[llvm-libtool-darwin] Add support for -dependency_info

When using llvm-libtool-darwin as a drop in replacement for cctools
libtool, Xcode expects you to create a dependency info file. This file
is a very simple format describing the input files, the output files,
and the version of the tool. This logic is mirrored from that of
ld64.lld, which supports creating this file as well. Ideally we could
extract it, but I don't think we want to throw this into one of the
grab-bag libraries given how small the logic is.

Differential Revision: https://reviews.llvm.org/D134322

1 files changed, 19 insertions, 1 deletions

diff --git a/llvm/tools/llvm-libtool-darwin/llvm-libtool-darwin.cpp b/llvm/tools/llvm-libtool-darwin/llvm-libtool-darwin.cpp
index 8d4529c..5fec847 100644
--- a/llvm/tools/llvm-libtool-darwin/llvm-libtool-darwin.cpp
+++ b/llvm/tools/llvm-libtool-darwin/llvm-libtool-darwin.cpp
@@ -10,6 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "DependencyInfo.h"
 #include "llvm/BinaryFormat/Magic.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/Object/ArchiveWriter.h"
@@ -87,6 +88,12 @@ static cl::list<std::string> LibrarySearchDirs(
         " libraries"),
     cl::Prefix, cl::cat(LibtoolCategory));
 
+static cl::opt<std::string> DependencyInfoPath(
+    "dependency_info",
+    cl::desc("Write an Xcode dependency info file describing the dependencies "
+             "of the created library"),
+    cl::cat(LibtoolCategory));
+
 static cl::opt<bool>
     VersionOption("V", cl::desc("Print the version number and exit"),
                   cl::cat(LibtoolCategory));
@@ -109,6 +116,8 @@ static const std::array<std::string, 3> StandardSearchDirs{
     "/usr/local/lib",
 };
 
+std::unique_ptr<DependencyInfo> GlobalDependencyInfo;
+
 struct Config {
   bool Deterministic = true; // Updated by 'D' and 'U' modifiers.
   uint32_t ArchCPUType;
@@ -116,7 +125,6 @@ struct Config {
 };
 
 static Expected<std::string> searchForFile(const Twine &FileName) {
-
   auto FindLib =
       [FileName](ArrayRef<std::string> SearchDirs) -> Optional<std::string> {
     for (StringRef Dir : SearchDirs) {
@@ -125,6 +133,8 @@ static Expected<std::string> searchForFile(const Twine &FileName) {
 
       if (sys::fs::exists(Path))
         return std::string(Path);
+
+      GlobalDependencyInfo->addMissingInput(Path);
     }
     return None;
   };
@@ -652,6 +662,11 @@ static Expected<Config> parseCommandLine(int Argc, char **Argv) {
     return C;
   }
 
+  GlobalDependencyInfo =
+      DependencyInfoPath.empty()
+          ? std::make_unique<DummyDependencyInfo>()
+          : std::make_unique<DependencyInfo>(DependencyInfoPath);
+
   if (OutputFile.empty()) {
     std::string Error;
     raw_string_ostream Stream(Error);
@@ -686,6 +701,9 @@ static Expected<Config> parseCommandLine(int Argc, char **Argv) {
             MachO::getArchitectureFromName(ArchType));
   }
 
+  GlobalDependencyInfo->write("llvm-libtool-darwin " LLVM_VERSION_STRING,
+                              InputFiles, OutputFile);
+
   return C;
 }