chore(fnmatch.c): added custom Posix function

Added custom implementations for islower and ispunch
since there is some issue with compilenace on some platforms

Signed-off-by: Harun Spago <harun.spago.code@gmail.com>

Author: Spago123

lib/posix/options/fnmatch.c

@@ -60,24 +60,24 @@ static inline int foldcase(int ch, int flags)
 
 /**
  * @brief Function to check for FNM_PERIOD condition
- * 
+ *
  * @param string string whose first character is checked if it is a period
  * @param flags passed flags to check for FNM_PERIOD
- * @return int 
+ * @return int
  * @retval 1 if first character is period and FNM_PERIOD flag is set
  * @retval 0 otherwise
  */
-static int check_fnm_period(const char* string, const int flags)
+static int check_fnm_period(const char *string, const int flags)
 {
 	return *string == '.' && (flags & FNM_PERIOD);
 }
 
 /**
  * @brief Function to check for FNM_PATHNAME condition
- * 
+ *
  * @param letter letter to be checked if it is a '/'
  * @param flags flags passed to check for FNM_PATHNAME
- * @return int 
+ * @return int
  * @retval 1 if letter is '/' and FNM_PATHNAME flag is set
  * @retval 0 otherwise
  */
@@ -88,45 +88,77 @@ static int check_for_pathname(const char letter, const int flags)
 
 #define FOLDCASE(ch, flags) foldcase((unsigned char)(ch), (flags))
 
+/**
+ * @brief Custom is_lower function implementation due to problems with
+ * standard library implementation on some platforms
+ *
+ * @param a of type int, to satisfy the islower function signature
+ * @return int
+ * @retval 1 if a is a lowercase letter
+ * @retval 0 otherwise
+ */
+static int is_lower(int a)
+{
+	char c = (char)a;
+	return (c >= 'a' && c <= 'z');
+}
+
+/**
+ * @brief Custom is_punct function implementation due to problems with
+ * standard library implementation on some platforms
+ *
+ * @param a of type int, to satisfy the ispunct function signature
+ * @return int
+ * @retval 1 if a is a punctuation character
+ * @retval 0 otherwise
+ */
+static int is_punct(int a)
+{
+	/** Explicit list of punctuation characters in ASCII */
+	const char *punct_chars = "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~";
+
+	char c = (char)a;
+
+	for (const char *p = punct_chars; *p != '\0'; p++) {
+		if (c == *p) {
+			return 1;
+		}
+	}
+	return 0;
+}
+
 /**
  * @brief Function to match POSIX character classes
- * 
+ *
  * @param pattern start of the pattern, should point to the character after '['
  * @param test next character in the string to be tested against the class
- * @return true 
- * @return false 
+ * @return true
+ * @return false
  */
-static bool match_posix_class(const char **pattern, int test) {
-    const struct {
-        const char *name;
-        int (*func)(int);
-    } classes[] = {
-        { "alnum", isalnum },
-        { "alpha", isalpha },
-        { "digit", isdigit },
-        { "lower", islower },
-        { "upper", isupper },
-        { "space", isspace },
-        { "xdigit", isxdigit },
-        { "punct", ispunct },
-        { "cntrl", iscntrl },
-        { "graph", isgraph },
-        { "print", isprint },
-    };
-
-    const char *p = *pattern;
-    if (*p != ':' ) {
+static bool match_posix_class(const char **pattern, int test)
+{
+	const struct {
+		const char *name;
+		int (*func)(int);
+	} classes[] = {
+		{"alnum", isalnum}, {"alpha", isalpha}, {"digit", isdigit},   {"lower", is_lower},
+		{"upper", isupper}, {"space", isspace}, {"xdigit", isxdigit}, {"punct", is_punct},
+		{"cntrl", iscntrl}, {"graph", isgraph}, {"print", isprint},
+	};
+
+	const char *p = *pattern;
+	if (*p != ':') {
 		return false;
 	}
-    p++;
-    for (size_t i = 0; i < sizeof(classes)/sizeof(classes[0]); i++) {
-        size_t len = strlen(classes[i].name);
-        if (strncmp(p, classes[i].name, len) == 0 && p[len] == ':' && p[len+1] == ']') {
-                *pattern = p + len + 2;  /* move past ":]" */
-                return classes[i].func(test);
-        }
-    }
-    return false;
+	p++;
+	for (size_t i = 0; i < sizeof(classes) / sizeof(classes[0]); i++) {
+		size_t len = strlen(classes[i].name);
+		if (strncmp(p, classes[i].name, len) == 0 && p[len] == ':' && p[len + 1] == ']') {
+			*pattern = p + len + 2; /* move past ":]" */
+			return classes[i].func(test);
+		}
+	}
+	return false;
 }
 
 static const char *rangematch(const char *pattern, int test, int flags)
@@ -174,12 +206,11 @@ static const char *rangematch(const char *pattern, int test, int flags)
 				continue;
 			} else {
 				/* skip over class if unrecognized */
-				while (*pattern && !(*pattern == ':' && *(pattern+1) == ']')) {
+				while (*pattern && !(*pattern == ':' && *(pattern + 1) == ']')) {
 					pattern++;
 				}
 
-				if (*pattern) 
-				{
+				if (*pattern) {
 					pattern += 2;
 				}
 				continue;
@@ -242,8 +273,7 @@ static int fnmatchx(const char *pattern, const char *string, int flags, size_t r
 			}
 
 			if (check_fnm_period(string, flags) &&
-			    (string == stringstart ||
-			     check_for_pathname(*(string - 1), flags))) {
+			    (string == stringstart || check_for_pathname(*(string - 1), flags))) {
 				return FNM_NOMATCH;
 			}
 
@@ -257,20 +287,18 @@ static int fnmatchx(const char *pattern, const char *string, int flags, size_t r
 			}
 
 			if (check_fnm_period(string, flags) &&
-			    (string == stringstart ||
-			     check_for_pathname(*(string - 1), flags))) {
+			    (string == stringstart || check_for_pathname(*(string - 1), flags))) {
 				return FNM_NOMATCH;
 			}
 
 			/* Optimize for pattern with * at end or before /. */
 			if (c == EOS) {
-				if(!(flags & FNM_PATHNAME)) {
+				if (!(flags & FNM_PATHNAME)) {
 					return 0;
 				}
-				return (flags & FNM_LEADING_DIR) ||
-								strchr(string, '/') == NULL
-							? 0
-							: FNM_NOMATCH;
+				return (flags & FNM_LEADING_DIR) || strchr(string, '/') == NULL
+					       ? 0
+					       : FNM_NOMATCH;
 			} else if (check_for_pathname(c, flags)) {
 				string = strchr(string, '/');
 				if (string == NULL) {
@@ -311,8 +339,7 @@ static int fnmatchx(const char *pattern, const char *string, int flags, size_t r
 			}
 
 			if (check_fnm_period(string, flags) &&
-			    (string == stringstart ||
-			     check_for_pathname(*(string - 1), flags))) {
+			    (string == stringstart || check_for_pathname(*(string - 1), flags))) {
 				return FNM_NOMATCH;
 			}