cmd/link/internal, cmd/internal/obj: introduce ctxt.Logf

Replace the various calls to Fprintf(ctxt.Bso, ...) with a helper,
ctxt.Logf. This also addresses the various inconsistent flushing of
ctxt.Bso.

Because we have two Link structures, add Link.Logf in both places.

Change-Id: I23093f9b9b3bf33089a0ffd7f815f92dcd1a1fa1
Reviewed-on: https://go-review.googlesource.com/27730Reviewed-by: Matthew Dempsky <mdempsky@google.com>

src/cmd/internal/obj/arm/asm5.go

@@ -648,7 +648,7 @@ func span5(ctxt *obj.Link, cursym *obj.LSym) {
 	var out [6 + 3]uint32
 	for {
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f span1\n", obj.Cputime())
+			ctxt.Logf("%5.2f span1\n", obj.Cputime())
 		}
 		bflag = 0
 		c = 0

src/cmd/internal/obj/arm/obj5.go

@@ -359,8 +359,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
 
 			if autosize == 0 && cursym.Text.Mark&LEAF == 0 {
 				if ctxt.Debugvlog != 0 {
-					fmt.Fprintf(ctxt.Bso, "save suppressed in: %s\n", cursym.Name)
-					ctxt.Bso.Flush()
+					ctxt.Logf("save suppressed in: %s\n", cursym.Name)
 				}
 
 				cursym.Text.Mark |= LEAF

src/cmd/internal/obj/arm64/asm7.go

@@ -585,7 +585,7 @@ func span7(ctxt *obj.Link, cursym *obj.LSym) {
 	 */
 	for bflag != 0 {
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f span1\n", obj.Cputime())
+			ctxt.Logf("%5.2f span1\n", obj.Cputime())
 		}
 		bflag = 0
 		c = 0
@@ -4197,7 +4197,7 @@ func omovlit(ctxt *obj.Link, as obj.As, p *obj.Prog, a *obj.Addr, dr int) uint32
 	var o1 int32
 	if p.Pcond == nil { /* not in literal pool */
 		aclass(ctxt, a)
-		fmt.Fprintf(ctxt.Bso, "omovlit add %d (%#x)\n", ctxt.Instoffset, uint64(ctxt.Instoffset))
+		ctxt.Logf("omovlit add %d (%#x)\n", ctxt.Instoffset, uint64(ctxt.Instoffset))
 
 		/* TODO: could be clever, and use general constant builder */
 		o1 = int32(opirr(ctxt, AADD))

src/cmd/internal/obj/arm64/obj7.go

@@ -617,7 +617,6 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
 	 * strip NOPs
 	 * expand RET
 	 */
-	ctxt.Bso.Flush()
 	q := (*obj.Prog)(nil)
 	var q1 *obj.Prog
 	for p := cursym.Text; p != nil; p = p.Link {
@@ -713,8 +712,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
 			p.To.Offset = int64(ctxt.Autosize) - 8
 			if ctxt.Autosize == 0 && !(cursym.Text.Mark&LEAF != 0) {
 				if ctxt.Debugvlog != 0 {
-					fmt.Fprintf(ctxt.Bso, "save suppressed in: %s\n", cursym.Text.From.Sym.Name)
-					ctxt.Bso.Flush()
+					ctxt.Logf("save suppressed in: %s\n", cursym.Text.From.Sym.Name)
 				}
 				cursym.Text.Mark |= LEAF
 			}

src/cmd/internal/obj/link.go

@@ -33,6 +33,7 @@ package obj
 import (
 	"bufio"
 	"cmd/internal/sys"
+	"fmt"
 )
 
 // An Addr is an argument to an instruction.
@@ -687,6 +688,11 @@ func (ctxt *Link) Diag(format string, args ...interface{}) {
 	ctxt.DiagFunc(format, args...)
 }
 
+func (ctxt *Link) Logf(format string, args ...interface{}) {
+	fmt.Fprintf(ctxt.Bso, format, args...)
+	ctxt.Bso.Flush()
+}
+
 // The smallest possible offset from the hardware stack pointer to a local
 // variable on the stack. Architectures that use a link register save its value
 // on the stack in the function prologue and so always have a pointer between

src/cmd/internal/obj/mips/asm0.go

@@ -370,7 +370,7 @@ func span0(ctxt *obj.Link, cursym *obj.LSym) {
 	var q *obj.Prog
 	for bflag != 0 {
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f span1\n", obj.Cputime())
+			ctxt.Logf("%5.2f span1\n", obj.Cputime())
 		}
 		bflag = 0
 		c = 0

src/cmd/internal/obj/mips/obj0.go

@@ -144,8 +144,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
 	 * expand BECOME pseudo
 	 */
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f noops\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f noops\n", obj.Cputime())
 	}
 
 	var q *obj.Prog
@@ -293,8 +292,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
 			} else if cursym.Text.Mark&LEAF == 0 {
 				if cursym.Text.From3.Offset&obj.NOSPLIT != 0 {
 					if ctxt.Debugvlog != 0 {
-						fmt.Fprintf(ctxt.Bso, "save suppressed in: %s\n", cursym.Name)
-						ctxt.Bso.Flush()
+						ctxt.Logf("save suppressed in: %s\n", cursym.Name)
 					}
 
 					cursym.Text.Mark |= LEAF

src/cmd/internal/obj/pcln.go

@@ -4,10 +4,7 @@
 
 package obj
 
-import (
-	"fmt"
-	"log"
-)
+import "log"
 
 func addvarint(ctxt *Link, d *Pcdata, val uint32) {
 	var v uint32
@@ -39,7 +36,7 @@ func funcpctab(ctxt *Link, dst *Pcdata, func_ *LSym, desc string, valfunc func(*
 	dst.P = dst.P[:0]
 
 	if ctxt.Debugpcln != 0 {
-		fmt.Fprintf(ctxt.Bso, "funcpctab %s [valfunc=%s]\n", func_.Name, desc)
+		ctxt.Logf("funcpctab %s [valfunc=%s]\n", func_.Name, desc)
 	}
 
 	val := int32(-1)
@@ -52,7 +49,7 @@ func funcpctab(ctxt *Link, dst *Pcdata, func_ *LSym, desc string, valfunc func(*
 	pc := func_.Text.Pc
 
 	if ctxt.Debugpcln != 0 {
-		fmt.Fprintf(ctxt.Bso, "%6x %6d %v\n", uint64(pc), val, func_.Text)
+		ctxt.Logf("%6x %6d %v\n", uint64(pc), val, func_.Text)
 	}
 
 	started := int32(0)
@@ -64,7 +61,7 @@ func funcpctab(ctxt *Link, dst *Pcdata, func_ *LSym, desc string, valfunc func(*
 		if val == oldval && started != 0 {
 			val = valfunc(ctxt, func_, val, p, 1, arg)
 			if ctxt.Debugpcln != 0 {
-				fmt.Fprintf(ctxt.Bso, "%6x %6s %v\n", uint64(p.Pc), "", p)
+				ctxt.Logf("%6x %6s %v\n", uint64(p.Pc), "", p)
 			}
 			continue
 		}
@@ -76,7 +73,7 @@ func funcpctab(ctxt *Link, dst *Pcdata, func_ *LSym, desc string, valfunc func(*
 		if p.Link != nil && p.Link.Pc == p.Pc {
 			val = valfunc(ctxt, func_, val, p, 1, arg)
 			if ctxt.Debugpcln != 0 {
-				fmt.Fprintf(ctxt.Bso, "%6x %6s %v\n", uint64(p.Pc), "", p)
+				ctxt.Logf("%6x %6s %v\n", uint64(p.Pc), "", p)
 			}
 			continue
 		}
@@ -96,7 +93,7 @@ func funcpctab(ctxt *Link, dst *Pcdata, func_ *LSym, desc string, valfunc func(*
 		// where the 0x80 bit indicates that the integer continues.
 
 		if ctxt.Debugpcln != 0 {
-			fmt.Fprintf(ctxt.Bso, "%6x %6d %v\n", uint64(p.Pc), val, p)
+			ctxt.Logf("%6x %6d %v\n", uint64(p.Pc), val, p)
 		}
 
 		if started != 0 {
@@ -118,18 +115,18 @@ func funcpctab(ctxt *Link, dst *Pcdata, func_ *LSym, desc string, valfunc func(*
 
 	if started != 0 {
 		if ctxt.Debugpcln != 0 {
-			fmt.Fprintf(ctxt.Bso, "%6x done\n", uint64(func_.Text.Pc+func_.Size))
+			ctxt.Logf("%6x done\n", uint64(func_.Text.Pc+func_.Size))
 		}
 		addvarint(ctxt, dst, uint32((func_.Size-pc)/int64(ctxt.Arch.MinLC)))
 		addvarint(ctxt, dst, 0) // terminator
 	}
 
 	if ctxt.Debugpcln != 0 {
-		fmt.Fprintf(ctxt.Bso, "wrote %d bytes to %p\n", len(dst.P), dst)
+		ctxt.Logf("wrote %d bytes to %p\n", len(dst.P), dst)
 		for i := 0; i < len(dst.P); i++ {
-			fmt.Fprintf(ctxt.Bso, " %02x", dst.P[i])
+			ctxt.Logf(" %02x", dst.P[i])
 		}
-		fmt.Fprintf(ctxt.Bso, "\n")
+		ctxt.Logf("\n")
 	}
 
 	ctxt.Debugpcln -= int32(dbg)

src/cmd/internal/obj/ppc64/asm9.go

@@ -459,7 +459,7 @@ func span9(ctxt *obj.Link, cursym *obj.LSym) {
 	var q *obj.Prog
 	for bflag != 0 {
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f span1\n", obj.Cputime())
+			ctxt.Logf("%5.2f span1\n", obj.Cputime())
 		}
 		bflag = 0
 		c = 0

src/cmd/internal/obj/ppc64/obj9.go

@@ -275,8 +275,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
 	 * expand BECOME pseudo
 	 */
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f noops\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f noops\n", obj.Cputime())
 	}
 
 	var q *obj.Prog

src/cmd/internal/obj/s390x/objz.go

@@ -242,8 +242,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
 	 * expand BECOME pseudo
 	 */
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f noops\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f noops\n", obj.Cputime())
 	}
 
 	var q *obj.Prog

src/cmd/link/internal/amd64/asm.go

@@ -34,7 +34,6 @@ import (
 	"cmd/internal/obj"
 	"cmd/link/internal/ld"
 	"debug/elf"
-	"fmt"
 	"log"
 )
 
@@ -600,13 +599,11 @@ func addgotsym(ctxt *ld.Link, s *ld.Symbol) {
 
 func asmb(ctxt *ld.Link) {
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f asmb\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f asmb\n", obj.Cputime())
 	}
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f codeblk\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f codeblk\n", obj.Cputime())
 	}
 
 	if ld.Iself {
@@ -624,8 +621,7 @@ func asmb(ctxt *ld.Link) {
 
 	if ld.Segrodata.Filelen > 0 {
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f rodatblk\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f rodatblk\n", obj.Cputime())
 		}
 
 		ld.Cseek(int64(ld.Segrodata.Fileoff))
@@ -633,8 +629,7 @@ func asmb(ctxt *ld.Link) {
 	}
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f datblk\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f datblk\n", obj.Cputime())
 	}
 
 	ld.Cseek(int64(ld.Segdata.Fileoff))
@@ -678,8 +673,7 @@ func asmb(ctxt *ld.Link) {
 	symo := int64(0)
 	if !*ld.FlagS {
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f sym\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f sym\n", obj.Cputime())
 		}
 		switch ld.HEADTYPE {
 		default:
@@ -715,7 +709,7 @@ func asmb(ctxt *ld.Link) {
 				ld.Cwrite(ld.Elfstrdat)
 
 				if ctxt.Debugvlog != 0 {
-					fmt.Fprintf(ctxt.Bso, "%5.2f dwarf\n", obj.Cputime())
+					ctxt.Logf("%5.2f dwarf\n", obj.Cputime())
 				}
 
 				if ld.Linkmode == ld.LinkExternal {
@@ -739,7 +733,7 @@ func asmb(ctxt *ld.Link) {
 
 		case obj.Hwindows:
 			if ctxt.Debugvlog != 0 {
-				fmt.Fprintf(ctxt.Bso, "%5.2f dwarf\n", obj.Cputime())
+				ctxt.Logf("%5.2f dwarf\n", obj.Cputime())
 			}
 
 		case obj.Hdarwin:
@@ -750,8 +744,7 @@ func asmb(ctxt *ld.Link) {
 	}
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f headr\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f headr\n", obj.Cputime())
 	}
 	ld.Cseek(0)
 	switch ld.HEADTYPE {

src/cmd/link/internal/arm/asm.go

@@ -583,8 +583,7 @@ func addgotsym(ctxt *ld.Link, s *ld.Symbol) {
 
 func asmb(ctxt *ld.Link) {
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f asmb\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f asmb\n", obj.Cputime())
 	}
 
 	if ld.Iself {
@@ -601,8 +600,7 @@ func asmb(ctxt *ld.Link) {
 
 	if ld.Segrodata.Filelen > 0 {
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f rodatblk\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f rodatblk\n", obj.Cputime())
 		}
 
 		ld.Cseek(int64(ld.Segrodata.Fileoff))
@@ -610,8 +608,7 @@ func asmb(ctxt *ld.Link) {
 	}
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f datblk\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f datblk\n", obj.Cputime())
 	}
 
 	ld.Cseek(int64(ld.Segdata.Fileoff))
@@ -633,8 +630,7 @@ func asmb(ctxt *ld.Link) {
 	if !*ld.FlagS {
 		// TODO: rationalize
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f sym\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f sym\n", obj.Cputime())
 		}
 		switch ld.HEADTYPE {
 		default:
@@ -655,7 +651,7 @@ func asmb(ctxt *ld.Link) {
 		default:
 			if ld.Iself {
 				if ctxt.Debugvlog != 0 {
-					fmt.Fprintf(ctxt.Bso, "%5.2f elfsym\n", obj.Cputime())
+					ctxt.Logf("%5.2f elfsym\n", obj.Cputime())
 				}
 				ld.Asmelfsym(ctxt)
 				ld.Cflush()
@@ -689,8 +685,7 @@ func asmb(ctxt *ld.Link) {
 
 	ctxt.Cursym = nil
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f header\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f header\n", obj.Cputime())
 	}
 	ld.Cseek(0)
 	switch ld.HEADTYPE {

src/cmd/link/internal/arm64/asm.go

@@ -392,8 +392,7 @@ func archrelocvariant(ctxt *ld.Link, r *ld.Reloc, s *ld.Symbol, t int64) int64 {
 
 func asmb(ctxt *ld.Link) {
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f asmb\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f asmb\n", obj.Cputime())
 	}
 
 	if ld.Iself {
@@ -410,8 +409,7 @@ func asmb(ctxt *ld.Link) {
 
 	if ld.Segrodata.Filelen > 0 {
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f rodatblk\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f rodatblk\n", obj.Cputime())
 		}
 
 		ld.Cseek(int64(ld.Segrodata.Fileoff))
@@ -419,8 +417,7 @@ func asmb(ctxt *ld.Link) {
 	}
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f datblk\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f datblk\n", obj.Cputime())
 	}
 
 	ld.Cseek(int64(ld.Segdata.Fileoff))
@@ -442,8 +439,7 @@ func asmb(ctxt *ld.Link) {
 	if !*ld.FlagS {
 		// TODO: rationalize
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f sym\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f sym\n", obj.Cputime())
 		}
 		switch ld.HEADTYPE {
 		default:
@@ -464,7 +460,7 @@ func asmb(ctxt *ld.Link) {
 		default:
 			if ld.Iself {
 				if ctxt.Debugvlog != 0 {
-					fmt.Fprintf(ctxt.Bso, "%5.2f elfsym\n", obj.Cputime())
+					ctxt.Logf("%5.2f elfsym\n", obj.Cputime())
 				}
 				ld.Asmelfsym(ctxt)
 				ld.Cflush()
@@ -498,8 +494,7 @@ func asmb(ctxt *ld.Link) {
 
 	ctxt.Cursym = nil
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f header\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f header\n", obj.Cputime())
 	}
 	ld.Cseek(0)
 	switch ld.HEADTYPE {

src/cmd/link/internal/ld/ar.go

@@ -69,7 +69,7 @@ func hostArchive(ctxt *Link, name string) {
 		if os.IsNotExist(err) {
 			// It's OK if we don't have a libgcc file at all.
 			if ctxt.Debugvlog != 0 {
-				fmt.Fprintf(ctxt.Bso, "skipping libgcc file: %v\n", err)
+				ctxt.Logf("skipping libgcc file: %v\n", err)
 			}
 			return
 		}

src/cmd/link/internal/ld/data.go

@@ -648,8 +648,7 @@ func relocsym(ctxt *Link, s *Symbol) {
 
 func (ctxt *Link) reloc() {
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f reloc\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f reloc\n", obj.Cputime())
 	}
 
 	for _, s := range ctxt.Textp {
@@ -724,8 +723,7 @@ func dynreloc(ctxt *Link, data *[obj.SXREF][]*Symbol) {
 		return
 	}
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f reloc\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f reloc\n", obj.Cputime())
 	}
 
 	for _, s := range ctxt.Textp {
@@ -746,7 +744,7 @@ func Codeblk(ctxt *Link, addr int64, size int64) {
 }
 func CodeblkPad(ctxt *Link, addr int64, size int64, pad []byte) {
 	if *flagA {
-		fmt.Fprintf(ctxt.Bso, "codeblk [%#x,%#x) at offset %#x\n", addr, addr+size, coutbuf.Offset())
+		ctxt.Logf("codeblk [%#x,%#x) at offset %#x\n", addr, addr+size, coutbuf.Offset())
 	}
 
 	blk(ctxt, ctxt.Textp, addr, size, pad)
@@ -778,34 +776,33 @@ func CodeblkPad(ctxt *Link, addr int64, size int64, pad []byte) {
 		}
 
 		if addr < sym.Value {
-			fmt.Fprintf(ctxt.Bso, "%-20s %.8x|", "_", uint64(addr))
+			ctxt.Logf("%-20s %.8x|", "_", uint64(addr))
 			for ; addr < sym.Value; addr++ {
-				fmt.Fprintf(ctxt.Bso, " %.2x", 0)
+				ctxt.Logf(" %.2x", 0)
 			}
-			fmt.Fprintf(ctxt.Bso, "\n")
+			ctxt.Logf("\n")
 		}
 
-		fmt.Fprintf(ctxt.Bso, "%.6x\t%-20s\n", uint64(addr), sym.Name)
+		ctxt.Logf("%.6x\t%-20s\n", uint64(addr), sym.Name)
 		q = sym.P
 
 		for len(q) >= 16 {
-			fmt.Fprintf(ctxt.Bso, "%.6x\t% x\n", uint64(addr), q[:16])
+			ctxt.Logf("%.6x\t% x\n", uint64(addr), q[:16])
 			addr += 16
 			q = q[16:]
 		}
 
 		if len(q) > 0 {
-			fmt.Fprintf(ctxt.Bso, "%.6x\t% x\n", uint64(addr), q)
+			ctxt.Logf("%.6x\t% x\n", uint64(addr), q)
 			addr += int64(len(q))
 		}
 	}
 
 	if addr < eaddr {
-		fmt.Fprintf(ctxt.Bso, "%-20s %.8x|", "_", uint64(addr))
+		ctxt.Logf("%-20s %.8x|", "_", uint64(addr))
 		for ; addr < eaddr; addr++ {
-			fmt.Fprintf(ctxt.Bso, " %.2x", 0)
+			ctxt.Logf(" %.2x", 0)
 		}
-		ctxt.Bso.Flush()
 	}
 }
 
@@ -857,7 +854,7 @@ func blk(ctxt *Link, syms []*Symbol, addr, size int64, pad []byte) {
 
 func Datblk(ctxt *Link, addr int64, size int64) {
 	if *flagA {
-		fmt.Fprintf(ctxt.Bso, "datblk [%#x,%#x) at offset %#x\n", addr, addr+size, coutbuf.Offset())
+		ctxt.Logf("datblk [%#x,%#x) at offset %#x\n", addr, addr+size, coutbuf.Offset())
 	}
 
 	blk(ctxt, datap, addr, size, zeros[:])
@@ -881,23 +878,23 @@ func Datblk(ctxt *Link, addr int64, size int64) {
 			break
 		}
 		if addr < sym.Value {
-			fmt.Fprintf(ctxt.Bso, "\t%.8x| 00 ...\n", uint64(addr))
+			ctxt.Logf("\t%.8x| 00 ...\n", uint64(addr))
 			addr = sym.Value
 		}
 
-		fmt.Fprintf(ctxt.Bso, "%s\n\t%.8x|", sym.Name, uint64(addr))
+		ctxt.Logf("%s\n\t%.8x|", sym.Name, uint64(addr))
 		for i, b := range sym.P {
 			if i > 0 && i%16 == 0 {
-				fmt.Fprintf(ctxt.Bso, "\n\t%.8x|", uint64(addr)+uint64(i))
+				ctxt.Logf("\n\t%.8x|", uint64(addr)+uint64(i))
 			}
-			fmt.Fprintf(ctxt.Bso, " %.2x", b)
+			ctxt.Logf(" %.2x", b)
 		}
 
 		addr += int64(len(sym.P))
 		for ; addr < sym.Value+sym.Size; addr++ {
-			fmt.Fprintf(ctxt.Bso, " %.2x", 0)
+			ctxt.Logf(" %.2x", 0)
 		}
-		fmt.Fprintf(ctxt.Bso, "\n")
+		ctxt.Logf("\n")
 
 		if Linkmode != LinkExternal {
 			continue
@@ -916,19 +913,19 @@ func Datblk(ctxt *Link, addr int64, size int64) {
 			case obj.R_CALL:
 				typ = "call"
 			}
-			fmt.Fprintf(ctxt.Bso, "\treloc %.8x/%d %s %s+%#x [%#x]\n", uint(sym.Value+int64(r.Off)), r.Siz, typ, rsname, r.Add, r.Sym.Value+r.Add)
+			ctxt.Logf("\treloc %.8x/%d %s %s+%#x [%#x]\n", uint(sym.Value+int64(r.Off)), r.Siz, typ, rsname, r.Add, r.Sym.Value+r.Add)
 		}
 	}
 
 	if addr < eaddr {
-		fmt.Fprintf(ctxt.Bso, "\t%.8x| 00 ...\n", uint(addr))
+		ctxt.Logf("\t%.8x| 00 ...\n", uint(addr))
 	}
-	fmt.Fprintf(ctxt.Bso, "\t%.8x|\n", uint(eaddr))
+	ctxt.Logf("\t%.8x|\n", uint(eaddr))
 }
 
 func Dwarfblk(ctxt *Link, addr int64, size int64) {
 	if *flagA {
-		fmt.Fprintf(ctxt.Bso, "dwarfblk [%#x,%#x) at offset %#x\n", addr, addr+size, coutbuf.Offset())
+		ctxt.Logf("dwarfblk [%#x,%#x) at offset %#x\n", addr, addr+size, coutbuf.Offset())
 	}
 
 	blk(ctxt, dwarfp, addr, size, zeros[:])
@@ -1189,8 +1186,7 @@ var datap []*Symbol
 
 func (ctxt *Link) dodata() {
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f dodata\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f dodata\n", obj.Cputime())
 	}
 
 	// Collect data symbols by type into data.

src/cmd/link/internal/ld/deadcode.go

@@ -46,7 +46,7 @@ import (
 // Any unreached text symbols are removed from ctxt.Textp.
 func deadcode(ctxt *Link) {
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f deadcode\n", obj.Cputime())
+		ctxt.Logf("%5.2f deadcode\n", obj.Cputime())
 	}
 
 	d := &deadcodepass{
@@ -181,7 +181,7 @@ func (d *deadcodepass) cleanupReloc(r *Reloc) {
 		r.Type = obj.R_ADDROFF
 	} else {
 		if d.ctxt.Debugvlog > 1 {
-			fmt.Fprintf(d.ctxt.Bso, "removing method %s\n", r.Sym.Name)
+			d.ctxt.Logf("removing method %s\n", r.Sym.Name)
 		}
 		r.Sym = nil
 		r.Siz = 0
@@ -265,7 +265,7 @@ func (d *deadcodepass) flood() {
 		d.markQueue = d.markQueue[1:]
 		if s.Type == obj.STEXT {
 			if d.ctxt.Debugvlog > 1 {
-				fmt.Fprintf(d.ctxt.Bso, "marktext %s\n", s.Name)
+				d.ctxt.Logf("marktext %s\n", s.Name)
 			}
 			if s.FuncInfo != nil {
 				for _, a := range s.FuncInfo.Autom {
@@ -279,7 +279,7 @@ func (d *deadcodepass) flood() {
 			if decodetypeKind(s)&kindMask == kindInterface {
 				for _, sig := range decodeIfaceMethods(d.ctxt.Arch, s) {
 					if d.ctxt.Debugvlog > 1 {
-						fmt.Fprintf(d.ctxt.Bso, "reached iface method: %s\n", sig)
+						d.ctxt.Logf("reached iface method: %s\n", sig)
 					}
 					d.ifaceMethod[sig] = true
 				}

src/cmd/link/internal/ld/dwarf.go

@@ -1415,7 +1415,7 @@ func dwarfgeneratedebugsyms(ctxt *Link) {
 	}
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f dwarf\n", obj.Cputime())
+		ctxt.Logf("%5.2f dwarf\n", obj.Cputime())
 	}
 
 	// Forctxt.Diagnostic messages.

src/cmd/link/internal/ld/ld.go

@@ -33,7 +33,6 @@ package ld
 
 import (
 	"cmd/internal/obj"
-	"fmt"
 	"io/ioutil"
 	"os"
 	"path"
@@ -80,8 +79,8 @@ func addlib(ctxt *Link, src string, obj string, pathname string) {
 
 	pname = path.Clean(pname)
 
-	if ctxt.Debugvlog > 1 && ctxt.Bso != nil {
-		fmt.Fprintf(ctxt.Bso, "%5.2f addlib: %s %s pulls in %s isshlib %v\n", elapsed(), obj, src, pname, isshlib)
+	if ctxt.Debugvlog > 1 {
+		ctxt.Logf("%5.2f addlib: %s %s pulls in %s isshlib %v\n", elapsed(), obj, src, pname, isshlib)
 	}
 
 	if isshlib {
@@ -105,8 +104,8 @@ func addlibpath(ctxt *Link, srcref string, objref string, file string, pkg strin
 		}
 	}
 
-	if ctxt.Debugvlog > 1 && ctxt.Bso != nil {
-		fmt.Fprintf(ctxt.Bso, "%5.2f addlibpath: srcref: %s objref: %s file: %s pkg: %s shlibnamefile: %s\n", obj.Cputime(), srcref, objref, file, pkg, shlibnamefile)
+	if ctxt.Debugvlog > 1 {
+		ctxt.Logf("%5.2f addlibpath: srcref: %s objref: %s file: %s pkg: %s shlibnamefile: %s\n", obj.Cputime(), srcref, objref, file, pkg, shlibnamefile)
 	}
 
 	ctxt.Library = append(ctxt.Library, &Library{})

src/cmd/link/internal/ld/ldelf.go

@@ -395,7 +395,8 @@ func parseArmAttributes(ctxt *Link, e binary.ByteOrder, data []byte) {
 		ehdr.flags = 0x5000202
 	}
 	if data[0] != 'A' {
-		fmt.Fprintf(ctxt.Bso, ".ARM.attributes has unexpected format %c\n", data[0])
+		// TODO(dfc) should this be ctxt.Diag ?
+		ctxt.Logf(".ARM.attributes has unexpected format %c\n", data[0])
 		return
 	}
 	data = data[1:]
@@ -406,7 +407,8 @@ func parseArmAttributes(ctxt *Link, e binary.ByteOrder, data []byte) {
 
 		nulIndex := bytes.IndexByte(sectiondata, 0)
 		if nulIndex < 0 {
-			fmt.Fprintf(ctxt.Bso, "corrupt .ARM.attributes (section name not NUL-terminated)\n")
+			// TODO(dfc) should this be ctxt.Diag ?
+			ctxt.Logf("corrupt .ARM.attributes (section name not NUL-terminated)\n")
 			return
 		}
 		name := string(sectiondata[:nulIndex])
@@ -430,7 +432,8 @@ func parseArmAttributes(ctxt *Link, e binary.ByteOrder, data []byte) {
 					}
 				}
 				if attrList.err != nil {
-					fmt.Fprintf(ctxt.Bso, "could not parse .ARM.attributes\n")
+					// TODO(dfc) should this be ctxt.Diag ?
+					ctxt.Logf("could not parse .ARM.attributes\n")
 				}
 			}
 		}
@@ -439,7 +442,7 @@ func parseArmAttributes(ctxt *Link, e binary.ByteOrder, data []byte) {
 
 func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f ldelf %s\n", obj.Cputime(), pn)
+		ctxt.Logf("%5.2f ldelf %s\n", obj.Cputime(), pn)
 	}
 
 	ctxt.IncVersion()

src/cmd/link/internal/ld/ldpe.go

@@ -132,7 +132,7 @@ type PeObj struct {
 
 func ldpe(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f ldpe %s\n", obj.Cputime(), pn)
+		ctxt.Logf("%5.2f ldpe %s\n", obj.Cputime(), pn)
 	}
 
 	var sect *PeSect

src/cmd/link/internal/ld/lib.go

@@ -348,7 +348,7 @@ func loadinternal(ctxt *Link, name string) {
 		if *FlagLinkshared {
 			shlibname := filepath.Join(ctxt.Libdir[i], name+".shlibname")
 			if ctxt.Debugvlog != 0 {
-				fmt.Fprintf(ctxt.Bso, "searching for %s.a in %s\n", name, shlibname)
+				ctxt.Logf("searching for %s.a in %s\n", name, shlibname)
 			}
 			if _, err := os.Stat(shlibname); err == nil {
 				addlibpath(ctxt, "internal", "internal", "", name, shlibname)
@@ -358,7 +358,7 @@ func loadinternal(ctxt *Link, name string) {
 		}
 		pname := filepath.Join(ctxt.Libdir[i], name+".a")
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "searching for %s.a in %s\n", name, pname)
+			ctxt.Logf("searching for %s.a in %s\n", name, pname)
 		}
 		if _, err := os.Stat(pname); err == nil {
 			addlibpath(ctxt, "internal", "internal", pname, name, "")
@@ -368,7 +368,7 @@ func loadinternal(ctxt *Link, name string) {
 	}
 
 	if found == 0 {
-		fmt.Fprintf(ctxt.Bso, "warning: unable to find %s.a\n", name)
+		ctxt.Logf("warning: unable to find %s.a\n", name)
 	}
 }
 
@@ -400,7 +400,7 @@ func (ctxt *Link) loadlib() {
 		iscgo = iscgo || ctxt.Library[i].Pkg == "runtime/cgo"
 		if ctxt.Library[i].Shlib == "" {
 			if ctxt.Debugvlog > 1 {
-				fmt.Fprintf(ctxt.Bso, "%5.2f autolib: %s (from %s)\n", obj.Cputime(), ctxt.Library[i].File, ctxt.Library[i].Objref)
+				ctxt.Logf("%5.2f autolib: %s (from %s)\n", obj.Cputime(), ctxt.Library[i].File, ctxt.Library[i].Objref)
 			}
 			objfile(ctxt, ctxt.Library[i])
 		}
@@ -409,7 +409,7 @@ func (ctxt *Link) loadlib() {
 	for i = 0; i < len(ctxt.Library); i++ {
 		if ctxt.Library[i].Shlib != "" {
 			if ctxt.Debugvlog > 1 {
-				fmt.Fprintf(ctxt.Bso, "%5.2f autolib: %s (from %s)\n", obj.Cputime(), ctxt.Library[i].Shlib, ctxt.Library[i].Objref)
+				ctxt.Logf("%5.2f autolib: %s (from %s)\n", obj.Cputime(), ctxt.Library[i].Shlib, ctxt.Library[i].Objref)
 			}
 			ldshlibsyms(ctxt, ctxt.Library[i].Shlib)
 		}
@@ -579,13 +579,12 @@ func (ctxt *Link) loadlib() {
 				args := hostlinkArchArgs()
 				args = append(args, "--print-libgcc-file-name")
 				if ctxt.Debugvlog != 0 {
-					fmt.Fprintf(ctxt.Bso, "%s %v\n", *flagExtld, args)
+					ctxt.Logf("%s %v\n", *flagExtld, args)
 				}
 				out, err := exec.Command(*flagExtld, args...).Output()
 				if err != nil {
 					if ctxt.Debugvlog != 0 {
-						fmt.Fprintln(ctxt.Bso, "not using a libgcc file because compiler failed")
-						fmt.Fprintf(ctxt.Bso, "%v\n%s\n", err, out)
+						ctxt.Logf("not using a libgcc file because compiler failed\n%v\n%s\n", err, out)
 					}
 					*flagLibGCC = "none"
 				} else {
@@ -658,8 +657,7 @@ func objfile(ctxt *Link, lib *Library) {
 	pkg := pathtoprefix(lib.Pkg)
 
 	if ctxt.Debugvlog > 1 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f ldobj: %s (%s)\n", obj.Cputime(), lib.File, pkg)
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f ldobj: %s (%s)\n", obj.Cputime(), lib.File, pkg)
 	}
 	f, err := bio.Open(lib.File)
 	if err != nil {
@@ -926,8 +924,7 @@ func (ctxt *Link) archive() {
 	argv = append(argv, hostobjCopy()...)
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "archive: %s\n", strings.Join(argv, " "))
-		ctxt.Bso.Flush()
+		ctxt.Logf("archive: %s\n", strings.Join(argv, " "))
 	}
 
 	if out, err := exec.Command(argv[0], argv[1:]...).CombinedOutput(); err != nil {
@@ -1152,19 +1149,17 @@ func (l *Link) hostlink() {
 	}
 
 	if l.Debugvlog != 0 {
-		fmt.Fprintf(l.Bso, "host link:")
+		l.Logf("host link:")
 		for _, v := range argv {
-			fmt.Fprintf(l.Bso, " %q", v)
+			l.Logf(" %q", v)
 		}
-		fmt.Fprintf(l.Bso, "\n")
-		l.Bso.Flush()
+		l.Logf("\n")
 	}
 
 	if out, err := exec.Command(argv[0], argv[1:]...).CombinedOutput(); err != nil {
 		Exitf("running %s failed: %v\n%s", argv[0], err, out)
 	} else if l.Debugvlog != 0 && len(out) > 0 {
-		fmt.Fprintf(l.Bso, "%s", out)
-		l.Bso.Flush()
+		l.Logf("%s", out)
 	}
 
 	if !*FlagS && !debug_s && HEADTYPE == obj.Hdarwin {
@@ -1391,9 +1386,8 @@ func ldshlibsyms(ctxt *Link, shlib string) {
 			return
 		}
 	}
-	if ctxt.Debugvlog > 1 && ctxt.Bso != nil {
-		fmt.Fprintf(ctxt.Bso, "%5.2f ldshlibsyms: found library with name %s at %s\n", obj.Cputime(), shlib, libpath)
-		ctxt.Bso.Flush()
+	if ctxt.Debugvlog > 1 {
+		ctxt.Logf("%5.2f ldshlibsyms: found library with name %s at %s\n", obj.Cputime(), shlib, libpath)
 	}
 
 	f, err := elf.Open(libpath)
@@ -1944,8 +1938,7 @@ func genasmsym(ctxt *Link, put func(*Link, *Symbol, string, int, int64, int64, i
 	// Otherwise, off is addressing the saved program counter.
 	// Something underhanded is going on. Say nothing.
 	if ctxt.Debugvlog != 0 || *flagN {
-		fmt.Fprintf(ctxt.Bso, "%5.2f symsize = %d\n", obj.Cputime(), uint32(Symsize))
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f symsize = %d\n", obj.Cputime(), uint32(Symsize))
 	}
 }
 
@@ -2035,7 +2028,7 @@ func (ctxt *Link) callgraph() {
 				continue
 			}
 			if (r.Type == obj.R_CALL || r.Type == obj.R_CALLARM || r.Type == obj.R_CALLPOWER || r.Type == obj.R_CALLMIPS) && r.Sym.Type == obj.STEXT {
-				fmt.Fprintf(ctxt.Bso, "%s calls %s\n", s.Name, r.Sym.Name)
+				ctxt.Logf("%s calls %s\n", s.Name, r.Sym.Name)
 			}
 		}
 	}

src/cmd/link/internal/ld/link.go

@@ -208,6 +208,11 @@ func (l *Link) IncVersion() {
 	l.Hash = append(l.Hash, make(map[string]*Symbol))
 }
 
+func (l *Link) Logf(format string, args ...interface{}) {
+	fmt.Fprintf(l.Bso, format, args...)
+	l.Bso.Flush()
+}
+
 type Library struct {
 	Objref string
 	Srcref string

src/cmd/link/internal/ld/main.go

@@ -133,7 +133,6 @@ func Main() {
 	obj.Flagparse(usage)
 
 	startProfile()
-	ctxt.Bso = ctxt.Bso
 	if flagShared {
 		if Buildmode == BuildmodeUnset {
 			Buildmode = BuildmodeCShared
@@ -175,8 +174,7 @@ func Main() {
 	}
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "HEADER = -H%d -T0x%x -D0x%x -R0x%x\n", HEADTYPE, uint64(*FlagTextAddr), uint64(*FlagDataAddr), uint32(*FlagRound))
-		ctxt.Bso.Flush()
+		ctxt.Logf("HEADER = -H%d -T0x%x -D0x%x -R0x%x\n", HEADTYPE, uint64(*FlagTextAddr), uint64(*FlagDataAddr), uint32(*FlagRound))
 	}
 
 	if Buildmode == BuildmodeShared {
@@ -226,9 +224,9 @@ func Main() {
 	ctxt.hostlink()
 	ctxt.archive()
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f cpu time\n", obj.Cputime())
-		fmt.Fprintf(ctxt.Bso, "%d symbols\n", len(ctxt.Allsym))
-		fmt.Fprintf(ctxt.Bso, "%d liveness data\n", liveness)
+		ctxt.Logf("%5.2f cpu time\n", obj.Cputime())
+		ctxt.Logf("%d symbols\n", len(ctxt.Allsym))
+		ctxt.Logf("%d liveness data\n", liveness)
 	}
 
 	ctxt.Bso.Flush()

src/cmd/link/internal/ld/pcln.go

@@ -6,7 +6,6 @@ package ld
 
 import (
 	"cmd/internal/obj"
-	"fmt"
 	"log"
 	"os"
 	"path/filepath"
@@ -368,7 +367,7 @@ func (ctxt *Link) pclntab() {
 	ftab.Size = int64(len(ftab.P))
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f pclntab=%d bytes, funcdata total %d bytes\n", obj.Cputime(), ftab.Size, funcdataBytes)
+		ctxt.Logf("%5.2f pclntab=%d bytes, funcdata total %d bytes\n", obj.Cputime(), ftab.Size, funcdataBytes)
 	}
 }
 

src/cmd/link/internal/mips64/asm.go

@@ -184,8 +184,7 @@ func archrelocvariant(ctxt *ld.Link, r *ld.Reloc, s *ld.Symbol, t int64) int64 {
 
 func asmb(ctxt *ld.Link) {
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f asmb\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f asmb\n", obj.Cputime())
 	}
 
 	if ld.Iself {
@@ -202,8 +201,7 @@ func asmb(ctxt *ld.Link) {
 
 	if ld.Segrodata.Filelen > 0 {
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f rodatblk\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f rodatblk\n", obj.Cputime())
 		}
 
 		ld.Cseek(int64(ld.Segrodata.Fileoff))
@@ -211,8 +209,7 @@ func asmb(ctxt *ld.Link) {
 	}
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f datblk\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f datblk\n", obj.Cputime())
 	}
 
 	ld.Cseek(int64(ld.Segdata.Fileoff))
@@ -229,8 +226,7 @@ func asmb(ctxt *ld.Link) {
 	if !*ld.FlagS {
 		// TODO: rationalize
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f sym\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f sym\n", obj.Cputime())
 		}
 		switch ld.HEADTYPE {
 		default:
@@ -248,7 +244,7 @@ func asmb(ctxt *ld.Link) {
 		default:
 			if ld.Iself {
 				if ctxt.Debugvlog != 0 {
-					fmt.Fprintf(ctxt.Bso, "%5.2f elfsym\n", obj.Cputime())
+					ctxt.Logf("%5.2f elfsym\n", obj.Cputime())
 				}
 				ld.Asmelfsym(ctxt)
 				ld.Cflush()
@@ -277,8 +273,7 @@ func asmb(ctxt *ld.Link) {
 
 	ctxt.Cursym = nil
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f header\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f header\n", obj.Cputime())
 	}
 	ld.Cseek(0)
 	switch ld.HEADTYPE {

src/cmd/link/internal/ppc64/asm.go

@@ -805,8 +805,7 @@ func ensureglinkresolver(ctxt *ld.Link) *ld.Symbol {
 
 func asmb(ctxt *ld.Link) {
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f asmb\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f asmb\n", obj.Cputime())
 	}
 
 	if ld.Iself {
@@ -823,8 +822,7 @@ func asmb(ctxt *ld.Link) {
 
 	if ld.Segrodata.Filelen > 0 {
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f rodatblk\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f rodatblk\n", obj.Cputime())
 		}
 
 		ld.Cseek(int64(ld.Segrodata.Fileoff))
@@ -832,8 +830,7 @@ func asmb(ctxt *ld.Link) {
 	}
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f datblk\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f datblk\n", obj.Cputime())
 	}
 
 	ld.Cseek(int64(ld.Segdata.Fileoff))
@@ -850,8 +847,7 @@ func asmb(ctxt *ld.Link) {
 	if !*ld.FlagS {
 		// TODO: rationalize
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f sym\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f sym\n", obj.Cputime())
 		}
 		switch ld.HEADTYPE {
 		default:
@@ -869,7 +865,7 @@ func asmb(ctxt *ld.Link) {
 		default:
 			if ld.Iself {
 				if ctxt.Debugvlog != 0 {
-					fmt.Fprintf(ctxt.Bso, "%5.2f elfsym\n", obj.Cputime())
+					ctxt.Logf("%5.2f elfsym\n", obj.Cputime())
 				}
 				ld.Asmelfsym(ctxt)
 				ld.Cflush()
@@ -898,8 +894,7 @@ func asmb(ctxt *ld.Link) {
 
 	ctxt.Cursym = nil
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f header\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f header\n", obj.Cputime())
 	}
 	ld.Cseek(0)
 	switch ld.HEADTYPE {

src/cmd/link/internal/s390x/asm.go

@@ -500,8 +500,7 @@ func addgotsym(ctxt *ld.Link, s *ld.Symbol) {
 
 func asmb(ctxt *ld.Link) {
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f asmb\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f asmb\n", obj.Cputime())
 	}
 
 	if ld.Iself {
@@ -518,8 +517,7 @@ func asmb(ctxt *ld.Link) {
 
 	if ld.Segrodata.Filelen > 0 {
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f rodatblk\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f rodatblk\n", obj.Cputime())
 		}
 
 		ld.Cseek(int64(ld.Segrodata.Fileoff))
@@ -527,8 +525,7 @@ func asmb(ctxt *ld.Link) {
 	}
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f datblk\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f datblk\n", obj.Cputime())
 	}
 
 	ld.Cseek(int64(ld.Segdata.Fileoff))
@@ -547,22 +544,21 @@ func asmb(ctxt *ld.Link) {
 			ctxt.Diag("unsupported executable format")
 		}
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f sym\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f sym\n", obj.Cputime())
 		}
 		symo = uint32(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen)
 		symo = uint32(ld.Rnd(int64(symo), int64(*ld.FlagRound)))
 
 		ld.Cseek(int64(symo))
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f elfsym\n", obj.Cputime())
+			ctxt.Logf("%5.2f elfsym\n", obj.Cputime())
 		}
 		ld.Asmelfsym(ctxt)
 		ld.Cflush()
 		ld.Cwrite(ld.Elfstrdat)
 
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f dwarf\n", obj.Cputime())
+			ctxt.Logf("%5.2f dwarf\n", obj.Cputime())
 		}
 
 		if ld.Linkmode == ld.LinkExternal {
@@ -572,8 +568,7 @@ func asmb(ctxt *ld.Link) {
 
 	ctxt.Cursym = nil
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f header\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f header\n", obj.Cputime())
 	}
 	ld.Cseek(0)
 	switch ld.HEADTYPE {

src/cmd/link/internal/x86/asm.go

@@ -33,7 +33,6 @@ package x86
 import (
 	"cmd/internal/obj"
 	"cmd/link/internal/ld"
-	"fmt"
 	"log"
 )
 
@@ -626,8 +625,7 @@ func addgotsym(ctxt *ld.Link, s *ld.Symbol) {
 
 func asmb(ctxt *ld.Link) {
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f asmb\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f asmb\n", obj.Cputime())
 	}
 
 	if ld.Iself {
@@ -645,8 +643,7 @@ func asmb(ctxt *ld.Link) {
 
 	if ld.Segrodata.Filelen > 0 {
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f rodatblk\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f rodatblk\n", obj.Cputime())
 		}
 
 		ld.Cseek(int64(ld.Segrodata.Fileoff))
@@ -654,8 +651,7 @@ func asmb(ctxt *ld.Link) {
 	}
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f datblk\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f datblk\n", obj.Cputime())
 	}
 
 	ld.Cseek(int64(ld.Segdata.Fileoff))
@@ -676,8 +672,7 @@ func asmb(ctxt *ld.Link) {
 	if !*ld.FlagS {
 		// TODO: rationalize
 		if ctxt.Debugvlog != 0 {
-			fmt.Fprintf(ctxt.Bso, "%5.2f sym\n", obj.Cputime())
-			ctxt.Bso.Flush()
+			ctxt.Logf("%5.2f sym\n", obj.Cputime())
 		}
 		switch ld.HEADTYPE {
 		default:
@@ -702,7 +697,7 @@ func asmb(ctxt *ld.Link) {
 		default:
 			if ld.Iself {
 				if ctxt.Debugvlog != 0 {
-					fmt.Fprintf(ctxt.Bso, "%5.2f elfsym\n", obj.Cputime())
+					ctxt.Logf("%5.2f elfsym\n", obj.Cputime())
 				}
 				ld.Asmelfsym(ctxt)
 				ld.Cflush()
@@ -729,7 +724,7 @@ func asmb(ctxt *ld.Link) {
 
 		case obj.Hwindows:
 			if ctxt.Debugvlog != 0 {
-				fmt.Fprintf(ctxt.Bso, "%5.2f dwarf\n", obj.Cputime())
+				ctxt.Logf("%5.2f dwarf\n", obj.Cputime())
 			}
 
 		case obj.Hdarwin:
@@ -740,8 +735,7 @@ func asmb(ctxt *ld.Link) {
 	}
 
 	if ctxt.Debugvlog != 0 {
-		fmt.Fprintf(ctxt.Bso, "%5.2f headr\n", obj.Cputime())
-		ctxt.Bso.Flush()
+		ctxt.Logf("%5.2f headr\n", obj.Cputime())
 	}
 	ld.Cseek(0)
 	switch ld.HEADTYPE {