From d038bb196c51dcf80cbe771f4229b4e227c6c5b6 Mon Sep 17 00:00:00 2001
From: Ben Langmuir <blangmuir@apple.com>
Date: Fri, 5 Aug 2022 10:56:56 -0700
Subject: [PATCH] [clang] Fix redirection behaviour for cached FileEntryRef

In 6a79e2ff1989b we changed Filemanager::getEntryRef() to return the
redirecting FileEntryRef instead of looking through the redirection.
This commit fixes the case when looking up a cached file path to also
return the redirecting FileEntryRef. This mainly affects the behaviour
of calling getNameAsRequested() on the resulting entry ref.

Differential Revision: https://reviews.llvm.org/D131273
---
 clang/lib/Basic/FileManager.cpp           | 8 +-------
 clang/unittests/Basic/FileManagerTest.cpp | 6 ++++++
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/clang/lib/Basic/FileManager.cpp b/clang/lib/Basic/FileManager.cpp
index cb719762ec7c..4ef25358ec82 100644
--- a/clang/lib/Basic/FileManager.cpp
+++ b/clang/lib/Basic/FileManager.cpp
@@ -212,13 +212,7 @@ FileManager::getFileRef(StringRef Filename, bool openFile, bool CacheFailure) {
     if (!SeenFileInsertResult.first->second)
       return llvm::errorCodeToError(
           SeenFileInsertResult.first->second.getError());
-    // Construct and return and FileEntryRef, unless it's a redirect to another
-    // filename.
-    FileEntryRef::MapValue Value = *SeenFileInsertResult.first->second;
-    if (LLVM_LIKELY(Value.V.is<FileEntry *>()))
-      return FileEntryRef(*SeenFileInsertResult.first);
-    return FileEntryRef(*reinterpret_cast<const FileEntryRef::MapEntry *>(
-        Value.V.get<const void *>()));
+    return FileEntryRef(*SeenFileInsertResult.first);
   }
 
   // We've not seen this before. Fill it in.
diff --git a/clang/unittests/Basic/FileManagerTest.cpp b/clang/unittests/Basic/FileManagerTest.cpp
index 419c497e95d6..6fe4a3d65d17 100644
--- a/clang/unittests/Basic/FileManagerTest.cpp
+++ b/clang/unittests/Basic/FileManagerTest.cpp
@@ -340,6 +340,7 @@ TEST_F(FileManagerTest, getFileRefEquality) {
   auto F1Again = manager.getFileRef("dir/f1.cpp");
   auto F1Also = manager.getFileRef("dir/f1-also.cpp");
   auto F1Redirect = manager.getFileRef("dir/f1-redirect.cpp");
+  auto F1RedirectAgain = manager.getFileRef("dir/f1-redirect.cpp");
   auto F2 = manager.getFileRef("dir/f2.cpp");
 
   // Check Expected<FileEntryRef> for error.
@@ -347,6 +348,7 @@ TEST_F(FileManagerTest, getFileRefEquality) {
   ASSERT_FALSE(!F1Also);
   ASSERT_FALSE(!F1Again);
   ASSERT_FALSE(!F1Redirect);
+  ASSERT_FALSE(!F1RedirectAgain);
   ASSERT_FALSE(!F2);
 
   // Check names.
@@ -354,6 +356,7 @@ TEST_F(FileManagerTest, getFileRefEquality) {
   EXPECT_EQ("dir/f1.cpp", F1Again->getName());
   EXPECT_EQ("dir/f1-also.cpp", F1Also->getName());
   EXPECT_EQ("dir/f1.cpp", F1Redirect->getName());
+  EXPECT_EQ("dir/f1.cpp", F1RedirectAgain->getName());
   EXPECT_EQ("dir/f2.cpp", F2->getName());
 
   EXPECT_EQ("dir/f1.cpp", F1->getNameAsRequested());
@@ -363,6 +366,7 @@ TEST_F(FileManagerTest, getFileRefEquality) {
   EXPECT_EQ(&F1->getFileEntry(), *F1);
   EXPECT_EQ(*F1, &F1->getFileEntry());
   EXPECT_EQ(&F1->getFileEntry(), &F1Redirect->getFileEntry());
+  EXPECT_EQ(&F1->getFileEntry(), &F1RedirectAgain->getFileEntry());
   EXPECT_NE(&F2->getFileEntry(), *F1);
   EXPECT_NE(*F1, &F2->getFileEntry());
 
@@ -371,6 +375,7 @@ TEST_F(FileManagerTest, getFileRefEquality) {
   EXPECT_EQ(*F1, *F1Again);
   EXPECT_EQ(*F1, *F1Redirect);
   EXPECT_EQ(*F1Also, *F1Redirect);
+  EXPECT_EQ(*F1, *F1RedirectAgain);
   EXPECT_NE(*F2, *F1);
   EXPECT_NE(*F2, *F1Also);
   EXPECT_NE(*F2, *F1Again);
@@ -381,6 +386,7 @@ TEST_F(FileManagerTest, getFileRefEquality) {
   EXPECT_FALSE(F1->isSameRef(*F1Redirect));
   EXPECT_FALSE(F1->isSameRef(*F1Also));
   EXPECT_FALSE(F1->isSameRef(*F2));
+  EXPECT_TRUE(F1Redirect->isSameRef(*F1RedirectAgain));
 }
 
 // getFile() Should return the same entry as getVirtualFile if the file actually