[libcxx-commits] [libcxx] [libc++] Fix `money_get::do_get` with huge input (PR #126273)

[Mark de Wever via libcxx-commits]

================
@@ -0,0 +1,113 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <locale>
+
+// class money_get<charT, InputIterator>
+
+// iter_type get(iter_type b, iter_type e, bool intl, ios_base& iob,
+//               ios_base::iostate& err, long double& v) const;
+
+#include <cassert>
+#include <cstddef>
+#include <ios>
+#include <locale>
+#include <streambuf>
+#include <string>
+
+#include "test_macros.h"
+#include "test_iterators.h"
+
+typedef std::money_get<char, cpp17_input_iterator<const char*> > Fn;
+
+class my_facet : public Fn {
+public:
+  explicit my_facet(std::size_t refs = 0) : Fn(refs) {}
+};
+
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+typedef std::money_get<wchar_t, cpp17_input_iterator<const wchar_t*> > Fw;
+
+class my_facetw : public Fw {
+public:
+  explicit my_facetw(std::size_t refs = 0) : Fw(refs) {}
+};
+#endif
+
+int main(int, char**) {
+  struct digit_result_case {
+    std::size_t digit;
+    long double result;
+  };
+  const digit_result_case digit_result_cases[] = {
+      {60, 2.0E60L}, {120, 2.0E120L}, {180, 2.0E180L}, {240, 2.0E240L}, {300, 2.0E300L}};
+
+  std::ios ios(0);
+  {
+    const my_facet f(1);
+    for (std::size_t i = 0; i != sizeof(digit_result_cases) / sizeof(digit_result_cases[0]); ++i) {
+      {
+        std::string v = "2";
+        v.append(digit_result_cases[i].digit, '0');
+
+        typedef cpp17_input_iterator<const char*> I;
+        long double ex;
+        std::ios_base::iostate err = std::ios_base::goodbit;
+        I iter                     = f.get(I(v.data()), I(v.data() + v.size()), false, ios, err, ex);
+        assert(base(iter) == v.data() + v.size());
+        assert(err == std::ios_base::eofbit);
+        assert(ex == digit_result_cases[i].result);
+      }
+      {
+        std::string v = "-2";
+        v.append(digit_result_cases[i].digit, '0');
+
+        typedef cpp17_input_iterator<const char*> I;
+        long double ex;
+        std::ios_base::iostate err = std::ios_base::goodbit;
+        I iter                     = f.get(I(v.data()), I(v.data() + v.size()), false, ios, err, ex);
+        assert(base(iter) == v.data() + v.size());
+        assert(err == std::ios_base::eofbit);
+        assert(ex == -digit_result_cases[i].result);
+      }
+    }
+  }
----------------
mordante wrote:

Can we extract this in a templated function with CharT as arguement.
The call it twice, once with `char` and once with `wchar_t`.
We already have the tools in our test suite (`libcxx/test/support/make_string.h`) to easily do this.

https://github.com/llvm/llvm-project/pull/126273