Fixes for builds that require strict X/Open and POSIX compatiblity

Summary:
- Use alternative to MAP_ANONYMOUS for allocating mapped memory if it isn't available
- Use strtok_r instead of strsep as part of getting program path
- Don't try to find the width of a terminal using "struct winsize" and TIOCGWINSZ on POSIX builds. These aren't defined under POSIX (even though some platforms make them available when they shouldn't), so just check if we are doing a X/Open or POSIX compliant build first.

Author: daltenty

Reviewers: hubert.reinterpretcast, xingxue, andusy

Reviewed By: hubert.reinterpretcast

Subscribers: MaskRay, jsji, hiraditya, kristina, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61326

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360898 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Support/Unix/Memory.inc b/lib/Support/Unix/Memory.inc
index affdb7e70d95203aba28b96682c6bcbc7e8946cb..05c5ccbdb3dec13dc0d499c28fde12eacb1411bd 100644 (file)
--- a/lib/Support/Unix/Memory.inc
+++ b/lib/Support/Unix/Memory.inc
@@ -91,9 +91,24 @@ Memory::allocateMappedMemory(size_t NumBytes,
   if (NumBytes == 0)
     return MemoryBlock();
 
-  int fd = -1;
+  // On platforms that have it, we can use MAP_ANON to get a memory-mapped
+  // page without file backing, but we need a fallback of opening /dev/zero
+  // for strictly POSIX platforms instead.
+  int fd;
+#if defined(MAP_ANON)
+  fd = -1;
+#else
+  fd = open("/dev/zero", O_RDWR);
+  if (fd == -1) {
+    EC = std::error_code(errno, std::generic_category());
+    return MemoryBlock();
+  }
+#endif
 
-  int MMFlags = MAP_PRIVATE | MAP_ANON;
+  int MMFlags = MAP_PRIVATE;
+#if defined(MAP_ANON)
+  MMFlags |= MAP_ANON;
+#endif
   int Protect = getPosixProtectionFlags(PFlags);
 
 #if defined(__NetBSD__) && defined(PROT_MPROTECT)
@@ -111,13 +126,24 @@ Memory::allocateMappedMemory(size_t NumBytes,
   void *Addr = ::mmap(reinterpret_cast<void *>(Start), NumBytes, Protect,
                       MMFlags, fd, 0);
   if (Addr == MAP_FAILED) {
-    if (NearBlock) //Try again without a near hint
+    if (NearBlock) { //Try again without a near hint
+#if !defined(MAP_ANON)
+      close(fd);
+#endif
       return allocateMappedMemory(NumBytes, nullptr, PFlags, EC);
+    }
 
     EC = std::error_code(errno, std::generic_category());
+#if !defined(MAP_ANON)
+    close(fd);
+#endif
     return MemoryBlock();
   }
 
+#if !defined(MAP_ANON)
+  close(fd);
+#endif
+
   MemoryBlock Result;
   Result.Address = Addr;
   Result.Size = NumBytes;

diff --git a/lib/Support/Unix/Path.inc b/lib/Support/Unix/Path.inc
index c2f78e79b87687ec92733624ecdf037367ddff73..359202fc3161acabbc4434984300397f8562451b 100644 (file)
--- a/lib/Support/Unix/Path.inc
+++ b/lib/Support/Unix/Path.inc
@@ -132,8 +132,6 @@ test_dir(char ret[PATH_MAX], const char *dir, const char *bin)
 static char *
 getprogpath(char ret[PATH_MAX], const char *bin)
 {
-  char *pv, *s, *t;
-
   /* First approach: absolute path. */
   if (bin[0] == '/') {
     if (test_dir(ret, "/", bin) == 0)
@@ -152,18 +150,21 @@ getprogpath(char ret[PATH_MAX], const char *bin)
   }
 
   /* Third approach: $PATH */
+  char *pv;
   if ((pv = getenv("PATH")) == nullptr)
     return nullptr;
-  s = pv = strdup(pv);
-  if (!pv)
+  char *s = strdup(pv);
+  if (!s)
     return nullptr;
-  while ((t = strsep(&s, ":")) != nullptr) {
+  char *state;
+  for (char *t = strtok_r(s, ":", &state); t != nullptr;
+       t = strtok_r(nullptr, ":", &state)) {
     if (test_dir(ret, t, bin) == 0) {
-      free(pv);
+      free(s);
       return ret;
     }
   }
-  free(pv);
+  free(s);
   return nullptr;
 }
 #endif // __FreeBSD__ || __NetBSD__ || __FreeBSD_kernel__

diff --git a/lib/Support/Unix/Process.inc b/lib/Support/Unix/Process.inc
index 78c123493e1db4530a2050ad95b744a4aaf01dc0..4115ee3965822a62fa88fabb96b387f658eec331 100644 (file)
--- a/lib/Support/Unix/Process.inc
+++ b/lib/Support/Unix/Process.inc
@@ -291,7 +291,8 @@ static unsigned getColumns(int FileID) {
 
   unsigned Columns = 0;
 
-#if defined(HAVE_SYS_IOCTL_H) && defined(HAVE_TERMIOS_H)
+#if defined(HAVE_SYS_IOCTL_H) && defined(HAVE_TERMIOS_H) \
+  && !(defined(_XOPEN_SOURCE) || defined(_POSIX_C_SOURCE))
   // Try to determine the width of the terminal.
   struct winsize ws;
   if (ioctl(FileID, TIOCGWINSZ, &ws) == 0)