From d5721f1aaafe7e80751329d6c4c6aaa0a26d74ac Mon Sep 17 00:00:00 2001
From: Bryce Hutchings <5100250+brycehutchings@users.noreply.github.com>
Date: Thu, 11 Feb 2021 10:29:54 -0800
Subject: [PATCH] Remove canonicalization in Windows loader (#239)

* Remove canonicalization in Windows loader

* Add change fragment

* Remove submodule
---
 changes/sdk/pr.239.gh.OpenXR-SDK-Source.md |  1 +
 src/common/filesystem_utils.cpp            | 27 ++++++++--------------
 src/loader/CMakeLists.txt                  |  2 +-
 3 files changed, 11 insertions(+), 19 deletions(-)
 create mode 100644 changes/sdk/pr.239.gh.OpenXR-SDK-Source.md

diff --git a/changes/sdk/pr.239.gh.OpenXR-SDK-Source.md b/changes/sdk/pr.239.gh.OpenXR-SDK-Source.md
new file mode 100644
index 000000000..2ce44f406
--- /dev/null
+++ b/changes/sdk/pr.239.gh.OpenXR-SDK-Source.md
@@ -0,0 +1 @@
+Loader: Fix loader failing to load on Windows 7 due to pathcch dependency.
\ No newline at end of file
diff --git a/src/common/filesystem_utils.cpp b/src/common/filesystem_utils.cpp
index af3d1402a..3b0685de3 100644
--- a/src/common/filesystem_utils.cpp
+++ b/src/common/filesystem_utils.cpp
@@ -75,10 +75,6 @@
 #include <dirent.h>
 #endif
 
-#if defined(XR_USE_PLATFORM_WIN32)
-#include <pathcch.h>
-#endif
-
 #if defined(XR_USE_PLATFORM_WIN32)
 #define PATH_SEPARATOR ';'
 #define DIRECTORY_SYMBOL '\\'
@@ -121,14 +117,10 @@ bool FileSysUtilsGetAbsolutePath(const std::string& path, std::string& absolute)
 
 bool FileSysUtilsGetCanonicalPath(const std::string& path, std::string& canonical) {
 #if defined(XR_USE_PLATFORM_WIN32)
-    // std::filesystem::canonical fails on UWP and must be avoided. This alternative will not
-    // follow symbolic links but symbolic links are not needed on Windows since the loader uses
-    // the registry as a form of indirection instead.
-    wchar_t canonical_wide_path[MAX_PATH];
-    if (FAILED(PathCchCanonicalize(canonical_wide_path, MAX_PATH, utf8_to_wide(path).c_str()))) {
-        return false;
-    }
-    canonical = wide_to_utf8(canonical_wide_path);
+    // std::filesystem::canonical fails on UWP and must be avoided. Further, PathCchCanonicalize is not available on Windows 7 and
+    // PathCanonicalizeW is not available on UWP. However, symbolic links are not important on Windows since the loader uses the
+    // registry for indirection instead, and so this function can be a no-op on Windows.
+    canonical = path;
 #else
     canonical = FS_PREFIX::canonical(path).string();
 #endif
@@ -218,12 +210,11 @@ bool FileSysUtilsGetAbsolutePath(const std::string& path, std::string& absolute)
 }
 
 bool FileSysUtilsGetCanonicalPath(const std::string& path, std::string& absolute) {
-    wchar_t tmp_path[MAX_PATH];
-    if (SUCCEEDED(PathCchCanonicalize(tmp_path, MAX_PATH, utf8_to_wide(path).c_str()))) {
-        absolute = wide_to_utf8(tmp_path);
-        return true;
-    }
-    return false;
+    // PathCchCanonicalize is not available on Windows 7 and PathCanonicalizeW is not available on UWP. However, symbolic links are
+    // not important on Windows since the loader uses the registry for indirection instead, and so this function can be a no-op on
+    // Windows.
+    absolute = path;
+    return true;
 }
 
 bool FileSysUtilsCombinePaths(const std::string& parent, const std::string& child, std::string& combined) {
diff --git a/src/loader/CMakeLists.txt b/src/loader/CMakeLists.txt
index 50e166b77..cfc208ea5 100644
--- a/src/loader/CMakeLists.txt
+++ b/src/loader/CMakeLists.txt
@@ -193,7 +193,7 @@ elseif(WIN32)
         target_compile_options(openxr_loader PRIVATE /wd6386)
     endif()
 
-    target_link_libraries(openxr_loader PUBLIC advapi32 pathcch)
+    target_link_libraries(openxr_loader PUBLIC advapi32)
 
     # Need to copy DLL to client directories so clients can easily load it.
     if(DYNAMIC_LOADER AND (CMAKE_GENERATOR MATCHES "^Visual Studio.*"))