signal: Deprecate additional legacy signal handling functions

This needs a few test adjustments: In some cases, sigignore was
used for convenience (replaced with xsignal with SIG_IGN).  Tests
for the deprecated functions need to disable
-Wdeprecated-declarations, and for the sigmask deprecation,
-Wno-error.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

NEWS

@@ -39,6 +39,11 @@ Deprecated and removed features, and other changes affecting compatibility:
   Its implementation always returned with a failure, and the function
   was not declared in any header file.
 
+* The legacy signal handling functions siginterrupt, sigpause, sighold,
+  sigrelse, sigignore and sigset, and the sigmask macro have been
+  deprecated.  Applications should use the sigsuspend, sigprocmask and
+  sigaction functions instead.
+
 * ldconfig now defaults to the new format for ld.so.cache. glibc has
   already supported this format for almost 20 years.
 

manual/signal.texi

@@ -3250,6 +3250,9 @@ are interrupted by handling signal @var{signum}.  If @var{failflag} is
 false, signal @var{signum} restarts primitives.  If @var{failflag} is
 true, handling @var{signum} causes these primitives to fail with error
 code @code{EINTR}.  @xref{Interrupted Primitives}.
+
+This function has been replaced by the @code{SA_RESTART} flag of the
+@code{sigaction} function.  @xref{Advanced Signal Handling}.
 @end deftypefun
 
 @deftypefn Macro int sigmask (int @var{signum})
@@ -3267,6 +3270,9 @@ together to specify more than one signal.  For example,
 
 @noindent
 specifies a mask that includes all the job-control stop signals.
+
+This macro has been replaced by the @code{sigset_t} type and the
+associated signal set manipulation functions.  @xref{Signal Sets}.
 @end deftypefn
 
 @deftypefun int sigblock (int @var{mask})

nptl/Makefile

@@ -510,6 +510,13 @@ endif
 # function frequently to get a thread-specific handle.
 CFLAGS-pthread_self.os += -fomit-frame-pointer
 
+# The sigmask macro is deprecated and triggers are compiler warning
+# which cannot be suppressed (as of GCC 9).
+CFLAGS-tst-cancel4.c += -Wno-error
+CFLAGS-tst-cancel5.c += -Wno-error
+CFLAGS-tst-cancelx4.c += -Wno-error
+CFLAGS-tst-cancelx5.c += -Wno-error
+
 # Run the cancellation and cleanup tests also for the modern, exception-based
 # implementation.  For this we have to pass the -fexceptions parameter.
 CFLAGS-tst-cancelx2.c += -fexceptions

nptl/tst-cancel4.c

@@ -39,6 +39,7 @@
 #include <sys/wait.h>
 #include <sys/stat.h>
 #include <sys/uio.h>
+#include <libc-diag.h>
 
 
 /* Since STREAMS are not supported in the standard Linux kernel and
@@ -527,7 +528,13 @@ tf_sigpause (void *arg)
 
   pthread_cleanup_push (cl, NULL);
 
+  /* This tests the deprecated sigpause and sigmask functions.  The
+     file is compiled with -Wno-errno so that the sigmask deprecation
+     warning is not fatal.  */
+  DIAG_PUSH_NEEDS_COMMENT;
+  DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
   sigpause (sigmask (SIGINT));
+  DIAG_POP_NEEDS_COMMENT;
 
   pthread_cleanup_pop (0);
 

nptl/tst-exec1.c

@@ -27,6 +27,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include <support/xsignal.h>
 
 
 static void *
@@ -56,11 +57,7 @@ do_test (void)
     }
 
   /* Not interested in knowing when the pipe is closed.  */
-  if (sigignore (SIGPIPE) != 0)
-    {
-      puts ("sigignore failed");
-      exit (1);
-    }
+  xsignal (SIGPIPE, SIG_IGN);
 
   posix_spawn_file_actions_t a;
   if (posix_spawn_file_actions_init (&a) != 0)

nptl/tst-exec2.c

@@ -27,6 +27,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include <support/xsignal.h>
 
 
 static void *
@@ -56,11 +57,7 @@ do_test (void)
     }
 
   /* Not interested in knowing when the pipe is closed.  */
-  if (sigignore (SIGPIPE) != 0)
-    {
-      puts ("sigignore failed");
-      exit (1);
-    }
+  xsignal (SIGPIPE, SIG_IGN);
 
   pid_t pid = fork ();
   if (pid == -1)

nptl/tst-exec3.c

@@ -27,6 +27,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include <support/xsignal.h>
 
 
 static void *
@@ -50,11 +51,7 @@ do_test (void)
     }
 
   /* Not interested in knowing when the pipe is closed.  */
-  if (sigignore (SIGPIPE) != 0)
-    {
-      puts ("sigignore failed");
-      exit (1);
-    }
+  xsignal (SIGPIPE, SIG_IGN);
 
   pid_t pid = fork ();
   if (pid == -1)

nptl/tst-exec4.c

@@ -22,17 +22,13 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
-
+#include <support/xsignal.h>
 
 static void *
 tf (void *arg)
 {
   /* Ignore SIGUSR1 and block SIGUSR2.  */
-  if (sigignore (SIGUSR1) != 0)
-    {
-      puts ("sigignore failed");
-      exit (1);
-    }
+  xsignal (SIGUSR1, SIG_IGN);
 
   sigset_t ss;
   sigemptyset (&ss);

nptl/tst-exec5.c

@@ -86,11 +86,7 @@ do_test (void)
     }
 
   /* Not interested in knowing when the pipe is closed.  */
-  if (sigignore (SIGPIPE) != 0)
-    {
-      puts ("error: sigignore failed");
-      exit (1);
-    }
+  xsignal (SIGPIPE, SIG_IGN);
 
   /* To synchronize with the thread.  */
   if (pthread_barrier_init (&b, NULL, 2) != 0)

signal/signal.h

@@ -148,7 +148,8 @@ extern void psiginfo (const siginfo_t *__pinfo, const char *__s);
 
 #ifdef __USE_XOPEN_EXTENDED
 # ifdef __GNUC__
-extern int sigpause (int __sig) __asm__ ("__xpg_sigpause");
+extern int sigpause (int __sig) __asm__ ("__xpg_sigpause")
+  __attribute_deprecated_msg__ ("Use the sigsuspend function instead");
 # else
 extern int __sigpause (int __sig_or_mask, int __is_sig);
 /* Remove a signal from the signal mask and suspend the process.  */
@@ -164,7 +165,9 @@ extern int __sigpause (int __sig_or_mask, int __is_sig);
    simply do not work in many situations.  Use `sigprocmask' instead.  */
 
 /* Compute mask for signal SIG.  */
-# define sigmask(sig) ((int)(1u << ((sig) - 1)))
+# define sigmask(sig) \
+  __glibc_macro_warning ("sigmask is deprecated") \
+  ((int)(1u << ((sig) - 1)))
 
 /* Block signals in MASK, returning the old mask.  */
 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
@@ -311,7 +314,8 @@ extern int sigreturn (struct sigcontext *__scp) __THROW;
 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
    (causing them to fail with EINTR); if INTERRUPT is zero, make system
    calls be restarted after signal SIG.  */
-extern int siginterrupt (int __sig, int __interrupt) __THROW;
+extern int siginterrupt (int __sig, int __interrupt) __THROW
+  __attribute_deprecated_msg__ ("Use sigaction with SA_RESTART instead");
 
 # include <bits/sigstack.h>
 # include <bits/ss_flags.h>
@@ -340,16 +344,21 @@ extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
 /* Simplified interface for signal management.  */
 
 /* Add SIG to the calling process' signal mask.  */
-extern int sighold (int __sig) __THROW;
+extern int sighold (int __sig) __THROW
+  __attribute_deprecated_msg__ ("Use the sigprocmask function instead");
 
 /* Remove SIG from the calling process' signal mask.  */
-extern int sigrelse (int __sig) __THROW;
+extern int sigrelse (int __sig) __THROW
+  __attribute_deprecated_msg__ ("Use the sigprocmask function instead");
 
 /* Set the disposition of SIG to SIG_IGN.  */
-extern int sigignore (int __sig) __THROW;
+extern int sigignore (int __sig) __THROW
+  __attribute_deprecated_msg__ ("Use the signal function instead");
 
 /* Set the disposition of SIG.  */
-extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
+extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW
+  __attribute_deprecated_msg__
+    ("Use the signal and sigprocmask functions instead");
 #endif
 
 #if defined __USE_POSIX199506 || defined __USE_UNIX98

signal/tst-sigset2.c

@@ -9,6 +9,10 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <libc-diag.h>
+
+/* The sigset function is deprecated.  */
+DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
 
 #define TEST_SIG SIGINT
 

signal/tst-sigsimple.c

@@ -20,7 +20,10 @@
 #include <signal.h>
 #include <stdio.h>
 #include <string.h>
+#include <libc-diag.h>
 
+/* The sighold and sigrelse functions are deprecated.  */
+DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
 
 static int
 do_test (void)