[PATCH] Don't consider it a hard error if we fail to limit the pthread stack size.

[Thomas Schwinge]

The GNU Hurd's libpthread (currently) cannot support arbitrary stack size
limits, and as the stack size specified by pthread_attr_setstacksize is only
advisory anyway, ignore failure to set it.
---
 lib/Support/Threading.cpp |   15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git lib/Support/Threading.cpp lib/Support/Threading.cpp
index 13fba2e..3b9eb73 100644
--- lib/Support/Threading.cpp
+++ lib/Support/Threading.cpp
@@ -66,6 +66,10 @@ void llvm::llvm_release_global_lock() {
 #if LLVM_ENABLE_THREADS != 0 && defined(HAVE_PTHREAD_H)
 #include <pthread.h>
 
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/Errno.h"
+#include "llvm/Support/raw_ostream.h"
+
 struct ThreadInfo {
   void (*UserFn)(void *);
   void *UserData;
@@ -86,10 +90,15 @@ void llvm::llvm_execute_on_thread(void (*Fn)(void*), void *UserData,
   if (::pthread_attr_init(&Attr) != 0)
     return;
 
-  // Set the requested stack size, if given.
+  // Try to set the requested stack size, if given.  As this is only advisory
+  // (sets the *minimum* size), if this safety measure fails, we'll proceed
+  // anyway, hoping for the best instead of erroring out.
   if (RequestedStackSize != 0) {
-    if (::pthread_attr_setstacksize(&Attr, RequestedStackSize) != 0)
-      goto error;
+    int Err = ::pthread_attr_setstacksize(&Attr, RequestedStackSize);
+    if (Err != 0)
+      DEBUG(errs() << "pthread_attr_setstacksize(size_t = "
+            << RequestedStackSize << ") failed: " << llvm::sys::StrError(Err)
+            << "\n");
   }
 
   // Construct and execute the thread.
-- 
1.7.9.5