New go generator shakedown.

mojom/generators/go/templates/decoding.go

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package templates
 
 import (
         "text/template"
 )
 
+const ampersandIfNullable = `
+{{- define "AmpersandIfNullable" -}}

[vardhan, 2016/06/22 15:17:15]

haha

+{{- $info := . -}}
+{{- if $info.IsNullable -}}
+&
+{{- end -}}
+{{- end -}}
+`
+
 const fieldDecodingTmplText = `
 {{- define "FieldDecodingTmpl" -}}
 {{- $info := . -}}
 {{- if $info.IsPointer -}}
 pointer, err := decoder.ReadPointer()
 if err != nil {
         return err
 }
 if pointer == 0 {
 {{- if $info.IsNullable}}
         {{$info.Identifier}} = nil
 {{- else if $info.IsUnion}}
         return &bindings.ValidationError{bindings.UnexpectedNullPointer, "unexpected null union pointer"}
 {{- else}}
         return &bindings.ValidationError{bindings.UnexpectedNullPointer, "unexpected null pointer"}
 {{- end }}
 } else {
         {{ template "NonNullableFieldDecodingTmpl" $info }}
 }
 {{- else -}}
 {{ template "NonNullableFieldDecodingTmpl" $info }}
 {{- end -}}
 {{- end -}}
 `
 
 const nonNullableFieldDecodingTmplText = `
 {{- define "NonNullableFieldDecodingTmpl" -}}
 {{- $info := . -}}

[vardhan, 2016/06/22 15:17:15]

sorry for not mentioning earlier, but it might help a lot for future
contributors if you mentioned what go type the `.` is expecting, in a comment.
And similarly for other Tmpls as well.

feel free to address this in a future CL though

 {{- if or $info.IsEnum $info.IsSimple -}}
 value, err := decoder.{{$info.ReadFunction}}()
 if err != nil {
         return err
 }
 {{if $info.IsSimple -}}
 {{$info.Identifier}} = value
 {{- else -}}
 {{$info.Identifier}} = {{$info.GoType}}(value)
 {{- end -}}
@@ skipping 32 matching lines @@
         return err
 }
 {{- if not $info.IsNullable}}
 if {{$info.Identifier}} == nil {
         return &bindings.ValidationError{bindings.UnexpectedNullUnion, "unexpected null union"}
 }
 {{- end -}}
 {{- if $info.IsPointer}}
 decoder.Finish()
 {{- end -}}
+{{- else if $info.IsInterface -}}
+handle, err := decoder.{{$info.ReadFunction}}()
+if err != nil {
+        return err
+}
+if handle.IsValid() {
+        handleOwner := bindings.NewMessagePipeHandleOwner(handle)
+{{- if $info.IsInterfaceRequest}}
+        {{$info.Identifier}} = {{template "AmpersandIfNullable" $info}}{{$info.GoType}}_Request{handleOwner}
+{{- else}}
+        {{$info.Identifier}} = {{template "AmpersandIfNullable" $info}}{{$info.GoType}}_Pointer{handleOwner}
+{{- end -}}
+} else {
+{{- if $info.IsNullable}}
+        {{$info.Identifier}} = nil
+{{- else}}
+        return &bindings.ValidationError{bindings.UnexpectedInvalidHandle, "unexpected invalid handle"}
+{{- end -}}
+}
 {{- else if $info.IsArray -}}
 {{ $elInfo := $info.ElementEncodingInfo -}}
 len0, err := decoder.StartArray({{$elInfo.BitSize}})
 if err != nil {
         return err
 }
 {{$info.Identifier}} = make({{$info.GoType}}, len0)
 for i := uint32(0); i < len0; i++ {
         {{ template "FieldDecodingTmpl" $elInfo }}
         {{$info.Identifier}}[i] = {{$elInfo.Identifier}}
@@ skipping 29 matching lines @@
 for i := 0; i < len({{$keyInfo.Identifier}}); i++ {
         (*{{$info.Identifier}})[{{$keyInfo.Identifier}}[i]] = {{$valueInfo.Identifier}}[i]
 }
 {{- end -}}
 {{- end -}}
 `
 
 func initDecodingTemplates() {
         template.Must(goFileTmpl.Parse(nonNullableFieldDecodingTmplText))
         template.Must(goFileTmpl.Parse(fieldDecodingTmplText))
+        template.Must(goFileTmpl.Parse(ampersandIfNullable))
 }