Add --enable-newlib-reent-thread-local option

By default, Newlib uses a huge object of type struct _reent to store
thread-specific data.  This object is returned by __getreent() if the
__DYNAMIC_REENT__ Newlib configuration option is defined.

The reentrancy structure contains for example errno and the standard input,
output, and error file streams.  This means that if an application only uses
errno it has a dependency on the file stream support even if it does not use
it.  This is an issue for lower end targets and applications which need to
qualify the software according to safety standards (for example ECSS-E-ST-40C,
ECSS-Q-ST-80C, IEC 61508, ISO 26262, DO-178, DO-330, DO-333).

If the new _REENT_THREAD_LOCAL configuration option is enabled, then struct
_reent is replaced by dedicated thread-local objects for each struct _reent
member.  The thread-local objects are defined in translation units which use
the corresponding object.

14 files changed, 63 insertions, 0 deletions

diff --git a/newlib/libc/stdlib/dtoa.c b/newlib/libc/stdlib/dtoa.c
index e47a8bc77..198fa663a 100644
--- a/newlib/libc/stdlib/dtoa.c
+++ b/newlib/libc/stdlib/dtoa.c
@@ -32,6 +32,11 @@
 #include <string.h>
 #include "mprec.h"
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local struct _Bigint *_tls_mp_result;
+_Thread_local int _tls_mp_result_k;
+#endif
+
 static int
 quorem (_Bigint * b, _Bigint * S)
 {
diff --git a/newlib/libc/stdlib/ecvtbuf.c b/newlib/libc/stdlib/ecvtbuf.c
index 05f315108..514896682 100644
--- a/newlib/libc/stdlib/ecvtbuf.c
+++ b/newlib/libc/stdlib/ecvtbuf.c
@@ -57,6 +57,11 @@ Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
 #include "mprec.h"
 #include "local.h"
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local char *_tls_cvtbuf;
+_Thread_local int _tls_cvtlen;
+#endif
+
 static void
 print_f (struct _reent *ptr,
 	char *buf,
diff --git a/newlib/libc/stdlib/l64a.c b/newlib/libc/stdlib/l64a.c
index 45282e32d..6f12b6151 100644
--- a/newlib/libc/stdlib/l64a.c
+++ b/newlib/libc/stdlib/l64a.c
@@ -24,6 +24,10 @@
 #include <stdlib.h>
 #include <reent.h>
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local char _tls_l64a_buf[8];
+#endif
+
 static const char R64_ARRAY[] = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
 
 char *
diff --git a/newlib/libc/stdlib/lcong48.c b/newlib/libc/stdlib/lcong48.c
index 78e9e5746..d1109f0ac 100644
--- a/newlib/libc/stdlib/lcong48.c
+++ b/newlib/libc/stdlib/lcong48.c
@@ -13,6 +13,14 @@
 
 #include "rand48.h"
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local unsigned short _tls_rand48_seed[3] = {_RAND48_SEED_0, _RAND48_SEED_1,
+    _RAND48_SEED_2};
+_Thread_local unsigned short _tls_rand48_mult[3] = {_RAND48_MULT_0, _RAND48_MULT_1,
+    _RAND48_MULT_2};
+_Thread_local unsigned short _tls_rand48_add = _RAND48_ADD;
+#endif
+
 void
 _lcong48_r (struct _reent *r,
        unsigned short p[7])
diff --git a/newlib/libc/stdlib/mblen.c b/newlib/libc/stdlib/mblen.c
index 3753d3673..24df61519 100644
--- a/newlib/libc/stdlib/mblen.c
+++ b/newlib/libc/stdlib/mblen.c
@@ -42,6 +42,10 @@ effects vary with the locale.
 #include <wchar.h>
 #include "local.h"
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local _mbstate_t _tls_mblen_state;
+#endif
+
 int
 mblen (const char *s,
         size_t n)
diff --git a/newlib/libc/stdlib/mbrlen.c b/newlib/libc/stdlib/mbrlen.c
index 57a733fed..39e175e43 100644
--- a/newlib/libc/stdlib/mbrlen.c
+++ b/newlib/libc/stdlib/mbrlen.c
@@ -5,6 +5,10 @@
 #include <stdio.h>
 #include <errno.h>
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local _mbstate_t _tls_mbrlen_state;
+#endif
+
 size_t
 mbrlen(const char *__restrict s, size_t n, mbstate_t *__restrict ps)
 {
diff --git a/newlib/libc/stdlib/mbrtowc.c b/newlib/libc/stdlib/mbrtowc.c
index 521b7a5f4..e641b8cd6 100644
--- a/newlib/libc/stdlib/mbrtowc.c
+++ b/newlib/libc/stdlib/mbrtowc.c
@@ -7,6 +7,10 @@
 #include <string.h>
 #include "local.h"
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local _mbstate_t _tls_mbrtowc_state;
+#endif
+
 size_t
 _mbrtowc_r (struct _reent *ptr,
 	wchar_t *pwc,
diff --git a/newlib/libc/stdlib/mbsnrtowcs.c b/newlib/libc/stdlib/mbsnrtowcs.c
index 8f94b1da5..2effc501c 100644
--- a/newlib/libc/stdlib/mbsnrtowcs.c
+++ b/newlib/libc/stdlib/mbsnrtowcs.c
@@ -70,6 +70,10 @@ PORTABILITY
 #include <stdio.h>
 #include <errno.h>
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local _mbstate_t _tls_mbsrtowcs_state;
+#endif
+
 size_t
 _mbsnrtowcs_r (struct _reent *r,
 	wchar_t *dst,
diff --git a/newlib/libc/stdlib/mbtowc.c b/newlib/libc/stdlib/mbtowc.c
index 2dc413f2d..fbd8df61d 100644
--- a/newlib/libc/stdlib/mbtowc.c
+++ b/newlib/libc/stdlib/mbtowc.c
@@ -49,6 +49,10 @@ effects vary with the locale.
 #include <wchar.h>
 #include "local.h"
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local _mbstate_t _tls_mbtowc_state;
+#endif
+
 int
 mbtowc (wchar_t *__restrict pwc,
         const char *__restrict s,
diff --git a/newlib/libc/stdlib/mprec.c b/newlib/libc/stdlib/mprec.c
index 930c984ca..1f534b068 100644
--- a/newlib/libc/stdlib/mprec.c
+++ b/newlib/libc/stdlib/mprec.c
@@ -86,6 +86,11 @@
 #include <reent.h>
 #include "mprec.h"
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local struct _Bigint *_tls_mp_p5s;
+_Thread_local struct _Bigint **_tls_mp_freelist;
+#endif
+
 /* This is defined in sys/reent.h as (sizeof (size_t) << 3) now, as in NetBSD.
    The old value of 15 was wrong and made newlib vulnerable against buffer
    overrun attacks (CVE-2009-0689), same as other implementations of gdtoa
diff --git a/newlib/libc/stdlib/rand.c b/newlib/libc/stdlib/rand.c
index 209cb32ff..ba9cc80f2 100644
--- a/newlib/libc/stdlib/rand.c
+++ b/newlib/libc/stdlib/rand.c
@@ -58,6 +58,10 @@ on two different systems.
 #include <stdlib.h>
 #include <reent.h>
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local unsigned long long _tls_rand_next = 1;
+#endif
+
 void
 srand (unsigned int seed)
 {
diff --git a/newlib/libc/stdlib/wcrtomb.c b/newlib/libc/stdlib/wcrtomb.c
index 6d670e23a..1b84720ac 100644
--- a/newlib/libc/stdlib/wcrtomb.c
+++ b/newlib/libc/stdlib/wcrtomb.c
@@ -6,6 +6,10 @@
 #include <errno.h>
 #include "local.h"
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local _mbstate_t _tls_wcrtomb_state;
+#endif
+
 size_t
 _wcrtomb_r (struct _reent *ptr,
 	char *s,
diff --git a/newlib/libc/stdlib/wcsnrtombs.c b/newlib/libc/stdlib/wcsnrtombs.c
index dfd974f24..abef7ac36 100644
--- a/newlib/libc/stdlib/wcsnrtombs.c
+++ b/newlib/libc/stdlib/wcsnrtombs.c
@@ -72,6 +72,10 @@ PORTABILITY
 #include "local.h"
 #include "../locale/setlocale.h"
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local _mbstate_t _tls_wcsrtombs_state;
+#endif
+
 size_t
 _wcsnrtombs_l (struct _reent *r, char *dst, const wchar_t **src, size_t nwc,
 	       size_t len, mbstate_t *ps, struct __locale_t *loc)
diff --git a/newlib/libc/stdlib/wctomb.c b/newlib/libc/stdlib/wctomb.c
index e908d22c2..f56dccf25 100644
--- a/newlib/libc/stdlib/wctomb.c
+++ b/newlib/libc/stdlib/wctomb.c
@@ -45,6 +45,10 @@ effects vary with the locale.
 #include <errno.h>
 #include "local.h"
 
+#ifdef _REENT_THREAD_LOCAL
+_Thread_local _mbstate_t _tls_wctomb_state;
+#endif
+
 int
 wctomb (char *s,
         wchar_t wchar)