Change AllocateRWX/DeallocateRWX to not throw an exception.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29058 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 61 insertions, 31 deletions

diff --git a/lib/System/Unix/Memory.inc b/lib/System/Unix/Memory.inc
index 4475960..7faa220 100644
--- a/lib/System/Unix/Memory.inc
+++ b/lib/System/Unix/Memory.inc
@@ -18,14 +18,14 @@
 #include <sys/mman.h>
 #endif
 
-namespace llvm {
-
 /// AllocateRWXMemory - Allocate a slab of memory with read/write/execute
 /// permissions.  This is typically used for JIT applications where we want
 /// to emit code to the memory then jump to it.  Getting this type of memory
 /// is very OS specific.
 ///
-MemoryBlock Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock) {
+llvm::sys::MemoryBlock 
+llvm::sys::Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock,
+                               std::string *ErrMsg) {
   if (NumBytes == 0) return MemoryBlock();
 
   long pageSize = Process::GetPageSize();
@@ -35,7 +35,8 @@ MemoryBlock Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock)
 #ifdef NEED_DEV_ZERO_FOR_MMAP
   static int zero_fd = open("/dev/zero", O_RDWR);
   if (zero_fd == -1) {
-    ThrowErrno("Can't open /dev/zero device");
+    GetErrno("Can't open /dev/zero device", ErrMsg);
+    return MemoryBlock();
   }
   fd = zero_fd;
 #endif
@@ -48,15 +49,17 @@ MemoryBlock Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock)
 #endif
   ;
 
-  void* start = NearBlock ? (unsigned char*) NearBlock->base() + NearBlock->size() : 0;
+  void* start = NearBlock ? (unsigned char*)NearBlock->base() + 
+                            NearBlock->size() : 0;
 
   void *pa = ::mmap(start, pageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
                     flags, fd, 0);
   if (pa == MAP_FAILED) {
     if (NearBlock) //Try again without a near hint
       return AllocateRWX(NumBytes, 0);
-    else
-      ThrowErrno("Can't allocate RWX Memory");
+
+    GetErrno("Can't allocate RWX Memory", ErrMsg);
+    return MemoryBlock();
   }
   MemoryBlock result;
   result.Address = pa;
@@ -64,12 +67,10 @@ MemoryBlock Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock)
   return result;
 }
 
-void Memory::ReleaseRWX(MemoryBlock& M) {
-  if (M.Address == 0 || M.Size == 0) return;
-  if (0 != ::munmap(M.Address, M.Size)) {
-    ThrowErrno("Can't release RWX Memory");
-  }
-}
-
+bool llvm::sys::Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
+  if (M.Address == 0 || M.Size == 0) return false;
+  if (0 != ::munmap(M.Address, M.Size))
+    return GetErrno("Can't release RWX Memory", ErrMsg);
+  return false;
 }
 
diff --git a/lib/System/Unix/Unix.h b/lib/System/Unix/Unix.h
index 32609f2..4ef3896 100644
--- a/lib/System/Unix/Unix.h
+++ b/lib/System/Unix/Unix.h
@@ -66,28 +66,57 @@
 # define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
 #endif
 
+inline bool GetErrno(const std::string &prefix, std::string *ErrDest,
+                     int errnum = -1) {
+  char buffer[MAXPATHLEN];
+  
+  if (ErrDest == 0) return true;
+  
+  buffer[0] = 0;
+  if (errnum == -1)
+    errnum = errno;
+#ifdef HAVE_STRERROR_R
+  // strerror_r is thread-safe.
+  if (errnum)
+    strerror_r(errnum, buffer, MAXPATHLEN-1);
+#elif HAVE_STRERROR
+  // Copy the thread un-safe result of strerror into
+  // the buffer as fast as possible to minimize impact
+  // of collision of strerror in multiple threads.
+  if (errnum)
+    strncpy(buffer, strerror(errnum), MAXPATHLEN-1);
+  buffer[MAXPATHLEN-1] = 0;
+#else
+  // Strange that this system doesn't even have strerror
+  // but, oh well, just use a generic message
+  sprintf(buffer, "Error #%d", errnum);
+#endif
+  *ErrDest = prefix + ": " + buffer;
+  return true;
+}
+
 inline void ThrowErrno(const std::string& prefix, int errnum = -1) {
-    char buffer[MAXPATHLEN];
-    buffer[0] = 0;
-    if (errnum == -1)
-      errnum = errno;
+  char buffer[MAXPATHLEN];
+  buffer[0] = 0;
+  if (errnum == -1)
+    errnum = errno;
 #ifdef HAVE_STRERROR_R
-    // strerror_r is thread-safe.
-    if (errnum)
-      strerror_r(errnum,buffer,MAXPATHLEN-1);
+  // strerror_r is thread-safe.
+  if (errnum)
+    strerror_r(errnum,buffer,MAXPATHLEN-1);
 #elif HAVE_STRERROR
-    // Copy the thread un-safe result of strerror into
-    // the buffer as fast as possible to minimize impact
-    // of collision of strerror in multiple threads.
-    if (errnum)
-      strncpy(buffer,strerror(errnum),MAXPATHLEN-1);
-    buffer[MAXPATHLEN-1] = 0;
+  // Copy the thread un-safe result of strerror into
+  // the buffer as fast as possible to minimize impact
+  // of collision of strerror in multiple threads.
+  if (errnum)
+    strncpy(buffer,strerror(errnum),MAXPATHLEN-1);
+  buffer[MAXPATHLEN-1] = 0;
 #else
-    // Strange that this system doesn't even have strerror
-    // but, oh well, just use a generic message
-    sprintf(buffer, "Error #%d", errnum);
+  // Strange that this system doesn't even have strerror
+  // but, oh well, just use a generic message
+  sprintf(buffer, "Error #%d", errnum);
 #endif
-    throw prefix + ": " + buffer;
+  throw prefix + ": " + buffer;
 }
 
 #endif