Revert "[clang] Canonicalize absolute paths in dependency file" (#121638)

Reverts llvm/llvm-project#117458

https://github.com/llvm/llvm-project/pull/117458#issuecomment-2568804774

https://github.com/ninja-build/ninja/issues/2528

1 files changed, 3 insertions, 17 deletions

diff --git a/clang/lib/Frontend/DependencyFile.cpp b/clang/lib/Frontend/DependencyFile.cpp
index 8a36d83..15fa7de 100644
--- a/clang/lib/Frontend/DependencyFile.cpp
+++ b/clang/lib/Frontend/DependencyFile.cpp
@@ -23,10 +23,8 @@
 #include "llvm/ADT/StringSet.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
-#include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/Support/raw_ostream.h"
 #include <optional>
-#include <system_error>
 
 using namespace clang;
 
@@ -238,7 +236,6 @@ void DependencyFileGenerator::attachToPreprocessor(Preprocessor &PP) {
     PP.SetSuppressIncludeNotFoundError(true);
 
   DependencyCollector::attachToPreprocessor(PP);
-  FS = PP.getFileManager().getVirtualFileSystemPtr();
 }
 
 bool DependencyFileGenerator::sawDependency(StringRef Filename, bool FromModule,
@@ -315,22 +312,11 @@ void DependencyFileGenerator::finishedMainFile(DiagnosticsEngine &Diags) {
 /// https://msdn.microsoft.com/en-us/library/dd9y37ha.aspx for NMake info,
 /// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx
 /// for Windows file-naming info.
-static void printFilename(raw_ostream &OS, llvm::vfs::FileSystem *FS,
-                          StringRef Filename,
+static void PrintFilename(raw_ostream &OS, StringRef Filename,
                           DependencyOutputFormat OutputFormat) {
   // Convert filename to platform native path
   llvm::SmallString<256> NativePath;
   llvm::sys::path::native(Filename.str(), NativePath);
-  // Resolve absolute path. Make and Ninja canonicalize paths
-  // without checking for symbolic links in the path, for performance concerns.
-  // If there is something like `/bin/../lib64` -> `/usr/lib64`
-  // (where `/bin` links to `/usr/bin`), Make will see them as `/lib64`.
-  if (FS != nullptr && llvm::sys::path::is_absolute(NativePath)) {
-    llvm::SmallString<256> NativePathTmp = NativePath;
-    std::error_code EC = FS->getRealPath(NativePathTmp, NativePath);
-    if (EC)
-      NativePath = NativePathTmp;
-  }
 
   if (OutputFormat == DependencyOutputFormat::NMake) {
     // Add quotes if needed. These are the characters listed as "special" to
@@ -414,7 +400,7 @@ void DependencyFileGenerator::outputDependencyFile(llvm::raw_ostream &OS) {
       Columns = 2;
     }
     OS << ' ';
-    printFilename(OS, FS.get(), File, OutputFormat);
+    PrintFilename(OS, File, OutputFormat);
     Columns += N + 1;
   }
   OS << '\n';
@@ -425,7 +411,7 @@ void DependencyFileGenerator::outputDependencyFile(llvm::raw_ostream &OS) {
     for (auto I = Files.begin(), E = Files.end(); I != E; ++I) {
       if (Index++ == InputFileIndex)
         continue;
-      printFilename(OS, FS.get(), *I, OutputFormat);
+      PrintFilename(OS, *I, OutputFormat);
       OS << ":\n";
     }
   }