go/src/reflect/makefunc.go

type makeFuncImpl …

// MakeFunc returns a new function of the given [Type]
// that wraps the function fn. When called, that new function
// does the following:
//
//   - converts its arguments to a slice of Values.
//   - runs results := fn(args).
//   - returns the results as a slice of Values, one per formal result.
//
// The implementation fn can assume that the argument [Value] slice
// has the number and type of arguments given by typ.
// If typ describes a variadic function, the final Value is itself
// a slice representing the variadic arguments, as in the
// body of a variadic function. The result Value slice returned by fn
// must have the number and type of results given by typ.
//
// The [Value.Call] method allows the caller to invoke a typed function
// in terms of Values; in contrast, MakeFunc allows the caller to implement
// a typed function in terms of Values.
//
// The Examples section of the documentation includes an illustration
// of how to use MakeFunc to build a swap function for different types.
func MakeFunc(typ Type, fn func(args []Value) (results []Value)) Value { … }

// makeFuncStub is an assembly function that is the code half of
// the function returned from MakeFunc. It expects a *callReflectFunc
// as its context register, and its job is to invoke callReflect(ctxt, frame)
// where ctxt is the context register and frame is a pointer to the first
// word in the passed-in argument frame.
func makeFuncStub()

type methodValue …

// makeMethodValue converts v from the rcvr+method index representation
// of a method value to an actual method func value, which is
// basically the receiver value with a special bit set, into a true
// func value - a value holding an actual func. The output is
// semantically equivalent to the input as far as the user of package
// reflect can tell, but the true func representation can be handled
// by code like Convert and Interface and Assign.
func makeMethodValue(op string, v Value) Value { … }

func methodValueCallCodePtr() uintptr { … }

// methodValueCall is an assembly function that is the code half of
// the function returned from makeMethodValue. It expects a *methodValue
// as its context register, and its job is to invoke callMethod(ctxt, frame)
// where ctxt is the context register and frame is a pointer to the first
// word in the passed-in argument frame.
func methodValueCall()

type makeFuncCtxt …

// moveMakeFuncArgPtrs uses ctxt.regPtrs to copy integer pointer arguments
// in args.Ints to args.Ptrs where the GC can see them.
//
// This is similar to what reflectcallmove does in the runtime, except
// that happens on the return path, whereas this happens on the call path.
//
// nosplit because pointers are being held in uintptr slots in args, so
// having our stack scanned now could lead to accidentally freeing
// memory.
//
//go:nosplit
func moveMakeFuncArgPtrs(ctxt *makeFuncCtxt, args *abi.RegArgs) { … }