accept "nan(n-char-sequence)" in strtod/scanf functions

[musl] / src / internal / floatscan.c

diff --git a/src/internal/floatscan.c b/src/internal/floatscan.c
index 10123bf..0825121 100644 (file)
--- a/src/internal/floatscan.c
+++ b/src/internal/floatscan.c
@@ -24,6 +24,8 @@
 
 #define MASK (KMAX-1)
 
+#define CONCAT2(x,y) x ## y
+#define CONCAT(x,y) CONCAT2(x,y)
 
 static long long scanexp(FILE *f, int pok)
 {
@@ -44,7 +46,7 @@ static long long scanexp(FILE *f, int pok)
        }
        for (x=0; c-'0'<10U && x<INT_MAX/10; c = shgetc(f))
                x = 10*x + c-'0';
-       for (y=x; c-'0'<10U && x<LLONG_MAX/100; c = shgetc(f))
+       for (y=x; c-'0'<10U && y<LLONG_MAX/100; c = shgetc(f))
                y = 10*y + c-'0';
        for (; c-'0'<10U; c = shgetc(f));
        shunget(f);
@@ -57,12 +59,14 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
        uint32_t x[KMAX];
        static const uint32_t th[] = { LD_B1B_MAX };
        int i, j, k, a, z;
-       long long lrp=-1, dc=0;
+       long long lrp=0, dc=0;
        long long e10=0;
        int lnz = 0;
-       int gotdig = 0;
+       int gotdig = 0, gotrad = 0;
        int rp;
        int e2;
+       int emax = -emin-bits+3;
+       int denormal = 0;
        long double y;
        long double frac=0;
        long double bias=0;
@@ -74,15 +78,20 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
 
        /* Don't let leading zeros consume buffer space */
        for (; c=='0'; c = shgetc(f)) gotdig=1;
+       if (c=='.') {
+               gotrad = 1;
+               for (c = shgetc(f); c=='0'; c = shgetc(f)) gotdig=1, lrp--;
+       }
 
        x[0] = 0;
        for (; c-'0'<10U || c=='.'; c = shgetc(f)) {
                if (c == '.') {
-                       if (lrp!=-1) break;
+                       if (gotrad) break;
+                       gotrad = 1;
                        lrp = dc;
-               } else if (k < KMAX-2) {
-                       if (c!='0') lnz = dc;
+               } else if (k < KMAX-3) {
                        dc++;
+                       if (c!='0') lnz = dc;
                        if (j) x[k] = x[k]*10 + c-'0';
                        else x[k] = c-'0';
                        if (++j==9) {
@@ -92,10 +101,10 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
                        gotdig=1;
                } else {
                        dc++;
-                       if (c!='0') x[KMAX-3] |= 1;
+                       if (c!='0') x[KMAX-4] |= 1;
                }
        }
-       if (lrp==-1) lrp=dc;
+       if (!gotrad) lrp=dc;
 
        if (gotdig && (c|32)=='e') {
                e10 = scanexp(f, pok);
@@ -134,7 +143,7 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
        }
 
        /* Align incomplete final B1B digit */
-       if (k<KMAX && j) {
+       if (j) {
                for (; j<9; j++) x[k]*=10;
                k++;
                j=0;
@@ -190,11 +199,11 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
                }
                if (carry) {
                        rp += 9;
+                       a = (a-1 & MASK);
                        if (a == z) {
                                z = (z-1 & MASK);
                                x[z-1 & MASK] |= x[z];
                        }
-                       a = (a-1 & MASK);
                        x[a] = carry;
                }
        }
@@ -235,7 +244,7 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
 
        /* Assemble desired bits into floating point variable */
        for (y=i=0; i<LD_B1B_DIG; i++) {
-               if ((a+i & MASK)==z) x[z=(z+1 & MASK)] = 0;
+               if ((a+i & MASK)==z) x[(z=(z+1 & MASK))-1] = 0;
                y = 1000000000.0L * y + x[a+i & MASK];
        }
 
@@ -245,6 +254,7 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
        if (bits > LDBL_MANT_DIG+e2-emin) {
                bits = LDBL_MANT_DIG+e2-emin;
                if (bits<0) bits=0;
+               denormal = 1;
        }
 
        /* Calculate bias term to force rounding, move out lower bits */
@@ -275,11 +285,18 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
        y += frac;
        y -= bias;
 
-       y = scalbnl(y, e2);
-
-       if (!y) errno = ERANGE;
+       if ((e2+LDBL_MANT_DIG & INT_MAX) > emax-5) {
+               if (fabs(y) >= CONCAT(0x1p, LDBL_MANT_DIG)) {
+                       if (denormal && bits==LDBL_MANT_DIG+e2-emin)
+                               denormal = 0;
+                       y *= 0.5;
+                       e2++;
+               }
+               if (e2+LDBL_MANT_DIG>emax || (denormal && frac))
+                       errno = ERANGE;
+       }
 
-       return y;
+       return scalbnl(y, e2);
 }
 
 static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)
@@ -335,7 +352,7 @@ static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)
                } else {
                        shlim(f, 0);
                }
-               return 0;
+               return sign * 0.0;
        }
        if (!gotrad) rp = dc;
        while (dc<8) x *= 16, dc++;
@@ -394,12 +411,13 @@ static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)
        return scalbnl(y, e2);
 }
 
-long double __floatscan(FILE *f, int c, int prec, int pok)
+long double __floatscan(FILE *f, int prec, int pok)
 {
        int sign = 1;
-       int i;
+       size_t i;
        int bits;
        int emin;
+       int c;
 
        switch (prec) {
        case 0:
@@ -418,7 +436,7 @@ long double __floatscan(FILE *f, int c, int prec, int pok)
                return 0;
        }
 
-       if (c<0) c = shgetc(f);
+       while (isspace((c=shgetc(f))));
 
        if (c=='+' || c=='-') {
                sign -= 2*(c=='-');
@@ -428,14 +446,33 @@ long double __floatscan(FILE *f, int c, int prec, int pok)
        for (i=0; i<8 && (c|32)=="infinity"[i]; i++)
                if (i<7) c = shgetc(f);
        if (i==3 || i==8 || (i>3 && pok)) {
-               if (i==3) shunget(f);
-               if (pok) for (; i>3; i--) shunget(f);
-               else shlim(f, 0);
+               if (i!=8) {
+                       shunget(f);
+                       if (pok) for (; i>3; i--) shunget(f);
+               }
                return sign * INFINITY;
        }
        if (!i) for (i=0; i<3 && (c|32)=="nan"[i]; i++)
-               if (i<3) c = shgetc(f);
+               if (i<2) c = shgetc(f);
        if (i==3) {
+               if (shgetc(f) != '(') {
+                       shunget(f);
+                       return NAN;
+               }
+               for (i=1; ; i++) {
+                       c = shgetc(f);
+                       if (c-'0'<10U || c-'A'<26U || c-'a'<26U || c=='_')
+                               continue;
+                       if (c==')') return NAN;
+                       shunget(f);
+                       if (!pok) {
+                               errno = EINVAL;
+                               shlim(f, 0);
+                               return 0;
+                       }
+                       while (i--) shunget(f);
+                       return NAN;
+               }
                return NAN;
        }