Move x86 state definition to its own file.

PiperOrigin-RevId: 294271541

pkg/sentry/arch/BUILD

@@ -14,6 +14,7 @@ go_library(
         "arch_state_aarch64.go",
         "arch_state_x86.go",
         "arch_x86.go",
+        "arch_x86_impl.go",
         "auxv.go",
         "signal.go",
         "signal_act.go",

pkg/sentry/arch/arch_state_x86.go

@@ -43,8 +43,8 @@ func (e ErrFloatingPoint) Error() string {
 // and SSE state, so this is the equivalent XSTATE_BV value.
 const fxsaveBV uint64 = cpuid.XSAVEFeatureX87 | cpuid.XSAVEFeatureSSE
 
-// afterLoad is invoked by stateify.
-func (s *State) afterLoad() {
+// afterLoadFPState is invoked by afterLoad.
+func (s *State) afterLoadFPState() {
 	old := s.x86FPState
 
 	// Recreate the slice. This is done to ensure that it is aligned

pkg/sentry/arch/arch_x86.go

@@ -155,21 +155,6 @@ func NewFloatingPointData() *FloatingPointData {
 	return (*FloatingPointData)(&(newX86FPState()[0]))
 }
 
-// State contains the common architecture bits for X86 (the build tag of this
-// file ensures it's only built on x86).
-//
-// +stateify savable
-type State struct {
-	// The system registers.
-	Regs syscall.PtraceRegs `state:".(syscallPtraceRegs)"`
-
-	// Our floating point state.
-	x86FPState `state:"wait"`
-
-	// FeatureSet is a pointer to the currently active feature set.
-	FeatureSet *cpuid.FeatureSet
-}
-
 // Proto returns a protobuf representation of the system registers in State.
 func (s State) Proto() *rpb.Registers {
 	regs := &rpb.AMD64Registers{

pkg/sentry/arch/arch_x86_impl.go

@@ -0,0 +1,43 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build amd64 i386
+
+package arch
+
+import (
+	"syscall"
+
+	"gvisor.dev/gvisor/pkg/cpuid"
+)
+
+// State contains the common architecture bits for X86 (the build tag of this
+// file ensures it's only built on x86).
+//
+// +stateify savable
+type State struct {
+	// The system registers.
+	Regs syscall.PtraceRegs `state:".(syscallPtraceRegs)"`
+
+	// Our floating point state.
+	x86FPState `state:"wait"`
+
+	// FeatureSet is a pointer to the currently active feature set.
+	FeatureSet *cpuid.FeatureSet
+}
+
+// afterLoad is invoked by stateify.
+func (s *State) afterLoad() {
+	s.afterLoadFPState()
+}

tools/build/tags.bzl

@@ -3,22 +3,28 @@
 go_suffixes = [
     "_386",
     "_386_unsafe",
-    "_amd64",
-    "_amd64_unsafe",
     "_aarch64",
     "_aarch64_unsafe",
+    "_amd64",
+    "_amd64_unsafe",
     "_arm",
-    "_arm_unsafe",
     "_arm64",
     "_arm64_unsafe",
+    "_arm_unsafe",
+    "_impl",
+    "_impl_unsafe",
+    "_linux",
+    "_linux_unsafe",
     "_mips",
-    "_mips_unsafe",
-    "_mipsle",
-    "_mipsle_unsafe",
     "_mips64",
     "_mips64_unsafe",
     "_mips64le",
     "_mips64le_unsafe",
+    "_mips_unsafe",
+    "_mipsle",
+    "_mipsle_unsafe",
+    "_opts",
+    "_opts_unsafe",
     "_ppc64",
     "_ppc64_unsafe",
     "_ppc64le",
@@ -31,10 +37,4 @@ go_suffixes = [
     "_sparc64_unsafe",
     "_wasm",
     "_wasm_unsafe",
-    "_linux",
-    "_linux_unsafe",
-    "_opts",
-    "_opts_unsafe",
-    "_impl",
-    "_impl_unsafe",
 ]