--- /dev/null
+Allow C99-depending features of libstdc++ with uClibc
+
+The libstdc++ code is fairly restrictive on how it checks for C99
+compatibility: it requires *complete* C99 support to enable certain
+features. For example, uClibc provides a good number of C99 features,
+but not C99 complex number support. For this reason, libstdc++
+completely disables many the standard C++ methods that can in fact
+work because uClibc provides the necessary functions.
+
+This patch is similar and highly inspired from
+https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58393, but implemented in
+a way that doesn't involve changing the configure.ac script, as
+autoreconfiguring gcc is complicated. It simply relies on the fact
+that uClibc defines the __UCLIBC__ definition.
+
+Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+
+Index: b/libstdc++-v3/config/locale/generic/c_locale.h
+===================================================================
+--- a/libstdc++-v3/config/locale/generic/c_locale.h
++++ b/libstdc++-v3/config/locale/generic/c_locale.h
+@@ -71,7 +71,7 @@
+ __builtin_va_list __args;
+ __builtin_va_start(__args, __fmt);
+
+-#ifdef _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+ const int __ret = __builtin_vsnprintf(__out, __size, __fmt, __args);
+ #else
+ const int __ret = __builtin_vsprintf(__out, __fmt, __args);
+Index: b/libstdc++-v3/config/locale/gnu/c_locale.h
+===================================================================
+--- a/libstdc++-v3/config/locale/gnu/c_locale.h
++++ b/libstdc++-v3/config/locale/gnu/c_locale.h
+@@ -89,7 +89,7 @@
+ __builtin_va_list __args;
+ __builtin_va_start(__args, __fmt);
+
+-#ifdef _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+ const int __ret = __builtin_vsnprintf(__out, __size, __fmt, __args);
+ #else
+ const int __ret = __builtin_vsprintf(__out, __fmt, __args);
+Index: b/libstdc++-v3/include/bits/basic_string.h
+===================================================================
+--- a/libstdc++-v3/include/bits/basic_string.h
++++ b/libstdc++-v3/include/bits/basic_string.h
+@@ -2806,7 +2806,7 @@
+ _GLIBCXX_END_NAMESPACE_VERSION
+ } // namespace
+
+-#if (defined(__GXX_EXPERIMENTAL_CXX0X__) && defined(_GLIBCXX_USE_C99) \
++#if (defined(__GXX_EXPERIMENTAL_CXX0X__) && (defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)) \
+ && !defined(_GLIBCXX_HAVE_BROKEN_VSWPRINTF))
+
+ #include <ext/string_conversions.h>
+Index: b/libstdc++-v3/include/bits/locale_facets.tcc
+===================================================================
+--- a/libstdc++-v3/include/bits/locale_facets.tcc
++++ b/libstdc++-v3/include/bits/locale_facets.tcc
+@@ -989,7 +989,7 @@
+ char __fbuf[16];
+ __num_base::_S_format_float(__io, __fbuf, __mod);
+
+-#ifdef _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+ // First try a buffer perhaps big enough (most probably sufficient
+ // for non-ios_base::fixed outputs)
+ int __cs_size = __max_digits * 3;
+Index: b/libstdc++-v3/include/bits/locale_facets_nonio.tcc
+===================================================================
+--- a/libstdc++-v3/include/bits/locale_facets_nonio.tcc
++++ b/libstdc++-v3/include/bits/locale_facets_nonio.tcc
+@@ -572,7 +572,7 @@
+ {
+ const locale __loc = __io.getloc();
+ const ctype<_CharT>& __ctype = use_facet<ctype<_CharT> >(__loc);
+-#ifdef _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+ // First try a buffer perhaps big enough.
+ int __cs_size = 64;
+ char* __cs = static_cast<char*>(__builtin_alloca(__cs_size));
+Index: b/libstdc++-v3/include/c_compatibility/math.h
+===================================================================
+--- a/libstdc++-v3/include/c_compatibility/math.h
++++ b/libstdc++-v3/include/c_compatibility/math.h
+@@ -57,7 +57,7 @@
+ using std::floor;
+ using std::fmod;
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+ using std::fpclassify;
+ using std::isfinite;
+ using std::isinf;
+Index: b/libstdc++-v3/include/c_compatibility/wchar.h
+===================================================================
+--- a/libstdc++-v3/include/c_compatibility/wchar.h
++++ b/libstdc++-v3/include/c_compatibility/wchar.h
+@@ -103,7 +103,7 @@
+ using std::wmemset;
+ using std::wcsftime;
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+ using std::wcstold;
+ using std::wcstoll;
+ using std::wcstoull;
+Index: b/libstdc++-v3/include/c_global/cstdlib
+===================================================================
+--- a/libstdc++-v3/include/c_global/cstdlib
++++ b/libstdc++-v3/include/c_global/cstdlib
+@@ -146,7 +146,7 @@
+ _GLIBCXX_END_NAMESPACE_VERSION
+ } // namespace
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+
+ #undef _Exit
+ #undef llabs
+Index: b/libstdc++-v3/include/c_global/cwchar
+===================================================================
+--- a/libstdc++-v3/include/c_global/cwchar
++++ b/libstdc++-v3/include/c_global/cwchar
+@@ -234,7 +234,7 @@
+ _GLIBCXX_END_NAMESPACE_VERSION
+ } // namespace
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+
+ #undef wcstold
+ #undef wcstoll
+@@ -291,7 +291,7 @@
+ using std::vwscanf;
+ #endif
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+ using std::wcstold;
+ using std::wcstoll;
+ using std::wcstoull;
+Index: b/libstdc++-v3/include/c_std/cstdio
+===================================================================
+--- a/libstdc++-v3/include/c_std/cstdio
++++ b/libstdc++-v3/include/c_std/cstdio
+@@ -140,7 +140,7 @@
+ using ::vsprintf;
+ } // namespace std
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+
+ #undef snprintf
+ #undef vfscanf
+Index: b/libstdc++-v3/include/c_std/cstdlib
+===================================================================
+--- a/libstdc++-v3/include/c_std/cstdlib
++++ b/libstdc++-v3/include/c_std/cstdlib
+@@ -143,7 +143,7 @@
+ _GLIBCXX_END_NAMESPACE_VERSION
+ } // namespace
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+
+ #undef _Exit
+ #undef llabs
+Index: b/libstdc++-v3/include/c_std/cwchar
+===================================================================
+--- a/libstdc++-v3/include/c_std/cwchar
++++ b/libstdc++-v3/include/c_std/cwchar
+@@ -230,7 +230,7 @@
+ _GLIBCXX_END_NAMESPACE_VERSION
+ } // namespace
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+
+ #undef wcstold
+ #undef wcstoll
+Index: b/libstdc++-v3/include/ext/vstring.h
+===================================================================
+--- a/libstdc++-v3/include/ext/vstring.h
++++ b/libstdc++-v3/include/ext/vstring.h
+@@ -2537,7 +2537,7 @@
+ _GLIBCXX_END_NAMESPACE_VERSION
+ } // namespace
+
+-#if (defined(__GXX_EXPERIMENTAL_CXX0X__) && defined(_GLIBCXX_USE_C99))
++#if (defined(__GXX_EXPERIMENTAL_CXX0X__) && (defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)))
+
+ #include <ext/string_conversions.h>
+
+Index: b/libstdc++-v3/include/tr1/cstdio
+===================================================================
+--- a/libstdc++-v3/include/tr1/cstdio
++++ b/libstdc++-v3/include/tr1/cstdio
+@@ -33,7 +33,7 @@
+
+ #include <cstdio>
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+
+ namespace std _GLIBCXX_VISIBILITY(default)
+ {
+Index: b/libstdc++-v3/include/tr1/cstdlib
+===================================================================
+--- a/libstdc++-v3/include/tr1/cstdlib
++++ b/libstdc++-v3/include/tr1/cstdlib
+@@ -35,7 +35,7 @@
+
+ #if _GLIBCXX_HOSTED
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+
+ namespace std _GLIBCXX_VISIBILITY(default)
+ {
+Index: b/libstdc++-v3/include/tr1/cwchar
+===================================================================
+--- a/libstdc++-v3/include/tr1/cwchar
++++ b/libstdc++-v3/include/tr1/cwchar
+@@ -52,7 +52,7 @@
+ using std::vwscanf;
+ #endif
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+ using std::wcstold;
+ using std::wcstoll;
+ using std::wcstoull;
+Index: b/libstdc++-v3/include/tr1/stdlib.h
+===================================================================
+--- a/libstdc++-v3/include/tr1/stdlib.h
++++ b/libstdc++-v3/include/tr1/stdlib.h
+@@ -33,7 +33,7 @@
+
+ #if _GLIBCXX_HOSTED
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+
+ using std::tr1::atoll;
+ using std::tr1::strtoll;
+Index: b/libstdc++-v3/src/c++11/debug.cc
+===================================================================
+--- a/libstdc++-v3/src/c++11/debug.cc
++++ b/libstdc++-v3/src/c++11/debug.cc
+@@ -783,7 +783,7 @@
+ int __n __attribute__ ((__unused__)),
+ const char* __fmt, _Tp __s) const throw ()
+ {
+-#ifdef _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+ std::snprintf(__buf, __n, __fmt, __s);
+ #else
+ std::sprintf(__buf, __fmt, __s);
+Index: b/libstdc++-v3/include/c_global/cstdio
+===================================================================
+--- a/libstdc++-v3/include/c_global/cstdio
++++ b/libstdc++-v3/include/c_global/cstdio
+@@ -140,7 +140,7 @@
+ using ::vsprintf;
+ } // namespace
+
+-#if _GLIBCXX_USE_C99
++#if defined(_GLIBCXX_USE_C99) || defined(__UCLIBC__)
+
+ #undef snprintf
+ #undef vfscanf