X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fstdio%2Fvfprintf.c;h=ea257720bf8088fb2e1106590fbe7f7df609eaba;hb=0206f596d5156af560e8af10e950d3cb2f29b73d;hp=1e7e6a477faeba521537d9146e003596ccaeba3e;hpb=835f9f950e2f6059532bd9ab9857a856ed21a4fd;p=musl

diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
index 1e7e6a47..ea257720 100644
--- a/src/stdio/vfprintf.c
+++ b/src/stdio/vfprintf.c
@@ -13,8 +13,6 @@
 
 #define MAX(a,b) ((a)>(b) ? (a) : (b))
 #define MIN(a,b) ((a)<(b) ? (a) : (b))
-#define CONCAT2(x,y) x ## y
-#define CONCAT(x,y) CONCAT2(x,y)
 
 /* Convenient bit representation for modifier flags, which all fall
  * within 31 codepoints of the space character. */
@@ -198,9 +196,17 @@ static char *fmt_u(uintmax_t x, char *s)
 	return s;
 }
 
+/* Do not override this check. The floating point printing code below
+ * depends on the float.h constants being right. If they are wrong, it
+ * may overflow the stack. */
+#if LDBL_MANT_DIG == 53
+typedef char compiler_defines_long_double_incorrectly[9-(int)sizeof(long double)];
+#endif
+
 static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
 {
-	uint32_t big[(LDBL_MAX_EXP+LDBL_MANT_DIG)/9+1];
+	uint32_t big[(LDBL_MANT_DIG+28)/29 + 1          // mantissa expansion
+		+ (LDBL_MAX_EXP+LDBL_MANT_DIG+28+8)/9]; // exponent expansion
 	uint32_t *a, *d, *r, *z;
 	int e2=0, e, i, j, l;
 	char buf[9+LDBL_MANT_DIG/4], *s;
@@ -300,13 +306,13 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
 			*d = x % 1000000000;
 			carry = x / 1000000000;
 		}
-		if (!z[-1] && z>a) z--;
 		if (carry) *--a = carry;
+		while (z>a && !z[-1]) z--;
 		e2-=sh;
 	}
 	while (e2<0) {
 		uint32_t carry=0, *b;
-		int sh=MIN(9,-e2);
+		int sh=MIN(9,-e2), need=1+(p+LDBL_MANT_DIG/3+8)/9;
 		for (d=a; d<z; d++) {
 			uint32_t rm = *d & (1<<sh)-1;
 			*d = (*d>>sh) + carry;
@@ -316,7 +322,7 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
 		if (carry) *z++ = carry;
 		/* Avoid (slow!) computation past requested precision */
 		b = (t|32)=='f' ? r : a;
-		if (z-b > 2+p/9) z = b+2+p/9;
+		if (z-b > need) z = b+need;
 		e2+=sh;
 	}
 
@@ -335,7 +341,7 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
 		x = *d % i;
 		/* Are there any significant digits past j? */
 		if (x || d+1!=z) {
-			long double round = CONCAT(0x1p,LDBL_MANT_DIG);
+			long double round = 2/LDBL_EPSILON;
 			long double small;
 			if (*d/i & 1) round += 2;
 			if (x<i/2) small=0x0.8p0;
@@ -348,15 +354,15 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
 				*d = *d + i;
 				while (*d > 999999999) {
 					*d--=0;
+					if (d<a) *--a=0;
 					(*d)++;
 				}
-				if (d<a) a=d;
 				for (i=10, e=9*(r-a); *a>=i; i*=10, e++);
 			}
 		}
 		if (z>d+1) z=d+1;
-		for (; !z[-1] && z>a; z--);
 	}
+	for (; z>a && !z[-1]; z--);
 	
 	if ((t|32)=='g') {
 		if (!p) p++;
@@ -523,7 +529,6 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
 		/* Check validity of argument type (nl/normal) */
 		if (st==NOARG) {
 			if (argpos>=0) return -1;
-			else if (!f) continue;
 		} else {
 			if (argpos>=0) nl_type[argpos]=st, arg=nl_arg[argpos];
 			else if (f) pop_arg(&arg, st, ap);
@@ -653,8 +658,12 @@ int vfprintf(FILE *restrict f, const char *restrict fmt, va_list ap)
 	unsigned char internal_buf[80], *saved_buf = 0;
 	int ret;
 
+	/* the copy allows passing va_list* even if va_list is an array */
 	va_copy(ap2, ap);
-	if (printf_core(0, fmt, &ap2, nl_arg, nl_type) < 0) return -1;
+	if (printf_core(0, fmt, &ap2, nl_arg, nl_type) < 0) {
+		va_end(ap2);
+		return -1;
+	}
 
 	FLOCK(f);
 	if (!f->buf_size) {