platform_build_soong/cc/xom.go

80 lines
2.1 KiB
Go

// Copyright 2018 Google Inc. All rights reserved.
//
// 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.
package cc
import (
"android/soong/android"
)
type XomProperties struct {
Xom *bool
}
type xom struct {
Properties XomProperties
}
func (xom *xom) props() []interface{} {
return []interface{}{&xom.Properties}
}
func (xom *xom) begin(ctx BaseModuleContext) {}
func (xom *xom) deps(ctx BaseModuleContext, deps Deps) Deps {
return deps
}
func (xom *xom) flags(ctx ModuleContext, flags Flags) Flags {
disableXom := false
if !ctx.Config().EnableXOM() || ctx.Config().XOMDisabledForPath(ctx.ModuleDir()) {
disableXom = true
}
if xom.Properties.Xom != nil && !*xom.Properties.Xom {
return flags
}
// If any static dependencies have XOM disabled, we should disable XOM in this module,
// the assumption being if it's been explicitly disabled then there's probably incompatible
// code in the library which may get pulled in.
if !disableXom {
ctx.VisitDirectDeps(func(m android.Module) {
cc, ok := m.(*Module)
if !ok || cc.xom == nil || !cc.static() {
return
}
if cc.xom.Properties.Xom != nil && !*cc.xom.Properties.Xom {
disableXom = true
return
}
})
}
// Enable execute-only if none of the dependencies disable it,
// also if it's explicitly set true (allows overriding dependencies disabling it).
if !disableXom || (xom.Properties.Xom != nil && *xom.Properties.Xom) {
// XOM is only supported on AArch64 when using lld.
if ctx.Arch().ArchType == android.Arm64 && ctx.useClangLld(ctx) {
flags.Local.LdFlags = append(flags.Local.LdFlags,
"-Wl,--execute-only",
"-Wl,-z,separate-code",
)
}
}
return flags
}