github.com/golangci/go-tools@v0.0.0-20190318060251-af6baa5dc196/functions/concrete.go (about)

     1  package functions
     2  
     3  import (
     4  	"go/token"
     5  	"go/types"
     6  
     7  	"github.com/golangci/go-tools/ssa"
     8  )
     9  
    10  func concreteReturnTypes(fn *ssa.Function) []*types.Tuple {
    11  	res := fn.Signature.Results()
    12  	if res == nil {
    13  		return nil
    14  	}
    15  	ifaces := make([]bool, res.Len())
    16  	any := false
    17  	for i := 0; i < res.Len(); i++ {
    18  		_, ifaces[i] = res.At(i).Type().Underlying().(*types.Interface)
    19  		any = any || ifaces[i]
    20  	}
    21  	if !any {
    22  		return []*types.Tuple{res}
    23  	}
    24  	var out []*types.Tuple
    25  	for _, block := range fn.Blocks {
    26  		if len(block.Instrs) == 0 {
    27  			continue
    28  		}
    29  		ret, ok := block.Instrs[len(block.Instrs)-1].(*ssa.Return)
    30  		if !ok {
    31  			continue
    32  		}
    33  		vars := make([]*types.Var, res.Len())
    34  		for i, v := range ret.Results {
    35  			var typ types.Type
    36  			if !ifaces[i] {
    37  				typ = res.At(i).Type()
    38  			} else if mi, ok := v.(*ssa.MakeInterface); ok {
    39  				// TODO(dh): if mi.X is a function call that returns
    40  				// an interface, call concreteReturnTypes on that
    41  				// function (or, really, go through Descriptions,
    42  				// avoid infinite recursion etc, just like nil error
    43  				// detection)
    44  
    45  				// TODO(dh): support Phi nodes
    46  				typ = mi.X.Type()
    47  			} else {
    48  				typ = res.At(i).Type()
    49  			}
    50  			vars[i] = types.NewParam(token.NoPos, nil, "", typ)
    51  		}
    52  		out = append(out, types.NewTuple(vars...))
    53  	}
    54  	// TODO(dh): deduplicate out
    55  	return out
    56  }