Makefile: don't compile all targets into target binaries

Currently target binaries contain support for all OS/arch combinations.
However, obviously a fuchsia target binary won't test windows.
For target binaries we need support only for a single target
(with the exception of 386/arm target in amd64/arm64 binaries).
So compile in only _the_ target into target binaries.
This reduces akaros/amd64 fuzzer binary from 33 to 7 MB
and execprog from 28 to 2 MB.

3 files changed, 10 insertions, 8 deletions

diff --git a/sys/netbsd/gen/amd64.go b/sys/netbsd/gen/amd64.go
index be9bbb998..cd7cdcd03 100644
--- a/sys/netbsd/gen/amd64.go
+++ b/sys/netbsd/gen/amd64.go
@@ -1,10 +1,14 @@
 // AUTOGENERATED FILE
+// +build !syz_target syz_target,syz_os_netbsd,syz_arch_amd64
 
 package gen
 
 import . "github.com/google/syzkaller/prog"
+import . "github.com/google/syzkaller/sys/netbsd"
 
-var Target_amd64 = &Target{OS: "netbsd", Arch: "amd64", Revision: revision_amd64, PtrSize: 8, PageSize: 4096, NumPages: 4096, DataOffset: 536870912, Syscalls: syscalls_amd64, Resources: resources_amd64, Structs: structDescs_amd64, Consts: consts_amd64}
+func init() {
+	RegisterTarget(&Target{OS: "netbsd", Arch: "amd64", Revision: revision_amd64, PtrSize: 8, PageSize: 4096, NumPages: 4096, DataOffset: 536870912, Syscalls: syscalls_amd64, Resources: resources_amd64, Structs: structDescs_amd64, Consts: consts_amd64}, InitTarget)
+}
 
 var resources_amd64 = []*ResourceDesc{
 	{Name: "fd", Type: &IntType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "int32", TypeSize: 4}}}, Kind: []string{"fd"}, Values: []uint64{18446744073709551615, 18446744073709551516}},
@@ -1673,4 +1677,4 @@ var consts_amd64 = []ConstValue{
 	{Name: "WUNTRACED", Value: 2},
 }
 
-const revision_amd64 = "cea6c87ab1f9e36df1927913a619e71cd29abcbf"
+const revision_amd64 = "c05720ceb16e651f6ae9addd1f5be83497d861e3"
diff --git a/sys/netbsd/gen/empty.go b/sys/netbsd/gen/empty.go
new file mode 100644
index 000000000..5baff07bf
--- /dev/null
+++ b/sys/netbsd/gen/empty.go
@@ -0,0 +1,3 @@
+// AUTOGENERATED FILE
+// This file is needed if OS is completely excluded by build tags.
+package gen
diff --git a/sys/netbsd/init.go b/sys/netbsd/init.go
index 908cbe655..7b6b1250e 100644
--- a/sys/netbsd/init.go
+++ b/sys/netbsd/init.go
@@ -5,15 +5,10 @@ package netbsd
 
 import (
 	"github.com/google/syzkaller/prog"
-	"github.com/google/syzkaller/sys/netbsd/gen"
 	"github.com/google/syzkaller/sys/targets"
 )
 
-func init() {
-	prog.RegisterTarget(gen.Target_amd64, initTarget)
-}
-
-func initTarget(target *prog.Target) {
+func InitTarget(target *prog.Target) {
 	arch := &arch{
 		MAP_FIXED: target.ConstMap["MAP_FIXED"],
 	}