go/importer: implement importing of exported aliases

Fixes #17592.

Change-Id: I914fa8c0729012990878b6e5c3e99b0f9b0e2be8
Reviewed-on: https://go-review.googlesource.com/32350
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>

diff --git a/src/go/internal/gcimporter/bimport.go b/src/go/internal/gcimporter/bimport.go
index f7d1ddab4b884adcefd112f00f9cad428b575eff..60e8c22594fc5b00de907387b01a7084a35e244b 100644 (file)
--- a/src/go/internal/gcimporter/bimport.go
+++ b/src/go/internal/gcimporter/bimport.go
@@ -222,22 +222,33 @@ func (p *importer) declare(obj types.Object) {
 }
 
 func (p *importer) obj(tag int) {
+       var aliasPos token.Pos
+       var aliasName string
+       if tag == aliasTag {
+               aliasPos = p.pos()
+               aliasName = p.string()
+               tag = p.tagOrIndex()
+       }
+
+       var obj types.Object
        switch tag {
        case constTag:
                pos := p.pos()
                pkg, name := p.qualifiedName()
                typ := p.typ(nil)
                val := p.value()
-               p.declare(types.NewConst(pos, pkg, name, typ, val))
+               obj = types.NewConst(pos, pkg, name, typ, val)
+               p.declare(obj)
 
        case typeTag:
-               _ = p.typ(nil)
+               obj = p.typ(nil).(*types.Named).Obj()
 
        case varTag:
                pos := p.pos()
                pkg, name := p.qualifiedName()
                typ := p.typ(nil)
-               p.declare(types.NewVar(pos, pkg, name, typ))
+               obj = types.NewVar(pos, pkg, name, typ)
+               p.declare(obj)
 
        case funcTag:
                pos := p.pos()
@@ -245,11 +256,16 @@ func (p *importer) obj(tag int) {
                params, isddd := p.paramList()
                result, _ := p.paramList()
                sig := types.NewSignature(nil, params, result, isddd)
-               p.declare(types.NewFunc(pos, pkg, name, sig))
+               obj = types.NewFunc(pos, pkg, name, sig)
+               p.declare(obj)
 
        default:
                errorf("unexpected object tag %d", tag)
        }
+
+       if aliasName != "" {
+               p.declare(types.NewAlias(aliasPos, p.pkgList[0], aliasName, 0, obj))
+       }
 }
 
 func (p *importer) pos() token.Pos {
@@ -845,7 +861,11 @@ const (
        fractionTag // not used by gc
        complexTag
        stringTag
+       nilTag     // only used by gc (appears in exported inlined function bodies)
        unknownTag // not used by gc (only appears in packages with errors)
+
+       // Aliases
+       aliasTag
 )
 
 var predeclared = []types.Type{

diff --git a/src/go/internal/gcimporter/testdata/exports.go b/src/go/internal/gcimporter/testdata/exports.go
index 8ee28b0942b69cab01baef4e6203a6ce12c63c26..0033f3027bc337a62fdcfafed70c2e54de64501b 100644 (file)
--- a/src/go/internal/gcimporter/testdata/exports.go
+++ b/src/go/internal/gcimporter/testdata/exports.go
@@ -9,6 +9,8 @@ package exports
 
 import (
        "go/ast"
+       "go/build"
+       "math"
 )
 
 // Issue 3682: Correctly read dotted identifiers from export data.
@@ -27,6 +29,10 @@ const (
        C7     = `bar\n`
 )
 
+const (
+       C8 => math.Pi
+)
+
 type (
        T1  int
        T2  [10]int
@@ -75,9 +81,19 @@ type (
        T28 func(T28) T28
 )
 
+type (
+       T29 => ast.File
+       T30 => build.Context
+)
+
 var (
        V0 int
-       V1 = -991.0
+       V1         = -991.0
+       V2 float32 = 1.2
+)
+
+var (
+       V3 => build.Default
 )
 
 func F1()         {}
@@ -87,3 +103,7 @@ func F4() float32 { return 0 }
 func F5(a, b, c int, u, v, w struct{ x, y T1 }, more ...interface{}) (p, q, r chan<- T10)
 
 func (p *T1) M1()
+
+func F6 => math.Sin
+func F7 => ast.IsExported
+func F8 => build.Import