diff options
| -rw-r--r-- | generic/tclStrToD.c | 85 |
1 files changed, 69 insertions, 16 deletions
diff --git a/generic/tclStrToD.c b/generic/tclStrToD.c index 3cee154..e87f714 100644 --- a/generic/tclStrToD.c +++ b/generic/tclStrToD.c @@ -721,9 +721,9 @@ TclParseNumber( if (!octalSignificandOverflow) { /* - * Shifting by more bits than are in the value being - * shifted is at least de facto nonportable. Check for - * too large shifts first. + * Shifting by as many or more bits than are in the + * value being shifted is undefined behavior. Check + * for too large shifts first. */ if ((octalSignificandWide != 0) @@ -737,8 +737,17 @@ TclParseNumber( } } if (!octalSignificandOverflow) { - octalSignificandWide = - (octalSignificandWide << shift) + (c - '0'); + /* + * When the significand is 0, it is possible for the + * amount to be shifted to equal or exceed the width + * of the significand. Do not shift when the + * significand is 0 to avoid undefined behavior. + */ + + if (octalSignificandWide != 0) { + octalSignificandWide <<= shift; + } + octalSignificandWide += c - '0'; } else { if (err == MP_OKAY) { err = mp_mul_2d(&octalSignificandBig, shift, @@ -863,9 +872,9 @@ TclParseNumber( shift = 4 * (numTrailZeros + 1); if (!significandOverflow) { /* - * Shifting by more bits than are in the value being - * shifted is at least de facto nonportable. Check for too - * large shifts first. + * Shifting by as many or more bits than are in the + * value being shifted is undefined behavior. Check + * for too large shifts first. */ if (significandWide != 0 && @@ -877,7 +886,17 @@ TclParseNumber( } } if (!significandOverflow) { - significandWide = (significandWide << shift) + d; + /* + * When the significand is 0, it is possible for the + * amount to be shifted to equal or exceed the width + * of the significand. Do not shift when the + * significand is 0 to avoid undefined behavior. + */ + + if (significandWide != 0) { + significandWide <<= shift; + } + significandWide += d; } else if (err == MP_OKAY) { err = mp_mul_2d(&significandBig, shift, &significandBig); if (err == MP_OKAY) { @@ -917,9 +936,9 @@ TclParseNumber( shift = numTrailZeros + 1; if (!significandOverflow) { /* - * Shifting by more bits than are in the value being - * shifted is at least de facto nonportable. Check for too - * large shifts first. + * Shifting by as many or more bits than are in the + * value being shifted is undefined behavior. Check + * for too large shifts first. */ if (significandWide != 0 && @@ -931,7 +950,17 @@ TclParseNumber( } } if (!significandOverflow) { - significandWide = (significandWide << shift) + 1; + /* + * When the significand is 0, it is possible for the + * amount to be shifted to equal or exceed the width + * of the significand. Do not shift when the + * significand is 0 to avoid undefined behavior. + */ + + if (significandWide != 0) { + significandWide <<= shift; + } + significandWide += 1; } else if (err == MP_OKAY) { err = mp_mul_2d(&significandBig, shift, &significandBig); if (err == MP_OKAY) { @@ -1330,7 +1359,15 @@ TclParseNumber( } if (shift) { if (!significandOverflow) { - significandWide <<= shift; + /* + * When the significand is 0, it is possible for the + * amount to be shifted to equal or exceed the width + * of the significand. Do not shift when the + * significand is 0 to avoid undefined behavior. + */ + if (significandWide != 0) { + significandWide <<= shift; + } } else if (err == MP_OKAY) { err = mp_mul_2d(&significandBig, shift, &significandBig); } @@ -1354,7 +1391,15 @@ TclParseNumber( } if (shift) { if (!significandOverflow) { - significandWide <<= shift; + /* + * When the significand is 0, it is possible for the + * amount to be shifted to equal or exceed the width + * of the significand. Do not shift when the + * significand is 0 to avoid undefined behavior. + */ + if (significandWide != 0) { + significandWide <<= shift; + } } else if (err == MP_OKAY) { err = mp_mul_2d(&significandBig, shift, &significandBig); } @@ -1379,7 +1424,15 @@ TclParseNumber( } if (shift) { if (!octalSignificandOverflow) { - octalSignificandWide <<= shift; + /* + * When the significand is 0, it is possible for the + * amount to be shifted to equal or exceed the width + * of the significand. Do not shift when the + * significand is 0 to avoid undefined behavior. + */ + if (octalSignificandWide != 0) { + octalSignificandWide <<= shift; + } } else if (err == MP_OKAY) { err = mp_mul_2d(&octalSignificandBig, shift, &octalSignificandBig); |