1 files changed, 51 insertions, 15 deletions

diff --git a/contrib/llvm/tools/clang/lib/Frontend/ModuleDependencyCollector.cpp b/contrib/llvm/tools/clang/lib/Frontend/ModuleDependencyCollector.cpp
index ca11f9b863bb..9b34d4211353 100644
--- a/contrib/llvm/tools/clang/lib/Frontend/ModuleDependencyCollector.cpp
+++ b/contrib/llvm/tools/clang/lib/Frontend/ModuleDependencyCollector.cpp
@@ -15,7 +15,6 @@
 #include "clang/Frontend/Utils.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Serialization/ASTReader.h"
-#include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
@@ -39,6 +38,24 @@ public:
   }
 };
 
+struct ModuleDependencyPPCallbacks : public PPCallbacks {
+  ModuleDependencyCollector &Collector;
+  SourceManager &SM;
+  ModuleDependencyPPCallbacks(ModuleDependencyCollector &Collector,
+                              SourceManager &SM)
+      : Collector(Collector), SM(SM) {}
+
+  void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
+                          StringRef FileName, bool IsAngled,
+                          CharSourceRange FilenameRange, const FileEntry *File,
+                          StringRef SearchPath, StringRef RelativePath,
+                          const Module *Imported) override {
+    if (!File)
+      return;
+    Collector.addFile(File->getName());
+  }
+};
+
 struct ModuleDependencyMMCallbacks : public ModuleMapCallbacks {
   ModuleDependencyCollector &Collector;
   ModuleDependencyMMCallbacks(ModuleDependencyCollector &Collector)
@@ -103,6 +120,8 @@ void ModuleDependencyCollector::attachToASTReader(ASTReader &R) {
 }
 
 void ModuleDependencyCollector::attachToPreprocessor(Preprocessor &PP) {
+  PP.addPPCallbacks(llvm::make_unique<ModuleDependencyPPCallbacks>(
+      *this, PP.getSourceManager()));
   PP.getHeaderSearchInfo().getModuleMap().addModuleMapCallbacks(
       llvm::make_unique<ModuleDependencyMMCallbacks>(*this));
 }
@@ -135,6 +154,10 @@ void ModuleDependencyCollector::writeFileMap() {
   // allows crash reproducer scripts to work across machines.
   VFSWriter.setOverlayDir(VFSDir);
 
+  // Do not ignore non existent contents otherwise we might skip something
+  // that should have been collected here.
+  VFSWriter.setIgnoreNonExistentContents(false);
+
   // Explicitly set case sensitivity for the YAML writer. For that, find out
   // the sensitivity at the path where the headers all collected to.
   VFSWriter.setCaseSensitivity(isCaseSensitivePath(VFSDir));
@@ -178,7 +201,8 @@ bool ModuleDependencyCollector::getRealPath(StringRef SrcPath,
   return true;
 }
 
-std::error_code ModuleDependencyCollector::copyToRoot(StringRef Src) {
+std::error_code ModuleDependencyCollector::copyToRoot(StringRef Src,
+                                                      StringRef Dst) {
   using namespace llvm::sys;
 
   // We need an absolute src path to append to the root.
@@ -190,23 +214,35 @@ std::error_code ModuleDependencyCollector::copyToRoot(StringRef Src) {
   AbsoluteSrc = path::remove_leading_dotslash(AbsoluteSrc);
 
   // Canonicalize the source path by removing "..", "." components.
-  SmallString<256> CanonicalPath = AbsoluteSrc;
-  path::remove_dots(CanonicalPath, /*remove_dot_dot=*/true);
+  SmallString<256> VirtualPath = AbsoluteSrc;
+  path::remove_dots(VirtualPath, /*remove_dot_dot=*/true);
 
   // If a ".." component is present after a symlink component, remove_dots may
   // lead to the wrong real destination path. Let the source be canonicalized
   // like that but make sure we always use the real path for the destination.
-  SmallString<256> RealPath;
-  if (!getRealPath(AbsoluteSrc, RealPath))
-    RealPath = CanonicalPath;
-  SmallString<256> Dest = getDest();
-  path::append(Dest, path::relative_path(RealPath));
+  SmallString<256> CopyFrom;
+  if (!getRealPath(AbsoluteSrc, CopyFrom))
+    CopyFrom = VirtualPath;
+  SmallString<256> CacheDst = getDest();
+
+  if (Dst.empty()) {
+    // The common case is to map the virtual path to the same path inside the
+    // cache.
+    path::append(CacheDst, path::relative_path(CopyFrom));
+  } else {
+    // When collecting entries from input vfsoverlays, copy the external
+    // contents into the cache but still map from the source.
+    if (!fs::exists(Dst))
+      return std::error_code();
+    path::append(CacheDst, Dst);
+    CopyFrom = Dst;
+  }
 
   // Copy the file into place.
-  if (std::error_code EC = fs::create_directories(path::parent_path(Dest),
-                                                   /*IgnoreExisting=*/true))
+  if (std::error_code EC = fs::create_directories(path::parent_path(CacheDst),
+                                                  /*IgnoreExisting=*/true))
     return EC;
-  if (std::error_code EC = fs::copy_file(RealPath, Dest))
+  if (std::error_code EC = fs::copy_file(CopyFrom, CacheDst))
     return EC;
 
   // Always map a canonical src path to its real path into the YAML, by doing
@@ -214,12 +250,12 @@ std::error_code ModuleDependencyCollector::copyToRoot(StringRef Src) {
   // overlay, which is a way to emulate symlink inside the VFS; this is also
   // needed for correctness, not doing that can lead to module redifinition
   // errors.
-  addFileMapping(CanonicalPath, Dest);
+  addFileMapping(VirtualPath, CacheDst);
   return std::error_code();
 }
 
-void ModuleDependencyCollector::addFile(StringRef Filename) {
+void ModuleDependencyCollector::addFile(StringRef Filename, StringRef FileDst) {
   if (insertSeen(Filename))
-    if (copyToRoot(Filename))
+    if (copyToRoot(Filename, FileDst))
       HasErrors = true;
 }