From 893c646938e906a20d8418f60f15a73257921c05 Mon Sep 17 00:00:00 2001
From: Nico Weber <nicolasweber@gmx.de>
Date: Wed, 5 Sep 2018 18:01:04 +0000
Subject: [PATCH] Handle zero-length debug directory entries.

Part of https://reviews.llvm.org/D51652 (tests will be in the lld repo)

llvm-svn: 341485
---
 llvm/lib/Object/COFFObjectFile.cpp     | 10 ++++++----
 llvm/tools/llvm-readobj/COFFDumper.cpp |  2 +-
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/llvm/lib/Object/COFFObjectFile.cpp b/llvm/lib/Object/COFFObjectFile.cpp
index dfb95ed..f094013 100644
--- a/llvm/lib/Object/COFFObjectFile.cpp
+++ b/llvm/lib/Object/COFFObjectFile.cpp
@@ -616,6 +616,8 @@ std::error_code COFFObjectFile::initBaseRelocPtr() {
       IntPtr);
   BaseRelocEnd = reinterpret_cast<coff_base_reloc_block_header *>(
       IntPtr + DataEntry->Size);
+  // FIXME: Verify the section containing BaseRelocHeader has at least
+  // DataEntry->Size bytes after DataEntry->RelativeVirtualAddress.
   return std::error_code();
 }
 
@@ -637,10 +639,10 @@ std::error_code COFFObjectFile::initDebugDirectoryPtr() {
   if (std::error_code EC = getRvaPtr(DataEntry->RelativeVirtualAddress, IntPtr))
     return EC;
   DebugDirectoryBegin = reinterpret_cast<const debug_directory *>(IntPtr);
-  if (std::error_code EC = getRvaPtr(
-          DataEntry->RelativeVirtualAddress + DataEntry->Size, IntPtr))
-    return EC;
-  DebugDirectoryEnd = reinterpret_cast<const debug_directory *>(IntPtr);
+  DebugDirectoryEnd = reinterpret_cast<const debug_directory *>(
+      IntPtr + DataEntry->Size);
+  // FIXME: Verify the section containing DebugDirectoryBegin has at least
+  // DataEntry->Size bytes after DataEntry->RelativeVirtualAddress.
   return std::error_code();
 }
 
diff --git a/llvm/tools/llvm-readobj/COFFDumper.cpp b/llvm/tools/llvm-readobj/COFFDumper.cpp
index c0579d6..4b6125e 100644
--- a/llvm/tools/llvm-readobj/COFFDumper.cpp
+++ b/llvm/tools/llvm-readobj/COFFDumper.cpp
@@ -751,7 +751,7 @@ void COFFDumper::printCOFFDebugDirectory() {
         W.printNumber("PDBAge", DebugInfo->PDB70.Age);
         W.printString("PDBFileName", PDBFileName);
       }
-    } else {
+    } else if (D.SizeOfData != 0) {
       // FIXME: Type values of 12 and 13 are commonly observed but are not in
       // the documented type enum.  Figure out what they mean.
       ArrayRef<uint8_t> RawData;
-- 
2.7.4