gotools/gopls/internal/golang/stubmethods/stubmethods.go

type IfaceStubInfo …

// GetIfaceStubInfo determines whether the "missing method error"
// can be used to deduced what the concrete and interface types are.
//
// TODO(adonovan): this function (and its following 5 helpers) tries
// to deduce a pair of (concrete, interface) types that are related by
// an assignment, either explicitly or through a return statement or
// function call. This is essentially what the refactor/satisfy does,
// more generally. Refactor to share logic, after auditing 'satisfy'
// for safety on ill-typed code.
func GetIfaceStubInfo(fset *token.FileSet, info *types.Info, path []ast.Node, pos token.Pos) *IfaceStubInfo { … }

// Emit writes to out the missing methods of si.Concrete required for it to implement si.Interface
func (si *IfaceStubInfo) Emit(out *bytes.Buffer, qual types.Qualifier) error { … }

// fromCallExpr tries to find an *ast.CallExpr's function declaration and
// analyzes a function call's signature against the passed in parameter to deduce
// the concrete and interface types.
func fromCallExpr(fset *token.FileSet, info *types.Info, pos token.Pos, call *ast.CallExpr) *IfaceStubInfo { … }

// fromReturnStmt analyzes a "return" statement to extract
// a concrete type that is trying to be returned as an interface type.
//
// For example, func() io.Writer { return myType{} }
// would return StubIfaceInfo with the interface being io.Writer and the concrete type being myType{}.
func fromReturnStmt(fset *token.FileSet, info *types.Info, pos token.Pos, path []ast.Node, ret *ast.ReturnStmt) (*IfaceStubInfo, error) { … }

// fromValueSpec returns *StubIfaceInfo from a variable declaration such as
// var x io.Writer = &T{}
func fromValueSpec(fset *token.FileSet, info *types.Info, spec *ast.ValueSpec, pos token.Pos) *IfaceStubInfo { … }

// fromAssignStmt returns *StubIfaceInfo from a variable assignment such as
// var x io.Writer
// x = &T{}
func fromAssignStmt(fset *token.FileSet, info *types.Info, assign *ast.AssignStmt, pos token.Pos) *IfaceStubInfo { … }

// ifaceType returns the named interface type to which e refers, if any.
func ifaceType(e ast.Expr, info *types.Info) *types.TypeName { … }

func ifaceObjFromType(t types.Type) *types.TypeName { … }

// concreteType tries to extract the *types.Named that defines
// the concrete type given the ast.Expr where the "missing method"
// or "conversion" errors happened. If the concrete type is something
// that cannot have methods defined on it (such as basic types), this
// method will return a nil *types.Named. The second return parameter
// is a boolean that indicates whether the concreteType was defined as a
// pointer or value.
func concreteType(e ast.Expr, info *types.Info) (*types.Named, bool) { … }

// enclosingFunction returns the signature and type of the function
// enclosing the given position.
func enclosingFunction(path []ast.Node, info *types.Info) *ast.FuncType { … }