                                                 const char *K, unsigned KLen);
 void LLVMRemoveCallSiteEnumAttribute(LLVMValueRef C, LLVMAttributeIndex Idx,
                                      unsigned KindID);

include/llvm/IR/AttributeSetNode.h

+//===-- AttributeSetNode.h - AttributeSet Internal Node ---------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief This file defines the node class used internally by AttributeSet.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_IR_ATTRIBUTESETNODE_H
+#define LLVM_IR_ATTRIBUTESETNODE_H
+
+#include "llvm/ADT/FoldingSet.h"
+#include "llvm/IR/Attributes.h"
+#include "llvm/Support/TrailingObjects.h"
+
+namespace llvm {
+
+//===----------------------------------------------------------------------===//
+/// \class
+/// \brief This class represents a group of attributes that apply to one
+/// element: function, return type, or parameter.
+class AttributeSetNode final
+    : public FoldingSetNode,
+      private TrailingObjects<AttributeSetNode, Attribute> {
+  friend TrailingObjects;
+
+  unsigned NumAttrs; ///< Number of attributes in this node.
+  /// Bitset with a bit for each available attribute Attribute::AttrKind.
+  uint64_t AvailableAttrs;
+
+  AttributeSetNode(ArrayRef<Attribute> Attrs)
+    : NumAttrs(Attrs.size()), AvailableAttrs(0) {
+    static_assert(Attribute::EndAttrKinds <= sizeof(AvailableAttrs) * CHAR_BIT,
+                  "Too many attributes for AvailableAttrs");
+    // There's memory after the node where we can store the entries in.
+    std::copy(Attrs.begin(), Attrs.end(), getTrailingObjects<Attribute>());
+
+    for (Attribute I : *this) {
+      if (!I.isStringAttribute()) {
+        AvailableAttrs |= ((uint64_t)1) << I.getKindAsEnum();
+      }
+    }
+  }
+
+  // AttributesSetNode is uniqued, these should not be publicly available.
+  void operator=(const AttributeSetNode &) = delete;
+  AttributeSetNode(const AttributeSetNode &) = delete;
+public:
+  void operator delete(void *p) { ::operator delete(p); }
+
+  static AttributeSetNode *get(LLVMContext &C, ArrayRef<Attribute> Attrs);
+
+  static AttributeSetNode *get(AttributeSet AS, unsigned Index) {
+    return AS.getAttributes(Index);
+  }
+
+  /// \brief Return the number of attributes this AttributeSet contains.
+  unsigned getNumAttributes() const { return NumAttrs; }
+
+  bool hasAttribute(Attribute::AttrKind Kind) const {
+    return AvailableAttrs & ((uint64_t)1) << Kind;
+  }
+  bool hasAttribute(StringRef Kind) const;
+  bool hasAttributes() const { return NumAttrs != 0; }
+
+  Attribute getAttribute(Attribute::AttrKind Kind) const;
+  Attribute getAttribute(StringRef Kind) const;
+
+  unsigned getAlignment() const;
+  unsigned getStackAlignment() const;
+  uint64_t getDereferenceableBytes() const;
+  uint64_t getDereferenceableOrNullBytes() const;
+  std::pair<unsigned, Optional<unsigned>> getAllocSizeArgs() const;
+  std::string getAsString(bool InAttrGrp) const;
+
+  typedef const Attribute *iterator;
+  iterator begin() const { return getTrailingObjects<Attribute>(); }
+  iterator end() const { return begin() + NumAttrs; }
+
+  void Profile(FoldingSetNodeID &ID) const {
+    Profile(ID, makeArrayRef(begin(), end()));
+  }
+  static void Profile(FoldingSetNodeID &ID, ArrayRef<Attribute> AttrList) {
+    for (unsigned I = 0, E = AttrList.size(); I != E; ++I)
+      AttrList[I].Profile(ID);
+  }
+};
+
+} // end llvm namespace
+
+#endif

include/llvm/IR/Attributes.h

public:
   enum AttrIndex : unsigned {
     ReturnIndex = 0U,
     FunctionIndex = ~0U
   };
 
 private:
   friend class AttrBuilder;
   friend class AttributeSetImpl;
+  friend class AttributeSetNode;
   template <typename Ty> friend struct DenseMapInfo;
 
   /// \brief The attributes that we are managing. This can be null to represent
   /// the empty attributes list.
   AttributeSetImpl *pImpl;
 
   /// \brief The attributes for the specified index are returned.
   AttributeSetNode *getAttributes(unsigned Index) const;

lib/IR/AttributeImpl.h

 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_IR_ATTRIBUTEIMPL_H
 #define LLVM_LIB_IR_ATTRIBUTEIMPL_H
 
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/IR/Attributes.h"
+#include "llvm/IR/AttributeSetNode.h"
 #include "llvm/Support/DataTypes.h"
-#include "llvm/Support/TrailingObjects.h"
 #include <climits>
 #include <string>
 
 namespace llvm {
 
 class Constant;
 class LLVMContext;
 

 public:
   StringAttributeImpl(StringRef Kind, StringRef Val = StringRef())
       : AttributeImpl(StringAttrEntry), Kind(Kind), Val(Val) {}
 
   StringRef getStringKind() const { return Kind; }
   StringRef getStringValue() const { return Val; }
 };
 
-//===----------------------------------------------------------------------===//
-/// \class
-/// \brief This class represents a group of attributes that apply to one
-/// element: function, return type, or parameter.
-class AttributeSetNode final
-    : public FoldingSetNode,
-      private TrailingObjects<AttributeSetNode, Attribute> {
-  friend TrailingObjects;
-
-  unsigned NumAttrs; ///< Number of attributes in this node.
-  /// Bitset with a bit for each available attribute Attribute::AttrKind.
-  uint64_t AvailableAttrs;
-
-  AttributeSetNode(ArrayRef<Attribute> Attrs)
-    : NumAttrs(Attrs.size()), AvailableAttrs(0) {
-    static_assert(Attribute::EndAttrKinds <= sizeof(AvailableAttrs) * CHAR_BIT,
-                  "Too many attributes for AvailableAttrs");
-    // There's memory after the node where we can store the entries in.
-    std::copy(Attrs.begin(), Attrs.end(), getTrailingObjects<Attribute>());
-
-    for (Attribute I : *this) {
-      if (!I.isStringAttribute()) {
-        AvailableAttrs |= ((uint64_t)1) << I.getKindAsEnum();
-      }
-    }
-  }
-
-  // AttributesSetNode is uniqued, these should not be publicly available.
-  void operator=(const AttributeSetNode &) = delete;
-  AttributeSetNode(const AttributeSetNode &) = delete;
-public:
-  void operator delete(void *p) { ::operator delete(p); }
-
-  static AttributeSetNode *get(LLVMContext &C, ArrayRef<Attribute> Attrs);
-
-  /// \brief Return the number of attributes this AttributeSet contains.
-  unsigned getNumAttributes() const { return NumAttrs; }
-
-  bool hasAttribute(Attribute::AttrKind Kind) const {
-    return AvailableAttrs & ((uint64_t)1) << Kind;
-  }
-  bool hasAttribute(StringRef Kind) const;
-  bool hasAttributes() const { return NumAttrs != 0; }
-
-  Attribute getAttribute(Attribute::AttrKind Kind) const;
-  Attribute getAttribute(StringRef Kind) const;
-
-  unsigned getAlignment() const;
-  unsigned getStackAlignment() const;
-  uint64_t getDereferenceableBytes() const;
-  uint64_t getDereferenceableOrNullBytes() const;
-  std::pair<unsigned, Optional<unsigned>> getAllocSizeArgs() const;
-  std::string getAsString(bool InAttrGrp) const;
-
-  typedef const Attribute *iterator;
-  iterator begin() const { return getTrailingObjects<Attribute>(); }
-  iterator end() const { return begin() + NumAttrs; }
-
-  void Profile(FoldingSetNodeID &ID) const {
-    Profile(ID, makeArrayRef(begin(), end()));
-  }
-  static void Profile(FoldingSetNodeID &ID, ArrayRef<Attribute> AttrList) {
-    for (unsigned I = 0, E = AttrList.size(); I != E; ++I)
-      AttrList[I].Profile(ID);
-  }
-};
-
 typedef std::pair<unsigned, AttributeSetNode *> IndexAttrPair;
 
 //===----------------------------------------------------------------------===//
 /// \class
 /// \brief This class represents a set of attributes that apply to the function,
 /// return type, and parameters.
 class AttributeSetImpl final
     : public FoldingSetNode,

lib/IR/Core.cpp

 // for libLLVMCore.a, which implements the LLVM intermediate representation.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm-c/Core.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/IR/Attributes.h"
+#include "llvm/IR/AttributeSetNode.h"
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/DiagnosticPrinter.h"
 #include "llvm/IR/GlobalAlias.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/IRBuilder.h"
void LLVMAddFunctionAttr(LLVMValueRef Fn, LLVMAttribute PA) {
   Func->setAttributes(PALnew);
 }
 
 void LLVMAddAttributeAtIndex(LLVMValueRef F, LLVMAttributeIndex Idx,
                              LLVMAttributeRef A) {
   unwrap<Function>(F)->addAttribute(Idx, unwrap(A));
 }
 
+unsigned LLVMGetAttributeCountAtIndex(LLVMValueRef F, LLVMAttributeIndex Idx) {
+  auto *ASN = AttributeSetNode::get(unwrap<Function>(F)->getAttributes(), Idx);
+  return ASN->getNumAttributes();
+}
+
+void LLVMGetAttributesAtIndex(LLVMValueRef F, LLVMAttributeIndex Idx,
+                              LLVMAttributeRef *Attrs) {
+  auto *ASN = AttributeSetNode::get(unwrap<Function>(F)->getAttributes(), Idx);
+  for (auto A: make_range(ASN->begin(), ASN->end()))
+    *Attrs++ = wrap(A);
+}
+
 LLVMAttributeRef LLVMGetEnumAttributeAtIndex(LLVMValueRef F,
                                              LLVMAttributeIndex Idx,
                                              unsigned KindID) {
   return wrap(unwrap<Function>(F)->getAttribute(Idx,
                                                 (Attribute::AttrKind)KindID));
 }
 
 LLVMAttributeRef LLVMGetStringAttributeAtIndex(LLVMValueRef F,
Call.setAttributes(Call.getAttributes()
                                                         index, B)));
 }
 
 void LLVMAddCallSiteAttribute(LLVMValueRef C, LLVMAttributeIndex Idx,
                               LLVMAttributeRef A) {
   CallSite(unwrap<Instruction>(C)).addAttribute(Idx, unwrap(A));
 }
 
+unsigned LLVMGetCallSiteAttributeCount(LLVMValueRef C,
+                                       LLVMAttributeIndex Idx) {
+  auto CS = CallSite(unwrap<Instruction>(C));
+  auto *ASN = AttributeSetNode::get(CS.getAttributes(), Idx);
+  return ASN->getNumAttributes();
+}
+
+void LLVMGetCallSiteAttributes(LLVMValueRef C, LLVMAttributeIndex Idx,
+                               LLVMAttributeRef *Attrs) {
+  auto CS = CallSite(unwrap<Instruction>(C));
+  auto *ASN = AttributeSetNode::get(CS.getAttributes(), Idx);
+  for (auto A: make_range(ASN->begin(), ASN->end()))
+    *Attrs++ = wrap(A);
+}
+
 LLVMAttributeRef LLVMGetCallSiteEnumAttribute(LLVMValueRef C,
                                               LLVMAttributeIndex Idx,
                                               unsigned KindID) {
   return wrap(CallSite(unwrap<Instruction>(C))
     .getAttribute(Idx, (Attribute::AttrKind)KindID));
 }
 
 LLVMAttributeRef LLVMGetCallSiteStringAttribute(LLVMValueRef C,