From 2542ef83ed7c5a10f8b394ec8e7764558dc71d32 Mon Sep 17 00:00:00 2001
From: Sam McCall <sam.mccall@gmail.com>
Date: Mon, 7 Dec 2020 12:54:38 +0100
Subject: [PATCH] [clangd] Fix windows slashes in project config diagnostics

---
 clang-tools-extra/clangd/ConfigProvider.cpp                | 4 +++-
 clang-tools-extra/clangd/unittests/ConfigProviderTests.cpp | 2 --
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/clang-tools-extra/clangd/ConfigProvider.cpp b/clang-tools-extra/clangd/ConfigProvider.cpp
index 8a3991ed1c1e..0933e7e2c283 100644
--- a/clang-tools-extra/clangd/ConfigProvider.cpp
+++ b/clang-tools-extra/clangd/ConfigProvider.cpp
@@ -83,7 +83,7 @@ Provider::fromAncestorRelativeYAMLFiles(llvm::StringRef RelPath,
     const ThreadsafeFS &FS;
 
     mutable std::mutex Mu;
-    // Keys are the ancestor directory, not the actual config path within it.
+    // Keys are the (posix-style) ancestor directory, not the config within it.
     // We only insert into this map, so pointers to values are stable forever.
     // Mutex guards the map itself, not the values (which are threadsafe).
     mutable llvm::StringMap<FileConfigCache> Cache;
@@ -117,6 +117,8 @@ Provider::fromAncestorRelativeYAMLFiles(llvm::StringRef RelPath,
           if (It == Cache.end()) {
             llvm::SmallString<256> ConfigPath = Ancestor;
             path::append(ConfigPath, RelPath);
+            // Use native slashes for reading the file, affects diagnostics.
+            llvm::sys::path::native(ConfigPath);
             It = Cache.try_emplace(Ancestor, ConfigPath.str(), Ancestor).first;
           }
           Caches.push_back(&It->second);
diff --git a/clang-tools-extra/clangd/unittests/ConfigProviderTests.cpp b/clang-tools-extra/clangd/unittests/ConfigProviderTests.cpp
index 4e44af6fad58..9c45266d1a83 100644
--- a/clang-tools-extra/clangd/unittests/ConfigProviderTests.cpp
+++ b/clang-tools-extra/clangd/unittests/ConfigProviderTests.cpp
@@ -144,11 +144,9 @@ TEST(ProviderTest, FromAncestorRelativeYAMLFiles) {
   Cfg = P->getConfig(ABCParams, Diags.callback());
   EXPECT_THAT(Diags.Diagnostics,
               ElementsAre(DiagMessage("Unknown CompileFlags key Unknown")));
-#ifdef LLVM_ON_UNIX
   // FIXME: fails on windows: paths have mixed slashes like C:\a/b\c.yaml
   EXPECT_THAT(Diags.Files,
               ElementsAre(testPath("a/foo.yaml"), testPath("a/b/c/foo.yaml")));
-#endif
   EXPECT_THAT(getAddedArgs(Cfg), ElementsAre("foo", "bar", "baz"));
   Diags.clear();