commit 6a8bfd758fd8b24659d4e60356120cde264bce25
author Martin Storsjö <martin@martin.st> Sun Nov 01 23:39:03 2020 +0200
committer Copybara-Service <copybara-worker@google.com> Fri Feb 19 01:07:24 2021 -0800
tree 37b2f0140a7c896bfd2d82cab6d47bcab45f20ef
parent 62fbf34873170fdaa6dbed08a5ef0453e33fa794

[libcxx] Implement is_absolute properly for windows

Differential Revision: https://reviews.llvm.org/D91177

GitOrigin-RevId: 8a783e68452f646360d9902d2c2bc0e115d7bfa9

include/filesystem

diff --git a/include/filesystem b/include/filesystem
index 8d0b0f5..754fe36 100644
--- a/include/filesystem
+++ b/include/filesystem
@@ -1341,7 +1341,28 @@
   }
 
   _LIBCPP_INLINE_VISIBILITY bool is_absolute() const {
+#if defined(_LIBCPP_WIN32API)
+    __string_view __root_name_str = __root_name();
+    __string_view __root_dir = __root_directory();
+    if (__root_name_str.size() == 2 && __root_name_str[1] == ':') {
+      // A drive letter with no root directory is relative, e.g. x:example.
+      return !__root_dir.empty();
+    }
+    // If no root name, it's relative, e.g. \example is relative to the current drive
+    if (__root_name_str.empty())
+      return false;
+    if (__root_name_str.size() < 3)
+      return false;
+    // A server root name, like \\server, is always absolute
+    if (__root_name_str[0] != '/' && __root_name_str[0] != '\\')
+      return false;
+    if (__root_name_str[1] != '/' && __root_name_str[1] != '\\')
+      return false;
+    // Seems to be a server root name
+    return true;
+#else
     return has_root_directory();
+#endif
   }
   _LIBCPP_INLINE_VISIBILITY bool is_relative() const { return !is_absolute(); }