3 files changed, 232 insertions, 29 deletions

diff --git a/lib/Support/Unix/Memory.inc b/lib/Support/Unix/Memory.inc
index 5a57a28..9a8abd2 100644
--- a/lib/Support/Unix/Memory.inc
+++ b/lib/Support/Unix/Memory.inc
@@ -13,6 +13,7 @@
 
 #include "Unix.h"
 #include "llvm/Support/DataTypes.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Process.h"
 
 #ifdef HAVE_SYS_MMAN_H
@@ -23,14 +24,146 @@
 #include <mach/mach.h>
 #endif
 
+#if defined(__mips__)
+#  if defined(__OpenBSD__)
+#    include <mips64/sysarch.h>
+#  else
+#    include <sys/cachectl.h>
+#  endif
+#endif
+
+extern "C" void sys_icache_invalidate(const void *Addr, size_t len);
+
+namespace {
+
+int getPosixProtectionFlags(unsigned Flags) {
+  switch (Flags) {
+  case llvm::sys::Memory::MF_READ:
+    return PROT_READ;
+  case llvm::sys::Memory::MF_WRITE:
+    return PROT_WRITE;
+  case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_WRITE:
+    return PROT_READ | PROT_WRITE;
+  case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_EXEC:
+    return PROT_READ | PROT_EXEC;
+  case llvm::sys::Memory::MF_READ |
+	 llvm::sys::Memory::MF_WRITE |
+	 llvm::sys::Memory::MF_EXEC:
+    return PROT_READ | PROT_WRITE | PROT_EXEC;
+  case llvm::sys::Memory::MF_EXEC:
+    return PROT_EXEC;
+  default:
+    llvm_unreachable("Illegal memory protection flag specified!");
+  }
+  // Provide a default return value as required by some compilers.
+  return PROT_NONE;
+}
+
+} // namespace
+
+namespace llvm {
+namespace sys {
+
+MemoryBlock
+Memory::allocateMappedMemory(size_t NumBytes,
+                             const MemoryBlock *const NearBlock,
+                             unsigned PFlags,
+                             error_code &EC) {
+  EC = error_code::success();
+  if (NumBytes == 0)
+    return MemoryBlock();
+
+  static const size_t PageSize = Process::GetPageSize();
+  const size_t NumPages = (NumBytes+PageSize-1)/PageSize;
+
+  int fd = -1;
+#ifdef NEED_DEV_ZERO_FOR_MMAP
+  static int zero_fd = open("/dev/zero", O_RDWR);
+  if (zero_fd == -1) {
+    EC = error_code(errno, system_category());
+    return MemoryBlock();
+  }
+  fd = zero_fd;
+#endif
+
+  int MMFlags = MAP_PRIVATE |
+#ifdef HAVE_MMAP_ANONYMOUS
+  MAP_ANONYMOUS
+#else
+  MAP_ANON
+#endif
+  ; // Ends statement above
+
+  int Protect = getPosixProtectionFlags(PFlags);
+
+  // Use any near hint and the page size to set a page-aligned starting address
+  uintptr_t Start = NearBlock ? reinterpret_cast<uintptr_t>(NearBlock->base()) +
+                                      NearBlock->size() : 0;
+  if (Start && Start % PageSize)
+    Start += PageSize - Start % PageSize;
+
+  void *Addr = ::mmap(reinterpret_cast<void*>(Start), PageSize*NumPages,
+                      Protect, MMFlags, fd, 0);
+  if (Addr == MAP_FAILED) {
+    if (NearBlock) //Try again without a near hint
+      return allocateMappedMemory(NumBytes, 0, PFlags, EC);
+
+    EC = error_code(errno, system_category());
+    return MemoryBlock();
+  }
+
+  MemoryBlock Result;
+  Result.Address = Addr;
+  Result.Size = NumPages*PageSize;
+
+  if (PFlags & MF_EXEC)
+    Memory::InvalidateInstructionCache(Result.Address, Result.Size);
+
+  return Result;
+}
+
+error_code
+Memory::releaseMappedMemory(MemoryBlock &M) {
+  if (M.Address == 0 || M.Size == 0)
+    return error_code::success();
+
+  if (0 != ::munmap(M.Address, M.Size))
+    return error_code(errno, system_category());
+
+  M.Address = 0;
+  M.Size = 0;
+
+  return error_code::success();
+}
+
+error_code
+Memory::protectMappedMemory(const MemoryBlock &M, unsigned Flags) {
+  if (M.Address == 0 || M.Size == 0)
+    return error_code::success();
+
+  if (!Flags)
+    return error_code(EINVAL, generic_category());
+
+  int Protect = getPosixProtectionFlags(Flags);
+
+  int Result = ::mprotect(M.Address, M.Size, Protect);
+  if (Result != 0)
+    return error_code(errno, system_category());
+
+  if (Flags & MF_EXEC)
+    Memory::InvalidateInstructionCache(M.Address, M.Size);
+
+  return error_code::success();
+}
+
 /// AllocateRWX - 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.
 ///
-llvm::sys::MemoryBlock
-llvm::sys::Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
-                               std::string *ErrMsg) {
+MemoryBlock
+Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
+                    std::string *ErrMsg) {
   if (NumBytes == 0) return MemoryBlock();
 
   size_t pageSize = Process::GetPageSize();
@@ -78,7 +211,7 @@ llvm::sys::Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
                                 VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
   if (KERN_SUCCESS != kr) {
     MakeErrMsg(ErrMsg, "vm_protect max RX failed");
-    return sys::MemoryBlock();
+    return MemoryBlock();
   }
 
   kr = vm_protect(mach_task_self(), (vm_address_t)pa,
@@ -86,7 +219,7 @@ llvm::sys::Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
                   VM_PROT_READ | VM_PROT_WRITE);
   if (KERN_SUCCESS != kr) {
     MakeErrMsg(ErrMsg, "vm_protect RW failed");
-    return sys::MemoryBlock();
+    return MemoryBlock();
   }
 #endif
 
@@ -97,17 +230,17 @@ llvm::sys::Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
   return result;
 }
 
-bool llvm::sys::Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
+bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
   if (M.Address == 0 || M.Size == 0) return false;
   if (0 != ::munmap(M.Address, M.Size))
     return MakeErrMsg(ErrMsg, "Can't release RWX Memory");
   return false;
 }
 
-bool llvm::sys::Memory::setWritable (MemoryBlock &M, std::string *ErrMsg) {
+bool Memory::setWritable (MemoryBlock &M, std::string *ErrMsg) {
 #if defined(__APPLE__) && defined(__arm__)
   if (M.Address == 0 || M.Size == 0) return false;
-  sys::Memory::InvalidateInstructionCache(M.Address, M.Size);
+  Memory::InvalidateInstructionCache(M.Address, M.Size);
   kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
     (vm_size_t)M.Size, 0, VM_PROT_READ | VM_PROT_WRITE);
   return KERN_SUCCESS == kr;
@@ -116,10 +249,10 @@ bool llvm::sys::Memory::setWritable (MemoryBlock &M, std::string *ErrMsg) {
 #endif
 }
 
-bool llvm::sys::Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
+bool Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
 #if defined(__APPLE__) && defined(__arm__)
   if (M.Address == 0 || M.Size == 0) return false;
-  sys::Memory::InvalidateInstructionCache(M.Address, M.Size);
+  Memory::InvalidateInstructionCache(M.Address, M.Size);
   kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
     (vm_size_t)M.Size, 0, VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
   return KERN_SUCCESS == kr;
@@ -128,7 +261,7 @@ bool llvm::sys::Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
 #endif
 }
 
-bool llvm::sys::Memory::setRangeWritable(const void *Addr, size_t Size) {
+bool Memory::setRangeWritable(const void *Addr, size_t Size) {
 #if defined(__APPLE__) && defined(__arm__)
   kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)Addr,
                                 (vm_size_t)Size, 0,
@@ -139,7 +272,7 @@ bool llvm::sys::Memory::setRangeWritable(const void *Addr, size_t Size) {
 #endif
 }
 
-bool llvm::sys::Memory::setRangeExecutable(const void *Addr, size_t Size) {
+bool Memory::setRangeExecutable(const void *Addr, size_t Size) {
 #if defined(__APPLE__) && defined(__arm__)
   kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)Addr,
                                 (vm_size_t)Size, 0,
@@ -149,3 +282,52 @@ bool llvm::sys::Memory::setRangeExecutable(const void *Addr, size_t Size) {
   return true;
 #endif
 }
+
+/// InvalidateInstructionCache - Before the JIT can run a block of code
+/// that has been emitted it must invalidate the instruction cache on some
+/// platforms.
+void Memory::InvalidateInstructionCache(const void *Addr,
+                                        size_t Len) {
+
+// icache invalidation for PPC and ARM.
+#if defined(__APPLE__)
+
+#  if (defined(__POWERPC__) || defined (__ppc__) || \
+     defined(_POWER) || defined(_ARCH_PPC)) || defined(__arm__)
+  sys_icache_invalidate(const_cast<void *>(Addr), Len);
+#  endif
+
+#else
+
+#  if (defined(__POWERPC__) || defined (__ppc__) || \
+       defined(_POWER) || defined(_ARCH_PPC)) && defined(__GNUC__)
+  const size_t LineSize = 32;
+
+  const intptr_t Mask = ~(LineSize - 1);
+  const intptr_t StartLine = ((intptr_t) Addr) & Mask;
+  const intptr_t EndLine = ((intptr_t) Addr + Len + LineSize - 1) & Mask;
+
+  for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
+    asm volatile("dcbf 0, %0" : : "r"(Line));
+  asm volatile("sync");
+
+  for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
+    asm volatile("icbi 0, %0" : : "r"(Line));
+  asm volatile("isync");
+#  elif defined(__arm__) && defined(__GNUC__)
+  // FIXME: Can we safely always call this for __GNUC__ everywhere?
+  const char *Start = static_cast<const char *>(Addr);
+  const char *End = Start + Len;
+  __clear_cache(const_cast<char *>(Start), const_cast<char *>(End));
+#  elif defined(__mips__)
+  const char *Start = static_cast<const char *>(Addr);
+  cacheflush(const_cast<char *>(Start), Len, BCACHE);
+#  endif
+
+#endif  // end apple
+
+  ValgrindDiscardTranslations(Addr, Len);
+}
+
+} // namespace sys
+} // namespace llvm
diff --git a/lib/Support/Unix/Path.inc b/lib/Support/Unix/Path.inc
index 6bddbdf..6a5ebb8 100644
--- a/lib/Support/Unix/Path.inc
+++ b/lib/Support/Unix/Path.inc
@@ -261,7 +261,8 @@ Path::GetCurrentDirectory() {
 }
 
 #if defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
-    defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__)
+    defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__) || \
+    defined(__linux__) || defined(__CYGWIN__)
 static int
 test_dir(char buf[PATH_MAX], char ret[PATH_MAX],
     const char *dir, const char *bin)
@@ -337,9 +338,17 @@ Path Path::GetMainExecutable(const char *argv0, void *MainAddr) {
     return Path(exe_path);
 #elif defined(__linux__) || defined(__CYGWIN__)
   char exe_path[MAXPATHLEN];
-  ssize_t len = readlink("/proc/self/exe", exe_path, sizeof(exe_path));
-  if (len >= 0)
-    return Path(StringRef(exe_path, len));
+  StringRef aPath("/proc/self/exe");
+  if (sys::fs::exists(aPath)) {
+      // /proc is not always mounted under Linux (chroot for example).
+      ssize_t len = readlink(aPath.str().c_str(), exe_path, sizeof(exe_path));
+      if (len >= 0)
+          return Path(StringRef(exe_path, len));
+  } else {
+      // Fall back to the classical detection.
+      if (getprogpath(exe_path, argv0) != NULL)
+          return Path(exe_path);
+  }
 #elif defined(HAVE_DLFCN_H)
   // Use dladdr to get executable path if available.
   Dl_info DLInfo;
diff --git a/lib/Support/Unix/Signals.inc b/lib/Support/Unix/Signals.inc
index 5195116..9e94068 100644
--- a/lib/Support/Unix/Signals.inc
+++ b/lib/Support/Unix/Signals.inc
@@ -121,17 +121,29 @@ static void UnregisterHandlers() {
 /// NB: This must be an async signal safe function. It cannot allocate or free
 /// memory, even in debug builds.
 static void RemoveFilesToRemove() {
-  // Note: avoid iterators in case of debug iterators that allocate or release
+  // We avoid iterators in case of debug iterators that allocate or release
   // memory.
   for (unsigned i = 0, e = FilesToRemove.size(); i != e; ++i) {
-    // Note that we don't want to use any external code here, and we don't care
-    // about errors. We're going to try as hard as we can as often as we need
-    // to to make these files go away. If these aren't files, too bad.
-    //
-    // We do however rely on a std::string implementation for which repeated
-    // calls to 'c_str()' don't allocate memory. We pre-call 'c_str()' on all
-    // of these strings to try to ensure this is safe.
-    unlink(FilesToRemove[i].c_str());
+    // We rely on a std::string implementation for which repeated calls to
+    // 'c_str()' don't allocate memory. We pre-call 'c_str()' on all of these
+    // strings to try to ensure this is safe.
+    const char *path = FilesToRemove[i].c_str();
+
+    // Get the status so we can determine if it's a file or directory. If we
+    // can't stat the file, ignore it.
+    struct stat buf;
+    if (stat(path, &buf) != 0)
+      continue;
+
+    // If this is not a regular file, ignore it. We want to prevent removal of
+    // special files like /dev/null, even if the compiler is being run with the
+    // super-user permissions.
+    if (!S_ISREG(buf.st_mode))
+      continue;
+  
+    // Otherwise, remove the file. We ignore any errors here as there is nothing
+    // else we can do.
+    unlink(path);
   }
 }
 
@@ -243,7 +255,7 @@ void llvm::sys::AddSignalHandler(void (*FnPtr)(void *), void *Cookie) {
 // On glibc systems we have the 'backtrace' function, which works nicely, but
 // doesn't demangle symbols.
 static void PrintStackTrace(void *) {
-#ifdef HAVE_BACKTRACE
+#if defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
   static void* StackTrace[256];
   // Use backtrace() to output a backtrace on Linux systems with glibc.
   int depth = backtrace(StackTrace,
@@ -293,7 +305,7 @@ static void PrintStackTrace(void *) {
 #endif
 }
 
-/// PrintStackTraceOnErrorSignal - When an error signal (such as SIBABRT or
+/// PrintStackTraceOnErrorSignal - When an error signal (such as SIGABRT or
 /// SIGSEGV) is delivered to the process, print a stack trace and then exit.
 void llvm::sys::PrintStackTraceOnErrorSignal() {
   AddSignalHandler(PrintStackTrace, 0);
@@ -305,10 +317,10 @@ void llvm::sys::PrintStackTraceOnErrorSignal() {
 
     exception_mask_t mask = EXC_MASK_CRASH;
 
-    kern_return_t ret = task_set_exception_ports(self, 
+    kern_return_t ret = task_set_exception_ports(self,
                              mask,
                              MACH_PORT_NULL,
-                             EXCEPTION_STATE_IDENTITY | MACH_EXCEPTION_CODES, 
+                             EXCEPTION_STATE_IDENTITY | MACH_EXCEPTION_CODES,
                              THREAD_STATE_NONE);
     (void)ret;
   }