cmd/compile: remove global bout variable

Change-Id: I7054bbec080708c3a11ed62d7f6594e82aa33747
Reviewed-on: https://go-review.googlesource.com/61691
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>

src/cmd/compile/internal/gc/export.go

@@ -19,7 +19,7 @@ var (
 	Debug_export int // if set, print debugging information about export data
 )
 
-func exportf(format string, args ...interface{}) {
+func exportf(bout *bio.Writer, format string, args ...interface{}) {
 	fmt.Fprintf(bout, format, args...)
 	if Debug_export != 0 {
 		fmt.Printf(format, args...)
@@ -222,14 +222,14 @@ func (x methodbyname) Len() int           { return len(x) }
 func (x methodbyname) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
 func (x methodbyname) Less(i, j int) bool { return x[i].Sym.Name < x[j].Sym.Name }
 
-func dumpexport() {
+func dumpexport(bout *bio.Writer) {
 	if buildid != "" {
-		exportf("build id %q\n", buildid)
+		exportf(bout, "build id %q\n", buildid)
 	}
 
 	size := 0 // size of export section without enclosing markers
 	// The linker also looks for the $$ marker - use char after $$ to distinguish format.
-	exportf("\n$$B\n") // indicate binary export format
+	exportf(bout, "\n$$B\n") // indicate binary export format
 	if debugFormat {
 		// save a copy of the export data
 		var copy bytes.Buffer
@@ -253,7 +253,7 @@ func dumpexport() {
 	} else {
 		size = export(bout.Writer, Debug_export != 0)
 	}
-	exportf("\n$$\n")
+	exportf(bout, "\n$$\n")
 
 	if Debug_export != 0 {
 		fmt.Printf("export data size = %d bytes\n", size)

src/cmd/compile/internal/gc/go.go

@@ -7,7 +7,6 @@ package gc
 import (
 	"cmd/compile/internal/ssa"
 	"cmd/compile/internal/types"
-	"cmd/internal/bio"
 	"cmd/internal/obj"
 	"cmd/internal/src"
 	"sync"
@@ -85,8 +84,6 @@ var outfile string
 var linkobj string
 var dolinkobj bool
 
-var bout *bio.Writer
-
 // nerrors is the number of compiler errors reported
 // since the last call to saveerrors.
 var nerrors int

src/cmd/compile/internal/gc/obj.go

@@ -56,8 +56,7 @@ func dumpobj() {
 }
 
 func dumpobj1(outfile string, mode int) {
-	var err error
-	bout, err = bio.Create(outfile)
+	bout, err := bio.Create(outfile)
 	if err != nil {
 		flusherrors()
 		fmt.Printf("can't create %s: %v\n", outfile, err)
@@ -92,7 +91,7 @@ func dumpobj1(outfile string, mode int) {
 	printheader()
 
 	if mode&modeCompilerObj != 0 {
-		dumpexport()
+		dumpexport(bout)
 	}
 
 	if writearchive {