[AutoDiff] Rename "associated function" to "derivative function". (#27603)

`assocFn` -> `derivativeFn`
`AssocFn` -> `DerivativeFn`
`assocFunc` -> `derivativeFunc`
`AssocFunc` -> `DerivativeFunc`
`associatedFunction` -> `derivativeFunction`
`AssociatedFunction` -> `DerivativeFunction`
`autodiff associated function` -> `derivative function`
`autodiff-associated function` -> `derivative function`
`AD associated function` -> `derivative function`
`associated differentiation function` -> `derivative function`

This is a follow-up to #27597.

Resolves [TF-882](https://bugs.swift.org/browse/TF-882).

Author: rxwei

docs/SIL.rst

@@ -5609,35 +5609,34 @@ differentiable_function
                       sil-differentiable-function-parameter-indices?
                       sil-differentiable-function-order?
                       sil-value ':' sil-type
-                      sil-differentiable-function-associated-functions-clause?
+                      sil-differentiable-function-derivative-functions-clause?
                       
   sil-differentiable-function-parameter-indices ::=
       '[' 'wrt' [0-9]+ (',', [0-9]+)* ']'
   sil-differentiable-function-order ::= '[' 'order' [0-9]+ ']'
-  sil-differentiable-associated-functions-clause ::=
-      'with' sil-differentiable-associated-function-list
-      (',' sil-differentiable-associated-function-list)*
-  sil-differentiable-function-associated-function-list ::=
+  sil-differentiable-derivative-functions-clause ::=
+      'with' sil-differentiable-derivative-function-list
+      (',' sil-differentiable-derivative-function-list)*
+  sil-differentiable-function-derivative-function-list ::=
       '{' sil-value ',' sil-value '}'
 
   differentiable_function [wrt 0] %0 : $(T) -> T \
     with {%1 : $(T) -> (T, (T) -> T), %2 : $(T) -> (T, (T) -> T)}
 
-Bundles a function with its associated differentiation functions into a
-``@differentiable`` function. There are two associated functions:
-a Jacobian-vector products (JVP) function and a vector-Jacobian products (VJP)
-function.
+Bundles a function with its derivative functions into a ``@differentiable``
+function. There are two derivative functions: a Jacobian-vector products (JVP)
+function and a vector-Jacobian products (VJP) function.
 
 ``[wrt ...]`` specifies parameter indices that the original function is
 differentiable with respect to. When not specified, it defaults to all
 parameters.
 
 A ``with`` clause specifies the differentiation functions associated
 with the original function. When a ``with`` clause is not specified, the first
-operand will be differentiated to produce associated functions, and a ``with``
+operand will be differentiated to produce derivative functions, and a ``with``
 clause will be added to the instruction.
 
-In raw SIL, it is optional to provide an associated function ``with`` clause.
+In raw SIL, it is optional to provide a derivative function ``with`` clause.
 In canonical SIL, a ``with`` clause is mandatory.
 
 
@@ -5660,7 +5659,7 @@ differentiable_function_extract
   differentiable_function_extract [jvp] %0 : $@differentiable (T) -> T
   differentiable_function_extract [vjp] %0 : $@differentiable (T) -> T
 
-Extracts the original function or an associated function from the given
+Extracts the original function or a derivative function from the given
 ``@differentiable`` function. It must be provided with an extractee:
 ``[original]``, ``[jvp]`` or ``[vjp]``.
 

include/swift/AST/ASTMangler.h

@@ -155,12 +155,12 @@ class ASTMangler : public Mangler {
                                              ModuleDecl *Module);
 
   // SWIFT_ENABLE_TENSORFLOW
-  // Mangle the autodiff associated function (JVP/VJP) with the given:
+  // Mangle the derivative function (JVP/VJP) with the given:
   // - Mangled original function name.
-  // - Associated function kind.
+  // - Derivative function kind.
   // - Parameter/result indices.
-  std::string mangleAutoDiffAssociatedFunctionHelper(
-      StringRef name, AutoDiffAssociatedFunctionKind kind,
+  std::string mangleAutoDiffDerivativeFunctionHelper(
+      StringRef name, AutoDiffDerivativeFunctionKind kind,
       const SILAutoDiffIndices &indices);
 
   // SWIFT_ENABLE_TENSORFLOW

include/swift/AST/Attr.h

@@ -1555,7 +1555,7 @@ class DifferentiableAttr final
   AutoDiffIndexSubset *ParameterIndices = nullptr;
   /// The trailing where clause (optional).
   TrailingWhereClause *WhereClause = nullptr;
-  /// The generic signature for autodiff associated functions. Resolved by the
+  /// The generic signature for autodiff derivative functions. Resolved by the
   /// type checker based on the original function's generic signature and the
   /// attribute's where clause requirements. This is set only if the attribute
   /// has a where clause.
@@ -1650,10 +1650,10 @@ class DifferentiableAttr final
 
   // Print the attribute to the given stream.
   // If `omitWrtClause` is true, omit printing the `wrt:` clause.
-  // If `omitAssociatedFunctions` is true, omit printing associated functions.
+  // If `omitDerivativeFunctions` is true, omit printing derivative functions.
   void print(llvm::raw_ostream &OS, const Decl *D,
              bool omitWrtClause = false,
-             bool omitAssociatedFunctions = false) const;
+             bool omitDerivativeFunctions = false) const;
 
   static bool classof(const DeclAttribute *DA) {
     return DA->getKind() == DAK_Differentiable;

include/swift/AST/AutoDiff.h

@@ -431,48 +431,48 @@ struct AutoDiffLinearMapKind {
   operator innerty() const { return rawValue; }
 };
 
-/// The kind of an associated function.
-struct AutoDiffAssociatedFunctionKind {
+/// The kind of a derivative function.
+struct AutoDiffDerivativeFunctionKind {
   enum innerty : uint8_t {
    // The Jacobian-vector products function.
    JVP = 0,
    // The vector-Jacobian products function.
    VJP = 1
   } rawValue;
 
-  AutoDiffAssociatedFunctionKind() = default;
-  AutoDiffAssociatedFunctionKind(innerty rawValue) : rawValue(rawValue) {}
-  AutoDiffAssociatedFunctionKind(AutoDiffLinearMapKind linMapKind)
+  AutoDiffDerivativeFunctionKind() = default;
+  AutoDiffDerivativeFunctionKind(innerty rawValue) : rawValue(rawValue) {}
+  AutoDiffDerivativeFunctionKind(AutoDiffLinearMapKind linMapKind)
       : rawValue(static_cast<innerty>(linMapKind.rawValue)) {}
-  explicit AutoDiffAssociatedFunctionKind(StringRef string);
+  explicit AutoDiffDerivativeFunctionKind(StringRef string);
   operator innerty() const { return rawValue; }
   AutoDiffLinearMapKind getLinearMapKind() {
     return (AutoDiffLinearMapKind::innerty)rawValue;
   }
 };
 
 /// In conjunction with the original function declaration, identifies an
-/// autodiff associated function.
+/// autodiff derivative function.
 ///
 /// Is uniquely allocated within an ASTContext so that it can be hashed and
 /// compared by opaque pointer value.
-class AutoDiffAssociatedFunctionIdentifier : public llvm::FoldingSetNode {
-  const AutoDiffAssociatedFunctionKind kind;
+class AutoDiffDerivativeFunctionIdentifier : public llvm::FoldingSetNode {
+  const AutoDiffDerivativeFunctionKind kind;
   AutoDiffIndexSubset *const parameterIndices;
 
-  AutoDiffAssociatedFunctionIdentifier(
-      AutoDiffAssociatedFunctionKind kind,
+  AutoDiffDerivativeFunctionIdentifier(
+      AutoDiffDerivativeFunctionKind kind,
       AutoDiffIndexSubset *parameterIndices) :
     kind(kind), parameterIndices(parameterIndices) {}
 
 public:
-  AutoDiffAssociatedFunctionKind getKind() const { return kind; }
+  AutoDiffDerivativeFunctionKind getKind() const { return kind; }
   AutoDiffIndexSubset *getParameterIndices() const {
     return parameterIndices;
   }
 
-  static AutoDiffAssociatedFunctionIdentifier *get(
-      AutoDiffAssociatedFunctionKind kind,
+  static AutoDiffDerivativeFunctionIdentifier *get(
+      AutoDiffDerivativeFunctionKind kind,
       AutoDiffIndexSubset *parameterIndices, ASTContext &C);
 
   void Profile(llvm::FoldingSetNodeID &ID) {
@@ -520,15 +520,15 @@ AutoDiffIndexSubset *getLoweredParameterIndices(AutoDiffIndexSubset *indices,
 /// `Builtin.autodiffApply`, e.g. `Builtin.autodiffApply_jvp_arity2_order1`.
 /// Returns true if the function name is parsed successfully.
 bool getBuiltinAutoDiffApplyConfig(StringRef operationName,
-                                   AutoDiffAssociatedFunctionKind &kind,
+                                   AutoDiffDerivativeFunctionKind &kind,
                                    unsigned &arity, bool &rethrows);
 
-/// Computes the correct linkage for an associated function given the linkage of
+/// Computes the correct linkage for a derivative function given the linkage of
 /// the original function. If the original linkage is not external and
-/// `isAssocFnExported` is true, use the original function's linkage. Otherwise,
-/// return hidden linkage.
-SILLinkage getAutoDiffAssociatedFunctionLinkage(SILLinkage originalLinkage,
-                                                bool isAssocFnExported);
+/// `isDerivativeFnExported` is true, use the original function's linkage.
+/// Otherwise, return hidden linkage.
+SILLinkage getAutoDiffDerivativeFunctionLinkage(SILLinkage originalLinkage,
+                                                bool isDerivativeFnExported);
 
 } // end namespace autodiff
 

include/swift/AST/DiagnosticsParse.def

@@ -1597,15 +1597,15 @@ ERROR(sil_inst_autodiff_attr_expected_rsquare,PointsToFirstBadToken,
 ERROR(sil_inst_autodiff_expected_parameter_index,PointsToFirstBadToken,
       "expected the index of a parameter to differentiate with respect to", ())
 ERROR(sil_inst_autodiff_operand_list_expected_lbrace,PointsToFirstBadToken,
-      "expected '{' to start an associated function list", ())
+      "expected '{' to start a derivative function list", ())
 ERROR(sil_inst_autodiff_operand_list_expected_comma,PointsToFirstBadToken,
-      "expected ',' between operands in an associated function list", ())
+      "expected ',' between operands in a derivative function list", ())
 ERROR(sil_inst_autodiff_operand_list_expected_rbrace,PointsToFirstBadToken,
-      "expected '}' to start an associated function list", ())
+      "expected '}' to start a derivative function list", ())
 ERROR(sil_inst_autodiff_num_operand_list_order_mismatch,PointsToFirstBadToken,
       "the number of operand lists does not match the order", ())
 ERROR(sil_inst_autodiff_expected_associated_function_kind_attr,PointsToFirstBadToken,
-      "expected an associated function kind attribute, e.g. '[jvp]'", ())
+      "expected a derivative function kind attribute, e.g. '[jvp]'", ())
 ERROR(sil_inst_autodiff_expected_function_type_operand,PointsToFirstBadToken,
       "expected an operand of a function type", ())
 

include/swift/AST/DiagnosticsSema.def

@@ -2859,8 +2859,7 @@ ERROR(implements_attr_protocol_not_conformed_to,none,
 ERROR(differentiable_attr_void_result,none,
       "cannot differentiate void function %0", (DeclName))
 ERROR(differentiable_attr_associated_function_protocol,none,
-      "cannot specify associated differentiation function on protocol "
-      "requirement", ())
+      "cannot specify derivative functions on protocol requirements", ())
 ERROR(differentiable_attr_overload_not_found,none,
       "%0 does not have expected type %1", (DeclName, Type))
 ERROR(differentiable_attr_no_currying,none,
@@ -2874,17 +2873,17 @@ NOTE(differentiable_attr_duplicate_note,none,
 ERROR(differentiable_attr_function_not_same_type_context,none,
       "%0 is not defined in the current type context", (DeclName))
 ERROR(differentiable_attr_specified_not_function,none,
-      "%0 is not a function to be used as associated differentiation function",
+      "%0 is not a function to be used as derivative function",
       (DeclName))
 ERROR(differentiable_attr_class_derivative_not_final,none,
       "class member derivative must be final", ())
 ERROR(differentiable_attr_ambiguous_function_identifier,none,
       "ambiguous or overloaded identifier %0 cannot be used in '@differentiable' "
       "attribute", (DeclName))
 ERROR(differentiable_attr_invalid_access,none,
-      "associated differentiation function %0 is required to either be public "
-      "or @usableFromInline because the original function %1 is public or "
-      "@usableFromInline", (DeclName, DeclName))
+      "derivative function %0 is required to either be public or "
+      "'@usableFromInline' because the original function %1 is public or "
+      "'@usableFromInline'", (DeclName, DeclName))
 ERROR(differentiable_attr_result_not_differentiable,none,
       "can only differentiate functions with results that conform to "
       "'Differentiable', but %0 does not conform to 'Differentiable'", (Type))

include/swift/AST/Types.h

@@ -3100,10 +3100,10 @@ class AnyFunctionType : public TypeBase {
 
   // SWIFT_ENABLE_TENSORFLOW
   /// Given `indices` and `kind`, calculates the type of the corresponding
-  /// autodiff associated function.
+  /// autodiff derivative function.
   ///
   /// By default, if the original type has a self parameter list and parameter
-  /// indices include self, the computed associated function type will return a
+  /// indices include self, the computed derivative function type will return a
   /// linear map taking/returning self's tangent *last* instead of first, for
   /// consistency with SIL.
   ///
@@ -3114,18 +3114,18 @@ class AnyFunctionType : public TypeBase {
   /// \note The original function type (`self`) need not be `@differentiable`.
   /// The resulting function will preserve all `ExtInfo` of the original
   /// function, including `@differentiable`.
-  AnyFunctionType *getAutoDiffAssociatedFunctionType(
+  AnyFunctionType *getAutoDiffDerivativeFunctionType(
       AutoDiffIndexSubset *indices, unsigned resultIndex,
-      AutoDiffAssociatedFunctionKind kind,
+      AutoDiffDerivativeFunctionKind kind,
       LookupConformanceFn lookupConformance,
       GenericSignature *whereClauseGenericSignature = nullptr,
       bool makeSelfParamFirst = false);
 
-  /// Given the type of an autodiff associated function, returns the
+  /// Given the type of an autodiff derivative function, returns the
   /// corresponding original function type.
   AnyFunctionType *getAutoDiffOriginalFunctionType();
 
-  /// Given the type of a transposing associated function, returns the
+  /// Given the type of a transposing derivative function, returns the
   /// corresponding original function type.
   AnyFunctionType *
   getTransposeOriginalFunctionType(TransposingAttr *attr,
@@ -4222,11 +4222,11 @@ class SILFunctionType final : public TypeBase, public llvm::FoldingSetNode,
 
   /// Returns the type of a differentiation function that is associated with
   /// a function of this type.
-  CanSILFunctionType getAutoDiffAssociatedFunctionType(
+  CanSILFunctionType getAutoDiffDerivativeFunctionType(
       AutoDiffIndexSubset *parameterIndices, unsigned resultIndex,
-      AutoDiffAssociatedFunctionKind kind, Lowering::TypeConverter &TC,
+      AutoDiffDerivativeFunctionKind kind, Lowering::TypeConverter &TC,
       LookupConformanceFn lookupConformance,
-      CanGenericSignature associatedFunctionGenericSignature = nullptr);
+      CanGenericSignature derivativeFunctionGenericSignature = nullptr);
 
   /// Returns a bit vector that specifices which parameters you can
   /// differentiate with respect to for this differentiable function type. (e.g.

include/swift/SIL/SILCloner.h

@@ -973,7 +973,7 @@ void SILCloner<ImplClass>::visitDifferentiableFunctionInst(
   Optional<std::pair<SILValue, SILValue>> derivativeFns = None;
   if (Inst->hasDerivativeFunctions())
     derivativeFns = std::make_pair(getOpValue(Inst->getJVPFunction()),
-                              getOpValue(Inst->getVJPFunction()));
+                                   getOpValue(Inst->getVJPFunction()));
   recordClonedInstruction(
       Inst, getBuilder().createDifferentiableFunction(
                 getOpLocation(Inst->getLoc()), Inst->getParameterIndices(),