Use forward slashes for header paths

Author: Harald-R

clang-tools-extra/clangd/Headers.cpp

@@ -304,16 +304,17 @@ IncludeInserter::calculateIncludePath(const HeaderFile &InsertedHeader,
   // FIXME: should we allow (some limited number of) "../header.h"?
   if (llvm::sys::path::is_absolute(Suggested))
     return std::nullopt;
+  auto HeaderPath = llvm::sys::path::convert_to_slash(InsertedHeader.File);
   bool IsAngled = false;
   for (auto &Filter : AngledHeaders) {
-    if (Filter(InsertedHeader.File)) {
+    if (Filter(HeaderPath)) {
       IsAngled = true;
       break;
     }
   }
   bool IsQuoted = false;
   for (auto &Filter : QuotedHeaders) {
-    if (Filter(InsertedHeader.File)) {
+    if (Filter(HeaderPath)) {
       IsQuoted = true;
       break;
     }
@@ -324,7 +325,7 @@ IncludeInserter::calculateIncludePath(const HeaderFile &InsertedHeader,
     if (IsAngled && IsQuoted) {
       elog("Header '{0}' matches both quoted and angled regexes, default will "
            "be used.",
-           InsertedHeader.File);
+           HeaderPath);
     }
     IsAngled = IsAngledByDefault;
   }

clang-tools-extra/clangd/unittests/HeadersTests.cpp

@@ -348,11 +348,7 @@ TEST_F(HeadersTest, ShortenIncludesInSearchPathBracketedFilterByFullPath) {
   // The filter receives the full path of the header, so it is able to filter by
   // the parent directory, even if it is part of the include search path
   AngledHeaders.push_back([](auto Path) {
-#if defined(_WIN32)
-    llvm::Regex Pattern("sub\\.*");
-#else
     llvm::Regex Pattern("sub/.*");
-#endif
     return Pattern.match(Path);
   });
   std::string BarHeader = testPath("sub/bar.h");