[PATCH 1/1] libc: Added implementation for sig2str/str2sig.

[Matt Joyce <mfjoyce2004@gmail.com>]

Added implementations for sig2str() and str2sig() in libc/signal
in order to improve POSIX compliance. Added fucntion prototypes
in libc/include/sys/signal.h.
---
 newlib/libc/include/sys/signal.h |  17 ++
 newlib/libc/signal/Makefile.am   |   4 +-
 newlib/libc/signal/sig2str.c     | 297 +++++++++++++++++++++++++++++++
 3 files changed, 316 insertions(+), 2 deletions(-)
 create mode 100644 newlib/libc/signal/sig2str.c

diff --git a/newlib/libc/include/sys/signal.h b/newlib/libc/include/sys/signal.h
index 45cc0366c..9c1c0e3c2 100644
--- a/newlib/libc/include/sys/signal.h
+++ b/newlib/libc/include/sys/signal.h
@@ -12,6 +12,7 @@ extern "C" {
 #include <sys/types.h>
 #include <sys/_sigset.h>
 #include <sys/_timespec.h>
+#include <stdint.h>
 
 #if !defined(_SIGSET_T_DECLARED)
 #define	_SIGSET_T_DECLARED
@@ -238,6 +239,22 @@ int sigqueue (pid_t, int, const union sigval);
 
 #endif /* __POSIX_VISIBLE >= 199309 */
 
+/* Using __MISC_VISIBLE until POSIX Issue 8 is officially released */
+#if __MISC_VISIBLE
+
+/* POSIX Issue 8 adds sig2str() and str2sig() */
+
+#if __STDINT_EXP(INT_MAX) > 0x7fff
+#define SIG2STR_MAX (sizeof("RTMAX+") + sizeof("4294967295") - 1)
+#else
+#define SIG2STR_MAX (sizeof("RTMAX+") + sizeof("65535") - 1)
+#endif
+
+int sig2str(int, char *); 
+int str2sig(const char *__restrict, int *__restrict);
+
+#endif /* __MISC_VISIBLE */
+
 #if defined(___AM29K__)
 /* These all need to be defined for ANSI C, but I don't think they are
    meaningful.  */
diff --git a/newlib/libc/signal/Makefile.am b/newlib/libc/signal/Makefile.am
index a93dba7a9..89db26113 100644
--- a/newlib/libc/signal/Makefile.am
+++ b/newlib/libc/signal/Makefile.am
@@ -4,7 +4,7 @@ AUTOMAKE_OPTIONS = cygnus
 
 INCLUDES = $(NEWLIB_CFLAGS) $(CROSS_CFLAGS) $(TARGET_CFLAGS)
 
-LIB_SOURCES = psignal.c raise.c signal.c
+LIB_SOURCES = psignal.c raise.c signal.c sig2str.c
 
 libsignal_la_LDFLAGS = -Xcompiler -nostdlib
 
@@ -21,6 +21,6 @@ endif # USE_LIBTOOL
 
 include $(srcdir)/../../Makefile.shared
 
-CHEWOUT_FILES = psignal.def raise.def signal.def
+CHEWOUT_FILES = psignal.def raise.def signal.def sig2str.def
 
 CHAPTERS = signal.tex
diff --git a/newlib/libc/signal/sig2str.c b/newlib/libc/signal/sig2str.c
new file mode 100644
index 000000000..4b2c88be6
--- /dev/null
+++ b/newlib/libc/signal/sig2str.c
@@ -0,0 +1,297 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2021 Matthew Joyce
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+FUNCTION
+<<sig2str>>, <<str2sig>>---Translate between signal number and name
+
+INDEX
+          sig2str
+INDEX
+          str2sig
+
+SYNOPSIS
+          #include <signal.h>
+          int sig2str(int <[signum]>, char *<[str]>);
+
+          int str2sig(const char *restrict <[str]>, int *restrict <[pnum]>);
+
+DESCRIPTION
+The <<sig2str>> function translates the signal number specified by <[signum]> to
+a signal name and stores this string in the location specified by <[str]>. The
+application must ensure that <[str]> points to a location that can store the
+string including the terminating null byte. The symbolic constant 
+<[SIG2STR_MAX]> defined in `<<signal.h>>' gives the maximum number of bytes 
+required.
+
+The <<str2sig>> function translates the signal name in the string pointed to by 
+<[str]> to a signal number and stores this value in the location specified by 
+<[pnum]>.
+
+RETURNS
+<<sig2str>> returns <<0>> if <[signum]>> is a valid, supported signal number.
+Otherwise, it returns <<-1>>.
+
+<<str2sig>> returns <<0>> if it stores a value in the location pointed to by 
+<[pnum]>. Otherwise it returns <<-1>>.
+*/
+ 
+#include <signal.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define SPACES_TO_N 6 /* Allows indexing to RT Signal number in str2sig */
+#define NUM_OF_SIGS (sizeof(sig_array) / sizeof(sig_name_and_num))
+
+typedef struct sig_name_and_num {
+  const char *sig_name;
+  const int  sig_num; 
+} sig_name_and_num;
+
+static const sig_name_and_num sig_array[] = {
+      { "EXIT", 0 },
+    #ifdef SIGHUP
+      { "HUP", SIGHUP },
+    #endif
+    #ifdef SIGINT
+      { "INT", SIGINT },
+    #endif
+    #ifdef SIGQUIT
+      { "QUIT", SIGQUIT },
+    #endif
+    #ifdef SIGILL
+      { "ILL", SIGILL },
+    #endif
+    #ifdef SIGTRAP
+      { "TRAP", SIGTRAP },
+    #endif
+    #ifdef SIGABRT
+      { "ABRT", SIGABRT },
+    #endif
+    #ifdef SIGIOT
+      { "IOT", SIGIOT},
+    #endif
+    #ifdef SIGEMT
+      { "EMT", SIGEMT },
+    #endif
+    #ifdef SIGFPE
+      { "FPE", SIGFPE },
+    #endif
+    #ifdef SIGKILL
+      { "KILL", SIGKILL },
+    #endif
+    #ifdef SIGBUS
+      { "BUS", SIGBUS },
+    #endif
+    #ifdef SIGSEGV
+      { "SEGV", SIGSEGV },
+    #endif
+    #ifdef SIGSYS
+      { "SYS", SIGSYS },
+    #endif
+    #ifdef SIGPIPE
+      { "PIPE", SIGPIPE },
+    #endif
+    #ifdef SIGALRM
+      { "ALRM", SIGALRM },
+    #endif
+    #ifdef SIGTERM
+      { "TERM", SIGTERM },
+    #endif
+    #ifdef SIGURG
+      { "URG", SIGURG },
+    #endif
+    #ifdef SIGSTOP
+      { "STOP", SIGSTOP },
+    #endif
+    #ifdef SIGTSTP
+      { "TSTP", SIGTSTP },
+    #endif
+    #ifdef SIGCONT
+      { "CONT", SIGCONT },
+    #endif
+    #ifdef SIGCHLD
+      { "CHLD", SIGCHLD },
+    #endif
+    #ifdef SIGCLD
+      { "CLD", SIGCLD },
+    #endif
+    #ifdef SIGTTIN
+      { "TTIN", SIGTTIN },
+    #endif
+    #ifdef SIGTTOU
+      { "TTOU", SIGTTOU },
+    #endif
+    #ifdef SIGIO
+      { "IO", SIGIO },
+    #endif
+    #ifdef SIGPOLL
+      { "POLL", SIGPOLL },
+    #endif
+    #ifdef SIGWINCH
+      { "WINCH", SIGWINCH },
+    #endif
+    #ifdef SIGUSR1
+      { "USR1", SIGUSR1 },
+    #endif
+    #ifdef SIGUSR2
+      { "USR2", SIGUSR2 },
+    #endif
+    #ifdef SIGPWR
+      { "PWR", SIGPWR },
+    #endif
+    #ifdef SIGXCPU
+      { "XCPU", SIGXCPU },
+    #endif
+    #ifdef SIGXFSZ
+      { "XFSZ", SIGXFSZ },
+    #endif
+    #ifdef SIGVTALRM
+      { "VTALRM", SIGVTALRM },
+    #endif
+    #ifdef SIGPROF
+      { "PROF", SIGPROF },
+    #endif
+    #ifdef SIGLOST
+      { "LOST", SIGLOST },
+    #endif
+    /* The Issue 8 standard requires that SIGRTMIN and SIGRTMAX be included 
+     * as valid results to be saved from calls to sig2str/str2sig.  */
+    #ifdef SIGRTMIN
+      { "RTMIN", SIGRTMIN },
+    #endif
+    #ifdef SIGRTMAX
+      { "RTMAX", SIGRTMAX }
+    #endif
+}; 
+
+int
+sig2str(int signum, char *str)
+{
+  const sig_name_and_num *sptr;
+
+  /* If signum falls in lower half of the real time signals range, define
+   * the saved str value as "RTMIN+n" according to the Issue 8 standard */
+  if ((SIGRTMIN + 1) <= signum && 
+      signum <= (SIGRTMIN + SIGRTMAX) / 2) {
+    snprintf(str, SIG2STR_MAX, "RTMIN+%d", (signum-SIGRTMIN));
+    return 0; 
+  }
+  
+  /* If signum falls in upper half of the real time signals range, define
+   * the saved str value as "RTMAX-m" according to the Issue 8 standard */
+  if ((((SIGRTMIN + SIGRTMAX) / 2) + 1) <= signum &&
+         signum <= (SIGRTMAX - 1)) {
+    snprintf(str, SIG2STR_MAX, "RTMAX-%d", (SIGRTMAX - signum));
+    return 0; 
+  }
+
+  /* Otherwise, search for signal matching signum in sig_array. If found,
+   * save its string value in str. */ 
+  for (sptr = sig_array; sptr < &sig_array[NUM_OF_SIGS]; sptr++) {
+    if (sptr->sig_num == signum) {
+      strlcpy(str, sptr->sig_name, SIG2STR_MAX);
+      return 0; 
+    } 
+  }   
+
+  /* If signum is not a recognized signal number, return -1 */
+  return -1; 
+}
+
+int
+str2sig(const char *restrict str, int *restrict pnum)
+{
+  unsigned long j = 0; 
+  char *endp; 
+  const sig_name_and_num *sptr; 
+  unsigned long is_valid_decimal;
+
+  /* i686 Cygwin only supports one RT signal. For this case, skip checks 
+   * for "RTMIN+n" and "RTMAX-m". */
+  if (SIGRTMIN != SIGRTMAX) {
+
+    /* If str is in RT signal range, get number of of RT signal, save it as an 
+    * integer. */
+    if (strncmp(str, "RTMIN+", SPACES_TO_N) == 0) {
+      j = strtoul(&str[SPACES_TO_N], &endp, 10); 
+
+      /* If number is valid, save it in pnum. */
+      if (*endp == '\0') {
+        if (1 <= j &&
+            j <= ((SIGRTMAX - SIGRTMIN)-1)) {
+          *pnum = (SIGRTMIN + j);
+          return 0;
+        }
+        return -1; 
+      }
+      return -1;
+    }
+    
+    /* If str is in RT signal range, get number of of RT signal, save it as an 
+    * integer. */
+    if (strncmp(str, "RTMAX-", SPACES_TO_N) == 0) {
+      j = strtoul(&str[SPACES_TO_N], &endp, 10); // and endptr null check
+
+      /* If number is valid, save it in pnum. */
+      if (*endp == '\0') {
+        if (1 <= j &&
+            j <= ((SIGRTMAX - SIGRTMIN)-1)) {
+          *pnum = (SIGRTMAX - j);
+          return 0;
+        }
+        return -1; 
+      }
+      return -1;
+    }
+  }
+
+  /*If str is a valid signal name, save its corresponding number in pnum. */
+  for (sptr = sig_array; sptr < &sig_array[NUM_OF_SIGS]; sptr++) {
+    if (strcmp(sptr->sig_name, str) == 0) {
+      *pnum = sptr->sig_num;
+      return 0; 
+    }    
+  }
+  
+  /* str was not found in sig_array. Check whether str is a string 
+   * representation of a valid integer. */
+  is_valid_decimal = strtoul(str, &endp, 10);
+  
+  if (*endp != '\0') {
+    return -1;
+  }
+
+  /* If str is a representation of a decimal value, save its integer value
+   * in pnum. */
+  if (1 <= is_valid_decimal &&
+      is_valid_decimal <= SIGRTMAX) {
+    *pnum = is_valid_decimal;
+    return 0; 
+  } 
+  return -1; 
+}
-- 
2.31.1