cmd/link: deprecate -X name value in favor of -X name=value
People invoking the linker directly already have to change their scripts
to use the new "go tool link", so this is a good time to make the -X flag
behave like all other Go flags and take just a single argument.
The old syntax will continue to be accepted (it is rewritten into the new
syntax before flag parsing). Maybe some day we will be able to retire it.
Even if we never retire the old syntax, having the new syntax at least
makes the rewriting much less of a kludge.
Change-Id: I91e8df94f4c22b2186e81d7f1016b8767d777eac
Reviewed-on: https://go-review.googlesource.com/10310
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go
index 2ffba87..52c6f4c 100644
--- a/src/cmd/link/internal/ld/data.go
+++ b/src/cmd/link/internal/ld/data.go
@@ -917,14 +917,12 @@
}
}
-var addstrdata_name string
-
func addstrdata1(arg string) {
- if strings.HasPrefix(arg, "VALUE:") {
- addstrdata(addstrdata_name, arg[6:])
- } else {
- addstrdata_name = arg
+ i := strings.Index(arg, "=")
+ if i < 0 {
+ Exitf("-X flag requires argument of the form importpath.name=value")
}
+ addstrdata(arg[:i], arg[i+1:])
}
func addstrdata(name string, value string) {
diff --git a/src/cmd/link/internal/ld/pobj.go b/src/cmd/link/internal/ld/pobj.go
index 60d584f..20f060c 100644
--- a/src/cmd/link/internal/ld/pobj.go
+++ b/src/cmd/link/internal/ld/pobj.go
@@ -102,7 +102,7 @@
obj.Flagint64("T", "set text segment `address`", &INITTEXT)
obj.Flagfn0("V", "print version and exit", doversion)
obj.Flagcount("W", "disassemble input", &Debug['W'])
- obj.Flagfn1("X", "set the value of a string variable; the next two arguments are its name and value", addstrdata1)
+ obj.Flagfn1("X", "add string value `definition` of the form importpath.name=value", addstrdata1)
obj.Flagcount("Z", "clear stack frame on entry", &Debug['Z'])
obj.Flagcount("a", "disassemble output", &Debug['a'])
obj.Flagstr("buildid", "record `id` as Go toolchain build id", &buildid)
@@ -132,21 +132,39 @@
obj.Flagcount("v", "print link trace", &Debug['v'])
obj.Flagcount("w", "disable DWARF generation", &Debug['w'])
- // Clumsy hack to preserve old behavior of -X taking two arguments.
- for i := 0; i < len(os.Args); i++ {
- arg := os.Args[i]
- if (arg == "--X" || arg == "-X") && i+2 < len(os.Args) {
- os.Args[i+2] = "-X=VALUE:" + os.Args[i+2]
- i += 2
- } else if (strings.HasPrefix(arg, "--X=") || strings.HasPrefix(arg, "-X=")) && i+1 < len(os.Args) {
- os.Args[i+1] = "-X=VALUE:" + os.Args[i+1]
- i++
- }
- }
obj.Flagstr("cpuprofile", "write cpu profile to `file`", &cpuprofile)
obj.Flagstr("memprofile", "write memory profile to `file`", &memprofile)
obj.Flagint64("memprofilerate", "set runtime.MemProfileRate to `rate`", &memprofilerate)
+
+ // Clumsy hack to preserve old two-argument -X name val syntax for old scripts.
+ // Rewrite that syntax into new syntax -X name=val.
+ // TODO(rsc): Delete this hack in Go 1.6 or later.
+ var args []string
+ for i := 0; i < len(os.Args); i++ {
+ arg := os.Args[i]
+ if (arg == "-X" || arg == "--X") && i+2 < len(os.Args) && !strings.Contains(os.Args[i+1], "=") {
+ fmt.Fprintf(os.Stderr, "link: warning: option %s %s %s may not work in future releases; use %s %s=%s\n",
+ arg, os.Args[i+1], os.Args[i+2],
+ arg, os.Args[i+1], os.Args[i+2])
+ args = append(args, arg)
+ args = append(args, os.Args[i+1]+"="+os.Args[i+2])
+ i += 2
+ continue
+ }
+ if (strings.HasPrefix(arg, "-X=") || strings.HasPrefix(arg, "--X=")) && i+1 < len(os.Args) && strings.Count(arg, "=") == 1 {
+ fmt.Fprintf(os.Stderr, "link: warning: option %s %s may not work in future releases; use %s=%s\n",
+ arg, os.Args[i+1],
+ arg, os.Args[i+1])
+ args = append(args, arg+"="+os.Args[i+1])
+ i++
+ continue
+ }
+ args = append(args, arg)
+ }
+ os.Args = args
+
obj.Flagparse(usage)
+
startProfile()
Ctxt.Bso = &Bso
Ctxt.Debugvlog = int32(Debug['v'])
diff --git a/test/linkx.go b/test/linkx.go
index 151b6db..40ec1b9 100644
--- a/test/linkx.go
+++ b/test/linkx.go
@@ -9,10 +9,12 @@
package main
+import "fmt"
+
var tbd string
var overwrite string = "dibs"
func main() {
- println(tbd)
- println(overwrite)
+ fmt.Println(tbd)
+ fmt.Println(overwrite)
}
diff --git a/test/linkx_run.go b/test/linkx_run.go
index f3029f5..cc0f55c 100644
--- a/test/linkx_run.go
+++ b/test/linkx_run.go
@@ -10,23 +10,33 @@
package main
import (
+ "bytes"
"fmt"
"os"
"os/exec"
)
func main() {
+ test(" ") // old deprecated syntax
+ test("=") // new syntax
+}
+
+func test(sep string) {
// Successful run
- cmd := exec.Command("go", "run", "-ldflags=-X main.tbd hello -X main.overwrite trumped -X main.nosuchsymbol neverseen", "linkx.go")
- out, err := cmd.CombinedOutput()
+ cmd := exec.Command("go", "run", "-ldflags=-X main.tbd"+sep+"hello -X main.overwrite"+sep+"trumped -X main.nosuchsymbol"+sep+"neverseen", "linkx.go")
+ var out, errbuf bytes.Buffer
+ cmd.Stdout = &out
+ cmd.Stderr = &errbuf
+ err := cmd.Run()
if err != nil {
- fmt.Println(string(out))
+ fmt.Println(errbuf.String())
+ fmt.Println(out.String())
fmt.Println(err)
os.Exit(1)
}
want := "hello\ntrumped\n"
- got := string(out)
+ got := out.String()
if got != want {
fmt.Printf("got %q want %q\n", got, want)
os.Exit(1)
