From 5dfbc52264fc64db22e75f385be9efae3d0eba46 Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Tue, 10 Nov 2020 19:23:15 +0000
Subject: [PATCH] libstdc++: Avoid bad_alloc exceptions when changing locales
For the --enable-clocale=generic configuration, the current code can
fail with a bad_alloc exception. This patch uses the nothrow version of
operator new and reports allocation failures by setting failbit in the
iostate variable.
* config/locale/generic/c_locale.cc (__set_C_locale()): New function
to set the "C" locale and return the name of the previous locale.
(__convert_to_v<float>, __convert_to_v<double>)
(__convert_to_v<long double>): Use __set_C_locale and set failbit on
error.
---
.../config/locale/generic/c_locale.cc | 49 +++++++++++++------
1 file changed, 34 insertions(+), 15 deletions(-)
diff --git a/libstdc++-v3/config/locale/generic/c_locale.cc b/libstdc++-v3/config/locale/generic/c_locale.cc
index 61ead91ec1ed..648b8e182cc7 100644
--- a/libstdc++-v3/config/locale/generic/c_locale.cc
+++ b/libstdc++-v3/config/locale/generic/c_locale.cc
@@ -52,6 +52,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
~_Save_errno() { if (errno == 0) errno = _M_errno; }
int _M_errno;
};
+
+ // calls setlocale(LC_ALL, "C") and returns a string containing the old
+ // locale name. Caller must delete[] the string. Returns NULL on error.
+ const char*
+ __set_C_locale()
+ {
+ char* __old = setlocale(LC_ALL, 0);
+ const size_t __len = strlen(__old) + 1;
+ char* __sav = new(nothrow) char[__len];
+ if (__sav)
+ {
+ memcpy(__sav, __old, __len);
+ setlocale(LC_ALL, "C");
+ }
+ return __sav;
+ }
}
template<>
@@ -60,11 +76,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
const __c_locale&) throw()
{
// Assumes __s formatted for "C" locale.
- char* __old = setlocale(LC_ALL, 0);
- const size_t __len = strlen(__old) + 1;
- char* __sav = new char[__len];
- memcpy(__sav, __old, __len);
- setlocale(LC_ALL, "C");
+ const char* __sav = __set_C_locale();
+ if (!__sav)
+ {
+ __err = ios_base::failbit;
+ return;
+ }
char* __sanity;
bool __overflow = false;
@@ -125,11 +142,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
const __c_locale&) throw()
{
// Assumes __s formatted for "C" locale.
- char* __old = setlocale(LC_ALL, 0);
- const size_t __len = strlen(__old) + 1;
- char* __sav = new char[__len];
- memcpy(__sav, __old, __len);
- setlocale(LC_ALL, "C");
+ const char* __sav = __set_C_locale();
+ if (!__sav)
+ {
+ __err = ios_base::failbit;
+ return;
+ }
char* __sanity;
#if !__DBL_HAS_INFINITY__
@@ -170,11 +188,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
ios_base::iostate& __err, const __c_locale&) throw()
{
// Assumes __s formatted for "C" locale.
- char* __old = setlocale(LC_ALL, 0);
- const size_t __len = strlen(__old) + 1;
- char* __sav = new char[__len];
- memcpy(__sav, __old, __len);
- setlocale(LC_ALL, "C");
+ const char* __sav = __set_C_locale();
+ if (!__sav)
+ {
+ __err = ios_base::failbit;
+ return;
+ }
#if !__LDBL_HAS_INFINITY__
const _Save_errno __save_errno;
--
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