[llvm-readobj] Support -needed-libs option for COFF files

This implements the -needed-libs option in the COFF dumper.

Differential Revision: https://reviews.llvm.org/D41529

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@321498 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 27 insertions, 0 deletions

diff --git a/test/tools/llvm-readobj/Inputs/needed-libs.obj.coff-am64 b/test/tools/llvm-readobj/Inputs/needed-libs.obj.coff-am64
new file mode 100644
index 00000000000..4cfc6e25396
--- /dev/null
+++ b/test/tools/llvm-readobj/Inputs/needed-libs.obj.coff-am64
diff --git a/test/tools/llvm-readobj/coff-needed-libs.test b/test/tools/llvm-readobj/coff-needed-libs.test
new file mode 100644
index 00000000000..deb6bc299eb
--- /dev/null
+++ b/test/tools/llvm-readobj/coff-needed-libs.test
@@ -0,0 +1,5 @@
+RUN: llvm-readobj -needed-libs %p/Inputs/needed-libs.obj.coff-am64 | FileCheck %s
+
+CHECK:      NeededLibraries [
+CHECK-NEXT:   KERNEL32.dll
+CHECK-NEXT: ]
diff --git a/tools/llvm-readobj/COFFDumper.cpp b/tools/llvm-readobj/COFFDumper.cpp
index 8ac9f1a51cc..cf0228b1f10 100644
--- a/tools/llvm-readobj/COFFDumper.cpp
+++ b/tools/llvm-readobj/COFFDumper.cpp
@@ -81,6 +81,9 @@ public:
   void printSymbols() override;
   void printDynamicSymbols() override;
   void printUnwindInfo() override;
+
+  void printNeededLibraries() override;
+
   void printCOFFImports() override;
   void printCOFFExports() override;
   void printCOFFDirectives() override;
@@ -1522,6 +1525,25 @@ void COFFDumper::printUnwindInfo() {
   }
 }
 
+void COFFDumper::printNeededLibraries() {
+  ListScope D(W, "NeededLibraries");
+
+  using LibsTy = std::vector<StringRef>;
+  LibsTy Libs;
+
+  for (const ImportDirectoryEntryRef &DirRef : Obj->import_directories()) {
+    StringRef Name;
+    if (!DirRef.getName(Name))
+      Libs.push_back(Name);
+  }
+
+  std::stable_sort(Libs.begin(), Libs.end());
+
+  for (const auto &L : Libs) {
+    outs() << "  " << L << "\n";
+  }
+}
+
 void COFFDumper::printImportedSymbols(
     iterator_range<imported_symbol_iterator> Range) {
   for (const ImportedSymbolRef &I : Range) {