nptl: fix set-but-unused warning w/_STACK_GROWS_UP

On arches that set _STACK_GROWS_UP, the stacktop variable is declared
and set, but never actually used.  Refactor the code a bit so that the
variable is only declared/set under _STACK_GROWS_DOWN settings.

diff --git a/ChangeLog b/ChangeLog
index 4bbad33..37a825e 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2015-08-05  Mike Frysinger  <vapier@gentoo.org>
+
+       * nptl/allocatestack.c (allocate_stack): Move stacktop decl down to
+       bottom and under _STACK_GROWS_DOWN.  Move the stacktop assignment
+       in there too.
+
 2015-08-05  Carlos O'Donell  <carlos@systemhalted.org>
 
        * version.h (RELEASE): Set to "development".

diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c
index c56a4df..753da61 100644 (file)
--- a/nptl/allocatestack.c
+++ b/nptl/allocatestack.c
@@ -353,7 +353,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
   struct pthread *pd;
   size_t size;
   size_t pagesize_m1 = __getpagesize () - 1;
-  void *stacktop;
 
   assert (powerof2 (pagesize_m1 + 1));
   assert (TCB_ALIGNMENT >= STACK_ALIGN);
@@ -717,19 +716,23 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
   /* We place the thread descriptor at the end of the stack.  */
   *pdp = pd;
 
-#if TLS_TCB_AT_TP
+#if _STACK_GROWS_DOWN
+  void *stacktop;
+
+# if TLS_TCB_AT_TP
   /* The stack begins before the TCB and the static TLS block.  */
   stacktop = ((char *) (pd + 1) - __static_tls_size);
-#elif TLS_DTV_AT_TP
+# elif TLS_DTV_AT_TP
   stacktop = (char *) (pd - 1);
-#endif
+# endif
 
-#ifdef NEED_SEPARATE_REGISTER_STACK
+# ifdef NEED_SEPARATE_REGISTER_STACK
   *stack = pd->stackblock;
   *stacksize = stacktop - *stack;
-#elif _STACK_GROWS_DOWN
+# else
   *stack = stacktop;
-#elif _STACK_GROWS_UP
+# endif
+#else
   *stack = pd->stackblock;
   assert (*stack > 0);
 #endif