Add Path and Twine components from LLVM. (#10)

src/main/native/cpp/llvm/Unix/Path.inc

@@ -0,0 +1,129 @@
+//===- llvm/Support/Unix/Path.inc - Unix Path Implementation ----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Unix specific implementation of the Path API.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//===          is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+namespace llvm {
+namespace sys  {
+namespace path {
+
+bool home_directory(SmallVectorImpl<char> &result) {
+  if (char *RequestedDir = std::getenv("HOME")) {
+    result.clear();
+    result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
+    return true;
+  }
+
+  return false;
+}
+
+static bool getDarwinConfDir(bool TempDir, SmallVectorImpl<char> &Result) {
+  #if defined(_CS_DARWIN_USER_TEMP_DIR) && defined(_CS_DARWIN_USER_CACHE_DIR)
+  // On Darwin, use DARWIN_USER_TEMP_DIR or DARWIN_USER_CACHE_DIR.
+  // macros defined in <unistd.h> on darwin >= 9
+  int ConfName = TempDir ? _CS_DARWIN_USER_TEMP_DIR
+                         : _CS_DARWIN_USER_CACHE_DIR;
+  size_t ConfLen = confstr(ConfName, nullptr, 0);
+  if (ConfLen > 0) {
+    do {
+      Result.resize(ConfLen);
+      ConfLen = confstr(ConfName, Result.data(), Result.size());
+    } while (ConfLen > 0 && ConfLen != Result.size());
+
+    if (ConfLen > 0) {
+      assert(Result.back() == 0);
+      Result.pop_back();
+      return true;
+    }
+
+    Result.clear();
+  }
+  #endif
+  return false;
+}
+
+static bool getUserCacheDir(SmallVectorImpl<char> &Result) {
+  // First try using XDG_CACHE_HOME env variable,
+  // as specified in XDG Base Directory Specification at
+  // http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
+  if (const char *XdgCacheDir = std::getenv("XDG_CACHE_HOME")) {
+    Result.clear();
+    Result.append(XdgCacheDir, XdgCacheDir + strlen(XdgCacheDir));
+    return true;
+  }
+
+  // Try Darwin configuration query
+  if (getDarwinConfDir(false, Result))
+    return true;
+
+  // Use "$HOME/.cache" if $HOME is available
+  if (home_directory(Result)) {
+    append(Result, ".cache");
+    return true;
+  }
+
+  return false;
+}
+
+static const char *getEnvTempDir() {
+  // Check whether the temporary directory is specified by an environment
+  // variable.
+  const char *EnvironmentVariables[] = {"TMPDIR", "TMP", "TEMP", "TEMPDIR"};
+  for (const char *Env : EnvironmentVariables) {
+    if (const char *Dir = std::getenv(Env))
+      return Dir;
+  }
+
+  return nullptr;
+}
+
+static const char *getDefaultTempDir(bool ErasedOnReboot) {
+#ifdef P_tmpdir
+  if ((bool)P_tmpdir)
+    return P_tmpdir;
+#endif
+
+  if (ErasedOnReboot)
+    return "/tmp";
+  return "/var/tmp";
+}
+
+void system_temp_directory(bool ErasedOnReboot, SmallVectorImpl<char> &Result) {
+  Result.clear();
+
+  if (ErasedOnReboot) {
+    // There is no env variable for the cache directory.
+    if (const char *RequestedDir = getEnvTempDir()) {
+      Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
+      return;
+    }
+  }
+
+  if (getDarwinConfDir(ErasedOnReboot, Result))
+    return;
+
+  const char *RequestedDir = getDefaultTempDir(ErasedOnReboot);
+  Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
+}
+
+} // end namespace path
+} // end namespace sys
+} // end namespace llvm