| package analysis |
| |
| import ( |
| "go/ast" |
| "go/constant" |
| "go/token" |
| "go/types" |
| ) |
| |
| func BoolValue(expr ast.Expr, info *types.Info) (bool, bool) { |
| v := info.Types[expr].Value |
| if v != nil && v.Kind() == constant.Bool { |
| return constant.BoolVal(v), true |
| } |
| switch e := expr.(type) { |
| case *ast.BinaryExpr: |
| switch e.Op { |
| case token.LAND: |
| if b, ok := BoolValue(e.X, info); ok { |
| if !b { |
| return false, true |
| } |
| return BoolValue(e.Y, info) |
| } |
| case token.LOR: |
| if b, ok := BoolValue(e.X, info); ok { |
| if b { |
| return true, true |
| } |
| return BoolValue(e.Y, info) |
| } |
| } |
| case *ast.UnaryExpr: |
| if e.Op == token.NOT { |
| if b, ok := BoolValue(e.X, info); ok { |
| return !b, true |
| } |
| } |
| case *ast.ParenExpr: |
| return BoolValue(e.X, info) |
| } |
| return false, false |
| } |
