Usermode/libc - Fixed implementation of atexit and printf

- *printf now supports string precision and padding
- atexit implemented fully, but may not actually work

diff --git a/Usermode/Libraries/crt0.o_src/crt0.asm b/Usermode/Libraries/crt0.o_src/crt0.asm
index b8f5270..81400c5 100644 (file)
--- a/Usermode/Libraries/crt0.o_src/crt0.asm
+++ b/Usermode/Libraries/crt0.o_src/crt0.asm
@@ -15,5 +15,16 @@ _start:
 start:
        call main
        push eax
+
+       mov eax, [_crt0_exit_handler]
+       test eax, eax
+       jz .exit
+       call [eax]
+       
+.exit:
        call _exit
        jmp $   ; This should never be reached
+[section .bss]
+[global _crt0_exit_handler]
+_crt0_exit_handler:
+       resd    1

diff --git a/Usermode/Libraries/libc.so_src/fileIO.c b/Usermode/Libraries/libc.so_src/fileIO.c
index 4117b02..b588f24 100644 (file)
--- a/Usermode/Libraries/libc.so_src/fileIO.c
+++ b/Usermode/Libraries/libc.so_src/fileIO.c
@@ -299,12 +299,18 @@ EXPORT int vsprintf(char * __s, const char *__format, va_list __args)
 EXPORT int vsnprintf(char *buf, size_t __maxlen, const char *format, va_list args)\r
 {\r
        char    tmp[65];\r
-        int    c, minSize;\r
+        int    c, minSize, precision, len;\r
         int    pos = 0;\r
        char    *p;\r
        char    pad;\r
        uint64_t        arg;\r
-        int    bLongLong;\r
+        int    bLongLong, bPadLeft;\r
+\r
+       void _addchar(char ch)\r
+       {\r
+               if(buf && pos < __maxlen)       buf[pos] = ch;\r
+               pos ++;\r
+       }\r
 \r
        tmp[32] = '\0';\r
        \r
@@ -312,34 +318,64 @@ EXPORT int vsnprintf(char *buf, size_t __maxlen, const char *format, va_list arg
        {\r
                // Non-control character\r
                if (c != '%') {\r
-                       if(buf && pos < __maxlen)       buf[pos] = c;\r
-                       pos ++;\r
+                       _addchar(c);\r
                        continue;\r
                }\r
                \r
                // Control Character\r
                c = *format++;\r
                if(c == '%') {  // Literal %\r
-                       if(buf && pos < __maxlen)       buf[pos] = '%';\r
-                       pos ++;\r
+                       _addchar('%');\r
                        continue;\r
                }\r
                \r
-               // Padding\r
+               bPadLeft = 0;\r
+               bLongLong = 0;\r
+               minSize = 0;\r
+               precision = -1;\r
+               pad = ' ';\r
+               \r
+               // Padding Character\r
                if(c == '0') {\r
                        pad = '0';\r
                        c = *format++;\r
-               } else\r
-                       pad = ' ';\r
-               minSize = 0;\r
-               if('1' <= c && c <= '9')\r
-               {\r
-                       while('0' <= c && c <= '9')\r
+               }\r
+               // Padding length\r
+               if( c == '*' ) {\r
+                       // Variable length\r
+                       minSize = va_arg(args, size_t);\r
+                       c = *format++;\r
+               }\r
+               else {\r
+                       if('1' <= c && c <= '9')\r
                        {\r
-                               minSize *= 10;\r
-                               minSize += c - '0';\r
+                               minSize = 0;\r
+                               while('0' <= c && c <= '9')\r
+                               {\r
+                                       minSize *= 10;\r
+                                       minSize += c - '0';\r
+                                       c = *format++;\r
+                               }\r
+                       }\r
+               }\r
+\r
+               // Precision\r
+               if(c == '.') {\r
+                       c = *format++;\r
+                       if(c == '*') {\r
+                               precision = va_arg(args, size_t);\r
                                c = *format++;\r
                        }\r
+                       else if('1' <= c && c <= '9')\r
+                       {\r
+                               precision = 0;\r
+                               while('0' <= c && c <= '9')\r
+                               {\r
+                                       precision *= 10;\r
+                                       precision += c - '0';\r
+                                       c = *format++;\r
+                               }\r
+                       }\r
                }\r
        \r
                // Check for long long\r
@@ -351,7 +387,8 @@ EXPORT int vsnprintf(char *buf, size_t __maxlen, const char *format, va_list arg
                                bLongLong = 1;\r
                        }\r
                }\r
-                       \r
+               \r
+               // Just help things along later\r
                p = tmp;\r
                \r
                // Get Type\r
@@ -363,6 +400,7 @@ EXPORT int vsnprintf(char *buf, size_t __maxlen, const char *format, va_list arg
                        if(bLongLong)   arg = va_arg(args, int64_t);\r
                        else                    arg = va_arg(args, int32_t);\r
                        itoa(tmp, arg, 10, minSize, pad, 1);\r
+                       precision = -1;\r
                        goto sprintf_puts;\r
                \r
                // Unsigned Integer\r
@@ -371,25 +409,24 @@ EXPORT int vsnprintf(char *buf, size_t __maxlen, const char *format, va_list arg
                        if(bLongLong)   arg = va_arg(args, uint64_t);\r
                        else                    arg = va_arg(args, uint32_t);\r
                        itoa(tmp, arg, 10, minSize, pad, 0);\r
+                       precision = -1;\r
                        goto sprintf_puts;\r
                \r
                // Pointer\r
                case 'p':\r
-                       if(buf && pos+2 < __maxlen) {\r
-                               buf[pos] = '*';\r
-                               buf[pos+1] = '0';\r
-                               buf[pos+2] = 'x';\r
-                       }\r
-                       pos += 3;\r
+                       _addchar('*');\r
+                       _addchar('0');\r
+                       _addchar('x');\r
                        arg = va_arg(args, uint32_t);\r
                        itoa(tmp, arg, 16, minSize, pad, 0);\r
+                       precision = -1;\r
                        goto sprintf_puts;\r
-                       // Fall through to hex\r
                // Unsigned Hexadecimal\r
                case 'x':\r
                        if(bLongLong)   arg = va_arg(args, uint64_t);\r
                        else                    arg = va_arg(args, uint32_t);\r
                        itoa(tmp, arg, 16, minSize, pad, 0);\r
+                       precision = -1;\r
                        goto sprintf_puts;\r
                \r
                // Unsigned Octal\r
@@ -397,6 +434,7 @@ EXPORT int vsnprintf(char *buf, size_t __maxlen, const char *format, va_list arg
                        if(bLongLong)   arg = va_arg(args, uint64_t);\r
                        else                    arg = va_arg(args, uint32_t);\r
                        itoa(tmp, arg, 8, minSize, pad, 0);\r
+                       precision = -1;\r
                        goto sprintf_puts;\r
                \r
                // Unsigned binary\r
@@ -404,6 +442,7 @@ EXPORT int vsnprintf(char *buf, size_t __maxlen, const char *format, va_list arg
                        if(bLongLong)   arg = va_arg(args, uint64_t);\r
                        else                    arg = va_arg(args, uint32_t);\r
                        itoa(tmp, arg, 2, minSize, pad, 0);\r
+                       precision = -1;\r
                        goto sprintf_puts;\r
 \r
                // String\r
@@ -413,28 +452,28 @@ EXPORT int vsnprintf(char *buf, size_t __maxlen, const char *format, va_list arg
                sprintf_puts:\r
                        if(!p)  p = "(null)";\r
                        //_SysDebug("vsnprintf: p = '%s'", p);\r
-                       if(buf) {\r
-                               while(*p) {\r
-                                       if(pos < __maxlen)      buf[pos] = *p;\r
-                                       pos ++; p ++;\r
-                               }\r
-                       }\r
-                       else {\r
-                               while(*p) {\r
-                                       pos++; p++;\r
-                               }\r
+                       if(precision >= 0)\r
+                               len = strnlen(p, precision);\r
+                       else\r
+                               len = strlen(p);\r
+                       if(bPadLeft)    while(minSize > len++)  _addchar(pad);\r
+                       while( *p ) {\r
+                               if(precision >= 0 && precision -- == 0)\r
+                                       break;\r
+                               _addchar(*p++);\r
                        }\r
+                       if(!bPadLeft)   while(minSize > len++)  _addchar(pad);\r
                        break;\r
 \r
                // Unknown, just treat it as a character\r
                default:\r
                        arg = va_arg(args, uint32_t);\r
-                       if(buf && pos < __maxlen)       buf[pos] = arg;\r
-                       pos ++;\r
+                       _addchar(arg);\r
                        break;\r
                }\r
-    }\r
-       if(buf && pos < __maxlen)       buf[pos] = '\0';\r
+       }\r
+       _addchar('\0');\r
+       pos --;\r
        \r
        //_SysDebug("vsnprintf: buf = '%s'", buf);\r
        \r

diff --git a/Usermode/Libraries/libc.so_src/stdlib.c b/Usermode/Libraries/libc.so_src/stdlib.c
index 94d9d1d..191f526 100644 (file)
--- a/Usermode/Libraries/libc.so_src/stdlib.c
+++ b/Usermode/Libraries/libc.so_src/stdlib.c
@@ -13,6 +13,8 @@
 #define _stdout        1\r
 #define _stdin 0\r
 \r
+extern void    *_crt0_exit_handler;\r
+\r
 // === PROTOTYPES ===\r
 EXPORT int     atoi(const char *str);\r
 EXPORT void    exit(int status);\r
@@ -24,6 +26,8 @@ void  (*g_stdlib_exithandler)(void);
 void atexit(void (*__func)(void))\r
 {\r
        g_stdlib_exithandler = __func;\r
+       // TODO: Replace with meta-function to allow multiple atexit() handlers\r
+       _crt0_exit_handler = __func;    \r
 }\r
 \r
 /**\r

diff --git a/Usermode/Libraries/libc.so_src/string.c b/Usermode/Libraries/libc.so_src/string.c
index 607039e..1c05236 100644 (file)
--- a/Usermode/Libraries/libc.so_src/string.c
+++ b/Usermode/Libraries/libc.so_src/string.c
@@ -77,17 +77,27 @@ EXPORT char *strcat(char *dst, const char *src)
 }
 
 /**
- * \fn EXPORT int strlen(const char *str)
  * \brief Get the length of a string
  */
-EXPORT int strlen(const char *str)
+EXPORT size_t strlen(const char *str)
 {
-       int retval;
-       for(retval = 0; *str != '\0'; str++)
-               retval++;
+       size_t  retval;
+       for(retval = 0; *str != '\0'; str++, retval++);
        return retval;
 }
 
+/**
+ * \brief Get the length of a string, with a maximum of \a maxlen
+ * 
+ * Gets the length of a string (excluding the terminating \0 byte)
+ */
+EXPORT size_t strnlen(const char *str, size_t maxlen)
+{
+       size_t  len;
+       for( len = 0; maxlen -- && *str; str ++, len ++ );
+       return len;
+}
+
 /**
  * \fn EXPORT char *strdup(const char *str)
  * \brief Duplicate a string using heap memory

diff --git a/Usermode/include/string.h b/Usermode/include/string.h
index 00f748d..611dacb 100644 (file)
--- a/Usermode/include/string.h
+++ b/Usermode/include/string.h
@@ -8,7 +8,8 @@
 #include <stddef.h>
 
 // Strings
-extern int     strlen(const char *string);
+extern size_t  strlen(const char *string);
+extern size_t  strnlen(const char *string, size_t maxlen);
 extern int     strcmp(const char *str1, const char *str2);
 extern int     strncmp(const char *str1, const char *str2, size_t len);
 extern char    *strcpy(char *dst, const char *src);