cmd/compile: move dumpFileSeq

I noticed that there is a Todo comment here. This variable is only used for filename when dump a function's ssa passes result in details. It is no problem to print a function alone, but may be edited by not only one goroutine if dump multiple functions at the same time. Although it looks only dump one function's ssa passes now. As far as I am concerned this variable can be a member variable of the struct Func. I'm not sure if this change is necessary. Looking forward to your advices, thank you very much.

Change-Id: I35dd7247889e0cc7f19c0b400b597206592dee75
Reviewed-on: https://go-review.googlesource.com/c/go/+/244918
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>

src/cmd/compile/internal/ssa/compile.go

@@ -160,15 +160,12 @@ func Compile(f *Func) {
 	phaseName = ""
 }
 
-// TODO: should be a config field
-var dumpFileSeq int
-
 // dumpFile creates a file from the phase name and function name
 // Dumping is done to files to avoid buffering huge strings before
 // output.
 func (f *Func) dumpFile(phaseName string) {
-	dumpFileSeq++
-	fname := fmt.Sprintf("%s_%02d__%s.dump", f.Name, dumpFileSeq, phaseName)
+	f.dumpFileSeq++
+	fname := fmt.Sprintf("%s_%02d__%s.dump", f.Name, int(f.dumpFileSeq), phaseName)
 	fname = strings.Replace(fname, " ", "_", -1)
 	fname = strings.Replace(fname, "/", "_", -1)
 	fname = strings.Replace(fname, ":", "_", -1)

src/cmd/compile/internal/ssa/func.go

@@ -47,6 +47,7 @@ type Func struct {
 	scheduled   bool  // Values in Blocks are in final order
 	laidout     bool  // Blocks are ordered
 	NoSplit     bool  // true if function is marked as nosplit.  Used by schedule check pass.
+	dumpFileSeq uint8 // the sequence numbers of dump file. (%s_%02d__%s.dump", funcname, dumpFileSeq, phaseName)
 
 	// when register allocation is done, maps value ids to locations
 	RegAlloc []Location