3 files changed, 57 insertions, 30 deletions

diff --git a/lldb/include/lldb/Utility/FileSpec.h b/lldb/include/lldb/Utility/FileSpec.h
index a7e634e32fe..a32dab96b40 100644
--- a/lldb/include/lldb/Utility/FileSpec.h
+++ b/lldb/include/lldb/Utility/FileSpec.h
@@ -532,7 +532,14 @@ public:
   void AppendPathComponent(llvm::StringRef component);
   void AppendPathComponent(const FileSpec &new_path);
 
-  void RemoveLastPathComponent();
+  //------------------------------------------------------------------
+  /// Removes the last path component by replacing the current path with its
+  /// parent. When the current path has no parent, this is a no-op.
+  ///
+  /// @return
+  ///     A boolean value indicating whether the path was updated.
+  //------------------------------------------------------------------
+  bool RemoveLastPathComponent();
 
   ConstString GetLastPathComponent() const;
 
diff --git a/lldb/source/Utility/FileSpec.cpp b/lldb/source/Utility/FileSpec.cpp
index ac404cea435..cc36f47e48d 100644
--- a/lldb/source/Utility/FileSpec.cpp
+++ b/lldb/source/Utility/FileSpec.cpp
@@ -785,36 +785,15 @@ void FileSpec::AppendPathComponent(const FileSpec &new_path) {
   return AppendPathComponent(new_path.GetPath(false));
 }
 
-void FileSpec::RemoveLastPathComponent() {
-  // CLEANUP: Use StringRef for string handling.
-
-  const bool resolve = false;
-  if (m_filename.IsEmpty() && m_directory.IsEmpty()) {
-    SetFile("", resolve);
-    return;
-  }
-  if (m_directory.IsEmpty()) {
-    SetFile("", resolve);
-    return;
+bool FileSpec::RemoveLastPathComponent() {
+  llvm::SmallString<64> current_path;
+  GetPath(current_path, false);
+  if (llvm::sys::path::has_parent_path(current_path, m_style)) {
+    SetFile(llvm::sys::path::parent_path(current_path, m_style), false,
+            m_style);
+    return true;
   }
-  if (m_filename.IsEmpty()) {
-    const char *dir_cstr = m_directory.GetCString();
-    const char *last_slash_ptr = ::strrchr(dir_cstr, '/');
-
-    // check for obvious cases before doing the full thing
-    if (!last_slash_ptr) {
-      SetFile("", resolve);
-      return;
-    }
-    if (last_slash_ptr == dir_cstr) {
-      SetFile("/", resolve);
-      return;
-    }
-    size_t last_slash_pos = last_slash_ptr - dir_cstr + 1;
-    ConstString new_path(dir_cstr, last_slash_pos);
-    SetFile(new_path.GetCString(), resolve);
-  } else
-    SetFile(m_directory.GetCString(), resolve);
+  return false;
 }
 //------------------------------------------------------------------
 /// Returns true if the filespec represents an implementation source
diff --git a/lldb/unittests/Utility/FileSpecTest.cpp b/lldb/unittests/Utility/FileSpecTest.cpp
index 03c9793fc15..2e02579797a 100644
--- a/lldb/unittests/Utility/FileSpecTest.cpp
+++ b/lldb/unittests/Utility/FileSpecTest.cpp
@@ -320,3 +320,44 @@ TEST(FileSpecTest, IsRelative) {
   }
 }
 
+TEST(FileSpecTest, RemoveLastPathComponent) {
+  FileSpec fs_posix("/foo/bar/baz", false, FileSpec::Style::posix);
+  EXPECT_STREQ("/foo/bar/baz", fs_posix.GetCString());
+  EXPECT_TRUE(fs_posix.RemoveLastPathComponent());
+  EXPECT_STREQ("/foo/bar", fs_posix.GetCString());
+  EXPECT_TRUE(fs_posix.RemoveLastPathComponent());
+  EXPECT_STREQ("/foo", fs_posix.GetCString());
+  EXPECT_TRUE(fs_posix.RemoveLastPathComponent());
+  EXPECT_STREQ("/", fs_posix.GetCString());
+  EXPECT_FALSE(fs_posix.RemoveLastPathComponent());
+  EXPECT_STREQ("/", fs_posix.GetCString());
+
+  FileSpec fs_posix_relative("./foo/bar/baz", false, FileSpec::Style::posix);
+  EXPECT_STREQ("foo/bar/baz", fs_posix_relative.GetCString());
+  EXPECT_TRUE(fs_posix_relative.RemoveLastPathComponent());
+  EXPECT_STREQ("foo/bar", fs_posix_relative.GetCString());
+  EXPECT_TRUE(fs_posix_relative.RemoveLastPathComponent());
+  EXPECT_STREQ("foo", fs_posix_relative.GetCString());
+  EXPECT_FALSE(fs_posix_relative.RemoveLastPathComponent());
+  EXPECT_STREQ("foo", fs_posix_relative.GetCString());
+
+  FileSpec fs_posix_relative2("./", false, FileSpec::Style::posix);
+  EXPECT_STREQ(".", fs_posix_relative2.GetCString());
+  EXPECT_FALSE(fs_posix_relative2.RemoveLastPathComponent());
+  EXPECT_STREQ(".", fs_posix_relative2.GetCString());
+  EXPECT_FALSE(fs_posix_relative.RemoveLastPathComponent());
+  EXPECT_STREQ(".", fs_posix_relative2.GetCString());
+
+  FileSpec fs_windows("C:\\foo\\bar\\baz", false, FileSpec::Style::windows);
+  EXPECT_STREQ("C:\\foo\\bar\\baz", fs_windows.GetCString());
+  EXPECT_TRUE(fs_windows.RemoveLastPathComponent());
+  EXPECT_STREQ("C:\\foo\\bar", fs_windows.GetCString());
+  EXPECT_TRUE(fs_windows.RemoveLastPathComponent());
+  EXPECT_STREQ("C:\\foo", fs_windows.GetCString());
+  EXPECT_TRUE(fs_windows.RemoveLastPathComponent());
+  EXPECT_STREQ("C:\\", fs_windows.GetCString());
+  EXPECT_TRUE(fs_windows.RemoveLastPathComponent());
+  EXPECT_STREQ("C:", fs_windows.GetCString());
+  EXPECT_FALSE(fs_windows.RemoveLastPathComponent());
+  EXPECT_STREQ("C:", fs_windows.GetCString());
+}