[libcxx-commits] [libcxx] [libc++] LWG2381: Inconsistency in parsing floating point numbers (PR #77948)
via libcxx-commits
libcxx-commits at lists.llvm.org
Fri Jan 12 09:14:17 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libcxx
Author: A. Jiang (frederick-vs-ja)
<details>
<summary>Changes</summary>
This PR implements [LWG2381](https://cplusplus.github.io/LWG/issue2381) by rejecting `'i'`, `'I'`, `'n'`, `'N'` in FP parsing, as inf and NaN are intendedly rejected by that LWG issue. Also replaces magic numbers 26 and 28 (formerly 32) are with named constants.
As a driven-by change, some parts of `get_long_double.pass.cpp` are guarded with `LDBL_MANT_DIG >= 64`, because these parts fail on platforms (e.g. MSVC) where long double is of binary64 format.
#<!-- -->65168 may be rendered invalid, see https://github.com/llvm/llvm-project/pull/65168#issuecomment-1868533342.
---
Full diff: https://github.com/llvm/llvm-project/pull/77948.diff
5 Files Affected:
- (modified) libcxx/docs/Status/Cxx23Issues.csv (+1-1)
- (modified) libcxx/include/locale (+15-12)
- (modified) libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_double.pass.cpp (+18-18)
- (modified) libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_float.pass.cpp (+18-18)
- (modified) libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_long_double.pass.cpp (+21-18)
``````````diff
diff --git a/libcxx/docs/Status/Cxx23Issues.csv b/libcxx/docs/Status/Cxx23Issues.csv
index b24ecc5525a149..a835a57ba90c54 100644
--- a/libcxx/docs/Status/Cxx23Issues.csv
+++ b/libcxx/docs/Status/Cxx23Issues.csv
@@ -98,7 +98,7 @@
`3555 <https://wg21.link/LWG3555>`__,"``{transform,elements}_view::iterator::iterator_concept`` should consider const-qualification of the underlying range","June 2021","","","|ranges|"
"","","","","",""
`2191 <https://wg21.link/LWG2191>`__,"Incorrect specification of ``match_results(match_results&&)``","October 2021","|Nothing To Do|",""
-`2381 <https://wg21.link/LWG2381>`__,"Inconsistency in parsing floating point numbers","October 2021","",""
+`2381 <https://wg21.link/LWG2381>`__,"Inconsistency in parsing floating point numbers","October 2021","|Complete|","18.0"
`2762 <https://wg21.link/LWG2762>`__,"``unique_ptr operator*()`` should be ``noexcept``","October 2021","",""
`3121 <https://wg21.link/LWG3121>`__,"``tuple`` constructor constraints for ``UTypes&&...`` overloads","October 2021","",""
`3123 <https://wg21.link/LWG3123>`__,"``duration`` constructor from representation shouldn't be effectively non-throwing","October 2021","","","|chrono|"
diff --git a/libcxx/include/locale b/libcxx/include/locale
index 70d22ff95e1ee1..839b7045fc3c30 100644
--- a/libcxx/include/locale
+++ b/libcxx/include/locale
@@ -366,9 +366,11 @@ _LIBCPP_HIDE_FROM_ABI _ForwardIterator __scan_keyword(
struct _LIBCPP_EXPORTED_FROM_ABI __num_get_base {
static const int __num_get_buf_sz = 40;
+ static const size_t __int_chr_cnt = 26;
+ static const size_t __fp_chr_cnt = 28;
static int __get_base(ios_base&);
- static const char __src[33];
+ static const char __src[33]; // "0123456789abcdefABCDEFxX+-pPiInN"
};
_LIBCPP_EXPORTED_FROM_ABI void
@@ -431,7 +433,7 @@ private:
template <typename _Tp>
const _Tp* __do_widen_p(ios_base& __iob, _Tp* __atoms) const {
locale __loc = __iob.getloc();
- use_facet<ctype<_Tp> >(__loc).widen(__src, __src + 26, __atoms);
+ use_facet<ctype<_Tp> >(__loc).widen(__src, __src + __int_chr_cnt, __atoms);
return __atoms;
}
@@ -447,7 +449,7 @@ private:
template <class _CharT>
string __num_get<_CharT>::__stage2_int_prep(ios_base& __iob, _CharT* __atoms, _CharT& __thousands_sep) {
locale __loc = __iob.getloc();
- std::use_facet<ctype<_CharT> >(__loc).widen(__src, __src + 26, __atoms);
+ std::use_facet<ctype<_CharT> >(__loc).widen(__src, __src + __int_chr_cnt, __atoms);
const numpunct<_CharT>& __np = std::use_facet<numpunct<_CharT> >(__loc);
__thousands_sep = __np.thousands_sep();
return __np.grouping();
@@ -458,7 +460,7 @@ template <class _CharT>
string __num_get<_CharT>::__stage2_float_prep(
ios_base& __iob, _CharT* __atoms, _CharT& __decimal_point, _CharT& __thousands_sep) {
locale __loc = __iob.getloc();
- std::use_facet<ctype<_CharT> >(__loc).widen(__src, __src + 32, __atoms);
+ std::use_facet<ctype<_CharT> >(__loc).widen(__src, __src + __fp_chr_cnt, __atoms);
const numpunct<_CharT>& __np = std::use_facet<numpunct<_CharT> >(__loc);
__decimal_point = __np.decimal_point();
__thousands_sep = __np.thousands_sep();
@@ -490,7 +492,7 @@ __num_get<_CharT>::__stage2_int_loop(_CharT __ct, int __base, char* __a, char*&
}
return 0;
}
- ptrdiff_t __f = std::find(__atoms, __atoms + 26, __ct) - __atoms;
+ ptrdiff_t __f = std::find(__atoms, __atoms + __int_chr_cnt, __ct) - __atoms;
if (__f >= 24)
return -1;
switch (__base) {
@@ -546,8 +548,8 @@ int __num_get<_CharT>::__stage2_float_loop(
}
return 0;
}
- ptrdiff_t __f = std::find(__atoms, __atoms + 32, __ct) - __atoms;
- if (__f >= 32)
+ ptrdiff_t __f = std::find(__atoms, __atoms + __num_get_base::__fp_chr_cnt, __ct) - __atoms;
+ if (__f >= __num_get_base::__fp_chr_cnt)
return -1;
char __x = __src[__f];
if (__x == '-' || __x == '+') {
@@ -846,7 +848,7 @@ _InputIterator num_get<_CharT, _InputIterator>::__do_get_signed(
int __base = this->__get_base(__iob);
// Stage 2
char_type __thousands_sep;
- const int __atoms_size = 26;
+ const int __atoms_size = __num_get_base::__int_chr_cnt;
#ifdef _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
char_type __atoms1[__atoms_size];
const char_type* __atoms = this->__do_widen(__iob, __atoms1);
@@ -895,7 +897,7 @@ _InputIterator num_get<_CharT, _InputIterator>::__do_get_unsigned(
int __base = this->__get_base(__iob);
// Stage 2
char_type __thousands_sep;
- const int __atoms_size = 26;
+ const int __atoms_size = __num_get_base::__int_chr_cnt;
#ifdef _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
char_type __atoms1[__atoms_size];
const char_type* __atoms = this->__do_widen(__iob, __atoms1);
@@ -942,7 +944,7 @@ _InputIterator num_get<_CharT, _InputIterator>::__do_get_floating_point(
iter_type __b, iter_type __e, ios_base& __iob, ios_base::iostate& __err, _Fp& __v) const {
// Stage 1, nothing to do
// Stage 2
- char_type __atoms[32];
+ char_type __atoms[__num_get_base::__fp_chr_cnt];
char_type __decimal_point;
char_type __thousands_sep;
string __grouping = this->__stage2_float_prep(__iob, __atoms, __decimal_point, __thousands_sep);
@@ -996,10 +998,11 @@ _InputIterator num_get<_CharT, _InputIterator>::do_get(
// Stage 1
int __base = 16;
// Stage 2
- char_type __atoms[26];
+ char_type __atoms[__num_get_base::__int_chr_cnt];
char_type __thousands_sep = char_type();
string __grouping;
- std::use_facet<ctype<_CharT> >(__iob.getloc()).widen(__num_get_base::__src, __num_get_base::__src + 26, __atoms);
+ std::use_facet<ctype<_CharT> >(__iob.getloc())
+ .widen(__num_get_base::__src, __num_get_base::__src + __num_get_base::__int_chr_cnt, __atoms);
string __buf;
__buf.resize(__buf.capacity());
char* __a = &__buf[0];
diff --git a/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_double.pass.cpp b/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_double.pass.cpp
index c802ab787682aa..ce56bf1c1877b5 100644
--- a/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_double.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_double.pass.cpp
@@ -116,9 +116,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(v == INFINITY);
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v == 0.0);
}
{
const char str[] = "INF";
@@ -128,9 +128,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(v == INFINITY);
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v == 0.0);
}
{
const char str[] = "-inf";
@@ -140,9 +140,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(v == -INFINITY);
+ assert(base(iter) == str+1);
+ assert(err == ios.failbit);
+ assert(v == 0.0);
}
{
const char str[] = "-INF";
@@ -152,9 +152,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(v == -INFINITY);
+ assert(base(iter) == str+1);
+ assert(err == ios.failbit);
+ assert(v == 0.0);
}
{
const char str[] = "nan";
@@ -164,9 +164,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(std::isnan(v));
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v = 0.0);
}
{
const char str[] = "NAN";
@@ -176,9 +176,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(std::isnan(v));
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v = 0.0);
}
{
v = -1;
diff --git a/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_float.pass.cpp b/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_float.pass.cpp
index 79c8480d0699b0..38d713a46076e2 100644
--- a/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_float.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_float.pass.cpp
@@ -105,9 +105,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(v == INFINITY);
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v == 0.0f);
}
{
const char str[] = "INF";
@@ -117,9 +117,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(v == INFINITY);
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v == 0.0f);
}
{
const char str[] = "-inf";
@@ -129,9 +129,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(v == -INFINITY);
+ assert(base(iter) == str+1);
+ assert(err == ios.failbit);
+ assert(v == 0.0f);
}
{
const char str[] = "-INF";
@@ -141,9 +141,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(v == -INFINITY);
+ assert(base(iter) == str+1);
+ assert(err == ios.failbit);
+ assert(v == 0.0f);
}
{
const char str[] = "nan";
@@ -153,9 +153,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(std::isnan(v));
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v == 0.0f);
}
{
const char str[] = "NAN";
@@ -165,9 +165,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(std::isnan(v));
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v == 0.0f);
}
{
v = -1;
diff --git a/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_long_double.pass.cpp b/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_long_double.pass.cpp
index e2b2aeafd1ef92..406187f46121e6 100644
--- a/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_long_double.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_long_double.pass.cpp
@@ -16,6 +16,7 @@
#include <locale>
#include <ios>
#include <cassert>
+#include <cfloat>
#include <streambuf>
#include <cmath>
#include "test_macros.h"
@@ -105,9 +106,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(v == INFINITY);
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v == 0.0l);
}
{
const char str[] = "INF";
@@ -117,9 +118,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(v == INFINITY);
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v == 0.0l);
}
{
const char str[] = "-inf";
@@ -129,9 +130,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(v == -INFINITY);
+ assert(base(iter) == str+1);
+ assert(err == ios.failbit);
+ assert(v == 0.0l);
}
{
const char str[] = "-INF";
@@ -141,9 +142,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(v == -INFINITY);
+ assert(base(iter) == str+1);
+ assert(err == ios.failbit);
+ assert(v == 0.0l);
}
{
const char str[] = "nan";
@@ -153,9 +154,9 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(std::isnan(v));
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v == 0.0l);
}
{
const char str[] = "NAN";
@@ -165,10 +166,11 @@ int main(int, char**)
f.get(cpp17_input_iterator<const char*>(str),
cpp17_input_iterator<const char*>(str+sizeof(str)),
ios, err, v);
- assert(base(iter) == str+sizeof(str)-1);
- assert(err == ios.goodbit);
- assert(std::isnan(v));
+ assert(base(iter) == str);
+ assert(err == ios.failbit);
+ assert(v == 0.0l);
}
+#if LDBL_MANT_DIG >= 64
{
const char str[] = "1.189731495357231765021264e+49321";
std::ios_base::iostate err = ios.goodbit;
@@ -229,6 +231,7 @@ int main(int, char**)
assert(err != ios.failbit);
assert(v == 304888344611713860501504000000.0L);
}
+#endif // LDBL_MANT_DIG >= 64
{
v = -1;
const char str[] = "1.19973e+4933"; // unrepresentable
``````````
</details>
https://github.com/llvm/llvm-project/pull/77948
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