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| author | Jonathan Wakely <jwakely@redhat.com> | 2020-10-08 15:14:58 +0100 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2020-10-08 15:24:21 +0100 |
| commit | b2a96bf9dce41ee777b1669e4a8b4c6df3ff3613 (patch) | |
| tree | 1232ac1c462cbd462331ca81914b23cc948acbf7 | |
| parent | 5a448362da6133c3b16ffdb0c795b657af7fa5a4 (diff) | |
| download | gcc-b2a96bf9dce41ee777b1669e4a8b4c6df3ff3613.zip gcc-b2a96bf9dce41ee777b1669e4a8b4c6df3ff3613.tar.gz gcc-b2a96bf9dce41ee777b1669e4a8b4c6df3ff3613.tar.bz2 | |
libstdc++: Add assertions for preconditions in sampling distributions [PR 82584]
These three distributions all require 0 < S where S is the sum of the
weights. When the sum is zero there's an undefined FP division by zero.
Add assertions to help users diagnose the problem.
libstdc++-v3/ChangeLog:
PR libstdc++/82584
* include/bits/random.tcc
(discrete_distribution::param_type::_M_initialize)
(piecewise_constant_distribution::param_type::_M_initialize)
(piecewise_linear_distribution::param_type::_M_initialize):
Add assertions for positive sums..
* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error
line.
| -rw-r--r-- | libstdc++-v3/include/bits/random.tcc | 3 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc | 2 |
2 files changed, 4 insertions, 1 deletions
diff --git a/libstdc++-v3/include/bits/random.tcc b/libstdc++-v3/include/bits/random.tcc index f67b2fe..a921b9b 100644 --- a/libstdc++-v3/include/bits/random.tcc +++ b/libstdc++-v3/include/bits/random.tcc @@ -2630,6 +2630,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION const double __sum = std::accumulate(_M_prob.begin(), _M_prob.end(), 0.0); + __glibcxx_assert(__sum > 0); // Now normalize the probabilites. __detail::__normalize(_M_prob.begin(), _M_prob.end(), _M_prob.begin(), __sum); @@ -2794,6 +2795,7 @@ namespace __detail const double __sum = std::accumulate(_M_den.begin(), _M_den.end(), 0.0); + __glibcxx_assert(__sum > 0); __detail::__normalize(_M_den.begin(), _M_den.end(), _M_den.begin(), __sum); @@ -3016,6 +3018,7 @@ namespace __detail _M_cp.push_back(__sum); _M_m.push_back((_M_den[__k + 1] - _M_den[__k]) / __delta); } + __glibcxx_assert(__sum > 0); // Now normalize the densities... __detail::__normalize(_M_den.begin(), _M_den.end(), _M_den.begin(), diff --git a/libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc b/libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc index 139abbb..9cffc3d 100644 --- a/libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc +++ b/libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc @@ -12,4 +12,4 @@ auto x = std::generate_canonical<std::size_t, // { dg-error "static assertion failed: template argument must be a floating point type" "" { target *-*-* } 167 } -// { dg-error "static assertion failed: template argument must be a floating point type" "" { target *-*-* } 3281 } +// { dg-error "static assertion failed: template argument must be a floating point type" "" { target *-*-* } 3284 } |