> compile NEMU

221220000 张三
Linux zzy 5.15.146.1-microsoft-standard-WSL2 #1 SMP Thu Jan 11 04:09:03 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
 16:04:02 up  6:43,  1 user,  load average: 0.22, 0.22, 0.21

abstract-machine/klib/include/klib.h

@@ -9,7 +9,7 @@
 extern "C" {
 #endif
 
-//#define __NATIVE_USE_KLIB__
+#define __NATIVE_USE_KLIB__
 
 // string.h
 void  *memset    (void *s, int c, size_t n);

abstract-machine/klib/src/stdio.c

@@ -19,7 +19,8 @@ int printf(const char *fmt, ...) {
 }
 
 int vsprintf(char *out, const char *fmt, va_list ap) {
-    return vsnprintf(out, SIZE_MAX, fmt, ap);
+    // FIXME
+    return vsnprintf(out, 999, fmt, ap);
 }
 
 int sprintf(char *out, const char *fmt, ...) {
@@ -46,79 +47,64 @@ int vsnprintf(char *out, size_t n, const char *fmt, va_list ap) {
 }
 
 __attribute__((noinline))
-static int fmt_d(char* out, size_t n, const char* fmt, va_list ap) {
-    char buf[16];
-    int in = va_arg(ap, int);
-    if (in == 0) {
-        *out = '0';
-        out ++;
-        return 1;
-    }
-
-    int i;
-    for (i = 0; in; in /= 10, i ++) {
-        buf[i] = in % 10;
-        buf[i] += '0';
-    }
-    
-    for (int j = i - 1; j >= 0; j --) {
-        *out = buf[j];
-    }
-    return i;
-}
-
-__attribute__((noinline))
-static int fmt_s(char* out, size_t n, const char* fmt, va_list ap) {
-    const char* ch = va_arg(ap, const char*); 
-    size_t len = strlen(ch);
-    strncpy(out, ch, len);
-    return len;
-}
-
-__attribute__((noinline))
-static int fmt_match(char* out, size_t n, const char* fmt, va_list ap) {
-    int res;
-    assert(*(fmt - 1) == '%');
-    switch(*fmt) {
+static int print_fmt(char **out, int n, const char** fmt, va_list ap) {
+    int ret = 0;
+    switch (**fmt) {
         case 'd':
-            res = fmt_d(out, n, fmt, ap);
+            // 
+            (*fmt) ++;
+            int num = va_arg(ap, int), i = 0;
+            char buf[sizeof(num) * 3];
+            if (num == 0) {
+                buf[i++] = '0';
+            }
+            for (i = 0; num; i ++) {
+                buf[i] = '0' + num % 10;
+                num /= 10;
+            }
+            if (i > n) {
+                break; // error buffer overflow
+            }
+            ret = i;
+
+            // reverse buf
+            for (i --; i >= 0; i --, (*out) ++ ) {
+                **out = buf[i];
+            }
             break;
         case 's':
-            res = fmt_s(out, n, fmt, ap);
+            (*fmt) ++;
+            const char* str = va_arg(ap, const char*);
+            int n = 999; // FIXME
+            if (ret > n) break; // error buffer overflow
+            for (; *str; str ++, (*out) ++ ) {
+                **out = *str;
+            }
             break;
         default:
-            res = 0;
             break;
     }
-    return res;
+    return ret;
 }
 
+__attribute__((noinline))
 static int rvsnprintf(char* out, size_t n, const char* fmt, va_list ap) {
+    int ret = 0;
     char* _out = out;
-    size_t _n = n;
-    const char* _fmt = fmt;
-    while (_n) {
-        switch (*_fmt) {
-            case '\0':
-                *_out = *_fmt;
-                _n = 0;
-                break;
-            case '%':
-                int len = fmt_match(_out, _n, _fmt, ap);
-                _out += len;
-                _n -= len;
-                _fmt += 2;
-                break;
-            default:
-                *_out = *_fmt;
-                _out ++;
-                _fmt ++;
-                _n ++;
-                break;
+    while(*fmt) {
+        if (*fmt == '%') {
+            // FIXME
+            fmt++;
+            print_fmt(&out, 123, &fmt, ap);
+            continue;
         }
+        *out = *fmt;
+        out ++;
+        fmt ++;
     }
-    assert(*_out == '\0');
-    return 1;
+    *out = '\0';
+    putstr(_out);
+    return ret;
 }
 
 #endif