perror: fix POSIX compliance and work with recent newlib change

* cygtls.h (strerror_r_buf): New buffer.
* errno.cc (strerror): Move guts...
(_strerror_r): ...to new function demanded by newlib.
(strerror_r): Don't clobber strerror buffer.
(_user_strerror): Drop unused declaration.
* tlsoffsets.h: Regenerate.

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 238d763..8114f68 100644 (file)
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,12 @@
+2011-05-25  Eric Blake  <eblake@redhat.com>
+
+       * cygtls.h (strerror_r_buf): New buffer.
+       * errno.cc (strerror): Move guts...
+       (_strerror_r): ...to new function demanded by newlib.
+       (strerror_r): Don't clobber strerror buffer.
+       (_user_strerror): Drop unused declaration.
+       * tlsoffsets.h: Regenerate.
+
 2011-05-25  Corinna Vinschen  <corinna@vinschen.de>
 
        * init.cc (dll_entry): Reinstantiate wow64_test_stack_marker and

diff --git a/winsup/cygwin/cygtls.h b/winsup/cygwin/cygtls.h
index 6359e7c..a1642b1 100644 (file)
--- a/winsup/cygwin/cygtls.h
+++ b/winsup/cygwin/cygtls.h
@@ -110,6 +110,7 @@ struct _local_storage
 
   /* strerror errno.cc */
   char strerror_buf[sizeof ("Unknown error -2147483648")];
+  char strerror_r_buf[sizeof ("Unknown error -2147483648")];
 
   /* times.cc */
   char timezone_buf[20];

diff --git a/winsup/cygwin/errno.cc b/winsup/cygwin/errno.cc
index aa311b7..f3b925e 100644 (file)
--- a/winsup/cygwin/errno.cc
+++ b/winsup/cygwin/errno.cc
@@ -360,8 +360,6 @@ seterrno (const char *file, int line)
   seterrno_from_win_error (file, line, GetLastError ());
 }
 
-extern char *_user_strerror _PARAMS ((int));
-
 static char *
 strerror_worker (int errnum)
 {
@@ -373,22 +371,38 @@ strerror_worker (int errnum)
   return res;
 }
 
-/* strerror: convert from errno values to error strings.  Newlib's
-   strerror_r returns "" for unknown values, so we override it to
-   provide a nicer thread-safe result string and set errno.  */
+/* Newlib requires this override for perror and friends to avoid
+   clobbering strerror() buffer, without having to differentiate
+   between strerror_r signatures.  This function is intentionally not
+   exported, so that only newlib can use it.  */
 extern "C" char *
-strerror (int errnum)
+_strerror_r (struct _reent *, int errnum, int internal, int *errptr)
 {
   char *errstr = strerror_worker (errnum);
   if (!errstr)
     {
-      __small_sprintf (errstr = _my_tls.locals.strerror_buf, "Unknown error %d",
-                       errnum);
-      errno = _impure_ptr->_errno = EINVAL;
+      errstr = internal ? _my_tls.locals.strerror_r_buf
+        : _my_tls.locals.strerror_buf;
+      __small_sprintf (errstr, "Unknown error %d", errnum);
+      if (errptr)
+        *errptr = EINVAL;
     }
   return errstr;
 }
 
+/* strerror: convert from errno values to error strings.  Newlib's
+   strerror_r returns "" for unknown values, so we override it to
+   provide a nicer thread-safe result string and set errno.  */
+extern "C" char *
+strerror (int errnum)
+{
+  int error = 0;
+  char *result = _strerror_r (NULL, errnum, 0, &error);
+  if (error)
+    set_errno (error);
+  return result;
+}
+
 /* Newlib's <string.h> provides declarations for two strerror_r
    variants, according to preprocessor feature macros.  However, it
    returns "" instead of "Unknown error ...", so we override both
@@ -396,10 +410,13 @@ strerror (int errnum)
 extern "C" char *
 strerror_r (int errnum, char *buf, size_t n)
 {
-  char *error = strerror (errnum);
-  if (strlen (error) >= n)
-    return error;
-  return strcpy (buf, error);
+  int error = 0;
+  char *errstr = _strerror_r (NULL, errnum, 1, &error);
+  if (error)
+    set_errno (error);
+  if (strlen (errstr) >= n)
+    return errstr;
+  return strcpy (buf, errstr);
 }
 
 extern "C" int

diff --git a/winsup/cygwin/tlsoffsets.h b/winsup/cygwin/tlsoffsets.h
index 4e459df..3ef7963 100644 (file)
--- a/winsup/cygwin/tlsoffsets.h
+++ b/winsup/cygwin/tlsoffsets.h
@@ -1,6 +1,6 @@
 //;# autogenerated:  Do not edit.
 
-//; $tls::sizeof__cygtls = 3984;
+//; $tls::sizeof__cygtls = 4012;
 //; $tls::func = -12700;
 //; $tls::pfunc = 0;
 //; $tls::saved_errno = -12696;
@@ -37,26 +37,26 @@
 //; $tls::p__dontuse = 412;
 //; $tls::locals = -11200;
 //; $tls::plocals = 1500;
-//; $tls::_ctinfo = -9800;
-//; $tls::p_ctinfo = 2900;
-//; $tls::andreas = -9796;
-//; $tls::pandreas = 2904;
-//; $tls::wq = -9792;
-//; $tls::pwq = 2908;
-//; $tls::sig = -9764;
-//; $tls::psig = 2936;
-//; $tls::incyg = -9760;
-//; $tls::pincyg = 2940;
-//; $tls::spinning = -9756;
-//; $tls::pspinning = 2944;
-//; $tls::stacklock = -9752;
-//; $tls::pstacklock = 2948;
-//; $tls::stackptr = -9748;
-//; $tls::pstackptr = 2952;
-//; $tls::stack = -9744;
-//; $tls::pstack = 2956;
-//; $tls::initialized = -8720;
-//; $tls::pinitialized = 3980;
+//; $tls::_ctinfo = -9772;
+//; $tls::p_ctinfo = 2928;
+//; $tls::andreas = -9768;
+//; $tls::pandreas = 2932;
+//; $tls::wq = -9764;
+//; $tls::pwq = 2936;
+//; $tls::sig = -9736;
+//; $tls::psig = 2964;
+//; $tls::incyg = -9732;
+//; $tls::pincyg = 2968;
+//; $tls::spinning = -9728;
+//; $tls::pspinning = 2972;
+//; $tls::stacklock = -9724;
+//; $tls::pstacklock = 2976;
+//; $tls::stackptr = -9720;
+//; $tls::pstackptr = 2980;
+//; $tls::stack = -9716;
+//; $tls::pstack = 2984;
+//; $tls::initialized = -8692;
+//; $tls::pinitialized = 4008;
 //; __DATA__
 
 #define tls_func (-12700)
@@ -95,23 +95,23 @@
 #define tls_p__dontuse (412)
 #define tls_locals (-11200)
 #define tls_plocals (1500)
-#define tls__ctinfo (-9800)
-#define tls_p_ctinfo (2900)
-#define tls_andreas (-9796)
-#define tls_pandreas (2904)
-#define tls_wq (-9792)
-#define tls_pwq (2908)
-#define tls_sig (-9764)
-#define tls_psig (2936)
-#define tls_incyg (-9760)
-#define tls_pincyg (2940)
-#define tls_spinning (-9756)
-#define tls_pspinning (2944)
-#define tls_stacklock (-9752)
-#define tls_pstacklock (2948)
-#define tls_stackptr (-9748)
-#define tls_pstackptr (2952)
-#define tls_stack (-9744)
-#define tls_pstack (2956)
-#define tls_initialized (-8720)
-#define tls_pinitialized (3980)
+#define tls__ctinfo (-9772)
+#define tls_p_ctinfo (2928)
+#define tls_andreas (-9768)
+#define tls_pandreas (2932)
+#define tls_wq (-9764)
+#define tls_pwq (2936)
+#define tls_sig (-9736)
+#define tls_psig (2964)
+#define tls_incyg (-9732)
+#define tls_pincyg (2968)
+#define tls_spinning (-9728)
+#define tls_pspinning (2972)
+#define tls_stacklock (-9724)
+#define tls_pstacklock (2976)
+#define tls_stackptr (-9720)
+#define tls_pstackptr (2980)
+#define tls_stack (-9716)
+#define tls_pstack (2984)
+#define tls_initialized (-8692)
+#define tls_pinitialized (4008)