cmd/compile: remove -dolinkobj flag

This used to be used by cmd/vet and some assembly generation tests, but
those were removed in CL 37691 and CL 107336. No point in keeping an
unneeded flag around.

Fixes #28220.

Change-Id: I59f8546954ab36ea61ceba81c10d6e16d74b966a
Reviewed-on: https://go-review.googlesource.com/c/142677
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

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

@@ -92,7 +92,6 @@ var pragcgobuf [][]string
 
 var outfile string
 var linkobj string
-var dolinkobj bool
 
 // nerrors is the number of compiler errors reported
 // since the last call to saveerrors.

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

@@ -218,7 +218,6 @@ func Main(archInit func(*Arch)) {
 	if sys.MSanSupported(objabi.GOOS, objabi.GOARCH) {
 		flag.BoolVar(&flag_msan, "msan", false, "build code compatible with C/C++ memory sanitizer")
 	}
-	flag.BoolVar(&dolinkobj, "dolinkobj", true, "generate linker-specific objects; if false, some invalid code may compile")
 	flag.BoolVar(&nolocalimports, "nolocalimports", false, "reject local (relative) imports")
 	flag.StringVar(&outfile, "o", "", "write output to `file`")
 	flag.StringVar(&myimportpath, "p", "", "set expected package import `path`")
@@ -606,71 +605,69 @@ func Main(archInit func(*Arch)) {
 	timings.Start("fe", "escapes")
 	escapes(xtop)
 
-	if dolinkobj {
-		// Collect information for go:nowritebarrierrec
-		// checking. This must happen before transformclosure.
-		// We'll do the final check after write barriers are
-		// inserted.
-		if compiling_runtime {
-			nowritebarrierrecCheck = newNowritebarrierrecChecker()
-		}
+	// Collect information for go:nowritebarrierrec
+	// checking. This must happen before transformclosure.
+	// We'll do the final check after write barriers are
+	// inserted.
+	if compiling_runtime {
+		nowritebarrierrecCheck = newNowritebarrierrecChecker()
+	}
 
-		// Phase 7: Transform closure bodies to properly reference captured variables.
-		// This needs to happen before walk, because closures must be transformed
-		// before walk reaches a call of a closure.
-		timings.Start("fe", "xclosures")
-		for _, n := range xtop {
-			if n.Op == ODCLFUNC && n.Func.Closure != nil {
-				Curfn = n
-				transformclosure(n)
-			}
+	// Phase 7: Transform closure bodies to properly reference captured variables.
+	// This needs to happen before walk, because closures must be transformed
+	// before walk reaches a call of a closure.
+	timings.Start("fe", "xclosures")
+	for _, n := range xtop {
+		if n.Op == ODCLFUNC && n.Func.Closure != nil {
+			Curfn = n
+			transformclosure(n)
 		}
+	}
 
-		// Prepare for SSA compilation.
-		// This must be before peekitabs, because peekitabs
-		// can trigger function compilation.
-		initssaconfig()
-
-		// Just before compilation, compile itabs found on
-		// the right side of OCONVIFACE so that methods
-		// can be de-virtualized during compilation.
-		Curfn = nil
-		peekitabs()
-
-		// Phase 8: Compile top level functions.
-		// Don't use range--walk can add functions to xtop.
-		timings.Start("be", "compilefuncs")
-		fcount = 0
-		for i := 0; i < len(xtop); i++ {
-			n := xtop[i]
-			if n.Op == ODCLFUNC {
-				funccompile(n)
-				fcount++
-			}
-		}
-		timings.AddEvent(fcount, "funcs")
+	// Prepare for SSA compilation.
+	// This must be before peekitabs, because peekitabs
+	// can trigger function compilation.
+	initssaconfig()
+
+	// Just before compilation, compile itabs found on
+	// the right side of OCONVIFACE so that methods
+	// can be de-virtualized during compilation.
+	Curfn = nil
+	peekitabs()
 
-		if nsavederrors+nerrors == 0 {
-			fninit(xtop)
+	// Phase 8: Compile top level functions.
+	// Don't use range--walk can add functions to xtop.
+	timings.Start("be", "compilefuncs")
+	fcount = 0
+	for i := 0; i < len(xtop); i++ {
+		n := xtop[i]
+		if n.Op == ODCLFUNC {
+			funccompile(n)
+			fcount++
 		}
+	}
+	timings.AddEvent(fcount, "funcs")
 
-		compileFunctions()
+	if nsavederrors+nerrors == 0 {
+		fninit(xtop)
+	}
 
-		if nowritebarrierrecCheck != nil {
-			// Write barriers are now known. Check the
-			// call graph.
-			nowritebarrierrecCheck.check()
-			nowritebarrierrecCheck = nil
-		}
+	compileFunctions()
 
-		// Finalize DWARF inline routine DIEs, then explicitly turn off
-		// DWARF inlining gen so as to avoid problems with generated
-		// method wrappers.
-		if Ctxt.DwFixups != nil {
-			Ctxt.DwFixups.Finalize(myimportpath, Debug_gendwarfinl != 0)
-			Ctxt.DwFixups = nil
-			genDwarfInline = 0
-		}
+	if nowritebarrierrecCheck != nil {
+		// Write barriers are now known. Check the
+		// call graph.
+		nowritebarrierrecCheck.check()
+		nowritebarrierrecCheck = nil
+	}
+
+	// Finalize DWARF inline routine DIEs, then explicitly turn off
+	// DWARF inlining gen so as to avoid problems with generated
+	// method wrappers.
+	if Ctxt.DwFixups != nil {
+		Ctxt.DwFixups.Finalize(myimportpath, Debug_gendwarfinl != 0)
+		Ctxt.DwFixups = nil
+		genDwarfInline = 0
 	}
 
 	// Phase 9: Check external declarations.

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

@@ -43,10 +43,6 @@ const (
 )
 
 func dumpobj() {
-	if !dolinkobj {
-		dumpobj1(outfile, modeCompilerObj)
-		return
-	}
 	if linkobj == "" {
 		dumpobj1(outfile, modeCompilerObj|modeLinkerObj)
 		return