import newlib-2000-02-17 snapshot

5 files changed, 742 insertions, 0 deletions

diff --git a/newlib/libc/signal/Makefile.am b/newlib/libc/signal/Makefile.am
new file mode 100644
index 000000000..038948b6d
--- /dev/null
+++ b/newlib/libc/signal/Makefile.am
@@ -0,0 +1,26 @@
+## Process this file with automake to generate Makefile.in
+
+AUTOMAKE_OPTIONS = cygnus
+
+INCLUDES = $(NEWLIB_CFLAGS) $(CROSS_CFLAGS) $(TARGET_CFLAGS)
+
+noinst_LIBRARIES = lib.a
+
+lib_a_SOURCES = raise.c signal.c
+
+CHEWOUT_FILES = raise.def signal.def
+
+SUFFIXES = .def
+
+CHEW = ../../doc/makedoc -f $(srcdir)/../../doc/doc.str
+
+.c.def:
+	$(CHEW) < $< > $*.def 2> $*.ref
+	touch stmp-def
+
+TARGETDOC = ../tmp.texi
+
+doc: $(CHEWOUT_FILES)
+	cat $(srcdir)/signal.tex >> $(TARGETDOC)
+
+CLEANFILES = $(CHEWOUT_FILES) *.ref
diff --git a/newlib/libc/signal/Makefile.in b/newlib/libc/signal/Makefile.in
new file mode 100644
index 000000000..9d2cb1ee5
--- /dev/null
+++ b/newlib/libc/signal/Makefile.in
@@ -0,0 +1,297 @@
+# Makefile.in generated automatically by automake 1.4 from Makefile.am
+
+# Copyright (C) 1994, 1995-8, 1999 Free Software Foundation, Inc.
+# This Makefile.in is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
+# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE.
+
+
+SHELL = @SHELL@
+
+srcdir = @srcdir@
+top_srcdir = @top_srcdir@
+VPATH = @srcdir@
+prefix = @prefix@
+exec_prefix = @exec_prefix@
+
+bindir = @bindir@
+sbindir = @sbindir@
+libexecdir = @libexecdir@
+datadir = @datadir@
+sysconfdir = @sysconfdir@
+sharedstatedir = @sharedstatedir@
+localstatedir = @localstatedir@
+libdir = @libdir@
+infodir = @infodir@
+mandir = @mandir@
+includedir = @includedir@
+oldincludedir = /usr/include
+
+DESTDIR =
+
+pkgdatadir = $(datadir)/@PACKAGE@
+pkglibdir = $(libdir)/@PACKAGE@
+pkgincludedir = $(includedir)/@PACKAGE@
+
+top_builddir = ..
+
+ACLOCAL = @ACLOCAL@
+AUTOCONF = @AUTOCONF@
+AUTOMAKE = @AUTOMAKE@
+AUTOHEADER = @AUTOHEADER@
+
+INSTALL = @INSTALL@
+INSTALL_PROGRAM = @INSTALL_PROGRAM@ $(AM_INSTALL_PROGRAM_FLAGS)
+INSTALL_DATA = @INSTALL_DATA@
+INSTALL_SCRIPT = @INSTALL_SCRIPT@
+transform = @program_transform_name@
+
+NORMAL_INSTALL = :
+PRE_INSTALL = :
+POST_INSTALL = :
+NORMAL_UNINSTALL = :
+PRE_UNINSTALL = :
+POST_UNINSTALL = :
+host_alias = @host_alias@
+host_triplet = @host@
+AR = @AR@
+AS = @AS@
+CC = @CC@
+CPP = @CPP@
+CRT0 = @CRT0@
+EXEEXT = @EXEEXT@
+LIBC_MACHINE_LIB = @LIBC_MACHINE_LIB@
+LIBC_POSIX_LIB = @LIBC_POSIX_LIB@
+LIBC_SIGNAL_DEF = @LIBC_SIGNAL_DEF@
+LIBC_SIGNAL_LIB = @LIBC_SIGNAL_LIB@
+LIBC_SYSCALL_LIB = @LIBC_SYSCALL_LIB@
+LIBC_SYS_LIB = @LIBC_SYS_LIB@
+LIBC_UNIX_LIB = @LIBC_UNIX_LIB@
+MAINT = @MAINT@
+MAKEINFO = @MAKEINFO@
+NEWLIB_CFLAGS = @NEWLIB_CFLAGS@
+PACKAGE = @PACKAGE@
+RANLIB = @RANLIB@
+VERSION = @VERSION@
+machine_dir = @machine_dir@
+newlib_basedir = @newlib_basedir@
+sys_dir = @sys_dir@
+
+AUTOMAKE_OPTIONS = cygnus
+
+INCLUDES = $(NEWLIB_CFLAGS) $(CROSS_CFLAGS) $(TARGET_CFLAGS)
+
+noinst_LIBRARIES = lib.a
+
+lib_a_SOURCES = raise.c signal.c
+
+CHEWOUT_FILES = raise.def signal.def
+
+SUFFIXES = .def
+
+CHEW = ../../doc/makedoc -f $(srcdir)/../../doc/doc.str
+
+TARGETDOC = ../tmp.texi
+
+CLEANFILES = $(CHEWOUT_FILES) *.ref
+mkinstalldirs = $(SHELL) $(top_srcdir)/../../mkinstalldirs
+CONFIG_CLEAN_FILES = 
+LIBRARIES =  $(noinst_LIBRARIES)
+
+
+DEFS = @DEFS@ -I. -I$(srcdir) 
+CPPFLAGS = @CPPFLAGS@
+LDFLAGS = @LDFLAGS@
+LIBS = @LIBS@
+lib_a_LIBADD = 
+lib_a_OBJECTS =  raise.o signal.o
+CFLAGS = @CFLAGS@
+COMPILE = $(CC) $(DEFS) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS)
+CCLD = $(CC)
+LINK = $(CCLD) $(AM_CFLAGS) $(CFLAGS) $(LDFLAGS) -o $@
+DIST_COMMON =  Makefile.am Makefile.in
+
+
+DISTFILES = $(DIST_COMMON) $(SOURCES) $(HEADERS) $(TEXINFOS) $(EXTRA_DIST)
+
+TAR = tar
+GZIP_ENV = --best
+SOURCES = $(lib_a_SOURCES)
+OBJECTS = $(lib_a_OBJECTS)
+
+all: all-redirect
+.SUFFIXES:
+.SUFFIXES: .S .c .def .o .s
+$(srcdir)/Makefile.in: @MAINTAINER_MODE_TRUE@ Makefile.am $(top_srcdir)/configure.in $(ACLOCAL_M4) 
+	cd $(top_srcdir) && $(AUTOMAKE) --cygnus signal/Makefile
+
+Makefile: $(srcdir)/Makefile.in  $(top_builddir)/config.status
+	cd $(top_builddir) \
+	  && CONFIG_FILES=$(subdir)/$@ CONFIG_HEADERS= $(SHELL) ./config.status
+
+
+mostlyclean-noinstLIBRARIES:
+
+clean-noinstLIBRARIES:
+	-test -z "$(noinst_LIBRARIES)" || rm -f $(noinst_LIBRARIES)
+
+distclean-noinstLIBRARIES:
+
+maintainer-clean-noinstLIBRARIES:
+
+.c.o:
+	$(COMPILE) -c $<
+
+.s.o:
+	$(COMPILE) -c $<
+
+.S.o:
+	$(COMPILE) -c $<
+
+mostlyclean-compile:
+	-rm -f *.o core *.core
+
+clean-compile:
+
+distclean-compile:
+	-rm -f *.tab.c
+
+maintainer-clean-compile:
+
+lib.a: $(lib_a_OBJECTS) $(lib_a_DEPENDENCIES)
+	-rm -f lib.a
+	$(AR) cru lib.a $(lib_a_OBJECTS) $(lib_a_LIBADD)
+	$(RANLIB) lib.a
+
+tags: TAGS
+
+ID: $(HEADERS) $(SOURCES) $(LISP)
+	list='$(SOURCES) $(HEADERS)'; \
+	unique=`for i in $$list; do echo $$i; done | \
+	  awk '    { files[$$0] = 1; } \
+	       END { for (i in files) print i; }'`; \
+	here=`pwd` && cd $(srcdir) \
+	  && mkid -f$$here/ID $$unique $(LISP)
+
+TAGS:  $(HEADERS) $(SOURCES)  $(TAGS_DEPENDENCIES) $(LISP)
+	tags=; \
+	here=`pwd`; \
+	list='$(SOURCES) $(HEADERS)'; \
+	unique=`for i in $$list; do echo $$i; done | \
+	  awk '    { files[$$0] = 1; } \
+	       END { for (i in files) print i; }'`; \
+	test -z "$(ETAGS_ARGS)$$unique$(LISP)$$tags" \
+	  || (cd $(srcdir) && etags $(ETAGS_ARGS) $$tags  $$unique $(LISP) -o $$here/TAGS)
+
+mostlyclean-tags:
+
+clean-tags:
+
+distclean-tags:
+	-rm -f TAGS ID
+
+maintainer-clean-tags:
+
+distdir = $(top_builddir)/$(PACKAGE)-$(VERSION)/$(subdir)
+
+subdir = signal
+
+distdir: $(DISTFILES)
+	@for file in $(DISTFILES); do \
+	  if test -f $$file; then d=.; else d=$(srcdir); fi; \
+	  if test -d $$d/$$file; then \
+	    cp -pr $$/$$file $(distdir)/$$file; \
+	  else \
+	    test -f $(distdir)/$$file \
+	    || ln $$d/$$file $(distdir)/$$file 2> /dev/null \
+	    || cp -p $$d/$$file $(distdir)/$$file || :; \
+	  fi; \
+	done
+info-am:
+info: info-am
+dvi-am:
+dvi: dvi-am
+check-am:
+check: check-am
+installcheck-am:
+installcheck: installcheck-am
+install-info-am: 
+install-info: install-info-am
+install-exec-am:
+install-exec: install-exec-am
+
+install-data-am:
+install-data: install-data-am
+
+install-am: all-am
+	@$(MAKE) $(AM_MAKEFLAGS) install-exec-am install-data-am
+install: install-am
+uninstall-am:
+uninstall: uninstall-am
+all-am: Makefile $(LIBRARIES)
+all-redirect: all-am
+install-strip:
+	$(MAKE) $(AM_MAKEFLAGS) AM_INSTALL_PROGRAM_FLAGS=-s install
+installdirs:
+
+
+mostlyclean-generic:
+
+clean-generic:
+	-test -z "$(CLEANFILES)" || rm -f $(CLEANFILES)
+
+distclean-generic:
+	-rm -f Makefile $(CONFIG_CLEAN_FILES)
+	-rm -f config.cache config.log stamp-h stamp-h[0-9]*
+
+maintainer-clean-generic:
+mostlyclean-am:  mostlyclean-noinstLIBRARIES mostlyclean-compile \
+		mostlyclean-tags mostlyclean-generic
+
+mostlyclean: mostlyclean-am
+
+clean-am:  clean-noinstLIBRARIES clean-compile clean-tags clean-generic \
+		mostlyclean-am
+
+clean: clean-am
+
+distclean-am:  distclean-noinstLIBRARIES distclean-compile \
+		distclean-tags distclean-generic clean-am
+
+distclean: distclean-am
+
+maintainer-clean-am:  maintainer-clean-noinstLIBRARIES \
+		maintainer-clean-compile maintainer-clean-tags \
+		maintainer-clean-generic distclean-am
+	@echo "This command is intended for maintainers to use;"
+	@echo "it deletes files that may require special tools to rebuild."
+
+maintainer-clean: maintainer-clean-am
+
+.PHONY: mostlyclean-noinstLIBRARIES distclean-noinstLIBRARIES \
+clean-noinstLIBRARIES maintainer-clean-noinstLIBRARIES \
+mostlyclean-compile distclean-compile clean-compile \
+maintainer-clean-compile tags mostlyclean-tags distclean-tags \
+clean-tags maintainer-clean-tags distdir info-am info dvi-am dvi check \
+check-am installcheck-am installcheck install-info-am install-info \
+install-exec-am install-exec install-data-am install-data install-am \
+install uninstall-am uninstall all-redirect all-am all installdirs \
+mostlyclean-generic distclean-generic clean-generic \
+maintainer-clean-generic clean mostlyclean distclean maintainer-clean
+
+
+.c.def:
+	$(CHEW) < $< > $*.def 2> $*.ref
+	touch stmp-def
+
+doc: $(CHEWOUT_FILES)
+	cat $(srcdir)/signal.tex >> $(TARGETDOC)
+
+# Tell versions [3.59,3.63) of GNU make to not export all variables.
+# Otherwise a system limit (for SysV at least) may be exceeded.
+.NOEXPORT:
diff --git a/newlib/libc/signal/raise.c b/newlib/libc/signal/raise.c
new file mode 100644
index 000000000..bc47864e8
--- /dev/null
+++ b/newlib/libc/signal/raise.c
@@ -0,0 +1,80 @@
+/* Embedded systems may want the simulated signals if no other form exists,
+   but UNIX versions will want to use the host facilities.
+   Define SIMULATED_SIGNALS when you want to use the simulated versions.
+*/
+
+/*
+FUNCTION
+<<raise>>---send a signal
+
+INDEX
+	raise
+INDEX
+	_raise_r
+
+ANSI_SYNOPSIS
+	#include <signal.h>
+	int raise(int <[sig]>);
+
+	int _raise_r(void *<[reent]>, int <[sig]>);
+
+TRAD_SYNOPSIS
+	#include <signal.h>
+	int raise(<[sig]>)
+	int <[sig]>;
+
+	int _raise_r(<[reent]>, <[sig]>)
+	char *<[reent]>;
+	int <[sig]>;
+
+DESCRIPTION
+Send the signal <[sig]> (one of the macros from `<<sys/signal.h>>').
+This interrupts your program's normal flow of execution, and allows a signal
+handler (if you've defined one, using <<signal>>) to take control.
+
+The alternate function <<_raise_r>> is a reentrant version.  The extra
+argument <[reent]> is a pointer to a reentrancy structure.
+
+RETURNS
+The result is <<0>> if <[sig]> was successfully raised, <<1>>
+otherwise.  However, the return value (since it depends on the normal
+flow of execution) may not be visible, unless the signal handler for
+<[sig]> terminates with a <<return>> or unless <<SIG_IGN>> is in
+effect for this signal.
+
+PORTABILITY
+ANSI C requires <<raise>>, but allows the full set of signal numbers
+to vary from one implementation to another.
+
+Required OS subroutines: <<getpid>>, <<kill>>.
+*/
+
+#ifndef SIGNAL_PROVIDED
+
+int _dummy_raise;
+
+#else
+
+#include <reent.h>
+#include <signal.h>
+
+#ifndef _REENT_ONLY
+
+int
+_DEFUN (raise, (sig),
+	int sig)
+{
+  return _raise_r (_REENT, sig);
+}
+
+#endif
+
+int
+_DEFUN (_raise_r, (reent, sig),
+	struct _reent *reent _AND
+	int sig)
+{
+  return _kill_r (reent, _getpid_r (reent), sig);
+}
+
+#endif /* SIGNAL_PROVIDED */
diff --git a/newlib/libc/signal/signal.c b/newlib/libc/signal/signal.c
new file mode 100644
index 000000000..fc52bbab5
--- /dev/null
+++ b/newlib/libc/signal/signal.c
@@ -0,0 +1,269 @@
+/*
+FUNCTION
+<<signal>>---specify handler subroutine for a signal
+
+INDEX
+	signal
+INDEX
+	_signal_r
+INDEX
+	raise
+INDEX
+	_raise_r
+
+ANSI_SYNOPSIS
+	#include <signal.h>
+	void ( * signal(int <[sig]>, void(*<[func]>)(int)) )(int);
+
+	void ( * _signal_r(void *<[reent]>, 
+                           int <[sig]>, void(*<[func]>)(int)) )(int);
+
+	int raise (int <[sig]>);
+
+	int _raise_r (void *<[reent]>, int <[sig]>);
+
+TRAD_SYNOPSIS
+	#include <signal.h>
+	char ( * signal(<[sig]>, <[func]>) )()
+	int <[sig]>;
+	char ( * <[func]> )();
+
+	char ( * _signal_r(<[reent]>, <[sig]>, <[func]>) )()
+	char *<[reent]>;
+	int <[sig]>;
+	char ( * <[func]> )();
+
+	int raise (<[sig]>)()
+	int <[sig]>;
+
+	int _raise_r (<[reent]>, <[sig]>)()
+	char *<[reent]>;
+	int <[sig]>;
+
+DESCRIPTION
+<<signal, raise>> provide a simple signal/raise implementation for embedded
+targets.
+
+<<signal>> allows you to request changed treatment for a particular
+signal <[sig]>.  You can use one of the predefined macros <<SIG_DFL>>
+(select system default handling) or <<SIG_IGN>> (ignore this signal)
+as the value of <[func]>; otherwise, <[func]> is a function pointer
+that identifies a subroutine in your program as the handler for this signal.
+
+Some of the execution environment for signal handlers is
+unpredictable; notably, the only library function required to work
+correctly from within a signal handler is @code{signal} itself, and
+only when used to redefine the handler for the current signal value.
+
+Static storage is likewise unreliable for signal handlers, with one
+exception: if you declare a static storage location as `<<volatile
+sig_atomic_t>>', then you may use that location in a signal handler to
+store signal values.
+
+If your signal handler terminates using <<return>> (or implicit
+return), your program's execution continues at the point
+where it was when the signal was raised (whether by your program
+itself, or by an external event).  Signal handlers can also
+use functions such as <<exit>> and <<abort>> to avoid returning.
+
+<<raise>> sends the signal sig to the executing program.  It returns zero if
+successful, non-zero if unsuccessful.
+
+The alternate functions <<_signal_r, _raise_r>> are the reentrant versions.
+The extra argument <[reent]> is a pointer to a reentrancy structure.
+
+
+@c FIXME: do we have setjmp.h and assoc fns?
+
+RETURNS
+If your request for a signal handler cannot be honored, the result is
+<<SIG_ERR>>; a specific error number is also recorded in <<errno>>.
+
+Otherwise, the result is the previous handler (a function pointer or
+one of the predefined macros).
+
+PORTABILITY
+ANSI C requires <<raise>>, <<signal>>.
+
+No supporting OS subroutines are required to link with <<signal>>, but
+it will not have any useful effects, except for software generated signals,
+without an operating system that can actually raise exceptions.
+*/
+
+/*
+ * signal.c
+ * Original Author:	G. Haley
+ *
+ * signal associates the function pointed to by func with the signal sig. When
+ * a signal occurs, the value of func determines the action taken as follows:
+ * if func is SIG_DFL, the default handling for that signal will occur; if func
+ * is SIG_IGN, the signal will be ignored; otherwise, the default handling for
+ * the signal is restored (SIG_DFL), and the function func is called with sig
+ * as its argument. Returns the value of func for the previous call to signal
+ * for the signal sig, or SIG_ERR if the request fails.
+ */
+
+/* _init_signal initialises the signal handlers for each signal. This function
+   is called by crt0 at program startup.  */
+
+#ifdef SIGNAL_PROVIDED
+
+int _dummy_simulated_signal;
+
+#else
+
+#include <errno.h>
+#include <signal.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <reent.h>
+#include <_syslist.h>
+
+int
+_DEFUN (_init_signal_r, (ptr),
+	struct _reent *ptr)
+{
+  int i;
+
+  if (ptr->_sig_func == NULL)
+    {
+      ptr->_sig_func = (_sig_func_ptr *)_malloc_r (ptr, sizeof (_sig_func_ptr) * NSIG);
+      if (ptr->_sig_func == NULL)
+	return -1;
+
+      for (i = 0; i < NSIG; i++)
+	ptr->_sig_func[i] = SIG_DFL;
+    }
+
+  return 0;
+}
+
+_sig_func_ptr
+_DEFUN (_signal_r, (ptr, sig, func),
+	struct _reent *ptr _AND
+	int sig _AND
+	_sig_func_ptr func)
+{
+  _sig_func_ptr old_func, *temp;
+
+  if (sig < 0 || sig >= NSIG)
+    {
+      ptr->_errno = EINVAL;
+      return SIG_ERR;
+    }
+
+  if (ptr->_sig_func == NULL && _init_signal_r (ptr) != 0)
+    return SIG_ERR;
+  
+  old_func = ptr->_sig_func[sig];
+  ptr->_sig_func[sig] = func;
+
+  return old_func;
+}
+
+int 
+_raise_r (ptr, sig)
+     struct _reent *ptr;
+     int sig;
+{
+  _sig_func_ptr func;
+  int result = 0;
+
+  if (sig < 0 || sig >= NSIG)
+    {
+      ptr->_errno = EINVAL;
+      return -1;
+    }
+
+  if (ptr->_sig_func == NULL && _init_signal_r (ptr) != 0)
+    return -1;
+  
+  switch ((_POINTER_INT) ptr->_sig_func[sig])
+    {
+    case SIG_DFL:
+      return _kill_r (ptr, _getpid_r (ptr), sig);
+
+    case SIG_IGN:
+      break;
+
+    case SIG_ERR:
+      ptr->_errno = EINVAL;
+      result = 1;
+      break;
+
+    default:
+      func = ptr->_sig_func[sig];
+      ptr->_sig_func[sig] = SIG_DFL;
+      func (sig);
+      break;
+    }
+
+  return result;
+}
+
+int
+__sigtramp_r (ptr, sig)
+     struct _reent *ptr;
+     int sig;
+{
+  _sig_func_ptr func;
+
+  if (sig < 0 || sig >= NSIG)
+    {
+      return -1;
+    }
+
+  if (ptr->_sig_func == NULL && _init_signal_r (ptr) != 0)
+    return -1;
+  
+  switch ((_POINTER_INT) ptr->_sig_func[sig])
+    {
+    case SIG_DFL:
+      return 1;
+
+    case SIG_ERR:
+      return 2;
+
+    case SIG_IGN:
+      return 3;
+
+    default:
+      func = ptr->_sig_func[sig];
+      ptr->_sig_func[sig] = SIG_DFL;
+      func (sig);
+      return 0;
+    }
+}
+
+#ifndef _REENT_ONLY
+
+int 
+raise (sig)
+     int sig;
+{
+  return _raise_r (_REENT, sig);
+}
+
+_sig_func_ptr
+_DEFUN (signal, (sig, func),
+	int sig _AND
+	_sig_func_ptr func)
+{
+  return _signal_r (_REENT, sig, func);
+}
+
+int 
+_init_signal ()
+{
+  return _init_signal_r (_REENT);
+}
+
+int
+__sigtramp (int sig)
+{
+  return __sigtramp_r (_REENT, sig);
+}
+
+#endif
+
+#endif /* !SIGNAL_PROVIDED */
diff --git a/newlib/libc/signal/signal.tex b/newlib/libc/signal/signal.tex
new file mode 100644
index 000000000..08c15bed8
--- /dev/null
+++ b/newlib/libc/signal/signal.tex
@@ -0,0 +1,70 @@
+@node Signals
+@chapter Signal Handling (@file{signal.h})
+
+A @dfn{signal} is an event that interrupts the normal flow of control
+in your program.  Your operating environment normally defines the full
+set of signals available (see @file{sys/signal.h}), as well as the
+default means of dealing with them---typically, either printing an
+error message and aborting your program, or ignoring the signal.
+
+All systems support at least the following signals:
+@table @code
+@item SIGABRT
+Abnormal termination of a program; raised by the <<abort>> function.
+
+@item SIGFPE
+A domain error in arithmetic, such as overflow, or division by zero.
+
+@item SIGILL
+Attempt to execute as a function data that is not executable.
+
+@item SIGINT
+Interrupt; an interactive attention signal.
+
+@item SIGSEGV
+An attempt to access a memory location that is not available.
+
+@item SIGTERM
+A request that your program end execution.
+@end table
+
+Two functions are available for dealing with asynchronous
+signals---one to allow your program to send signals to itself (this is
+called @dfn{raising} a signal), and one to specify subroutines (called
+@dfn{handlers} to handle particular signals that you anticipate may
+occur---whether raised by your own program or the operating environment.
+
+To support these functions, @file{signal.h} defines three macros:
+
+@table @code
+@item SIG_DFL
+Used with the @code{signal} function in place of a pointer to a
+handler subroutine, to select the operating environment's default
+handling of a signal.
+
+@item SIG_IGN
+Used with the @code{signal} function in place of a pointer to a
+handler, to ignore a particular signal.
+
+@item SIG_ERR
+Returned by the @code{signal} function in place of a pointer to a
+handler, to indicate that your request to set up a handler could not
+be honored for some reason.
+@end table
+
+@file{signal.h} also defines an integral type, @code{sig_atomic_t}.
+This type is not used in any function declarations; it exists only to
+allow your signal handlers to declare a static storage location where
+they may store a signal value.  (Static storage is not otherwise
+reliable from signal handlers.)
+
+@menu
+* raise::   Send a signal
+* signal::  Specify handler subroutine for a signal
+@end menu
+
+@page
+@include signal/raise.def
+
+@page
+@include signal/signal.def