func checkVarValue(t *testing.T, prog *ssa.Program, pkg *ssa.Package, ref []ast.Node, obj *types.Var, expKind string, wantAddr bool) {
// The prefix of all assertions messages.
prefix := fmt.Sprintf("VarValue(%s @ L%d)",
obj, prog.Fset.Position(ref[0].Pos()).Line)
v := prog.VarValue(obj, pkg, ref)
// Kind is the concrete type of the ssa Value.
gotKind := "nil"
if v != nil {
gotKind = fmt.Sprintf("%T", v)[len("*ssa."):]
}
// fmt.Printf("%s = %v (kind %q; expect %q) addr=%t\n", prefix, v, gotKind, expKind, wantAddr) // debugging
// Check the kinds match.
// "nil" indicates expected failure (e.g. optimized away).
if expKind != gotKind {
t.Errorf("%s concrete type == %s, want %s", prefix, gotKind, expKind)
}
// Check the types match.
// If wantAddr, the expected type is the object's address.
if v != nil {
expType := obj.Type()
if wantAddr {
expType = types.NewPointer(expType)
}
if !types.IsIdentical(v.Type(), expType) {
t.Errorf("%s.Type() == %s, want %s", prefix, v.Type(), expType)
}
}
}
// ssaValueForIdent returns the ssa.Value for the ast.Ident whose path
// to the root of the AST is path. isAddr reports whether the
// ssa.Value is the address denoted by the ast.Ident, not its value.
//
func ssaValueForIdent(prog *ssa.Program, qinfo *importer.PackageInfo, obj types.Object, path []ast.Node) (value ssa.Value, isAddr bool, err error) {
switch obj := obj.(type) {
case *types.Var:
pkg := prog.Package(qinfo.Pkg)
pkg.Build()
if v, addr := prog.VarValue(obj, pkg, path); v != nil {
return v, addr, nil
}
return nil, false, fmt.Errorf("can't locate SSA Value for var %s", obj.Name())
case *types.Func:
return prog.FuncValue(obj), false, nil
}
panic(obj)
}
// ssaValueForIdent returns the ssa.Value for the ast.Ident whose path
// to the root of the AST is path. It may return a nil Value without
// an error to indicate the pointer analysis is not appropriate.
//
func ssaValueForIdent(prog *ssa.Program, qinfo *importer.PackageInfo, obj types.Object, path []ast.Node) (ssa.Value, error) {
if obj, ok := obj.(*types.Var); ok {
pkg := prog.Package(qinfo.Pkg)
pkg.Build()
if v := prog.VarValue(obj, pkg, path); v != nil {
// Don't run pointer analysis on a ref to a const expression.
if _, ok := v.(*ssa.Const); ok {
v = nil
}
return v, nil
}
return nil, fmt.Errorf("can't locate SSA Value for var %s", obj.Name())
}
// Don't run pointer analysis on const/func objects.
return nil, nil
}
