3 files changed, 62 insertions, 10 deletions

diff --git a/llvm/tools/llvm-lto/llvm-lto.cpp b/llvm/tools/llvm-lto/llvm-lto.cpp
index 9aabe0a4282..585207b2518 100644
--- a/llvm/tools/llvm-lto/llvm-lto.cpp
+++ b/llvm/tools/llvm-lto/llvm-lto.cpp
@@ -204,6 +204,10 @@ static cl::opt<bool> ListSymbolsOnly(
     "list-symbols-only", cl::init(false),
     cl::desc("Instead of running LTO, list the symbols in each IR file"));
 
+static cl::opt<bool> ListDependentLibrariesOnly(
+    "list-dependent-libraries-only", cl::init(false),
+    cl::desc("Instead of running LTO, list the dependent libraries in each IR file"));
+
 static cl::opt<bool> SetMergedModule(
     "set-merged-module", cl::init(false),
     cl::desc("Use the first input module as the merged module"));
@@ -372,6 +376,34 @@ static void listSymbols(const TargetOptions &Options) {
   }
 }
 
+static std::unique_ptr<MemoryBuffer> loadFile(StringRef Filename) {
+    ExitOnError ExitOnErr("llvm-lto: error loading file '" + Filename.str() +
+        "': ");
+    return ExitOnErr(errorOrToExpected(MemoryBuffer::getFileOrSTDIN(Filename)));
+}
+
+static void listDependentLibraries() {
+  for (auto &Filename : InputFilenames) {
+    auto Buffer = loadFile(Filename);
+    std::string E;
+    std::unique_ptr<lto::InputFile> Input(LTOModule::createInputFile(
+        Buffer->getBufferStart(), Buffer->getBufferSize(), Filename.c_str(),
+        E));
+    if (!Input)
+      error(E);
+
+    // List the dependent libraries.
+    outs() << Filename << ":\n";
+    for (size_t I = 0, C = LTOModule::getDependentLibraryCount(Input.get());
+         I != C; ++I) {
+      size_t L = 0;
+      const char *S = LTOModule::getDependentLibrary(Input.get(), I, &L);
+      assert(S);
+      outs() << StringRef(S, L) << "\n";
+    }
+  }
+}
+
 /// Create a combined index file from the input IR files and write it.
 ///
 /// This is meant to enable testing of ThinLTO combined index generation,
@@ -449,12 +481,6 @@ std::unique_ptr<ModuleSummaryIndex> loadCombinedIndex() {
   return ExitOnErr(getModuleSummaryIndexForFile(ThinLTOIndex));
 }
 
-static std::unique_ptr<MemoryBuffer> loadFile(StringRef Filename) {
-  ExitOnError ExitOnErr("llvm-lto: error loading file '" + Filename.str() +
-                        "': ");
-  return ExitOnErr(errorOrToExpected(MemoryBuffer::getFileOrSTDIN(Filename)));
-}
-
 static std::unique_ptr<lto::InputFile> loadInputFile(MemoryBufferRef Buffer) {
   ExitOnError ExitOnErr("llvm-lto: error loading input '" +
                         Buffer.getBufferIdentifier().str() + "': ");
@@ -854,6 +880,11 @@ int main(int argc, char **argv) {
     return 0;
   }
 
+  if (ListDependentLibrariesOnly) {
+    listDependentLibraries();
+    return 0;
+  }
+
   if (IndexStats) {
     printIndexStats();
     return 0;
diff --git a/llvm/tools/lto/lto.cpp b/llvm/tools/lto/lto.cpp
index 01dc141ffd0..fc2d3da43c0 100644
--- a/llvm/tools/lto/lto.cpp
+++ b/llvm/tools/lto/lto.cpp
@@ -18,6 +18,7 @@
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/DiagnosticPrinter.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/LTO/LTO.h"
 #include "llvm/LTO/legacy/LTOCodeGenerator.h"
 #include "llvm/LTO/legacy/LTOModule.h"
 #include "llvm/LTO/legacy/ThinLTOCodeGenerator.h"
@@ -325,10 +326,6 @@ const char* lto_module_get_linkeropts(lto_module_t mod) {
   return unwrap(mod)->getLinkerOpts().data();
 }
 
-const char* lto_module_get_dependent_libraries(lto_module_t mod) {
-    return unwrap(mod)->getDependentLibraries().data();
-}
-
 void lto_codegen_set_diagnostic_handler(lto_code_gen_t cg,
                                         lto_diagnostic_handler_t diag_handler,
                                         void *ctxt) {
@@ -635,3 +632,23 @@ lto_bool_t thinlto_codegen_set_pic_model(thinlto_code_gen_t cg,
   sLastErrorString = "Unknown PIC model";
   return true;
 }
+
+DEFINE_SIMPLE_CONVERSION_FUNCTIONS(lto::InputFile, lto_input_t)
+
+lto_input_t lto_input_create(const void *buffer, size_t buffer_size, const char *path) {
+  return wrap(LTOModule::createInputFile(buffer, buffer_size, path, sLastErrorString));
+}
+
+void lto_input_dispose(lto_input_t input) {
+  delete unwrap(input);
+}
+
+extern unsigned lto_input_get_num_dependent_libraries(lto_input_t input) {
+  return LTOModule::getDependentLibraryCount(unwrap(input));
+}
+
+extern const char *lto_input_get_dependent_library(lto_input_t input,
+                                                   size_t index,
+                                                   size_t *size) {
+  return LTOModule::getDependentLibrary(unwrap(input), index, size);
+}
diff --git a/llvm/tools/lto/lto.exports b/llvm/tools/lto/lto.exports
index cb881d104fb..34922c820d6 100644
--- a/llvm/tools/lto/lto.exports
+++ b/llvm/tools/lto/lto.exports
@@ -72,3 +72,7 @@ thinlto_codegen_disable_codegen
 thinlto_module_get_num_object_files
 thinlto_module_get_object_file
 thinlto_set_generated_objects_dir
+lto_input_create
+lto_input_destroy
+lto_input_get_num_dependent_libraries
+lto_input_get_dependent_library