From 38a7dde1c5dfcbb69f90ee961e6b2583f0928257 Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <peter@pcc.me.uk>
Date: Wed, 18 Mar 2015 08:34:40 +0000
Subject: [PATCH] llgoi: Fix type identity for imported binary packages.

go/loader creates a fresh package map for each source package it imports. In
llgoi this caused binary imported packages to be imported anew for every input
line, resulting in spurious type errors and panics in go/ssa when encountering
previously imported types. Fix this by setting types.Config.Packages to our
internal package map.

Differential Revision: http://reviews.llvm.org/D8409

llvm-svn: 232617
---
 llgo/cmd/llgoi/llgoi.go            | 11 ++++-------
 llgo/irgen/compiler.go             |  8 ++++++--
 llgo/test/llgoi/import-source.test | 12 +++++++++++-
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/llgo/cmd/llgoi/llgoi.go b/llgo/cmd/llgoi/llgoi.go
index e331c31..09d05e5 100644
--- a/llgo/cmd/llgoi/llgoi.go
+++ b/llgo/cmd/llgoi/llgoi.go
@@ -76,8 +76,8 @@ type interp struct {
 	imports []*types.Package
 	scope   map[string]types.Object
 
-	pkgmap, inputPkgmap map[string]*types.Package
-	pkgnum              int
+	pkgmap map[string]*types.Package
+	pkgnum int
 }
 
 func (in *interp) makeCompilerOptions() error {
@@ -91,6 +91,7 @@ func (in *interp) makeCompilerOptions() error {
 		TargetTriple:  llvm.DefaultTargetTriple(),
 		ImportPaths:   importPaths,
 		GenerateDebug: true,
+		Packages:      in.pkgmap,
 	}
 	err = in.copts.MakeImporter()
 	if err != nil {
@@ -99,9 +100,6 @@ func (in *interp) makeCompilerOptions() error {
 
 	origImporter := in.copts.Importer
 	in.copts.Importer = func(pkgmap map[string]*types.Package, pkgpath string) (*types.Package, error) {
-		if pkg, ok := in.inputPkgmap[pkgpath]; ok {
-			return pkg, nil
-		}
 		if pkg, ok := pkgmap[pkgpath]; ok && pkg.Complete() {
 			return pkg, nil
 		}
@@ -113,7 +111,6 @@ func (in *interp) makeCompilerOptions() error {
 func (in *interp) init() error {
 	in.scope = make(map[string]types.Object)
 	in.pkgmap = make(map[string]*types.Package)
-	in.inputPkgmap = make(map[string]*types.Package)
 
 	err := in.makeCompilerOptions()
 	if err != nil {
@@ -174,7 +171,7 @@ func (in *interp) loadSourcePackage(fset *token.FileSet, files []*ast.File, pkgp
 		}
 	}()
 	importfunc()
-	in.inputPkgmap[pkgpath] = pkg
+	in.pkgmap[pkgpath] = pkg
 	return
 }
 
diff --git a/llgo/irgen/compiler.go b/llgo/irgen/compiler.go
index 36d35b78..1676921 100644
--- a/llgo/irgen/compiler.go
+++ b/llgo/irgen/compiler.go
@@ -102,6 +102,9 @@ type CompilerOptions struct {
 	// DisableUnusedImportCheck disables the unused import check performed
 	// by go/types if set to true.
 	DisableUnusedImportCheck bool
+
+	// Packages is used by go/types as the imported package map if non-nil.
+	Packages map[string]*types.Package
 }
 
 type Compiler struct {
@@ -208,8 +211,9 @@ func (compiler *compiler) compile(fset *token.FileSet, astFiles []*ast.File, imp
 	impcfg := &loader.Config{
 		Fset: fset,
 		TypeChecker: types.Config{
-			Import: compiler.Importer,
-			Sizes:  compiler.llvmtypes,
+			Packages: compiler.Packages,
+			Import:   compiler.Importer,
+			Sizes:    compiler.llvmtypes,
 			DisableUnusedImportCheck: compiler.DisableUnusedImportCheck,
 		},
 		Build:          &buildctx.Context,
diff --git a/llgo/test/llgoi/import-source.test b/llgo/test/llgoi/import-source.test
index c5a3eab..b545b52 100644
--- a/llgo/test/llgoi/import-source.test
+++ b/llgo/test/llgoi/import-source.test
@@ -1,4 +1,4 @@
-// RUN: env GOPATH=%S/Inputs llgoi < %s | FileCheck %s
+// RUN: env GOPATH=%S/Inputs llgoi < %s 2>&1 | FileCheck %s
 
 // make sure user symbols do not conflict with imported source package
 Answer := 1
@@ -16,5 +16,15 @@ foo.Answer()
 strconv.FormatBool(true)
 // CHECK: #0 string = true
 
+var v1 strconv.NumError
+var v2 strconv.NumError
+
+// v1 and v2 should have the same type identity.
+// CHECK-NOT: cannot assign
+v1 = v2
+
+// Method lookup relies on v1 having a consistent type.
+v1.Error
+
 import "foo_cgo"
 // CHECK: foo_cgo: cannot load cgo package
-- 
2.7.4