tools/nolibc/printf: Use goto and reduce indentation

Upcoming changes will need to use goto to jump to the code that
outputs characters.
Use 'goto do_output' to output a known number of characters.
Use 'goto do_strlen_output' to output a '\0' terminated string.

Removes a level of indentation from the format processing code.

The change is best reviewed using 'git diff -b' after applying it.

Signed-off-by: David Laight <david.laight.linux@gmail.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260308113742.12649-8-david.laight.linux@gmail.com
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index 876bb2b2eb732beea8f34fbb32512a362a8d30e3..0365f48fb049baaa15b6ed73785bf6e115153b28 100644 (file)
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -329,103 +329,118 @@ int __nolibc_printf(__nolibc_printf_cb cb, void *state, const char *fmt, va_list
                                fmt++;
                        /* Output characters from the format string. */
                        len = fmt - outstr;
-               } else {
-                       /* we're in a format sequence */
+                       goto do_output;
+               }
 
-                       ch = *fmt++;
+               /* we're in a format sequence */
 
-                       /* width */
-                       while (ch >= '0' && ch <= '9') {
-                               width *= 10;
-                               width += ch - '0';
+               ch = *fmt++;
 
-                               ch = *fmt++;
-                       }
+               /* width */
+               while (ch >= '0' && ch <= '9') {
+                       width *= 10;
+                       width += ch - '0';
 
-                       /* Length modifiers */
+                       ch = *fmt++;
+               }
+
+               /* Length modifiers */
+               if (ch == 'l') {
+                       lpref = 1;
+                       ch = *fmt++;
                        if (ch == 'l') {
-                               lpref = 1;
-                               ch = *fmt++;
-                               if (ch == 'l') {
-                                       lpref = 2;
-                                       ch = *fmt++;
-                               }
-                       } else if (ch == 'j') {
-                               /* intmax_t is long long */
                                lpref = 2;
                                ch = *fmt++;
-                       } else {
-                               lpref = 0;
                        }
+               } else if (ch == 'j') {
+                       /* intmax_t is long long */
+                       lpref = 2;
+                       ch = *fmt++;
+               } else {
+                       lpref = 0;
+               }
 
-                       if (ch == 'c' || ch == 'd' || ch == 'u' || ch == 'x' || ch == 'p') {
-                               char *out = outbuf;
+               if (ch == 'c' || ch == 'd' || ch == 'u' || ch == 'x' || ch == 'p') {
+                       char *out = outbuf;
 
-                               if (ch == 'p')
+                       if (ch == 'p') {
+                               v = va_arg(args, unsigned long);
+                       } else if (lpref) {
+                               if (lpref > 1)
+                                       v = va_arg(args, unsigned long long);
+                               else
                                        v = va_arg(args, unsigned long);
-                               else if (lpref) {
-                                       if (lpref > 1)
-                                               v = va_arg(args, unsigned long long);
-                                       else
-                                               v = va_arg(args, unsigned long);
-                               } else
-                                       v = va_arg(args, unsigned int);
-
-                               if (ch == 'd') {
-                                       /* sign-extend the value */
-                                       if (lpref == 0)
-                                               v = (long long)(int)v;
-                                       else if (lpref == 1)
-                                               v = (long long)(long)v;
-                               }
+                       } else {
+                               v = va_arg(args, unsigned int);
+                       }
 
-                               switch (ch) {
-                               case 'c':
-                                       out[0] = v;
-                                       out[1] = 0;
-                                       break;
-                               case 'd':
-                                       i64toa_r(v, out);
-                                       break;
-                               case 'u':
-                                       u64toa_r(v, out);
-                                       break;
-                               case 'p':
-                                       *(out++) = '0';
-                                       *(out++) = 'x';
-                                       __nolibc_fallthrough;
-                               default: /* 'x' and 'p' above */
-                                       u64toh_r(v, out);
-                                       break;
-                               }
-                               outstr = outbuf;
+                       if (ch == 'd') {
+                               /* sign-extend the value */
+                               if (lpref == 0)
+                                       v = (long long)(int)v;
+                               else if (lpref == 1)
+                                       v = (long long)(long)v;
                        }
-                       else if (ch == 's') {
-                               outstr = va_arg(args, char *);
-                               if (!outstr)
-                                       outstr="(null)";
+
+                       switch (ch) {
+                       case 'c':
+                               out[0] = v;
+                               out[1] = 0;
+                               break;
+                       case 'd':
+                               i64toa_r(v, out);
+                               break;
+                       case 'u':
+                               u64toa_r(v, out);
+                               break;
+                       case 'p':
+                               *(out++) = '0';
+                               *(out++) = 'x';
+                               __nolibc_fallthrough;
+                       default: /* 'x' and 'p' above */
+                               u64toh_r(v, out);
+                               break;
                        }
-                       else if (ch == 'm') {
+                       outstr = outbuf;
+                       goto do_strlen_output;
+               }
+
+               if (ch == 's') {
+                       outstr = va_arg(args, char *);
+                       if (!outstr)
+                               outstr = "(null)";
+                       goto do_strlen_output;
+               }
+
+               if (ch == 'm') {
 #ifdef NOLIBC_IGNORE_ERRNO
-                               outstr = "unknown error";
+                       outstr = "unknown error";
 #else
-                               outstr = strerror(errno);
+                       outstr = strerror(errno);
 #endif /* NOLIBC_IGNORE_ERRNO */
-                       } else {
-                               if (ch != '%') {
-                                       /* Invalid format: back up to output the format characters */
-                                       fmt = outstr + 1;
-                                       /* and output a '%' now. */
-                               }
-                               /* %% is documented as a 'conversion specifier'.
-                                * Any flags, precision or length modifier are ignored.
-                                */
-                               width = 0;
-                               outstr = "%";
-                       }
-                       len = strlen(outstr);
+                       goto do_strlen_output;
                }
 
+               if (ch != '%') {
+                       /* Invalid format: back up to output the format characters */
+                       fmt = outstr + 1;
+                       /* and output a '%' now. */
+               }
+               /* %% is documented as a 'conversion specifier'.
+                * Any flags, precision or length modifier are ignored.
+                */
+               len = 1;
+               width = 0;
+               outstr = fmt - 1;
+               goto do_output;
+
+do_strlen_output:
+               /* Open coded strlen() (slightly smaller). */
+               for (len = 0;; len++)
+                       if (!outstr[len])
+                               break;
+
+do_output:
                written += len;
 
                width -= len;