Build ForkWithFlags and part of NamespaceSandbox under nonsfi newlib.

sandbox/linux/system_headers/linux_signal.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SANDBOX_LINUX_SYSTEM_HEADERS_LINUX_SIGNAL_H_
 #define SANDBOX_LINUX_SYSTEM_HEADERS_LINUX_SIGNAL_H_
 
 // NOTE: On some toolchains, signal related ABI is incompatible with Linux's
 // (not undefined, but defined different values and in different memory
 // layouts). So, fill the gap here.
 
 #if defined(__native_client_nonsfi__)
 #if !defined(__i386__) && !defined(__arm__)
 #error "Unsupported platform"
 #endif
 
 #include <signal.h>
 
+
+#define LINUX_SIGHUP 1    // 1 in PNaCl toolchain. Defined for consistency.

[rickyz (no longer on Chrome), 2015/06/16 20:57:07]

I got these from
native_client/toolchain/linux_x86/pnacl_newlib/le32-nacl/include/sys/signal.h -
is that correct?

+#define LINUX_SIGINT 2    // 2 in PNaCl toolchain. Defined for consistency.
+#define LINUX_SIGQUIT 3   // 3 in PNaCl toolchain. Defined for consistency.
+#define LINUX_SIGABRT 6   // 6 in PNaCl toolchain. Defined for consistency.
 #define LINUX_SIGBUS 7    // 10 in PNaCl toolchain.
+#define LINUX_SIGUSR1 10  // 30 in PNaCl toolchain.
 #define LINUX_SIGSEGV 11  // 11 in PNaCl toolchain. Defined for consistency.
+#define LINUX_SIGUSR2 12  // 31 in PNaCl toolchain.
+#define LINUX_SIGPIPE 13  // 13 in PNaCl toolchain. Defined for consistency.
+#define LINUX_SIGTERM 15  // 15 in PNaCl toolchain. Defined for consistency.
 #define LINUX_SIGCHLD 17  // 20 in PNaCl toolchain.
 #define LINUX_SIGSYS 31   // 12 in PNaCl toolchain.
 
 #define LINUX_SIG_BLOCK 0    // 1 in PNaCl toolchain.
 #define LINUX_SIG_UNBLOCK 1  // 2 in PNaCl toolchain.
 
 #define LINUX_SA_SIGINFO 4           // 2 in PNaCl toolchain.
 #define LINUX_SA_NODEFER 0x40000000  // Undefined in PNaCl toolchain.
 #define LINUX_SA_RESTART 0x10000000  // Undefined in PNaCl toolchain.
 
 #define LINUX_SIG_DFL 0  // In PNaCl toolchain, unneeded cast is applied.
 
 struct LinuxSigInfo {
   int si_signo;
   int si_errno;
   int si_code;
 
   // Extra data is followed by the |si_code|. The length depends on the
   // signal number.
   char _sifields[1];
 };
 
 #include "sandbox/linux/system_headers/linux_ucontext.h"
 
 #else  // !defined(__native_client_nonsfi__)
 
 // Just alias the toolchain's value.
 #include <signal.h>
 
+#define LINUX_SIGHUP SIGHUP

[jln (very slow on Chromium), 2015/06/18 18:23:20]

Wouldn't it be better to:

1. Always use the #define above for LINUX_* always
2. Add a COMPILE_ASSERT for each to check that they match when we do have the
system headers

[rickyz (no longer on Chrome), 2015/06/18 22:50:57]

Done.

+#define LINUX_SIGINT SIGINT
+#define LINUX_SIGQUIT SIGQUIT
+#define LINUX_SIGABRT SIGABRT
 #define LINUX_SIGBUS SIGBUS
+#define LINUX_SIGUSR1 SIGUSR1
 #define LINUX_SIGSEGV SIGSEGV
+#define LINUX_SIGUSR2 SIGUSR2
+#define LINUX_SIGPIPE SIGPIPE
+#define LINUX_SIGTERM SIGTERM
 #define LINUX_SIGCHLD SIGCHLD
 #define LINUX_SIGSYS SIGSYS
 
 #define LINUX_SIG_BLOCK SIG_BLOCK
 #define LINUX_SIG_UNBLOCK SIG_UNBLOCK
 
 #define LINUX_SA_SIGINFO SA_SIGINFO
 #define LINUX_SA_NODEFER SA_NODEFER
 #define LINUX_SA_RESTART SA_RESTART
 
 #define LINUX_SIG_DFL SIG_DFL
 
 typedef siginfo_t LinuxSigInfo;
 
 #if defined(__ANDROID__)
 // Android's signal.h doesn't define ucontext etc.
 #include "sandbox/linux/system_headers/linux_ucontext.h"
 #endif  // defined(__ANDROID__)
 
 #endif  // !defined(__native_client_nonsfi__)
 
 #endif  // SANDBOX_LINUX_SYSTEM_HEADERS_LINUX_SIGNAL_H_