Revert "go/printer: support for printing alias declarations"

This reverts commit 59c63c711c73f3872c3047c2e80debba5ff1b802.

Reason: Decision to back out current alias implementation.

For #16339.

Change-Id: Idd135fe84b7ce4814cb3632f717736fc6985634c
Reviewed-on: https://go-review.googlesource.com/32822
Reviewed-by: Chris Manghane <cmang@golang.org>

diff --git a/src/go/printer/nodes.go b/src/go/printer/nodes.go
index 4e5cd1e20bf38b5388fcb399fd2a5b6d895e6653..11f26d45ea39429afb6eed2f4ee03588812dbaf5 100644 (file)
--- a/src/go/printer/nodes.go
+++ b/src/go/printer/nodes.go
@@ -1309,26 +1309,13 @@ func keepTypeColumn(specs []ast.Spec) []bool {
                }
        }
 
-       i0 := -1          // if i0 >= 0 we are in a run and i0 is the start of the run
-       var keepType bool // valid if we are in a run (i0 >= 0)
+       i0 := -1 // if i0 >= 0 we are in a run and i0 is the start of the run
+       var keepType bool
        for i, s := range specs {
-               var hasValues, hasType bool
-               switch t := s.(type) {
-               case *ast.AliasSpec:
-                       // like a ValueSpec with values (alias origin), but no type
-                       hasValues = true
-
-               case *ast.ValueSpec:
-                       hasValues = len(t.Values) > 0
-                       hasType = t.Type != nil
-
-               default:
-                       panic("internal error: unexpected ast.Spec")
-               }
-
-               if hasValues {
+               t := s.(*ast.ValueSpec)
+               if t.Values != nil {
                        if i0 < 0 {
-                               // start of a run with values
+                               // start of a run of ValueSpecs with non-nil Values
                                i0 = i
                                keepType = false
                        }
@@ -1339,7 +1326,7 @@ func keepTypeColumn(specs []ast.Spec) []bool {
                                i0 = -1
                        }
                }
-               if hasType {
+               if t.Type != nil {
                        keepType = true
                }
        }
@@ -1351,25 +1338,6 @@ func keepTypeColumn(specs []ast.Spec) []bool {
        return m
 }
 
-func (p *printer) aliasSpec(s *ast.AliasSpec, keepTypeCol bool) {
-       p.setComment(s.Doc)
-       p.expr(s.Name)
-       extraTabs := 3
-       if keepTypeCol {
-               p.print(vtab)
-               extraTabs--
-       }
-       p.print(vtab, token.ALIAS, blank)
-       p.expr(s.Orig)
-       extraTabs--
-       if s.Comment != nil {
-               for ; extraTabs > 0; extraTabs-- {
-                       p.print(vtab)
-               }
-               p.setComment(s.Comment)
-       }
-}
-
 func (p *printer) valueSpec(s *ast.ValueSpec, keepType bool) {
        p.setComment(s.Doc)
        p.identList(s.Names, false) // always present
@@ -1453,17 +1421,6 @@ func (p *printer) spec(spec ast.Spec, n int, doIndent bool) {
                p.setComment(s.Comment)
                p.print(s.EndPos)
 
-       case *ast.AliasSpec:
-               p.setComment(s.Doc)
-               p.expr(s.Name)
-               if n == 1 {
-                       p.print(blank)
-               } else {
-                       p.print(vtab)
-               }
-               p.print(token.ALIAS, blank)
-               p.expr(s.Orig)
-
        case *ast.ValueSpec:
                if n != 1 {
                        p.internalError("expected n = 1; got", n)
@@ -1515,16 +1472,7 @@ func (p *printer) genDecl(d *ast.GenDecl) {
                                                p.linebreak(p.lineFor(s.Pos()), 1, ignore, p.linesFrom(line) > 0)
                                        }
                                        p.recordLine(&line)
-                                       switch t := s.(type) {
-                                       case *ast.AliasSpec:
-                                               p.aliasSpec(t, keepType[i])
-
-                                       case *ast.ValueSpec:
-                                               p.valueSpec(t, keepType[i])
-
-                                       default:
-                                               p.internalError("unknown ast.Spec type: %T", t)
-                                       }
+                                       p.valueSpec(s.(*ast.ValueSpec), keepType[i])
                                }
                        } else {
                                var line int

diff --git a/src/go/printer/testdata/declarations.golden b/src/go/printer/testdata/declarations.golden
index ff14aba1a79156a693c6ba022c3ee197b825907e..82f5e0f9147be69128d1a0183bfb058d65443b55 100644 (file)
--- a/src/go/printer/testdata/declarations.golden
+++ b/src/go/printer/testdata/declarations.golden
@@ -985,47 +985,3 @@ func _(struct {
        x       int
        y       int
 })     // no extra comma between } and )
-
-// alias declarations
-const c => C
-const c => p.C
-const (
-       a               = 123
-       b       int     = 456
-       c               => foo
-       ddd             => p.Foo
-)
-
-// TODO(gri) Currently = and => line up in the formatted output,
-//           but because = and => have different lengths, the
-//           text following doesn't line up. Consider putting that
-//           text into its own column.
-const (
-       a       int     = iota  // a comment
-       b               => p.B  // b comment
-       c                       // c comment
-       d       => p.C          // d comment
-       e       => p.E
-       f
-       g       float32 = 9.8
-)
-
-type c => C
-type c => p.C
-type (
-       s       struct{}
-       a       => A
-       ddd     => p.Foo
-)
-
-var c => C
-var c => p.C
-var (
-       a               = 123
-       b       int     = 456
-       c               => foo
-       ddd             => p.Foo
-)
-
-func f => F
-func f_long => p.F

diff --git a/src/go/printer/testdata/declarations.input b/src/go/printer/testdata/declarations.input
index 748db3b6b18e72cf101459393ab8d0e5d015bce4..a0a3783b846fbed661713caee409bdc41ec1afef 100644 (file)
--- a/src/go/printer/testdata/declarations.input
+++ b/src/go/printer/testdata/declarations.input
@@ -999,47 +999,3 @@ func _(struct {
        x int
        y int
 }) // no extra comma between } and )
-
-// alias declarations
-const c => C
-const c => p.C
-const (
-       a = 123
-       b int = 456
-       c => foo
-       ddd => p.Foo
-)
-
-// TODO(gri) Currently = and => line up in the formatted output,
-//           but because = and => have different lengths, the
-//           text following doesn't line up. Consider putting that
-//           text into its own column.
-const (
-       a int = iota // a comment
-       b => p.B // b comment
-       c // c comment
-       d => p.C // d comment
-       e => p.E
-       f
-       g float32 = 9.8
-)
-
-type c => C
-type c => p.C
-type (
-       s struct{}
-       a => A
-       ddd => p.Foo
-)
-
-var c => C
-var c => p.C
-var (
-       a = 123
-       b int = 456
-       c => foo
-       ddd => p.Foo
-)
-
-func f => F
-func f_long => p.F
\ No newline at end of file