Merge with LLVM upstream r160668 (Jul 24th 2012)

Conflicts:
	include/llvm/Support/ELF.h
	lib/CodeGen/AsmPrinter/AsmPrinter.cpp
	lib/Support/Memory.cpp
	lib/Transforms/Instrumentation/AddressSanitizer.cpp

Change-Id: Iddd658cf2eadc7165b2805b446d31af2c5c9917f

5 files changed, 173 insertions, 64 deletions

diff --git a/lib/Support/Unix/Path.inc b/lib/Support/Unix/Path.inc
index ddc1e0f..b41390a 100644
--- a/lib/Support/Unix/Path.inc
+++ b/lib/Support/Unix/Path.inc
@@ -884,7 +884,8 @@ const char *Path::MapInFilePages(int FD, size_t FileSize, off_t Offset) {
 }
 
 void Path::UnMapFilePages(const char *BasePtr, size_t FileSize) {
-  ::munmap((void*)BasePtr, FileSize);
+  const void *Addr = static_cast<const void *>(BasePtr);
+  ::munmap(const_cast<void *>(Addr), FileSize);
 }
 
 } // end llvm namespace
diff --git a/lib/Support/Unix/PathV2.inc b/lib/Support/Unix/PathV2.inc
index 7d259a3..93ccd1a 100644
--- a/lib/Support/Unix/PathV2.inc
+++ b/lib/Support/Unix/PathV2.inc
@@ -17,12 +17,16 @@
 //===----------------------------------------------------------------------===//
 
 #include "Unix.h"
+#include "llvm/Support/Process.h"
 #if HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
 #if HAVE_FCNTL_H
 #include <fcntl.h>
 #endif
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
 #if HAVE_DIRENT_H
 # include <dirent.h>
 # define NAMLEN(dirent) strlen((dirent)->d_name)
@@ -274,8 +278,7 @@ error_code exists(const Twine &path, bool &result) {
   SmallString<128> path_storage;
   StringRef p = path.toNullTerminatedStringRef(path_storage);
 
-  struct stat status;
-  if (::stat(p.begin(), &status) == -1) {
+  if (::access(p.begin(), F_OK) == -1) {
     if (errno != errc::no_such_file_or_directory)
       return error_code(errno, system_category());
     result = false;
@@ -287,8 +290,8 @@ error_code exists(const Twine &path, bool &result) {
 
 bool equivalent(file_status A, file_status B) {
   assert(status_known(A) && status_known(B));
-  return A.st_dev == B.st_dev &&
-         A.st_ino == B.st_ino;
+  return A.fs_st_dev == B.fs_st_dev &&
+         A.fs_st_ino == B.fs_st_ino;
 }
 
 error_code equivalent(const Twine &A, const Twine &B, bool &result) {
@@ -327,30 +330,62 @@ error_code status(const Twine &path, file_status &result) {
     return ec;
   }
 
+  perms prms = static_cast<perms>(status.st_mode & perms_mask);
+  
   if (S_ISDIR(status.st_mode))
-    result = file_status(file_type::directory_file);
+    result = file_status(file_type::directory_file, prms);
   else if (S_ISREG(status.st_mode))
-    result = file_status(file_type::regular_file);
+    result = file_status(file_type::regular_file, prms);
   else if (S_ISBLK(status.st_mode))
-    result = file_status(file_type::block_file);
+    result = file_status(file_type::block_file, prms);
   else if (S_ISCHR(status.st_mode))
-    result = file_status(file_type::character_file);
+    result = file_status(file_type::character_file, prms);
   else if (S_ISFIFO(status.st_mode))
-    result = file_status(file_type::fifo_file);
+    result = file_status(file_type::fifo_file, prms);
   else if (S_ISSOCK(status.st_mode))
-    result = file_status(file_type::socket_file);
+    result = file_status(file_type::socket_file, prms);
   else
-    result = file_status(file_type::type_unknown);
+    result = file_status(file_type::type_unknown, prms);
+
+  result.fs_st_dev = status.st_dev;
+  result.fs_st_ino = status.st_ino;
+
+  return error_code::success();
+}
+
+// Modifies permissions on a file.
+error_code permissions(const Twine &path, perms prms) {
+  if ((prms & add_perms) && (prms & remove_perms))
+    llvm_unreachable("add_perms and remove_perms are mutually exclusive");
 
-  result.st_dev = status.st_dev;
-  result.st_ino = status.st_ino;
+  // Get current permissions
+  file_status info;
+  if (error_code ec = status(path, info)) {
+    return ec;
+  }
+  
+  // Set updated permissions.
+  SmallString<128> path_storage;
+  StringRef p = path.toNullTerminatedStringRef(path_storage);
+  perms permsToSet;
+  if (prms & add_perms) {
+    permsToSet = (info.permissions() | prms) & perms_mask;
+  } else if (prms & remove_perms) {
+    permsToSet = (info.permissions() & ~prms) & perms_mask;
+  } else {
+    permsToSet = prms & perms_mask;
+  }
+  if (::chmod(p.begin(), static_cast<mode_t>(permsToSet))) {
+    return error_code(errno, system_category()); 
+  }
 
   return error_code::success();
 }
 
+// Since this is most often used for temporary files, mode defaults to 0600.
 error_code unique_file(const Twine &model, int &result_fd,
-                             SmallVectorImpl<char> &result_path,
-                             bool makeAbsolute) {
+                       SmallVectorImpl<char> &result_path,
+                       bool makeAbsolute, unsigned mode) {
   SmallString<128> Model;
   model.toVector(Model);
   // Null terminate.
@@ -367,37 +402,20 @@ error_code unique_file(const Twine &model, int &result_fd,
     }
   }
 
-  // Replace '%' with random chars. From here on, DO NOT modify model. It may be
-  // needed if the randomly chosen path already exists.
-  SmallString<128> RandomPath;
-  RandomPath.reserve(Model.size() + 1);
-  ::srand(::time(NULL));
+  // From here on, DO NOT modify model. It may be needed if the randomly chosen
+  // path already exists.
+  SmallString<128> RandomPath = Model;
 
 retry_random_path:
-  // This is opened here instead of above to make it easier to track when to
-  // close it. Collisions should be rare enough for the possible extra syscalls
-  // not to matter.
-  FILE *RandomSource = ::fopen("/dev/urandom", "r");
-  RandomPath.set_size(0);
-  for (SmallVectorImpl<char>::const_iterator i = Model.begin(),
-                                             e = Model.end(); i != e; ++i) {
-    if (*i == '%') {
-      char val = 0;
-      if (RandomSource)
-        val = fgetc(RandomSource);
-      else
-        val = ::rand();
-      RandomPath.push_back("0123456789abcdef"[val & 15]);
-    } else
-      RandomPath.push_back(*i);
+  // Replace '%' with random chars.
+  for (unsigned i = 0, e = Model.size(); i != e; ++i) {
+    if (Model[i] == '%')
+      RandomPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15];
   }
 
-  if (RandomSource)
-    ::fclose(RandomSource);
-
   // Try to open + create the file.
 rety_open_create:
-  int RandomFD = ::open(RandomPath.c_str(), O_RDWR | O_CREAT | O_EXCL, 0600);
+  int RandomFD = ::open(RandomPath.c_str(), O_RDWR | O_CREAT | O_EXCL, mode);
   if (RandomFD == -1) {
     // If the file existed, try again, otherwise, error.
     if (errno == errc::file_exists)
@@ -513,6 +531,36 @@ error_code get_magic(const Twine &path, uint32_t len,
   return error_code::success();
 }
 
+error_code map_file_pages(const Twine &path, off_t file_offset, size_t size,  
+                                            bool map_writable, void *&result) {
+  SmallString<128> path_storage;
+  StringRef name = path.toNullTerminatedStringRef(path_storage);
+  int oflags = map_writable ? O_RDWR : O_RDONLY;
+  int ofd = ::open(name.begin(), oflags);
+  if ( ofd == -1 )
+    return error_code(errno, system_category());
+  AutoFD fd(ofd);
+  int flags = map_writable ? MAP_SHARED : MAP_PRIVATE;
+  int prot = map_writable ? (PROT_READ|PROT_WRITE) : PROT_READ;
+#ifdef MAP_FILE
+  flags |= MAP_FILE;
+#endif
+  result = ::mmap(0, size, prot, flags, fd, file_offset);
+  if (result == MAP_FAILED) {
+    return error_code(errno, system_category());
+  }
+  
+  return error_code::success();
+}
+
+error_code unmap_file_pages(void *base, size_t size) {
+  if ( ::munmap(base, size) == -1 )
+    return error_code(errno, system_category());
+   
+  return error_code::success();
+}
+
+
 } // end namespace fs
 } // end namespace sys
 } // end namespace llvm
diff --git a/lib/Support/Unix/Process.inc b/lib/Support/Unix/Process.inc
index f640462..174112e 100644
--- a/lib/Support/Unix/Process.inc
+++ b/lib/Support/Unix/Process.inc
@@ -12,6 +12,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "Unix.h"
+#include "llvm/ADT/Hashing.h"
+#include "llvm/Support/TimeValue.h"
 #ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif
@@ -247,16 +249,18 @@ static bool terminalHasColors() {
   return false;
 }
 
+bool Process::FileDescriptorHasColors(int fd) {
+  // A file descriptor has colors if it is displayed and the terminal has
+  // colors.
+  return FileDescriptorIsDisplayed(fd) && terminalHasColors();
+}
+
 bool Process::StandardOutHasColors() {
-  if (!StandardOutIsDisplayed())
-    return false;
-  return terminalHasColors();
+  return FileDescriptorHasColors(STDOUT_FILENO);
 }
 
 bool Process::StandardErrHasColors() {
-  if (!StandardErrIsDisplayed())
-    return false;
-  return terminalHasColors();
+  return FileDescriptorHasColors(STDERR_FILENO);
 }
 
 bool Process::ColorNeedsFlush() {
@@ -297,3 +301,33 @@ const char *Process::OutputReverse() {
 const char *Process::ResetColor() {
   return "\033[0m";
 }
+
+#if !defined(HAVE_ARC4RANDOM)
+static unsigned GetRandomNumberSeed() {
+  // Attempt to get the initial seed from /dev/urandom, if possible.
+  if (FILE *RandomSource = ::fopen("/dev/urandom", "r")) {
+    unsigned seed;
+    int count = ::fread((void *)&seed, sizeof(seed), 1, RandomSource);
+    ::fclose(RandomSource);
+
+    // Return the seed if the read was successful.
+    if (count == 1)
+      return seed;
+  }
+
+  // Otherwise, swizzle the current time and the process ID to form a reasonable
+  // seed.
+  TimeValue Now = llvm::TimeValue::now();
+  return hash_combine(Now.seconds(), Now.nanoseconds(), ::getpid());
+}
+#endif
+
+unsigned llvm::sys::Process::GetRandomNumber() {
+#if defined(HAVE_ARC4RANDOM)
+  return arc4random();
+#else
+  static int x = (::srand(GetRandomNumberSeed()), 0);
+  (void)x;
+  return ::rand();
+#endif
+}
diff --git a/lib/Support/Unix/Signals.inc b/lib/Support/Unix/Signals.inc
index f5454cf..1d667ab 100644
--- a/lib/Support/Unix/Signals.inc
+++ b/lib/Support/Unix/Signals.inc
@@ -15,6 +15,7 @@
 #include "Unix.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Mutex.h"
+#include <string>
 #include <vector>
 #include <algorithm>
 #if HAVE_EXECINFO_H
@@ -43,7 +44,7 @@ static SmartMutex<true> SignalsMutex;
 /// InterruptFunction - The function to call if ctrl-c is pressed.
 static void (*InterruptFunction)() = 0;
 
-static std::vector<sys::Path> FilesToRemove;
+static std::vector<std::string> FilesToRemove;
 static std::vector<std::pair<void(*)(void*), void*> > CallBacksToRun;
 
 // IntSigs - Signals that may interrupt the program at any time.
@@ -117,10 +118,20 @@ static void UnregisterHandlers() {
 
 /// RemoveFilesToRemove - Process the FilesToRemove list. This function
 /// should be called with the SignalsMutex lock held.
+/// NB: This must be an async signal safe function. It cannot allocate or free
+/// memory, even in debug builds.
 static void RemoveFilesToRemove() {
-  while (!FilesToRemove.empty()) {
-    FilesToRemove.back().eraseFromDisk(true);
-    FilesToRemove.pop_back();
+  // Note: 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());
   }
 }
 
@@ -178,7 +189,19 @@ void llvm::sys::SetInterruptFunction(void (*IF)()) {
 bool llvm::sys::RemoveFileOnSignal(const sys::Path &Filename,
                                    std::string* ErrMsg) {
   SignalsMutex.acquire();
-  FilesToRemove.push_back(Filename);
+  std::string *OldPtr = FilesToRemove.empty() ? 0 : &FilesToRemove[0];
+  FilesToRemove.push_back(Filename.str());
+
+  // We want to call 'c_str()' on every std::string in this vector so that if
+  // the underlying implementation requires a re-allocation, it happens here
+  // rather than inside of the signal handler. If we see the vector grow, we
+  // have to call it on every entry. If it remains in place, we only need to
+  // call it on the latest one.
+  if (OldPtr == &FilesToRemove[0])
+    FilesToRemove.back().c_str();
+  else
+    for (unsigned i = 0, e = FilesToRemove.size(); i != e; ++i)
+      FilesToRemove[i].c_str();
 
   SignalsMutex.release();
 
@@ -189,10 +212,19 @@ bool llvm::sys::RemoveFileOnSignal(const sys::Path &Filename,
 // DontRemoveFileOnSignal - The public API
 void llvm::sys::DontRemoveFileOnSignal(const sys::Path &Filename) {
   SignalsMutex.acquire();
-  std::vector<sys::Path>::reverse_iterator I =
-    std::find(FilesToRemove.rbegin(), FilesToRemove.rend(), Filename);
-  if (I != FilesToRemove.rend())
-    FilesToRemove.erase(I.base()-1);
+  std::vector<std::string>::reverse_iterator RI =
+    std::find(FilesToRemove.rbegin(), FilesToRemove.rend(), Filename.str());
+  std::vector<std::string>::iterator I = FilesToRemove.end();
+  if (RI != FilesToRemove.rend())
+    I = FilesToRemove.erase(RI.base()-1);
+
+  // We need to call c_str() on every element which would have been moved by
+  // the erase. These elements, in a C++98 implementation where c_str()
+  // requires a reallocation on the first call may have had the call to c_str()
+  // made on insertion become invalid by being copied down an element.
+  for (std::vector<std::string>::iterator E = FilesToRemove.end(); I != E; ++I)
+    I->c_str();
+
   SignalsMutex.release();
 }
 
diff --git a/lib/Support/Unix/Unix.h b/lib/Support/Unix/Unix.h
index b7be311..361f297 100644
--- a/lib/Support/Unix/Unix.h
+++ b/lib/Support/Unix/Unix.h
@@ -44,16 +44,10 @@
 #include <assert.h>
 #endif
 
-#ifdef TIME_WITH_SYS_TIME
+#ifdef HAVE_SYS_TIME_H
 # include <sys/time.h>
-# include <time.h>
-#else
-# ifdef HAVE_SYS_TIME_H
-#  include <sys/time.h>
-# else
-#  include <time.h>
-# endif
 #endif
+#include <time.h>
 
 #ifdef HAVE_SYS_WAIT_H
 # include <sys/wait.h>