[Ada] Update signal constants for GNU/Linux

Add the signal SIGSYS and mark the glibc reserved real-time signals
(32-34) as reserved rather than not maskable.

2018-11-14  Patrick Bernardi  <bernardi@adacore.com>

gcc/ada/

	* libgnarl/a-intnam__linux.ads: Add SIGSYS.
	* libgnarl/s-linux__alpha.ads, libgnarl/s-linux__android.ads,
	libgnarl/s-linux__hppa.ads, libgnarl/s-linux__mips.ads,
	libgnarl/s-linux__riscv.ads, libgnarl/s-linux__sparc.ads,
	libgnarl/s-linux__x32.ads: Rename SIGLTHRRES, SIGLTHRCAN and
	SIGLTHRDBG to SIG32, SIG33 and SIG34 as their names are
	implementation specific.
	* libgnarl/s-osinte__linux.ads, libgnarl/s-linux.ads: Add
	SIGSYS.  Move SIG32, SIG33 and SIG34 from the unmasked list to
	the reserved list.

gcc/testsuite/

	* gnat.dg/rt_signals.adb: New testcase.

From-SVN: r266136

gcc/ada/ChangeLog

+2018-11-14  Patrick Bernardi  <bernardi@adacore.com>
+
+	* libgnarl/a-intnam__linux.ads: Add SIGSYS.
+	* libgnarl/s-linux__alpha.ads, libgnarl/s-linux__android.ads,
+	libgnarl/s-linux__hppa.ads, libgnarl/s-linux__mips.ads,
+	libgnarl/s-linux__riscv.ads, libgnarl/s-linux__sparc.ads,
+	libgnarl/s-linux__x32.ads: Rename SIGLTHRRES, SIGLTHRCAN and
+	SIGLTHRDBG to SIG32, SIG33 and SIG34 as their names are
+	implementation specific.
+	* libgnarl/s-osinte__linux.ads, libgnarl/s-linux.ads: Add
+	SIGSYS.  Move SIG32, SIG33 and SIG34 from the unmasked list to
+	the reserved list.
+
 2018-11-14  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* exp_aggr.adb (Is_Static_Element): New predicate extracted

gcc/ada/libgnarl/a-intnam__linux.ads

@@ -160,4 +160,7 @@ package Ada.Interrupts.Names is
    SIGPWR : constant Interrupt_ID :=
      System.OS_Interface.SIGPWR;        --  Power failure
 
+   SIGSYS : constant Interrupt_ID :=
+     System.OS_Interface.SIGSYS;       --  bad system call
+
 end Ada.Interrupts.Names;

gcc/ada/libgnarl/s-linux.ads

@@ -86,34 +86,35 @@ package System.Linux is
    SIGFPE     : constant := 8; --  floating point exception
    SIGKILL    : constant := 9; --  kill (cannot be caught or ignored)
    SIGBUS     : constant := 7; --  bus error
+   SIGUSR1    : constant := 10; --  user defined signal 1
    SIGSEGV    : constant := 11; --  segmentation violation
+   SIGUSR2    : constant := 12; --  user defined signal 2
    SIGPIPE    : constant := 13; --  write on a pipe with no one to read it
    SIGALRM    : constant := 14; --  alarm clock
    SIGTERM    : constant := 15; --  software termination signal from kill
-   SIGUSR1    : constant := 10; --  user defined signal 1
-   SIGUSR2    : constant := 12; --  user defined signal 2
+   SIGSTKFLT  : constant := 16; --  coprocessor stack fault (Linux)
    SIGCLD     : constant := 17; --  alias for SIGCHLD
    SIGCHLD    : constant := 17; --  child status change
-   SIGPWR     : constant := 30; --  power-fail restart
-   SIGWINCH   : constant := 28; --  window size change
-   SIGURG     : constant := 23; --  urgent condition on IO channel
-   SIGPOLL    : constant := 29; --  pollable event occurred
-   SIGIO      : constant := 29; --  I/O now possible (4.2 BSD)
-   SIGLOST    : constant := 29; --  File lock lost
    SIGSTOP    : constant := 19; --  stop (cannot be caught or ignored)
    SIGTSTP    : constant := 20; --  user stop requested from tty
    SIGCONT    : constant := 18; --  stopped process has been continued
    SIGTTIN    : constant := 21; --  background tty read attempted
    SIGTTOU    : constant := 22; --  background tty write attempted
-   SIGVTALRM  : constant := 26; --  virtual timer expired
-   SIGPROF    : constant := 27; --  profiling timer expired
+   SIGURG     : constant := 23; --  urgent condition on IO channel
    SIGXCPU    : constant := 24; --  CPU time limit exceeded
    SIGXFSZ    : constant := 25; --  filesize limit exceeded
-   SIGUNUSED  : constant := 31; --  unused signal (GNU/Linux)
-   SIGSTKFLT  : constant := 16; --  coprocessor stack fault (Linux)
-   SIGLTHRRES : constant := 32; --  GNU/LinuxThreads restart signal
-   SIGLTHRCAN : constant := 33; --  GNU/LinuxThreads cancel signal
-   SIGLTHRDBG : constant := 34; --  GNU/LinuxThreads debugger signal
+   SIGVTALRM  : constant := 26; --  virtual timer expired
+   SIGPROF    : constant := 27; --  profiling timer expired
+   SIGWINCH   : constant := 28; --  window size change
+   SIGPOLL    : constant := 29; --  pollable event occurred
+   SIGIO      : constant := 29; --  I/O now possible (4.2 BSD)
+   SIGLOST    : constant := 29; --  File lock lost
+   SIGPWR     : constant := 30; --  power-fail restart
+   SIGSYS     : constant := 31; --  bad system call
+   SIGUNUSED  : constant := 31; --  unused signal (mapped to SIGSYS)
+   SIG32      : constant := 32; --  glibc internal signal
+   SIG33      : constant := 33; --  glibc internal signal
+   SIG34      : constant := 34; --  glibc internal signal
 
    --  struct_sigaction offsets
 

gcc/ada/libgnarl/s-linux__alpha.ads

@@ -109,9 +109,9 @@ package System.Linux is
    SIGUSR1    : constant := 30; --  user defined signal 1
    SIGUSR2    : constant := 31; --  user defined signal 2
 
-   SIGLTHRRES : constant := 32; --  GNU/LinuxThreads restart signal
-   SIGLTHRCAN : constant := 33; --  GNU/LinuxThreads cancel signal
-   SIGLTHRDBG : constant := 34; --  GNU/LinuxThreads debugger signal
+   SIG32      : constant := 32; --  glibc internal signal
+   SIG33      : constant := 33; --  glibc internal signal
+   SIG34      : constant := 34; --  glibc internal signal
 
    SIGADAABORT : constant := SIGABRT;
    --  Change this if you want to use another signal for task abort.

gcc/ada/libgnarl/s-linux__android.ads

@@ -111,9 +111,9 @@ package System.Linux is
    SIGXFSZ    : constant := 25; --  filesize limit exceeded
    SIGUNUSED  : constant := 31; --  unused signal (GNU/Linux)
    SIGSTKFLT  : constant := 16; --  coprocessor stack fault (Linux)
-   SIGLTHRRES : constant := 32; --  GNU/LinuxThreads restart signal
-   SIGLTHRCAN : constant := 33; --  GNU/LinuxThreads cancel signal
-   SIGLTHRDBG : constant := 34; --  GNU/LinuxThreads debugger signal
+   SIG32      : constant := 32; --  glibc internal signal
+   SIG33      : constant := 33; --  glibc internal signal
+   SIG34      : constant := 34; --  glibc internal signal
 
    --  struct_sigaction offsets
 

gcc/ada/libgnarl/s-linux__hppa.ads

@@ -113,9 +113,9 @@ package System.Linux is
    SIGXCPU    : constant := 33; --  CPU time limit exceeded
    SIGXFSZ    : constant := 34; --  filesize limit exceeded
    SIGSTKFLT  : constant := 36; --  coprocessor stack fault (Linux)
-   SIGLTHRRES : constant := 37; --  GNU/LinuxThreads restart signal
-   SIGLTHRCAN : constant := 38; --  GNU/LinuxThreads cancel signal
-   SIGLTHRDBG : constant := 39; --  GNU/LinuxThreads debugger signal
+   SIG32      : constant := 37; --  glibc internal signal
+   SIG33      : constant := 38; --  glibc internal signal
+   SIG34      : constant := 39; --  glibc internal signal
 
    --  struct_sigaction offsets
 

gcc/ada/libgnarl/s-linux__mips.ads

@@ -111,9 +111,9 @@ package System.Linux is
    SIGXCPU    : constant := 30; --  CPU time limit exceeded
    SIGXFSZ    : constant := 31; --  filesize limit exceeded
 
-   SIGLTHRRES : constant := 32; --  GNU/LinuxThreads restart signal
-   SIGLTHRCAN : constant := 33; --  GNU/LinuxThreads cancel signal
-   SIGLTHRDBG : constant := 34; --  GNU/LinuxThreads debugger signal
+   SIG32      : constant := 32; --  glibc internal signal
+   SIG33      : constant := 33; --  glibc internal signal
+   SIG34      : constant := 34; --  glibc internal signal
 
    --  These don't exist for Linux/MIPS.  The constants are present
    --  so that we can continue to use a-intnam-linux.ads.

gcc/ada/libgnarl/s-linux__riscv.ads

@@ -110,10 +110,9 @@ package System.Linux is
    SIGIO      : constant := 29; --  I/O now possible (4.2 BSD)
    SIGPWR     : constant := 30; --  power-fail restart
    SIGSYS     : constant := 31; --  bad system call
-
-   SIGLTHRRES : constant := 0; --  GNU/LinuxThreads restart signal
-   SIGLTHRCAN : constant := 0; --  GNU/LinuxThreads cancel signal
-   SIGLTHRDBG : constant := 0; --  GNU/LinuxThreads debugger signal
+   SIG32      : constant := 32; --  glibc internal signal
+   SIG33      : constant := 33; --  glibc internal signal
+   SIG34      : constant := 34; --  glibc internal signal
 
    --  These don't exist for Linux/RISC-V.  The constants are present
    --  so that we can continue to use a-intnam-linux.ads.

gcc/ada/libgnarl/s-linux__sparc.ads

@@ -112,9 +112,9 @@ package System.Linux is
    SIGUSR1    : constant := 30; --  user defined signal 1
    SIGUSR2    : constant := 31; --  user defined signal 2
 
-   SIGLTHRRES : constant := 32; --  GNU/LinuxThreads restart signal
-   SIGLTHRCAN : constant := 33; --  GNU/LinuxThreads cancel signal
-   SIGLTHRDBG : constant := 34; --  GNU/LinuxThreads debugger signal
+   SIG32      : constant := 32; --  glibc internal signal
+   SIG33      : constant := 33; --  glibc internal signal
+   SIG34      : constant := 34; --  glibc internal signal
 
    SIGUNUSED  : constant := 0;
    SIGSTKFLT  : constant := 0;

gcc/ada/libgnarl/s-linux__x32.ads

@@ -111,9 +111,9 @@ package System.Linux is
    SIGXFSZ    : constant := 25; --  filesize limit exceeded
    SIGUNUSED  : constant := 31; --  unused signal (GNU/Linux)
    SIGSTKFLT  : constant := 16; --  coprocessor stack fault (Linux)
-   SIGLTHRRES : constant := 32; --  GNU/LinuxThreads restart signal
-   SIGLTHRCAN : constant := 33; --  GNU/LinuxThreads cancel signal
-   SIGLTHRDBG : constant := 34; --  GNU/LinuxThreads debugger signal
+   SIG32      : constant := 32; --  glibc internal signal
+   SIG33      : constant := 33; --  glibc internal signal
+   SIG34      : constant := 34; --  glibc internal signal
 
    --  struct_sigaction offsets
 

gcc/ada/libgnarl/s-osinte__linux.ads

@@ -30,7 +30,7 @@
 --                                                                          --
 ------------------------------------------------------------------------------
 
---  This is a GNU/Linux (GNU/LinuxThreads) version of this package
+--  This is a GNU/Linux version of this package
 
 --  This package encapsulates all direct interfaces to OS services
 --  that are needed by the tasking run-time (libgnarl).
@@ -90,37 +90,38 @@ package System.OS_Interface is
    SIGTRAP    : constant := System.Linux.SIGTRAP;
    SIGIOT     : constant := System.Linux.SIGIOT;
    SIGABRT    : constant := System.Linux.SIGABRT;
+   SIGBUS     : constant := System.Linux.SIGBUS;
    SIGFPE     : constant := System.Linux.SIGFPE;
    SIGKILL    : constant := System.Linux.SIGKILL;
-   SIGBUS     : constant := System.Linux.SIGBUS;
+   SIGUSR1    : constant := System.Linux.SIGUSR1;
    SIGSEGV    : constant := System.Linux.SIGSEGV;
+   SIGUSR2    : constant := System.Linux.SIGUSR2;
    SIGPIPE    : constant := System.Linux.SIGPIPE;
    SIGALRM    : constant := System.Linux.SIGALRM;
    SIGTERM    : constant := System.Linux.SIGTERM;
-   SIGUSR1    : constant := System.Linux.SIGUSR1;
-   SIGUSR2    : constant := System.Linux.SIGUSR2;
+   SIGSTKFLT  : constant := System.Linux.SIGSTKFLT;
    SIGCLD     : constant := System.Linux.SIGCLD;
    SIGCHLD    : constant := System.Linux.SIGCHLD;
-   SIGPWR     : constant := System.Linux.SIGPWR;
-   SIGWINCH   : constant := System.Linux.SIGWINCH;
-   SIGURG     : constant := System.Linux.SIGURG;
-   SIGPOLL    : constant := System.Linux.SIGPOLL;
-   SIGIO      : constant := System.Linux.SIGIO;
-   SIGLOST    : constant := System.Linux.SIGLOST;
+   SIGCONT    : constant := System.Linux.SIGCONT;
    SIGSTOP    : constant := System.Linux.SIGSTOP;
    SIGTSTP    : constant := System.Linux.SIGTSTP;
-   SIGCONT    : constant := System.Linux.SIGCONT;
    SIGTTIN    : constant := System.Linux.SIGTTIN;
    SIGTTOU    : constant := System.Linux.SIGTTOU;
-   SIGVTALRM  : constant := System.Linux.SIGVTALRM;
-   SIGPROF    : constant := System.Linux.SIGPROF;
+   SIGURG     : constant := System.Linux.SIGURG;
    SIGXCPU    : constant := System.Linux.SIGXCPU;
    SIGXFSZ    : constant := System.Linux.SIGXFSZ;
+   SIGVTALRM  : constant := System.Linux.SIGVTALRM;
+   SIGPROF    : constant := System.Linux.SIGPROF;
+   SIGWINCH   : constant := System.Linux.SIGWINCH;
+   SIGPOLL    : constant := System.Linux.SIGPOLL;
+   SIGIO      : constant := System.Linux.SIGIO;
+   SIGLOST    : constant := System.Linux.SIGLOST;
+   SIGPWR     : constant := System.Linux.SIGPWR;
+   SIGSYS     : constant := System.Linux.SIGSYS;
    SIGUNUSED  : constant := System.Linux.SIGUNUSED;
-   SIGSTKFLT  : constant := System.Linux.SIGSTKFLT;
-   SIGLTHRRES : constant := System.Linux.SIGLTHRRES;
-   SIGLTHRCAN : constant := System.Linux.SIGLTHRCAN;
-   SIGLTHRDBG : constant := System.Linux.SIGLTHRDBG;
+   SIG32      : constant := System.Linux.SIG32;
+   SIG33      : constant := System.Linux.SIG33;
+   SIG34      : constant := System.Linux.SIG34;
 
    SIGADAABORT : constant := SIGABRT;
    --  Change this to use another signal for task abort. SIGTERM might be a
@@ -142,16 +143,19 @@ package System.OS_Interface is
       SIGPROF,
       --  To avoid confusing the profiler
 
-      SIGKILL, SIGSTOP,
+      SIGKILL, SIGSTOP
       --  These two signals actually can't be masked (POSIX won't allow it)
-
-      SIGLTHRRES, SIGLTHRCAN, SIGLTHRDBG);
-      --  These three signals are used by GNU/LinuxThreads starting from glibc
-      --  2.1 (future 2.2).
-
-   Reserved : constant Signal_Set := (SIGVTALRM, SIGUNUSED);
-   --  Not clear why these two signals are reserved. Perhaps they are not
-   --  supported by this version of GNU/Linux ???
+      );
+
+   Reserved : constant Signal_Set := (
+      SIG32, SIG33, SIG34
+      --  glibc POSIX threads implementation uses two (NPTL) or three
+      --  (LinuxThreads) real-time signals for its own use (see SIGNAL(7)).
+      --  These signals are considered reserved and not unmasked as glibc does
+      --  not permit these signals to be used by the public signal.h API.
+      --  While LinuxThreads is mostly likely unused now, SIG34 is still
+      --  reserved as this behavior is consistent with past GNAT releases.
+      );
 
    type sigset_t is private;
 

gcc/testsuite/ChangeLog

+2018-11-14  Patrick Bernardi  <bernardi@adacore.com>
+
+	* gnat.dg/rt_signals.adb: New testcase.
+
 2018-11-14  Hristian Kirtchev  <kirtchev@adacore.com>
 
 	* gnat.dg/ghost1.adb, gnat.dg/ghost1.ads: New testcase.

gcc/testsuite/gnat.dg/rt_signals.adb

+--  { dg-do run }
+
+--  This program used to fail with a runtime built with assertions
+
+procedure RT_Signals is
+   task Task_A;
+
+   task body Task_A is
+   begin
+      null;
+   end Task_A;
+begin
+   null;
+end RT_Signals;