Windows, Java launcher: Support jar files under different drives

Create junctions to jar's directory when java launcher and its jar are under different drives

Fixed bazelbuild#5135

Change-Id: I21c5b28f5f36c1fe234f8b781fe40d526db846cc
PiperOrigin-RevId: 196477704

Author: meteorcloudy

src/main/cpp/util/file.cc

@@ -124,8 +124,8 @@ class DirectoryTreeWalker : public DirectoryEntryConsumer {
                       _ForEachDirectoryEntry walk_entries)
       : _files(files), _walk_entries(walk_entries) {}
 
-  void Consume(const string &path, bool is_directory) override {
-    if (is_directory) {
+  void Consume(const string &path, bool follow_directory) override {
+    if (follow_directory) {
       Walk(path);
     } else {
       _files->push_back(path);

src/main/cpp/util/file_windows.cc

@@ -1219,7 +1219,9 @@ void ForEachDirectoryEntry(const string &path,
       wstring wname = wpath + metadata.cFileName;
       string name(WstringToCstring(/* omit prefix */ 4 + wname.c_str()).get());
       bool is_dir = (metadata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
-      consume->Consume(name, is_dir);
+      bool is_junc =
+          (metadata.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) != 0;
+      consume->Consume(name, is_dir && !is_junc);
     }
   } while (::FindNextFileW(handle, &metadata));
   ::FindClose(handle);

src/test/shell/bazel/bazel_windows_example_test.sh

@@ -39,7 +39,6 @@ function set_up() {
 startup --host_jvm_args=-Dbazel.windows_unix_root=C:/fake/msys
 
 startup --batch
-build --cpu=x64_windows_msvc
 EOF
   export MSYS_NO_PATHCONV=1
   export MSYS2_ARG_CONV_EXCL="*"
@@ -129,6 +128,43 @@ function test_java() {
   assert_binary_run_from_subdir "bazel-bin/${java_pkg}/hello-world foo" "Hello foo"
 }
 
+function create_tmp_drive() {
+  mkdir "$TEST_TMPDIR/tmp_drive"
+
+  TMP_DRIVE_PATH=$(cygpath -w "$TEST_TMPDIR\\tmp_drive")
+  for X in {A..Z}
+  do
+    TMP_DRIVE=${X}
+    subst ${TMP_DRIVE}: ${TMP_DRIVE_PATH} >NUL || TMP_DRIVE=""
+    if [ -n "${TMP_DRIVE}" ]; then
+      break
+    fi
+  done
+
+  if [ -z "${TMP_DRIVE}" ]; then
+    fail "Cannot create temporary drive."
+  fi
+
+  export TMP_DRIVE
+}
+
+function delete_tmp_drive() {
+  if [ -n "${TMP_DRIVE}" ]; then
+    subst ${TMP_DRIVE}: /D
+  fi
+}
+
+function test_java_with_jar_under_different_drive() {
+  create_tmp_drive
+
+  trap delete_tmp_drive EXIT
+
+  local java_pkg=examples/java-native/src/main/java/com/example/myproject
+  bazel --output_user_root=${TMP_DRIVE}:/tmp build ${java_pkg}:hello-world
+
+  assert_binary_run_from_subdir "bazel-bin/${java_pkg}/hello-world --classpath_limit=0" "Hello world"
+}
+
 function test_java_test() {
   setup_javatest_support
   local java_native_tests=//examples/java-native/src/test/java/com/example/myproject

src/tools/launcher/java_launcher.cc

@@ -12,11 +12,16 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include <memory>
 #include <sstream>
 #include <string>
+#include <unordered_map>
 #include <vector>
 
+#include "src/main/cpp/util/file.h"
 #include "src/main/cpp/util/file_platform.h"
+#include "src/main/cpp/util/strings.h"
+#include "src/main/native/windows/file.h"
 #include "src/tools/launcher/java_launcher.h"
 #include "src/tools/launcher/util/launcher_util.h"
 
@@ -29,6 +34,7 @@ using std::ostringstream;
 using std::string;
 using std::stringstream;
 using std::vector;
+using std::wstring;
 
 // The runfile path of java binary, eg. local_jdk/bin/java.exe
 static constexpr const char* JAVA_BIN_PATH = "java_bin_path";
@@ -135,6 +141,52 @@ static string GetManifestJarDir(const string& binary_base_path) {
   return result;
 }
 
+static void WriteJarClasspath(const string& jar_path,
+                              ostringstream* manifest_classpath) {
+  *manifest_classpath << ' ';
+  if (jar_path.find_first_of(" \\") != string::npos) {
+    for (const auto& x : jar_path) {
+      if (x == ' ') {
+        *manifest_classpath << "%20";
+      }
+      if (x == '\\') {
+        *manifest_classpath << "/";
+      } else {
+        *manifest_classpath << x;
+      }
+    }
+  } else {
+    *manifest_classpath << jar_path;
+  }
+}
+
+string JavaBinaryLauncher::GetJunctionBaseDir() {
+  string binary_base_path =
+      GetBinaryPathWithExtension(this->GetCommandlineArguments()[0]);
+  string result;
+  if (!NormalizePath(binary_base_path + ".j", &result)) {
+    die("Failed to get normalized junction base directory.");
+  }
+  return result;
+}
+
+void JavaBinaryLauncher::DeleteJunctionBaseDir() {
+  string junction_base_dir_norm = GetJunctionBaseDir();
+  if (!DoesDirectoryPathExist(junction_base_dir_norm.c_str())) {
+    return;
+  }
+  vector<string> junctions;
+  blaze_util::GetAllFilesUnder(junction_base_dir_norm, &junctions);
+  for (const auto& junction : junctions) {
+    if (!DeleteDirectoryByPath(junction.c_str())) {
+      PrintError(GetLastErrorString().c_str());
+    }
+  }
+  if (!DeleteDirectoryByPath(junction_base_dir_norm.c_str())) {
+    PrintError(GetLastErrorString().c_str());
+  }
+}
+
 string JavaBinaryLauncher::CreateClasspathJar(const string& classpath) {
   string binary_base_path =
       GetBinaryPathWithoutExtension(this->GetCommandlineArguments()[0]);
@@ -144,28 +196,55 @@ string JavaBinaryLauncher::CreateClasspathJar(const string& classpath) {
   manifest_classpath << "Class-Path:";
   stringstream classpath_ss(classpath);
   string path, path_norm;
+
+  // A set to store all junctions created.
+  // The key is the target path, the value is the junction path.
+  std::unordered_map<string, string> jar_dirs;
+  string junction_base_dir_norm = GetJunctionBaseDir();
+  int junction_count = 0;
+  // Make sure the junction base directory doesn't exist already.
+  DeleteJunctionBaseDir();
+  blaze_util::MakeDirectories(junction_base_dir_norm, 0755);
+
   while (getline(classpath_ss, path, ';')) {
-    manifest_classpath << ' ';
     if (blaze_util::IsAbsolute(path)) {
-      if (!NormalizePath(path, &path_norm) ||
-          !RelativeTo(path_norm, abs_manifest_jar_dir_norm, &path)) {
+      if (!NormalizePath(path, &path_norm)) {
         die("CreateClasspathJar failed");
       }
-    }
-    if (path.find_first_of(" \\") != string::npos) {
-      for (const auto& x : path) {
-        if (x == ' ') {
-          manifest_classpath << "%20";
-        }
-        if (x == '\\') {
-          manifest_classpath << "/";
+
+      // If two paths are under different drives, we should create a junction to
+      // the jar's directory
+      if (path_norm[0] != abs_manifest_jar_dir_norm[0]) {
+        string jar_dir = GetParentDirFromPath(path_norm);
+        string jar_base_name = GetBaseNameFromPath(path_norm);
+        string junction;
+        auto search = jar_dirs.find(jar_dir);
+        if (search == jar_dirs.end()) {
+          junction =
+              junction_base_dir_norm + "\\" + std::to_string(junction_count++);
+
+          wstring wjar_dir(
+              blaze_util::CstringToWstring(junction.c_str()).get());
+          wstring wjunction(
+              blaze_util::CstringToWstring(jar_dir.c_str()).get());
+          wstring werror(bazel::windows::CreateJunction(wjar_dir, wjunction));
+          if (!werror.empty()) {
+            string error(werror.begin(), werror.end());
+            die("CreateClasspathJar failed: %s", error.c_str());
+          }
+
+          jar_dirs.insert(std::make_pair(jar_dir, junction));
         } else {
-          manifest_classpath << x;
+          junction = search->second;
         }
+        path_norm = junction + "\\" + jar_base_name;
+      }
+
+      if (!RelativeTo(path_norm, abs_manifest_jar_dir_norm, &path)) {
+        die("CreateClasspathJar failed");
       }
-    } else {
-      manifest_classpath << path;
     }
+    WriteJarClasspath(path, &manifest_classpath);
   }
 
   string rand_id = "-" + GetRandomStr(10);
@@ -335,6 +414,7 @@ ExitCode JavaBinaryLauncher::Launch() {
   // Delete classpath jar file after execution.
   if (!classpath_jar.empty()) {
     DeleteFileByPath(classpath_jar.c_str());
+    DeleteJunctionBaseDir();
   }
 
   return exit_code;

src/tools/launcher/java_launcher.h

@@ -90,6 +90,13 @@ class JavaBinaryLauncher : public BinaryLauncherBase {
   //
   // Return the path of the classpath jar created.
   std::string CreateClasspathJar(const std::string& classpath);
+
+  // Creat a directory based on the binary path, all the junctions will be
+  // generated under this directory.
+  std::string GetJunctionBaseDir();
+
+  // Delete all the junction directory and all the junctions under it.
+  void DeleteJunctionBaseDir();
 };
 
 }  // namespace launcher

src/tools/launcher/util/launcher_util.cc

@@ -100,6 +100,10 @@ bool DeleteFileByPath(const char* path) {
   return DeleteFileW(AsAbsoluteWindowsPath(path).c_str());
 }
 
+bool DeleteDirectoryByPath(const char* path) {
+  return RemoveDirectoryW(AsAbsoluteWindowsPath(path).c_str());
+}
+
 string GetBinaryPathWithoutExtension(const string& binary) {
   if (binary.find(".exe", binary.size() - 4) != string::npos) {
     return binary.substr(0, binary.length() - 4);
@@ -184,6 +188,14 @@ bool NormalizePath(const string& path, string* result) {
   return true;
 }
 
+string GetBaseNameFromPath(const string& path) {
+  return path.substr(path.find_last_of("\\/") + 1);
+}
+
+string GetParentDirFromPath(const string& path) {
+  return path.substr(0, path.find_last_of("\\/"));
+}
+
 bool RelativeTo(const string& path, const string& base, string* result) {
   if (blaze_util::IsAbsolute(path) != blaze_util::IsAbsolute(base)) {
     PrintError(

src/tools/launcher/util/launcher_util.h

@@ -61,6 +61,12 @@ bool DoesDirectoryPathExist(const char* path);
 // Delete a file at a given path.
 bool DeleteFileByPath(const char* path);
 
+// Delete a directory at a given path,.
+// If it's a real directory, it must be empty
+// If it's a junction, the target directory it points to doesn't have to be
+// empty, the junction will be deleted regardless of the state of the target.
+bool DeleteDirectoryByPath(const char* path);
+
 // Get the value of a specific environment variable
 //
 // Return true if succeeded and the result is stored in buffer.
@@ -79,6 +85,12 @@ std::string GetRandomStr(size_t len);
 // Normalize a path to a Windows path in lower case
 bool NormalizePath(const std::string& path, std::string* result);
 
+// Get the base name from a normalized absoulute path
+std::string GetBaseNameFromPath(const std::string& path);
+
+// Get parent directory from a normalized absoulute path
+std::string GetParentDirFromPath(const std::string& path);
+
 // Calculate a relative path from `path` to `base`.
 // This function expects normalized Windows path in lower case.
 // `path` and `base` should be both absolute or both relative.