1 files changed, 58 insertions, 3 deletions

diff --git a/lld/MachO/DriverUtils.cpp b/lld/MachO/DriverUtils.cpp
index faa9b760d904..064a509f47c8 100644
--- a/lld/MachO/DriverUtils.cpp
+++ b/lld/MachO/DriverUtils.cpp
@@ -10,6 +10,7 @@
 #include "Driver.h"
 #include "InputFiles.h"
 #include "ObjC.h"
+#include "Target.h"
 
 #include "lld/Common/Args.h"
 #include "lld/Common/ErrorHandler.h"
@@ -23,9 +24,10 @@
 #include "llvm/Option/ArgList.h"
 #include "llvm/Option/Option.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
-#include "llvm/TextAPI/MachO/InterfaceFile.h"
-#include "llvm/TextAPI/MachO/TextAPIReader.h"
+#include "llvm/TextAPI/InterfaceFile.h"
+#include "llvm/TextAPI/TextAPIReader.h"
 
 using namespace llvm;
 using namespace llvm::MachO;
@@ -164,12 +166,15 @@ Optional<std::string> macho::resolveDylibPath(StringRef path) {
   // they are consistent.
   if (fs::exists(path))
     return std::string(path);
+  else
+    depTracker->logFileNotFound(path);
 
   SmallString<261> location = path;
   path::replace_extension(location, ".tbd");
   if (fs::exists(location))
     return std::string(location);
-
+  else
+    depTracker->logFileNotFound(location);
   return {};
 }
 
@@ -240,3 +245,53 @@ void macho::printArchiveMemberLoad(StringRef reason, const InputFile *f) {
   if (config->printWhyLoad)
     message(reason + " forced load of " + toString(f));
 }
+
+macho::DependencyTracker::DependencyTracker(StringRef path)
+    : path(path), active(!path.empty()) {
+  if (active && fs::exists(path) && !fs::can_write(path)) {
+    warn("Ignoring dependency_info option since specified path is not "
+         "writeable.");
+    active = false;
+  }
+}
+
+void macho::DependencyTracker::write(llvm::StringRef version,
+                                     const llvm::SetVector<InputFile *> &inputs,
+                                     llvm::StringRef output) {
+  if (!active)
+    return;
+
+  std::error_code ec;
+  llvm::raw_fd_ostream os(path, ec, llvm::sys::fs::OF_None);
+  if (ec) {
+    warn("Error writing dependency info to file");
+    return;
+  }
+
+  auto addDep = [&os](DepOpCode opcode, const StringRef &path) {
+    // XXX: Even though DepOpCode's underlying type is uint8_t,
+    // this cast is still needed because Clang older than 10.x has a bug,
+    // where it doesn't know to cast the enum to its underlying type.
+    // Hence `<< DepOpCode` is ambiguous to it.
+    os << static_cast<uint8_t>(opcode);
+    os << path;
+    os << '\0';
+  };
+
+  addDep(DepOpCode::Version, version);
+
+  // Sort the input by its names.
+  std::vector<StringRef> inputNames;
+  inputNames.reserve(inputs.size());
+  for (InputFile *f : inputs)
+    inputNames.push_back(f->getName());
+  llvm::sort(inputNames);
+
+  for (const StringRef &in : inputNames)
+    addDep(DepOpCode::Input, in);
+
+  for (const std::string &f : notFounds)
+    addDep(DepOpCode::NotFound, f);
+
+  addDep(DepOpCode::Output, output);
+}