wire: update internal functions to return []error (google/go-cloud#197)

This represents no functional change, it purely changes the signature
used for functions that can possibly return multiple errors. A
follow-up commit will change the control flow to proceed in the face
of errors.
This commit is contained in:
Ross Light
2018-07-13 08:51:43 -07:00
parent fda05073e3
commit a2540bae2a
3 changed files with 96 additions and 77 deletions

View File

@@ -79,11 +79,11 @@ type call struct {
// solve finds the sequence of calls required to produce an output type
// with an optional set of provided inputs.
func solve(fset *token.FileSet, out types.Type, given []types.Type, set *ProviderSet) ([]call, error) {
func solve(fset *token.FileSet, out types.Type, given []types.Type, set *ProviderSet) ([]call, []error) {
for i, g := range given {
for _, h := range given[:i] {
if types.Identical(g, h) {
return nil, fmt.Errorf("multiple inputs of the same type %s", types.TypeString(g, nil))
return nil, []error{fmt.Errorf("multiple inputs of the same type %s", types.TypeString(g, nil))}
}
}
}
@@ -95,11 +95,11 @@ func solve(fset *token.FileSet, out types.Type, given []types.Type, set *Provide
if pv := set.For(g); !pv.IsNil() {
switch {
case pv.IsProvider():
return nil, fmt.Errorf("input of %s conflicts with provider %s at %s",
types.TypeString(g, nil), pv.Provider().Name, fset.Position(pv.Provider().Pos))
return nil, []error{fmt.Errorf("input of %s conflicts with provider %s at %s",
types.TypeString(g, nil), pv.Provider().Name, fset.Position(pv.Provider().Pos))}
case pv.IsValue():
return nil, fmt.Errorf("input of %s conflicts with value at %s",
types.TypeString(g, nil), fset.Position(pv.Value().Pos))
return nil, []error{fmt.Errorf("input of %s conflicts with value at %s",
types.TypeString(g, nil), fset.Position(pv.Value().Pos))}
default:
panic("unknown return value from ProviderSet.For")
}
@@ -126,10 +126,10 @@ func solve(fset *token.FileSet, out types.Type, given []types.Type, set *Provide
switch pv := set.For(curr.t); {
case pv.IsNil():
if curr.from == nil {
return nil, fmt.Errorf("no provider found for %s (output of injector)", types.TypeString(curr.t, nil))
return nil, []error{fmt.Errorf("no provider found for %s (output of injector)", types.TypeString(curr.t, nil))}
}
// TODO(light): Give name of provider.
return nil, fmt.Errorf("no provider found for %s (required by provider of %s)", types.TypeString(curr.t, nil), types.TypeString(curr.from, nil))
return nil, []error{fmt.Errorf("no provider found for %s (required by provider of %s)", types.TypeString(curr.t, nil), types.TypeString(curr.from, nil))}
case pv.IsProvider():
p := pv.Provider()
if !types.Identical(p.Out, curr.t) {
@@ -210,7 +210,7 @@ func solve(fset *token.FileSet, out types.Type, given []types.Type, set *Provide
// buildProviderMap creates the providerMap field for a given provider set.
// The given provider set's providerMap field is ignored.
func buildProviderMap(fset *token.FileSet, hasher typeutil.Hasher, set *ProviderSet) (*typeutil.Map, error) {
func buildProviderMap(fset *token.FileSet, hasher typeutil.Hasher, set *ProviderSet) (*typeutil.Map, []error) {
providerMap := new(typeutil.Map)
providerMap.SetHasher(hasher)
setMap := new(typeutil.Map) // to *ProviderSet, for error messages
@@ -220,7 +220,7 @@ func buildProviderMap(fset *token.FileSet, hasher typeutil.Hasher, set *Provider
for _, imp := range set.Imports {
for _, k := range imp.providerMap.Keys() {
if providerMap.At(k) != nil {
return nil, bindingConflictError(fset, imp.Pos, k, setMap.At(k).(*ProviderSet))
return nil, []error{bindingConflictError(fset, imp.Pos, k, setMap.At(k).(*ProviderSet))}
}
providerMap.Set(k, imp.providerMap.At(k))
setMap.Set(k, imp)
@@ -230,14 +230,14 @@ func buildProviderMap(fset *token.FileSet, hasher typeutil.Hasher, set *Provider
// Process non-binding providers in new set.
for _, p := range set.Providers {
if providerMap.At(p.Out) != nil {
return nil, bindingConflictError(fset, p.Pos, p.Out, setMap.At(p.Out).(*ProviderSet))
return nil, []error{bindingConflictError(fset, p.Pos, p.Out, setMap.At(p.Out).(*ProviderSet))}
}
providerMap.Set(p.Out, p)
setMap.Set(p.Out, set)
}
for _, v := range set.Values {
if providerMap.At(v.Out) != nil {
return nil, bindingConflictError(fset, v.Pos, v.Out, setMap.At(v.Out).(*ProviderSet))
return nil, []error{bindingConflictError(fset, v.Pos, v.Out, setMap.At(v.Out).(*ProviderSet))}
}
providerMap.Set(v.Out, v)
setMap.Set(v.Out, set)
@@ -247,13 +247,13 @@ func buildProviderMap(fset *token.FileSet, hasher typeutil.Hasher, set *Provider
// ensure the concrete type is being provided.
for _, b := range set.Bindings {
if providerMap.At(b.Iface) != nil {
return nil, bindingConflictError(fset, b.Pos, b.Iface, setMap.At(b.Iface).(*ProviderSet))
return nil, []error{bindingConflictError(fset, b.Pos, b.Iface, setMap.At(b.Iface).(*ProviderSet))}
}
concrete := providerMap.At(b.Provided)
if concrete == nil {
pos := fset.Position(b.Pos)
typ := types.TypeString(b.Provided, nil)
return nil, fmt.Errorf("%v: no binding for %s", pos, typ)
return nil, []error{fmt.Errorf("%v: no binding for %s", pos, typ)}
}
providerMap.Set(b.Iface, concrete)
setMap.Set(b.Iface, set)
@@ -261,7 +261,7 @@ func buildProviderMap(fset *token.FileSet, hasher typeutil.Hasher, set *Provider
return providerMap, nil
}
func verifyAcyclic(providerMap *typeutil.Map, hasher typeutil.Hasher) error {
func verifyAcyclic(providerMap *typeutil.Map, hasher typeutil.Hasher) []error {
// We must visit every provider type inside provider map, but we don't
// have a well-defined starting point and there may be several
// distinct graphs. Thus, we start a depth-first search at every
@@ -297,7 +297,7 @@ func verifyAcyclic(providerMap *typeutil.Map, hasher typeutil.Hasher) error {
fmt.Fprintf(sb, "%s (%s.%s) ->\n", types.TypeString(curr[j], nil), p.ImportPath, p.Name)
}
fmt.Fprintf(sb, "%s\n", types.TypeString(a, nil))
return errors.New(sb.String())
return []error{errors.New(sb.String())}
}
}
next := append(append([]types.Type(nil), curr...), a)

View File

@@ -207,7 +207,7 @@ func (id ProviderSetID) String() string {
// objectCache is a lazily evaluated mapping of objects to Wire structures.
type objectCache struct {
prog *loader.Program
objects map[objRef]interface{} // *Provider, *ProviderSet, *IfaceBinding, or *Value
objects map[objRef]objCacheEntry
hasher typeutil.Hasher
}
@@ -216,10 +216,15 @@ type objRef struct {
name string
}
type objCacheEntry struct {
val interface{} // *Provider, *ProviderSet, *IfaceBinding, or *Value
errs []error
}
func newObjectCache(prog *loader.Program) *objectCache {
return &objectCache{
prog: prog,
objects: make(map[objRef]interface{}),
objects: make(map[objRef]objCacheEntry),
hasher: typeutil.MakeHasher(),
}
}
@@ -227,22 +232,25 @@ func newObjectCache(prog *loader.Program) *objectCache {
// get converts a Go object into a Wire structure. It may return a
// *Provider, a structProviderPair, an *IfaceBinding, a *ProviderSet,
// or a *Value.
func (oc *objectCache) get(obj types.Object) (interface{}, error) {
func (oc *objectCache) get(obj types.Object) (val interface{}, errs []error) {
ref := objRef{
importPath: obj.Pkg().Path(),
name: obj.Name(),
}
if val, cached := oc.objects[ref]; cached {
if val == nil {
return nil, fmt.Errorf("%v is not a provider or a provider set", obj)
}
return val, nil
if ent, cached := oc.objects[ref]; cached {
return ent.val, append([]error(nil), ent.errs...)
}
defer func() {
oc.objects[ref] = objCacheEntry{
val: val,
errs: append([]error(nil), errs...),
}
}()
switch obj := obj.(type) {
case *types.Var:
spec := oc.varDecl(obj)
if len(spec.Values) == 0 {
return nil, fmt.Errorf("%v is not a provider or a provider set", obj)
return nil, []error{fmt.Errorf("%v is not a provider or a provider set", obj)}
}
var i int
for i = range spec.Names {
@@ -252,16 +260,9 @@ func (oc *objectCache) get(obj types.Object) (interface{}, error) {
}
return oc.processExpr(oc.prog.Package(obj.Pkg().Path()), spec.Values[i])
case *types.Func:
p, err := processFuncProvider(oc.prog.Fset, obj)
if err != nil {
oc.objects[ref] = nil
return nil, err
}
oc.objects[ref] = p
return p, nil
return processFuncProvider(oc.prog.Fset, obj)
default:
oc.objects[ref] = nil
return nil, fmt.Errorf("%v is not a provider or a provider set", obj)
return nil, []error{fmt.Errorf("%v is not a provider or a provider set", obj)}
}
}
@@ -288,55 +289,63 @@ func (oc *objectCache) varDecl(obj *types.Var) *ast.ValueSpec {
// processExpr converts an expression into a Wire structure. It may
// return a *Provider, a structProviderPair, an *IfaceBinding, a
// *ProviderSet, or a *Value.
func (oc *objectCache) processExpr(pkg *loader.PackageInfo, expr ast.Expr) (interface{}, error) {
func (oc *objectCache) processExpr(pkg *loader.PackageInfo, expr ast.Expr) (interface{}, []error) {
exprPos := oc.prog.Fset.Position(expr.Pos())
expr = astutil.Unparen(expr)
if obj := qualifiedIdentObject(&pkg.Info, expr); obj != nil {
item, err := oc.get(obj)
if err != nil {
return nil, fmt.Errorf("%v: %v", exprPos, err)
return nil, []error{fmt.Errorf("%v: %v", exprPos, err)}
}
return item, nil
}
if call, ok := expr.(*ast.CallExpr); ok {
fnObj := qualifiedIdentObject(&pkg.Info, call.Fun)
if fnObj == nil || !isWireImport(fnObj.Pkg().Path()) {
return nil, fmt.Errorf("%v: unknown pattern", exprPos)
return nil, []error{fmt.Errorf("%v: unknown pattern", exprPos)}
}
switch fnObj.Name() {
case "NewSet":
pset, err := oc.processNewSet(pkg, call)
if err != nil {
return nil, fmt.Errorf("%v: %v", exprPos, err)
pset, errs := oc.processNewSet(pkg, call)
if len(errs) > 0 {
errs = append([]error(nil), errs...)
for i := range errs {
errs[i] = fmt.Errorf("%v: %v", exprPos, errs[i])
}
return nil, errs
}
return pset, nil
case "Bind":
b, err := processBind(oc.prog.Fset, &pkg.Info, call)
if err != nil {
return nil, fmt.Errorf("%v: %v", exprPos, err)
return nil, []error{fmt.Errorf("%v: %v", exprPos, err)}
}
return b, nil
case "Value":
v, err := processValue(oc.prog.Fset, &pkg.Info, call)
if err != nil {
return nil, fmt.Errorf("%v: %v", exprPos, err)
return nil, []error{fmt.Errorf("%v: %v", exprPos, err)}
}
return v, nil
default:
return nil, fmt.Errorf("%v: unknown pattern", exprPos)
return nil, []error{fmt.Errorf("%v: unknown pattern", exprPos)}
}
}
if tn := structArgType(&pkg.Info, expr); tn != nil {
p, err := processStructProvider(oc.prog.Fset, tn)
if err != nil {
return nil, fmt.Errorf("%v: %v", exprPos, err)
p, errs := processStructProvider(oc.prog.Fset, tn)
if len(errs) > 0 {
errs = append([]error(nil), errs...)
for i := range errs {
errs[i] = fmt.Errorf("%v: %v", exprPos, errs[i])
}
return nil, errs
}
ptrp := new(Provider)
*ptrp = *p
ptrp.Out = types.NewPointer(p.Out)
return structProviderPair{p, ptrp}, nil
}
return nil, fmt.Errorf("%v: unknown pattern", exprPos)
return nil, []error{fmt.Errorf("%v: unknown pattern", exprPos)}
}
type structProviderPair struct {
@@ -344,7 +353,7 @@ type structProviderPair struct {
ptrProvider *Provider
}
func (oc *objectCache) processNewSet(pkg *loader.PackageInfo, call *ast.CallExpr) (*ProviderSet, error) {
func (oc *objectCache) processNewSet(pkg *loader.PackageInfo, call *ast.CallExpr) (*ProviderSet, []error) {
// Assumes that call.Fun is wire.NewSet or wire.Build.
pset := &ProviderSet{
@@ -371,13 +380,13 @@ func (oc *objectCache) processNewSet(pkg *loader.PackageInfo, call *ast.CallExpr
panic("unknown item type")
}
}
var err error
pset.providerMap, err = buildProviderMap(oc.prog.Fset, oc.hasher, pset)
if err != nil {
return nil, err
var errs []error
pset.providerMap, errs = buildProviderMap(oc.prog.Fset, oc.hasher, pset)
if len(errs) > 0 {
return nil, errs
}
if err := verifyAcyclic(pset.providerMap, oc.hasher); err != nil {
return nil, err
if errs := verifyAcyclic(pset.providerMap, oc.hasher); len(errs) > 0 {
return nil, errs
}
return pset, nil
}
@@ -420,12 +429,12 @@ func qualifiedIdentObject(info *types.Info, expr ast.Expr) types.Object {
}
// processFuncProvider creates a provider for a function declaration.
func processFuncProvider(fset *token.FileSet, fn *types.Func) (*Provider, error) {
func processFuncProvider(fset *token.FileSet, fn *types.Func) (*Provider, []error) {
sig := fn.Type().(*types.Signature)
fpos := fn.Pos()
providerSig, err := funcOutput(sig)
if err != nil {
return nil, fmt.Errorf("%v: wrong signature for provider %s: %v", fset.Position(fpos), fn.Name(), err)
return nil, []error{fmt.Errorf("%v: wrong signature for provider %s: %v", fset.Position(fpos), fn.Name(), err)}
}
params := sig.Params()
provider := &Provider{
@@ -443,7 +452,7 @@ func processFuncProvider(fset *token.FileSet, fn *types.Func) (*Provider, error)
}
for j := 0; j < i; j++ {
if types.Identical(provider.Args[i].Type, provider.Args[j].Type) {
return nil, fmt.Errorf("%v: provider has multiple parameters of type %s", fset.Position(fpos), types.TypeString(provider.Args[j].Type, nil))
return nil, []error{fmt.Errorf("%v: provider has multiple parameters of type %s", fset.Position(fpos), types.TypeString(provider.Args[j].Type, nil))}
}
}
}
@@ -493,11 +502,11 @@ func funcOutput(sig *types.Signature) (outputSignature, error) {
// processStructProvider creates a provider for a named struct type.
// It only produces the non-pointer variant.
func processStructProvider(fset *token.FileSet, typeName *types.TypeName) (*Provider, error) {
func processStructProvider(fset *token.FileSet, typeName *types.TypeName) (*Provider, []error) {
out := typeName.Type()
st, ok := out.Underlying().(*types.Struct)
if !ok {
return nil, fmt.Errorf("%v does not name a struct", typeName)
return nil, []error{fmt.Errorf("%v does not name a struct", typeName)}
}
pos := typeName.Pos()
@@ -518,7 +527,7 @@ func processStructProvider(fset *token.FileSet, typeName *types.TypeName) (*Prov
provider.Fields[i] = f.Name()
for j := 0; j < i; j++ {
if types.Identical(provider.Args[i].Type, provider.Args[j].Type) {
return nil, fmt.Errorf("%v: provider struct has multiple fields of type %s", fset.Position(pos), types.TypeString(provider.Args[j].Type, nil))
return nil, []error{fmt.Errorf("%v: provider struct has multiple fields of type %s", fset.Position(pos), types.TypeString(provider.Args[j].Type, nil))}
}
}
}

View File

@@ -80,9 +80,9 @@ func Generate(bctx *build.Context, wd string, pkg string) ([]byte, []error) {
}
pkgInfo := prog.InitialPackages()[0]
g := newGen(prog, pkgInfo.Pkg.Path())
injectorFiles, err := generateInjectors(g, pkgInfo)
if err != nil {
return nil, []error{err}
injectorFiles, errs := generateInjectors(g, pkgInfo)
if len(errs) > 0 {
return nil, errs
}
copyNonInjectorDecls(g, injectorFiles, &pkgInfo.Info)
goSrc := g.frame()
@@ -96,7 +96,7 @@ func Generate(bctx *build.Context, wd string, pkg string) ([]byte, []error) {
}
// generateInjectors generates the injectors for a given package.
func generateInjectors(g *gen, pkgInfo *loader.PackageInfo) (injectorFiles []*ast.File, _ error) {
func generateInjectors(g *gen, pkgInfo *loader.PackageInfo) (injectorFiles []*ast.File, _ []error) {
oc := newObjectCache(g.prog)
injectorFiles = make([]*ast.File, 0, len(pkgInfo.Files))
for _, f := range pkgInfo.Files {
@@ -116,13 +116,23 @@ func generateInjectors(g *gen, pkgInfo *loader.PackageInfo) (injectorFiles []*as
g.p("// Injectors from %s:\n\n", name)
injectorFiles = append(injectorFiles, f)
}
set, err := oc.processNewSet(pkgInfo, buildCall)
if err != nil {
return nil, fmt.Errorf("%v: %v", g.prog.Fset.Position(fn.Pos()), err)
set, errs := oc.processNewSet(pkgInfo, buildCall)
if len(errs) > 0 {
position := g.prog.Fset.Position(fn.Pos())
errs = append([]error(nil), errs...)
for i := range errs {
errs[i] = fmt.Errorf("%v: %v", position, errs[i])
}
return nil, errs
}
sig := pkgInfo.ObjectOf(fn.Name).Type().(*types.Signature)
if err := g.inject(fn.Name.Name, sig, set); err != nil {
return nil, fmt.Errorf("%v: %v", g.prog.Fset.Position(fn.Pos()), err)
if errs := g.inject(fn.Name.Name, sig, set); len(errs) > 0 {
position := g.prog.Fset.Position(fn.Pos())
errs = append([]error(nil), errs...)
for i := range errs {
errs[i] = fmt.Errorf("%v: %v", position, errs[i])
}
return nil, errs
}
}
}
@@ -208,19 +218,19 @@ func (g *gen) frame() []byte {
}
// inject emits the code for an injector.
func (g *gen) inject(name string, sig *types.Signature, set *ProviderSet) error {
func (g *gen) inject(name string, sig *types.Signature, set *ProviderSet) []error {
injectSig, err := funcOutput(sig)
if err != nil {
return fmt.Errorf("inject %s: %v", name, err)
return []error{fmt.Errorf("inject %s: %v", name, err)}
}
params := sig.Params()
given := make([]types.Type, params.Len())
for i := 0; i < params.Len(); i++ {
given[i] = params.At(i).Type()
}
calls, err := solve(g.prog.Fset, injectSig.out, given, set)
if err != nil {
return err
calls, errs := solve(g.prog.Fset, injectSig.out, given, set)
if len(errs) > 0 {
return errs
}
type pendingVar struct {
name string
@@ -231,16 +241,16 @@ func (g *gen) inject(name string, sig *types.Signature, set *ProviderSet) error
for i := range calls {
c := &calls[i]
if c.hasCleanup && !injectSig.cleanup {
return fmt.Errorf("inject %s: provider for %s returns cleanup but injection does not return cleanup function", name, types.TypeString(c.out, nil))
return []error{fmt.Errorf("inject %s: provider for %s returns cleanup but injection does not return cleanup function", name, types.TypeString(c.out, nil))}
}
if c.hasErr && !injectSig.err {
return fmt.Errorf("inject %s: provider for %s returns error but injection not allowed to fail", name, types.TypeString(c.out, nil))
return []error{fmt.Errorf("inject %s: provider for %s returns error but injection not allowed to fail", name, types.TypeString(c.out, nil))}
}
if c.kind == valueExpr {
if err := accessibleFrom(c.valueTypeInfo, c.valueExpr, g.currPackage); err != nil {
// TODO(light): Display line number of value expression.
ts := types.TypeString(c.out, nil)
return fmt.Errorf("inject %s: value %s can't be used: %v", name, ts, err)
return []error{fmt.Errorf("inject %s: value %s can't be used: %v", name, ts, err)}
}
if g.values[c.valueExpr] == "" {
t := c.valueTypeInfo.TypeOf(c.valueExpr)