[PATCH 2/2] libc: Edited implementations for sig2str/str2sig

[Matt Joyce]

Added features to function implementations to conform with POSIX standard.
---
 newlib/libc/signal/sig2str.c | 96 ++++++++++++++++++++++++++++++------
 1 file changed, 81 insertions(+), 15 deletions(-)

diff --git a/newlib/libc/signal/sig2str.c b/newlib/libc/signal/sig2str.c
index a07fa2a38..152d10cf7 100644
--- a/newlib/libc/signal/sig2str.c
+++ b/newlib/libc/signal/sig2str.c
@@ -1,9 +1,14 @@
 /* Placeholder  */
-//#define __GNU_VISIBLE // defining it to have access to SIG2STR_MAX
 
+/* Defining _GNU_SOURCE to have access to SIG2STR_MAX in signal.h. */
+#define _GNU_SOURCE 
 #include <signal.h>
 #include <string.h>
 #include <stdio.h>
+#include <stdlib.h>
+
+#define SPACES_TO_N 6
+#define NUM_OF_SIGS (sizeof(sig_array) / sizeof(sig_name_and_num))
 
 typedef struct sig_name_and_num {
   const char *sig_name;
@@ -101,12 +106,12 @@ static sig_name_and_num sig_array[] = {
     #ifdef SIGUSR2
     { "USR2", SIGUSR2 },
     #endif
-    // #ifdef SIGRTMIN
-    // { "RTMIN", SIGRTMIN },
-    // #endif
-    // #ifdef SIGRTMAX
-    // { "RTMAX", SIGRTMAX },
-    // #endif
+    #ifdef SIGRTMIN
+    { "RTMIN", SIGRTMIN },
+    #endif
+    #ifdef SIGRTMAX
+    { "RTMAX", SIGRTMAX },
+    #endif
     #ifdef SIGPWR
     { "PWR", SIGPWR },
     #endif
@@ -127,25 +132,86 @@ static sig_name_and_num sig_array[] = {
     #endif
 }; 
 
-#define NUM_OF_SIGS (sizeof(sig_array) / sizeof(sig_name_and_num))
-
 int
 sig2str(int signum, char *str)
 {
+  /* Real Time Signals, lower half */
+  if ((SIGRTMIN + 1) <= signum && signum <= (SIGRTMIN + SIGRTMAX) / 2){
+    sprintf(str, "RTMIN+%d", (signum-SIGRTMIN));
+    return 0; 
+  }
   
-  for (sig_name_and_num *i = sig_array; i < &sig_array[NUM_OF_SIGS]; i++){
-    if (i->sig_num == signum){
+  /* Real Time Signals, upper half */ 
+  else if ((((SIGRTMIN +SIGRTMAX)/ 2) + 1) <= signum && signum <= \
+  (SIGRTMAX - 1)){
+    sprintf(str, "RTMAX-%d", (SIGRTMAX-signum));
+    return 0; 
+  }
+  
+  /* All others, including SIGRTMIN / SIGRTMAX */ 
+  else{
+    for (sig_name_and_num * i = sig_array; i < &sig_array[NUM_OF_SIGS]; i++){
+      if (i->sig_num == signum){
         strcpy(str, i->sig_name);
         return 0; 
-    }    
+      } 
+    }   
+    sprintf(str, "Unknown signal %d", signum); 
+    return -1; 
   }
-  sprintf(str, "Unknown signal %d", signum); 
-  return -1; 
 }
 
 int
-str2sig(const char *__restrict str, int *__restrict pnum)
+str2sig(const char *restrict str, int *restrict pnum)
 {
+  int j = 0; 
+  char dest[SIG2STR_MAX];
+  int is_valid_decimal = atoi(str);
+
+  /* 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; 
+  }
+
+  /* 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){
+    for(int i = SPACES_TO_N; str[i] != '\0'; i++){
+      dest[j] = str[i];
+      j++;
+    }
+    dest[j] = '\0';
+    j = atoi(dest);
+
+    /* If number is valid, save it in pnum. */
+    if (1 <= j && j <= ((SIGRTMAX - SIGRTMIN)-1)){
+      *pnum = (SIGRTMIN + j);
+      return 0;  
+    }
+    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){
+    for(int i = SPACES_TO_N; str[i] != '\0'; i++){
+      dest[j] = str[i];
+      j++;
+    }
+    dest[j] = '\0';
+    j = atoi(dest);
+
+    /* If number is valid, save it in pnum. */
+    if (1 <= j && j <= ((SIGRTMAX - SIGRTMIN)-1)){
+      *pnum = (SIGRTMAX - j);
+      return 0;  
+    }
+    return -1; 
+  }
+  
+  /*If str is a valid signal name, save its corresponding number in pnum. */
   for (sig_name_and_num *i = sig_array; i < &sig_array[NUM_OF_SIGS]; i++){
     if (strcmp(i->sig_name, str) == 0){
         *pnum = i->sig_num;
-- 
2.31.1