service/debugger: merge attachErrorMessage, verifyBinaryFormat (#3142)

These functions don't need to be conditionally compiled and they share
substanatial amounts of code in all their OS-specific versions.

service/debugger/debugger.go

@@ -3,11 +3,15 @@ package debugger
 import (
 	"bytes"
 	"debug/dwarf"
+	"debug/elf"
+	"debug/macho"
+	"debug/pe"
 	"errors"
 	"fmt"
 	"go/parser"
 	"go/token"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"regexp"
 	"runtime"
@@ -2304,3 +2308,55 @@ func noDebugErrorWarning(err error) error {
 	}
 	return err
 }
+
+func verifyBinaryFormat(exePath string) error {
+	f, err := os.Open(exePath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	switch runtime.GOOS {
+	case "windows":
+		// Make sure the binary exists and is an executable file
+		if filepath.Base(exePath) == exePath {
+			if _, err := exec.LookPath(exePath); err != nil {
+				return err
+			}
+		}
+	default:
+		fi, err := f.Stat()
+		if err != nil {
+			return err
+		}
+		if (fi.Mode() & 0111) == 0 {
+			return api.ErrNotExecutable
+		}
+	}
+
+	// check that the binary format is what we expect for the host system
+	var exe interface{ Close() error }
+
+	switch runtime.GOOS {
+	case "darwin":
+		exe, err = macho.NewFile(f)
+	case "linux", "freebsd":
+		exe, err = elf.NewFile(f)
+	case "windows":
+		exe, err = pe.NewFile(f)
+	default:
+		panic("attempting to open file Delve cannot parse")
+	}
+
+	if err != nil {
+		return api.ErrNotExecutable
+	}
+	exe.Close()
+	return nil
+}
+
+var attachErrorMessage = attachErrorMessageDefault
+
+func attachErrorMessageDefault(pid int, err error) error {
+	return fmt.Errorf("could not attach to pid %d: %s", pid, err)
+}

service/debugger/debugger_darwin.go

@@ -1,10 +0,0 @@
-package debugger
-
-import (
-	"fmt"
-)
-
-func attachErrorMessage(pid int, err error) error {
-	//TODO: mention certificates?
-	return fmt.Errorf("could not attach to pid %d: %s", pid, err)
-}

service/debugger/debugger_freebsd.go

@@ -1,9 +0,0 @@
-package debugger
-
-import (
-	"fmt"
-)
-
-func attachErrorMessage(pid int, err error) error {
-	return fmt.Errorf("could not attach to pid %d: %s", pid, err)
-}

service/debugger/debugger_linux.go

@@ -7,9 +7,13 @@ import (
 	"syscall"
 )
 
+func init() {
+	attachErrorMessage = attachErrorMessageLinux
+}
+
 //lint:file-ignore ST1005 errors here can be capitalized
 
-func attachErrorMessage(pid int, err error) error {
+func attachErrorMessageLinux(pid int, err error) error {
 	fallbackerr := fmt.Errorf("could not attach to pid %d: %s", pid, err)
 	if serr, ok := err.(syscall.Errno); ok {
 		switch serr {

service/debugger/debugger_unix.go

@@ -1,45 +0,0 @@
-//go:build !windows
-// +build !windows
-
-package debugger
-
-import (
-	"debug/elf"
-	"debug/macho"
-	"os"
-	"runtime"
-
-	"github.com/go-delve/delve/service/api"
-)
-
-func verifyBinaryFormat(exePath string) error {
-	f, err := os.Open(exePath)
-	if err != nil {
-		return err
-	}
-	defer f.Close()
-
-	fi, err := f.Stat()
-	if err != nil {
-		return err
-	}
-	if (fi.Mode() & 0111) == 0 {
-		return api.ErrNotExecutable
-	}
-
-	// check that the binary format is what we expect for the host system
-	var exe interface{ Close() error }
-	switch runtime.GOOS {
-	case "darwin":
-		exe, err = macho.NewFile(f)
-	case "linux", "freebsd":
-		exe, err = elf.NewFile(f)
-	default:
-		panic("attempting to open file Delve cannot parse")
-	}
-	if err != nil {
-		return api.ErrNotExecutable
-	}
-	exe.Close()
-	return nil
-}

service/debugger/debugger_windows.go

@@ -1,37 +0,0 @@
-package debugger
-
-import (
-	"debug/pe"
-	"fmt"
-	"os"
-	"os/exec"
-	"path/filepath"
-
-	"github.com/go-delve/delve/service/api"
-)
-
-func attachErrorMessage(pid int, err error) error {
-	return fmt.Errorf("could not attach to pid %d: %s", pid, err)
-}
-
-func verifyBinaryFormat(exePath string) error {
-	f, err := os.Open(exePath)
-	if err != nil {
-		return err
-	}
-	defer f.Close()
-
-	// Make sure the binary exists and is an executable file
-	if filepath.Base(exePath) == exePath {
-		if _, err := exec.LookPath(exePath); err != nil {
-			return err
-		}
-	}
-
-	exe, err := pe.NewFile(f)
-	if err != nil {
-		return api.ErrNotExecutable
-	}
-	exe.Close()
-	return nil
-}