[THRIFT-3051] Go Thrift generator creates bad go code

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9.2
• Fix Version/s: 0.9.3
• Component/s: Go - Compiler

Environment

Mac OS X 10.10.2
Thrift 0.9.2 installed via homebrew, and Thrift HEAD (identifies as 1.0.0-dev) installed via homebrew

• Assignee: Jake Farrell
• Reporter: Silas Snider
• Created: 26/Mar/15 17:52
• Updated: 20/Feb/21 15:28
• Resolved: 15/Sep/15 19:47

Description

Motivation

I was attempting to build a go tool that used the Apache Aurora thrift interface, only to be stymied because thrift generates invalid code for the current api.thrift interface. (found under api/src/main/thrift/org/apache/aurora/gen/api.thrift)

Steps to replicate

1. Create a thrift file called test.thrift containing the text:
   test.thrift

   struct Option1 {
   }
   
   struct Option2 {
     1: optional string name
   }
   
   union Descendant {
     1: Option1 option1
     2: Option2 option2
   }
   
   struct TestStruct {
     1: optional Descendant descendant = { "option1": {}}
   }
   

2. Run thrift -o somedir -r --gen go test.thrift

Expected Result

The command indicates success, and the somedir directory contains a tree of go code that successfully compiles.

Actual Result

The above command outputs

/somedir/gen-go//test/ttypes.go:317:6: expected '}', found ':='
/somedir/gen-go//test/ttypes.go:318:3: expected declaration, found 'IDENT' descendant
WARNING - Running 'gofmt -w /somedir/gen-go//test/ttypes.go' failed.

The code fails to compile with similar errors. On inspection, it appears that the go compiler outputs

ttypes.go

var TestStruct_Descendant_DEFAULT *Descendant = &Descendant{
  v1 := &Option1{}
  descendant.Option1 = v1}

which is entirely incorrect. This code should instead be

ttypes.go

var TestStruct_Descendant_DEFAULT *Descendant = &Descendant{
 Option1: &Option1{}}

When this change is made, the compilation succeeds.