scc

commit 0e6a91f0ad480a0a2e1745679c3cf712f19b4719
parent ac419b4e9017c49736a13de9689992652c133b16
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Mon,  7 Nov 2022 13:04:56 +0100

libc/stdio: Simplify string output in vfprintf()

It is not needed to calculate the lenght of a string because
we already check it while we print it and it is cross checked
against the precision. We can use SIZE_MAX instead of -1 because
it works as a positive number, removing several of the problems
that the code had.

Diffstat:
M
src/libc/stdio/vfprintf.c
 | 
15
+++++----------

1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/src/libc/stdio/vfprintf.c b/src/libc/stdio/vfprintf.c
@@ -25,7 +25,7 @@ enum {
 
 struct conv {
 	int sign;
-	int prec;
+	size_t prec;
 	char *digs;
 	int base;
 };
@@ -75,7 +75,7 @@ numtostr(uintmax_t val, int flags, struct conv *conv, char *buf)
 	int base = conv->base, prec = conv->prec;
 	uintmax_t oval = val;
 
-	if (prec == -1)
+	if (prec == SIZE_MAX)
 		prec = 1;
 
 	for (*buf = '\0'; val > 0; val /= base)
@@ -158,8 +158,6 @@ strout(char *s, size_t len, int width, int fill, FILE *restrict fp)
 		left = 1;
 		width = -width;
 	}
-	if (len == (size_t) -1)
-		len = SIZE_MAX;
 
 	adjust = len < width ? width - len : 0;
 	if (left)
@@ -219,7 +217,7 @@ vfprintf(FILE *restrict fp, const char *restrict fmt, va_list va)
 
 		fill = ' ';
 		left = flags = width =  0;
-		conv.prec = -1;
+		conv.prec = SIZE_MAX;
 		conv.base = 10;
 		conv.sign = '\0';
 		conv.digs = "0123456789ABCDEFX";
@@ -324,7 +322,7 @@ flags:
 			conv.base = 8;
 			flags |= UNSIGNED;
 		numeric:
-			if (conv.prec != -1) {
+			if (conv.prec != SIZE_MAX) {
 				if (conv.prec > MAXPREC)
 					conv.prec = MAXPREC;
 				fill = ' ';
@@ -346,15 +344,12 @@ flags:
 			/* TODO */
 			break;
 		case 's':
+			len = conv.prec;
 			if (flags & LONG) {
 				ws = va_arg(va2, wchar_t *);
-				if ((len = wcslen(ws)) > conv.prec)
-					len = conv.prec;
 				goto wstrout;
 			} else {
 				s = va_arg(va2, char *);
-				if ((len = strlen(s)) > conv.prec)
-					len = conv.prec;
 				goto strout;
 			}
 		wstrout: