tools/syz-declextract: allow to run on subset of arches

This may be useful for downstream kernels that only build
and are supposed to be used with a subset of arches.
Some esoteric arches may be broken on such kernels.
Allow to ignore them.

2 files changed, 65 insertions, 0 deletions

diff --git a/pkg/tool/flags.go b/pkg/tool/flags.go
index ec0d3015f..c74026540 100644
--- a/pkg/tool/flags.go
+++ b/pkg/tool/flags.go
@@ -9,9 +9,11 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"sort"
 	"strings"
 
 	"github.com/google/syzkaller/pkg/log"
+	"github.com/google/syzkaller/sys/targets"
 )
 
 type Flag struct {
@@ -50,6 +52,30 @@ func ParseFlags(set *flag.FlagSet, args []string) error {
 	return nil
 }
 
+func ParseArchList(OS, archList string) ([]string, error) {
+	allArches := targets.List[OS]
+	if allArches == nil {
+		return nil, fmt.Errorf("bad OS %q", OS)
+	}
+	archMap := make(map[string]bool)
+	if archList != "" {
+		for _, arch := range strings.Split(archList, ",") {
+			if allArches[arch] == nil {
+				return nil, fmt.Errorf("bad arch %q for OS %q in arches flag", arch, OS)
+			}
+			archMap[arch] = true
+		}
+	}
+	var arches []string
+	for arch := range allArches {
+		if len(archMap) == 0 || archMap[arch] {
+			arches = append(arches, arch)
+		}
+	}
+	sort.Strings(arches)
+	return arches, nil
+}
+
 const optionalFlag = "optional"
 
 func serializeFlags(flags []Flag) string {
diff --git a/pkg/tool/flags_test.go b/pkg/tool/flags_test.go
index 0503c48fc..df642bca6 100644
--- a/pkg/tool/flags_test.go
+++ b/pkg/tool/flags_test.go
@@ -4,6 +4,7 @@
 package tool
 
 import (
+	"errors"
 	"flag"
 	"fmt"
 	"io"
@@ -11,6 +12,7 @@ import (
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
+	"github.com/stretchr/testify/assert"
 )
 
 func TestParseFlags(t *testing.T) {
@@ -84,3 +86,40 @@ func TestCfgsFlagAlreadySet(t *testing.T) {
 		t.Errorf("cfgs.Set got: nil, want: error")
 	}
 }
+
+func TestParseArchList(t *testing.T) {
+	type Test struct {
+		OS  string
+		In  string
+		Out []string
+		Err error
+	}
+	tests := []Test{
+		{
+			OS:  "foo",
+			Err: errors.New(`bad OS "foo"`),
+		},
+		{
+			OS:  "linux",
+			In:  "amd64,bar",
+			Err: errors.New(`bad arch "bar" for OS "linux" in arches flag`),
+		},
+		{
+			OS:  "linux",
+			In:  "",
+			Out: []string{"386", "amd64", "arm", "arm64", "mips64le", "ppc64le", "riscv64", "s390x"},
+		},
+		{
+			OS:  "linux",
+			In:  "ppc64le,386",
+			Out: []string{"386", "ppc64le"},
+		},
+	}
+	for i, test := range tests {
+		t.Run(fmt.Sprint(i), func(t *testing.T) {
+			got, err := ParseArchList(test.OS, test.In)
+			assert.Equal(t, err, test.Err)
+			assert.Equal(t, got, test.Out)
+		})
+	}
+}