[NFC] Remove some unclear attribute methods

[aeubanks]

Summary

To any downstream users broken by this change, please examine your uses
of these methods and see if you can use a better method. For example,
getAttribute(AttributeList::FunctionIndex) => getFnAttr(), or
addAttribute(AttributeList::FirstArgIndex + ArgNo) =>
addParamAttribute(ArgNo). 0 corresponds to ReturnIndex, ~0 corresponds
to FunctionIndex. This may make future cleanups less painful.

I've made the mistake of assuming that these indexes are for parameters
multiple times, but actually they're based off of a weird indexing
scheme AttributeList::AttrIndex where 0 is the return value and ~0 is
the function. Hopefully renaming these methods will make this clearer.
Ideally users should use more specific methods like
AttributeList::getFnAttr().

This touches all relevant methods in AttributeList, CallBase, and Function.

This hopefully will make easier a future change to cleanup AttrIndex. A
previous worry about cleaning up AttrIndex was that too many downstream
users would have to look through all uses of AttrIndex and relevant
attribute method calls to see if anything was unintentionally hardcoded
(e.g. using 0 instead of ReturnIndex). With this change hopefully
downstream users will look at existing usages of these methods and clean
them up.

[aeubanks]

update

[jdoerfert]

FWIW, I'm fine with this.

[dexonsmith]

Change SGTM. New names seem more clear / less dangerous. @bogner, @fhahn, or @t.p.northover, any thoughts?

BTW, staging this as (at least) two commits will make this easier for downstreams:

1. Add new APIs and update callers, leaving behind the old names forwarding to the new ones (for a bigger commit you might want to split this step up further)
2. Remove old APIs

That way a downstream can temporarily revert the "Remove old APIs" commit and continuing merging from main, while updating their own code as a background task. (No need to wait really for "Remove old APIs"; as long as it's an easy-to-revert standalone commit then there are good workflows for downstreams.)

[aeubanks]

In D108614#2962854, @dexonsmith wrote:

Change SGTM. New names seem more clear / less dangerous. @bogner, @fhahn, or @t.p.northover, any thoughts?

BTW, staging this as (at least) two commits will make this easier for downstreams:

1. Add new APIs and update callers, leaving behind the old names forwarding to the new ones (for a bigger commit you might want to split this step up further)
2. Remove old APIs

That way a downstream can temporarily revert the "Remove old APIs" commit and continuing merging from main, while updating their own code as a background task. (No need to wait really for "Remove old APIs"; as long as it's an easy-to-revert standalone commit then there are good workflows for downstreams.)

Renaming these methods downstream should be fairly straightforward and quick, I don't think we need to make it easier for downstream users to adapt to this change.

[aeubanks]

Actually, I'll go ahead and split out the patches. Part one: D108788.

[aeubanks]

rebase

[rnk]

lgtm, ship it!

llvm/include/llvm/IR/Attributes.h

public:
   static AttributeList get(LLVMContext &C, unsigned Index,
                            const AttrBuilder &B);
 
   // TODO: remove non-AtIndex versions of these methods.
   /// Add an attribute to the attribute set at the given index.
   /// Returns a new list because attribute lists are immutable.
   LLVM_NODISCARD AttributeList addAttributeAtIndex(
       LLVMContext &C, unsigned Index, Attribute::AttrKind Kind) const;
-  LLVM_NODISCARD AttributeList addAttribute(LLVMContext &C, unsigned Index,
-                                            Attribute::AttrKind Kind) const {
-    return addAttributeAtIndex(C, Index, Kind);
-  }
 
   /// Add an attribute to the attribute set at the given index.
   /// Returns a new list because attribute lists are immutable.
   LLVM_NODISCARD AttributeList
   addAttributeAtIndex(LLVMContext &C, unsigned Index, StringRef Kind,
                       StringRef Value = StringRef()) const;
-  LLVM_NODISCARD AttributeList
-  addAttribute(LLVMContext &C, unsigned Index, StringRef Kind,
-               StringRef Value = StringRef()) const {
-    return addAttributeAtIndex(C, Index, Kind, Value);
-  }
 
   /// Add an attribute to the attribute set at the given index.
   /// Returns a new list because attribute lists are immutable.
   LLVM_NODISCARD AttributeList addAttributeAtIndex(LLVMContext &C,
                                                    unsigned Index,
                                                    Attribute A) const;
-  LLVM_NODISCARD AttributeList addAttribute(LLVMContext &C, unsigned Index,
-                                            Attribute A) const {
-    return addAttributeAtIndex(C, Index, A);
-  }
 
   /// Add attributes to the attribute set at the given index.
   /// Returns a new list because attribute lists are immutable.
   LLVM_NODISCARD AttributeList addAttributesAtIndex(LLVMContext &C,
                                                     unsigned Index,
                                                     const AttrBuilder &B) const;
-  LLVM_NODISCARD AttributeList addAttributes(LLVMContext &C, unsigned Index,
-                                             const AttrBuilder &B) const {
-    return addAttributesAtIndex(C, Index, B);
-  }
 
   /// Add a function attribute to the list. Returns a new list because
   /// attribute lists are immutable.
   LLVM_NODISCARD AttributeList addFnAttribute(LLVMContext &C,
                                               Attribute::AttrKind Kind) const {
     return addAttributeAtIndex(C, FunctionIndex, Kind);
   }
 
LLVM_NODISCARD AttributeList addParamAttributes(LLVMContext &C,
                                                   const AttrBuilder &B) const {
     return addAttributesAtIndex(C, ArgNo + FirstArgIndex, B);
   }
 
   /// Remove the specified attribute at the specified index from this
   /// attribute list. Returns a new list because attribute lists are immutable.
   LLVM_NODISCARD AttributeList removeAttributeAtIndex(
       LLVMContext &C, unsigned Index, Attribute::AttrKind Kind) const;
-  LLVM_NODISCARD AttributeList removeAttribute(LLVMContext &C, unsigned Index,
-                                               Attribute::AttrKind Kind) const {
-    return removeAttributeAtIndex(C, Index, Kind);
-  }
 
   /// Remove the specified attribute at the specified index from this
   /// attribute list. Returns a new list because attribute lists are immutable.
   LLVM_NODISCARD AttributeList removeAttributeAtIndex(LLVMContext &C,
                                                       unsigned Index,
                                                       StringRef Kind) const;
   LLVM_NODISCARD AttributeList removeAttribute(LLVMContext &C, unsigned Index,
                                                StringRef Kind) const {
     return removeAttributeAtIndex(C, Index, Kind);
   }
 
   /// Remove the specified attributes at the specified index from this
   /// attribute list. Returns a new list because attribute lists are immutable.
   LLVM_NODISCARD AttributeList removeAttributesAtIndex(
       LLVMContext &C, unsigned Index, const AttrBuilder &AttrsToRemove) const;
-  LLVM_NODISCARD AttributeList removeAttributes(
-      LLVMContext &C, unsigned Index, const AttrBuilder &AttrsToRemove) const {
-    return removeAttributesAtIndex(C, Index, AttrsToRemove);
-  }
 
   /// Remove all attributes at the specified index from this
   /// attribute list. Returns a new list because attribute lists are immutable.
   LLVM_NODISCARD AttributeList removeAttributesAtIndex(LLVMContext &C,
                                                        unsigned Index) const;
-  LLVM_NODISCARD AttributeList removeAttributes(LLVMContext &C,
-                                                unsigned Index) const {
-    return removeAttributesAtIndex(C, Index);
-  }
 
   /// Remove the specified attribute at the function index from this
   /// attribute list. Returns a new list because attribute lists are immutable.
   LLVM_NODISCARD AttributeList
   removeFnAttribute(LLVMContext &C, Attribute::AttrKind Kind) const {
     return removeAttributeAtIndex(C, FunctionIndex, Kind);
   }
 
public:
   LLVM_NODISCARD AttributeList replaceAttributeTypeAtIndex(
       LLVMContext &C, unsigned ArgNo, Attribute::AttrKind Kind,
       Type *ReplacementTy) const {
     Attribute Attr = getAttributeAtIndex(ArgNo, Kind);
     auto Attrs = removeAttributeAtIndex(C, ArgNo, Kind);
     return Attrs.addAttributeAtIndex(C, ArgNo,
                                      Attr.getWithNewType(C, ReplacementTy));
   }
-  LLVM_NODISCARD AttributeList replaceAttributeType(LLVMContext &C,
-                                                    unsigned ArgNo,
-                                                    Attribute::AttrKind Kind,
-                                                    Type *ReplacementTy) const {
-    return replaceAttributeTypeAtIndex(C, ArgNo, Kind, ReplacementTy);
-  }
 
   /// \brief Add the dereferenceable attribute to the attribute set at the given
   /// index. Returns a new list because attribute lists are immutable.
   LLVM_NODISCARD AttributeList addDereferenceableRetAttr(LLVMContext &C,
                                                          uint64_t Bytes) const;
 
   /// \brief Add the dereferenceable attribute to the attribute set at the given
   /// arg index. Returns a new list because attribute lists are immutable.
public:
   /// The attributes for the ret value are returned.
   AttributeSet getRetAttrs() const;
 
   /// The function attributes are returned.
   AttributeSet getFnAttrs() const;
 
   /// Return true if the attribute exists at the given index.
   bool hasAttributeAtIndex(unsigned Index, Attribute::AttrKind Kind) const;
-  bool hasAttribute(unsigned Index, Attribute::AttrKind Kind) const {
-    return hasAttributeAtIndex(Index, Kind);
-  }
 
   /// Return true if the attribute exists at the given index.
   bool hasAttributeAtIndex(unsigned Index, StringRef Kind) const;
-  bool hasAttribute(unsigned Index, StringRef Kind) const {
-    return hasAttributeAtIndex(Index, Kind);
-  }
 
   /// Return true if attribute exists at the given index.
   bool hasAttributesAtIndex(unsigned Index) const;
-  bool hasAttributes(unsigned Index) const {
-    return hasAttributesAtIndex(Index);
-  }
 
   /// Return true if the attribute exists for the given argument
   bool hasParamAttr(unsigned ArgNo, Attribute::AttrKind Kind) const {
     return hasAttributeAtIndex(ArgNo + FirstArgIndex, Kind);
   }
 
   /// Return true if the attribute exists for the given argument
   bool hasParamAttr(unsigned ArgNo, StringRef Kind) const {
public:
   /// Return true if the specified attribute is set for at least one
   /// parameter or for the return value. If Index is not nullptr, the index
   /// of a parameter with the specified attribute is provided.
   bool hasAttrSomewhere(Attribute::AttrKind Kind,
                         unsigned *Index = nullptr) const;
 
   /// Return the attribute object that exists at the given index.
   Attribute getAttributeAtIndex(unsigned Index, Attribute::AttrKind Kind) const;
-  Attribute getAttribute(unsigned Index, Attribute::AttrKind Kind) const {
-    return getAttributeAtIndex(Index, Kind);
-  }
 
   /// Return the attribute object that exists at the given index.
   Attribute getAttributeAtIndex(unsigned Index, StringRef Kind) const;
-  Attribute getAttribute(unsigned Index, StringRef Kind) const {
-    return getAttributeAtIndex(Index, Kind);
-  }
 
   /// Return the attribute object that exists at the arg index.
   Attribute getParamAttr(unsigned ArgNo, Attribute::AttrKind Kind) const {
     return getAttributeAtIndex(ArgNo + FirstArgIndex, Kind);
   }
 
   /// Return the attribute object that exists at the given index.
   Attribute getParamAttr(unsigned ArgNo, StringRef Kind) const {

llvm/include/llvm/IR/Function.h

public:
   AttributeList getAttributes() const { return AttributeSets; }
 
   /// Set the attribute list for this Function.
   void setAttributes(AttributeList Attrs) { AttributeSets = Attrs; }
 
   // TODO: remove non-AtIndex versions of these methods.
   /// adds the attribute to the list of attributes.
   void addAttributeAtIndex(unsigned i, Attribute Attr);
-  void addAttribute(unsigned i, Attribute Attr) {
-    addAttributeAtIndex(i, Attr);
-  }
 
   /// Add function attributes to this function.
   void addFnAttr(Attribute::AttrKind Kind);
 
   /// Add function attributes to this function.
   void addFnAttr(StringRef Kind, StringRef Val = StringRef());
 
   /// Add function attributes to this function.
public:
   /// adds the attribute to the list of attributes for the given arg.
   void addParamAttr(unsigned ArgNo, Attribute Attr);
 
   /// adds the attributes to the list of attributes for the given arg.
   void addParamAttrs(unsigned ArgNo, const AttrBuilder &Attrs);
 
   /// removes the attribute from the list of attributes.
   void removeAttributeAtIndex(unsigned i, Attribute::AttrKind Kind);
-  void removeAttribute(unsigned i, Attribute::AttrKind Kind) {
-    removeAttributeAtIndex(i, Kind);
-  }
 
   /// removes the attribute from the list of attributes.
   void removeAttributeAtIndex(unsigned i, StringRef Kind);
-  void removeAttribute(unsigned i, StringRef Kind) {
-    removeAttributeAtIndex(i, Kind);
-  }
 
   /// Remove function attributes from this function.
   void removeFnAttr(Attribute::AttrKind Kind);
 
   /// Remove function attribute from this function.
   void removeFnAttr(StringRef Kind);
 
   void removeFnAttrs(const AttrBuilder &Attrs);
public:
   /// check if an attribute is in the list of attributes for the return value.
   bool hasRetAttribute(Attribute::AttrKind Kind) const;
 
   /// check if an attributes is in the list of attributes.
   bool hasParamAttribute(unsigned ArgNo, Attribute::AttrKind Kind) const;
 
   /// gets the attribute from the list of attributes.
   Attribute getAttributeAtIndex(unsigned i, Attribute::AttrKind Kind) const;
-  Attribute getAttribute(unsigned i, Attribute::AttrKind Kind) const {
-    return getAttributeAtIndex(i, Kind);
-  }
 
   /// gets the attribute from the list of attributes.
   Attribute getAttributeAtIndex(unsigned i, StringRef Kind) const;
-  Attribute getAttribute(unsigned i, StringRef Kind) const {
-    return getAttributeAtIndex(i, Kind);
-  }
 
   /// Return the attribute for the given attribute kind.
   Attribute getFnAttribute(Attribute::AttrKind Kind) const;
 
   /// Return the attribute for the given attribute kind.
   Attribute getFnAttribute(StringRef Kind) const;
 
   /// gets the specified attribute from the list of attributes.

llvm/include/llvm/IR/InstrTypes.h

public:
   /// the attribute is allowed for the call.
   bool hasFnAttr(StringRef Kind) const { return hasFnAttrImpl(Kind); }
 
   // TODO: remove non-AtIndex versions of these methods.
   /// adds the attribute to the list of attributes.
   void addAttributeAtIndex(unsigned i, Attribute::AttrKind Kind) {
     Attrs = Attrs.addAttributeAtIndex(getContext(), i, Kind);
   }
-  void addAttribute(unsigned i, Attribute::AttrKind Kind) {
-    addAttributeAtIndex(i, Kind);
-  }
 
   /// adds the attribute to the list of attributes.
   void addAttributeAtIndex(unsigned i, Attribute Attr) {
     Attrs = Attrs.addAttributeAtIndex(getContext(), i, Attr);
   }
-  void addAttribute(unsigned i, Attribute Attr) {
-    addAttributeAtIndex(i, Attr);
-  }
 
   /// Adds the attribute to the function.
   void addFnAttr(Attribute::AttrKind Kind) {
     Attrs = Attrs.addFnAttribute(getContext(), Kind);
   }
 
   /// Adds the attribute to the function.
   void addFnAttr(Attribute Attr) {
void addParamAttr(unsigned ArgNo, Attribute Attr) {
     assert(ArgNo < getNumArgOperands() && "Out of bounds");
     Attrs = Attrs.addParamAttribute(getContext(), ArgNo, Attr);
   }
 
   /// removes the attribute from the list of attributes.
   void removeAttributeAtIndex(unsigned i, Attribute::AttrKind Kind) {
     Attrs = Attrs.removeAttributeAtIndex(getContext(), i, Kind);
   }
-  void removeAttribute(unsigned i, Attribute::AttrKind Kind) {
-    removeAttributeAtIndex(i, Kind);
-  }
 
   /// removes the attribute from the list of attributes.
   void removeAttributeAtIndex(unsigned i, StringRef Kind) {
     Attrs = Attrs.removeAttributeAtIndex(getContext(), i, Kind);
   }
-  void removeAttribute(unsigned i, StringRef Kind) {
-    removeAttributeAtIndex(i, Kind);
-  }
 
   /// Removes the attributes from the function
   void removeFnAttrs(const AttrBuilder &AttrsToRemove) {
     Attrs = Attrs.removeFnAttributes(getContext(), AttrsToRemove);
   }
 
   /// Removes the attribute from the function
   void removeFnAttr(Attribute::AttrKind Kind) {
public:
 
   /// Determine whether the argument or parameter has the given attribute.
   bool paramHasAttr(unsigned ArgNo, Attribute::AttrKind Kind) const;
 
   /// Get the attribute of a given kind at a position.
   Attribute getAttributeAtIndex(unsigned i, Attribute::AttrKind Kind) const {
     return getAttributes().getAttributeAtIndex(i, Kind);
   }
-  Attribute getAttribute(unsigned i, Attribute::AttrKind Kind) const {
-    return getAttributeAtIndex(i, Kind);
-  }
 
   /// Get the attribute of a given kind at a position.
   Attribute getAttributeAtIndex(unsigned i, StringRef Kind) const {
     return getAttributes().getAttributeAtIndex(i, Kind);
   }
-  Attribute getAttribute(unsigned i, StringRef Kind) const {
-    return getAttributeAtIndex(i, Kind);
-  }
 
   /// Get the attribute of a given kind for the function.
   Attribute getFnAttr(StringRef Kind) const {
     return getAttributes().getFnAttr(Kind);
   }
 
   /// Get the attribute of a given kind for the function.
   Attribute getFnAttr(Attribute::AttrKind Kind) const {