From 16ebb7ab5c462518388527b6ebee2f0e1080b777 Mon Sep 17 00:00:00 2001
From: Pirama Arumuga Nainar <pirama@google.com>
Date: Mon, 2 Aug 2021 22:17:53 -0700
Subject: [PATCH] [llvm-objcopy] [COFF] Do not patch debug entries if
 PointerToRawData is zero

Fix an edge case missed by https://reviews.llvm.org/D78921.  For e.g.,
the Repro debug entry (generated with the /Brepro linker flag) does not
have a debug-directory payload.  Do not attempt to patch Debug entries
without a payload.

Differential Revision: https://reviews.llvm.org/D107324
---
 .../llvm-objcopy/COFF/debug-dir-unmapped.test |  2 +-
 .../COFF/debug-entry-no-payload.test          | 56 +++++++++++++++++++
 llvm/tools/llvm-objcopy/COFF/Writer.cpp       | 16 +++---
 3 files changed, 64 insertions(+), 10 deletions(-)
 create mode 100644 llvm/test/tools/llvm-objcopy/COFF/debug-entry-no-payload.test

diff --git a/llvm/test/tools/llvm-objcopy/COFF/debug-dir-unmapped.test b/llvm/test/tools/llvm-objcopy/COFF/debug-dir-unmapped.test
index b7966c14d7d9..29a08956a6c8 100644
--- a/llvm/test/tools/llvm-objcopy/COFF/debug-dir-unmapped.test
+++ b/llvm/test/tools/llvm-objcopy/COFF/debug-dir-unmapped.test
@@ -6,7 +6,7 @@
 
 # RUN: not llvm-objcopy --remove-section .rdata %t.in.exe %t.out.exe 2>&1 | FileCheck %s
 
-# CHECK: error: '{{.*}}{{/|\\}}debug-dir-unmapped.test.tmp.out.exe': debug directory payload outside of mapped sections not supported
+# CHECK: error: '{{.*}}{{/|\\}}debug-dir-unmapped.test.tmp.out.exe': debug directory payload not found
 
 --- !COFF
 OptionalHeader:
diff --git a/llvm/test/tools/llvm-objcopy/COFF/debug-entry-no-payload.test b/llvm/test/tools/llvm-objcopy/COFF/debug-entry-no-payload.test
new file mode 100644
index 000000000000..f8bfa109e857
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/COFF/debug-entry-no-payload.test
@@ -0,0 +1,56 @@
+## Check that llvm-objcopy does not produce an error for debug directory
+## entries without a payload (e.g. IMAGE_DEBUG_TYPE_REPRO,
+## IMAGE_DEBUG_TYPE_UNKNOWN) when patching entries that may have moved during
+## a requested operation. Also check that the such debug entries are present
+## in the output.
+
+## The code to patch debug entries is executed even when no operation is
+## requested. Hence the RUN line below invokes llvm-objcopy without any
+## arguments.
+
+# RUN: yaml2obj %s -o %t.in.exe
+# RUN: llvm-objcopy %t.in.exe %t.out.exe
+# RUN: llvm-readobj --coff-debug-directory %t.out.exe | FileCheck %s
+
+# CHECK: Type: Repro (0x10)
+# CHECK: Type: Unknown (0x0)
+
+--- !COFF
+OptionalHeader:
+  AddressOfEntryPoint: 4096
+  ImageBase:       1073741824
+  SectionAlignment: 4096
+  FileAlignment:   512
+  MajorOperatingSystemVersion: 6
+  MinorOperatingSystemVersion: 0
+  MajorImageVersion: 0
+  MinorImageVersion: 0
+  MajorSubsystemVersion: 6
+  MinorSubsystemVersion: 0
+  Subsystem:       IMAGE_SUBSYSTEM_WINDOWS_CUI
+  DLLCharacteristics: [  ]
+  SizeOfStackReserve: 1048576
+  SizeOfStackCommit: 4096
+  SizeOfHeapReserve: 1048576
+  SizeOfHeapCommit: 4096
+  Debug:
+    RelativeVirtualAddress: 8192
+    Size:            56
+header:
+  Machine:         IMAGE_FILE_MACHINE_AMD64
+  Characteristics: [  ]
+sections:
+  - Name:            .text
+    Characteristics: [  ]
+    VirtualAddress:  4096
+    VirtualSize:     3
+    SectionData:     31C0C3
+  - Name:            .rdata
+    Characteristics: [  ]
+    VirtualAddress:  8192
+    VirtualSize:     56
+    ## '10' in SectionData below indicates the Repro type for the first debug
+    ## entry.  The second entry has a type of Unknown ('00').
+    SectionData:     0000000047F96B2000000000100000000000000000000000000000000000000047F96B200000000000000000000000000000000000000000
+symbols:         []
+...
diff --git a/llvm/tools/llvm-objcopy/COFF/Writer.cpp b/llvm/tools/llvm-objcopy/COFF/Writer.cpp
index e7be64faab65..8cc2312d137c 100644
--- a/llvm/tools/llvm-objcopy/COFF/Writer.cpp
+++ b/llvm/tools/llvm-objcopy/COFF/Writer.cpp
@@ -426,15 +426,13 @@ Error COFFWriter::patchDebugDirectory() {
       uint8_t *End = Ptr + Dir->Size;
       while (Ptr < End) {
         debug_directory *Debug = reinterpret_cast<debug_directory *>(Ptr);
-        if (!Debug->AddressOfRawData)
-          return createStringError(object_error::parse_failed,
-                                   "debug directory payload outside of "
-                                   "mapped sections not supported");
-        if (Expected<uint32_t> FilePosOrErr =
-                virtualAddressToFileAddress(Debug->AddressOfRawData))
-          Debug->PointerToRawData = *FilePosOrErr;
-        else
-          return FilePosOrErr.takeError();
+        if (Debug->PointerToRawData) {
+          if (Expected<uint32_t> FilePosOrErr =
+                  virtualAddressToFileAddress(Debug->AddressOfRawData))
+            Debug->PointerToRawData = *FilePosOrErr;
+          else
+            return FilePosOrErr.takeError();
+        }
         Ptr += sizeof(debug_directory);
         Offset += sizeof(debug_directory);
       }
-- 
2.32.0.605.g8dce9f2422-goog