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Fytch
committed
change the behavior of str2flt to return an error if the value is too big and would be inf. Also fix UB from integer overflow
1 parent 3ec92cc commit cf8da88

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2 files changed

+65
-38
lines changed

2 files changed

+65
-38
lines changed

‎include/ProgramOptions.hxx

Lines changed: 21 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -659,6 +659,7 @@ namespace po {
659659
static_assert(std::numeric_limits<T>::is_iec559, "platform doesn't meet requirements");
660660
static_assert(std::numeric_limits<T>::has_quiet_NaN, "type insufficient; doesn't support quiet NaNs");
661661
static_assert(std::numeric_limits<T>::has_infinity, "type insufficient; doesn't support infinities");
662+
using std::isinf;
662663

663664
for(; first != last && std::isspace(*first); ++first);
664665
const bool neg = expect(first, last, '-');
@@ -692,13 +693,28 @@ namespace po {
692693
expect(first, last, '+');
693694
if(first == last || !is_digit(*first))
694695
return error_code::conversion_error;
695-
int exp{};
696-
for(int d{}; first != last && (d = get_digit(*first)) >= 0; ++first)
696+
int exp = 0;
697+
bool exp_overflow = false;
698+
for(int d{}; first != last && (d = get_digit(*first)) >= 0; ++first) {
697699
exp = 10 * exp + static_cast<int>(d);
698-
if(neg_exp)
699-
exp = -exp;
700-
result *= std::pow(T{ 10 }, exp);
700+
if((exp_overflow |= (exp > std::numeric_limits<T>::max_exponent10))) {
701+
for(; first != last && is_digit(*first); ++first);
702+
break;
703+
}
704+
}
705+
if(exp_overflow) {
706+
if(neg_exp)
707+
result = 0;
708+
else
709+
return error_code::out_of_range;
710+
} else {
711+
if(neg_exp)
712+
exp = -exp;
713+
result *= std::pow(T(10), exp);
714+
}
701715
}
716+
if(isinf(result))
717+
return error_code::out_of_range;
702718
}
703719
for(; first != last && std::isspace(*first); ++first);
704720
if(first != last)

‎test/str2flt.cxx

Lines changed: 44 additions & 33 deletions
Original file line numberDiff line numberDiff line change
@@ -1,11 +1,15 @@
11
#include <catch2/catch.hpp>
22
#define PROGRAMOPTIONS_EXCEPTIONS
33
#include <ProgramOptions.hxx>
4-
#include <string>
54
#include <limits>
5+
#include <string>
66
#include <cmath>
77

88
TEST_CASE("str2flt", "[ProgramOptions]") {
9+
const double inf = std::numeric_limits<double>::infinity();
10+
11+
CHECK(po::str2flt<double>("").error == po::error_code::conversion_error);
12+
913
CHECK(po::str2flt<double>("+0").good());
1014
CHECK(po::str2flt<double>("+0") == 0.0);
1115
CHECK(po::str2flt<double>("-0").good());
@@ -14,50 +18,57 @@ TEST_CASE("str2flt", "[ProgramOptions]") {
1418
CHECK(po::str2flt<double>("-42.36") == Approx(-42.36));
1519
CHECK(po::str2flt<double>(".53") == Approx(0.53));
1620
CHECK(po::str2flt<double>("21.") == Approx(21.0));
21+
CHECK(po::str2flt<double>("-.07") == Approx(-0.07));
22+
CHECK(po::str2flt<double>("-07.") == Approx(-7.0));
1723

1824
CHECK(po::str2flt<double>("123.456e-12") == Approx(123.456e-12));
1925
CHECK(po::str2flt<double>("-42.36E8") == Approx(-42.36e+8));
2026
CHECK(po::str2flt<double>(".53e0") == Approx(0.53));
2127
CHECK(po::str2flt<double>("21.e+3") == Approx(21.0e+3));
22-
CHECK(std::isinf(po::str2flt<double>("15.3e+806").get()));
28+
29+
CHECK(po::str2flt<double>("15.3e+806").error == po::error_code::out_of_range);
30+
CHECK(po::str2flt<double>("1e9999999999999999999999999999").error == po::error_code::out_of_range);
31+
std::string big(500, '9');
32+
CHECK(po::str2flt<double>(big.begin(), big.end()).error == po::error_code::out_of_range);
2333
CHECK(po::str2flt<double>("15.3e-806") == Approx(0.0));
34+
CHECK(po::str2flt<double>("1e-9999999999999999999999999999") == Approx(0.0));
35+
36+
CHECK(po::str2flt<double>(".").error == po::error_code::conversion_error);
37+
CHECK(po::str2flt<double>("-.").error == po::error_code::conversion_error);
38+
CHECK(po::str2flt<double>("++0").error == po::error_code::conversion_error);
39+
CHECK(po::str2flt<double>("+-0").error == po::error_code::conversion_error);
40+
CHECK(po::str2flt<double>("-+0").error == po::error_code::conversion_error);
41+
CHECK(po::str2flt<double>("--0").error == po::error_code::conversion_error);
42+
CHECK(po::str2flt<double>("4.a").error == po::error_code::conversion_error);
43+
CHECK(po::str2flt<double>("2.5 a").error == po::error_code::conversion_error);
44+
CHECK(po::str2flt<double>("e3").error == po::error_code::conversion_error);
45+
CHECK(po::str2flt<double>("1e").error == po::error_code::conversion_error);
46+
CHECK(po::str2flt<double>("1e+").error == po::error_code::conversion_error);
47+
CHECK(po::str2flt<double>("1e+2.0").error == po::error_code::conversion_error);
2448

25-
CHECK(!po::str2flt<double>(".").good());
26-
CHECK(!po::str2flt<double>("-.").good());
27-
CHECK(!po::str2flt<double>("++0").good());
28-
CHECK(!po::str2flt<double>("+-0").good());
29-
CHECK(!po::str2flt<double>("-+0").good());
30-
CHECK(!po::str2flt<double>("--0").good());
31-
CHECK(!po::str2flt<double>("4.a").good());
32-
CHECK(!po::str2flt<double>("2.5 a").good());
33-
CHECK(!po::str2flt<double>("e3").good());
34-
CHECK(!po::str2flt<double>("1e").good());
35-
CHECK(!po::str2flt<double>("1e+").good());
36-
CHECK(!po::str2flt<double>("1e+2.0").good());
37-
38-
CHECK(!po::str2flt<double>("n").good());
39-
CHECK(!po::str2flt<double>("na").good());
49+
CHECK(po::str2flt<double>("n").error == po::error_code::conversion_error);
50+
CHECK(po::str2flt<double>("na").error == po::error_code::conversion_error);
4051
CHECK(po::str2flt<double>("nan").good());
41-
CHECK(!po::str2flt<double>("nann").good());
42-
CHECK(!po::str2flt<double>("nanE0").good());
52+
CHECK(po::str2flt<double>("nann").error == po::error_code::conversion_error);
53+
CHECK(po::str2flt<double>("nanE0").error == po::error_code::conversion_error);
4354
CHECK(std::isnan(po::str2flt<double>("nan").get()));
4455
CHECK(std::isnan(po::str2flt<double>("+nan").get()));
4556
CHECK(std::isnan(po::str2flt<double>("-nan").get()));
4657

47-
CHECK(!po::str2flt<double>("i").good());
48-
CHECK(!po::str2flt<double>("in").good());
58+
CHECK(po::str2flt<double>("i").error == po::error_code::conversion_error);
59+
CHECK(po::str2flt<double>("in").error == po::error_code::conversion_error);
4960
CHECK(po::str2flt<double>("inf").good());
50-
CHECK(!po::str2flt<double>("infi").good());
51-
CHECK(!po::str2flt<double>("infin").good());
52-
CHECK(!po::str2flt<double>("infini").good());
53-
CHECK(!po::str2flt<double>("infinit").good());
61+
CHECK(po::str2flt<double>("infi").error == po::error_code::conversion_error);
62+
CHECK(po::str2flt<double>("infin").error == po::error_code::conversion_error);
63+
CHECK(po::str2flt<double>("infini").error == po::error_code::conversion_error);
64+
CHECK(po::str2flt<double>("infinit").error == po::error_code::conversion_error);
5465
CHECK(po::str2flt<double>("infinity").good());
55-
CHECK(!po::str2flt<double>("infinityy").good());
56-
CHECK(!po::str2flt<double>("infinityE0").good());
57-
CHECK(std::isinf(po::str2flt<double>("inf").get()));
58-
CHECK(std::isinf(po::str2flt<double>("+inf").get()));
59-
CHECK(std::isinf(po::str2flt<double>("-inf").get()));
60-
CHECK(std::isinf(po::str2flt<double>("infinity").get()));
61-
CHECK(std::isinf(po::str2flt<double>("+infinity").get()));
62-
CHECK(std::isinf(po::str2flt<double>("-infinity").get()));
66+
CHECK(po::str2flt<double>("infinityy").error == po::error_code::conversion_error);
67+
CHECK(po::str2flt<double>("infinityE0").error == po::error_code::conversion_error);
68+
CHECK(po::str2flt<double>("inf") == inf);
69+
CHECK(po::str2flt<double>("+inf") == inf);
70+
CHECK(po::str2flt<double>("-inf") == -inf);
71+
CHECK(po::str2flt<double>("infinity") == inf);
72+
CHECK(po::str2flt<double>("+infinity") == inf);
73+
CHECK(po::str2flt<double>("-infinity") == -inf);
6374
}

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