Linux Sandbox: get everything to compile on Android.

sandbox/linux/seccomp-bpf/sandbox_bpf.cc

Index: sandbox/linux/seccomp-bpf/sandbox_bpf.cc
diff --git a/sandbox/linux/seccomp-bpf/sandbox_bpf.cc b/sandbox/linux/seccomp-bpf/sandbox_bpf.cc
index 740320fa326045c29e847a79a9c537970fd2fa8b..b999430ed07d4c3c1c5b700c4fbf522dd7aa590e 100644
--- a/sandbox/linux/seccomp-bpf/sandbox_bpf.cc
+++ b/sandbox/linux/seccomp-bpf/sandbox_bpf.cc
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <signal.h>
+#include <sys/syscall.h>
+
 #ifndef SECCOMP_BPF_STANDALONE
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
@@ -13,6 +16,11 @@
 #include "sandbox/linux/seccomp-bpf/syscall_iterator.h"
 #include "sandbox/linux/seccomp-bpf/verifier.h"
 
+// Android's signal.h doesn't define ucontext etc.
+#if defined(OS_ANDROID) && defined(__arm__)
+#include "sandbox/linux/services/android_arm_ucontext.h"
+#endif
+
 namespace {
 
 void WriteFailedStderrSetupMessage(int out_fd) {
@@ -39,7 +47,9 @@ void WriteFailedStderrSetupMessage(int out_fd) {
 // realtime signals. There are plenty of them. Unfortunately, there is no
 // way to mark a signal as allocated. So, the potential for collision is
 // possibly even worse.
-bool GetIsInSigHandler(const ucontext_t *ctx) {
+// Note: we can't use "const ucontext_t" because on Android, sigismember does
+// not take a pointer to const.
+bool GetIsInSigHandler(ucontext_t *ctx) {

[Markus (顧孟勤), 2012/12/19 00:44:54]

I probably would have left the function signature unchanged, as it looks more
correct with the "const". And I would then have performed a const_cast<>() in
the function body.

But it's really your call. I doesn't much matter either way.

[jln (very slow on Chromium), 2012/12/19 01:45:32]

I was worried that sigismember() might touch the sigmask, but it is crazy. Added
a const_cast.

   return sigismember(&ctx->uc_sigmask, SIGBUS);
 }