From 59c15e920c9873804f3150d0c13357696f09e300 Mon Sep 17 00:00:00 2001
From: Kevin Enderby <enderby@apple.com>
Date: Fri, 18 May 2012 00:13:56 +0000
Subject: [PATCH] Fixed a bug in llvm-objdump when disassembling using -macho
 option for a binary containing no symbols.  Fixed the crash and fixed it not
 disassembling anything.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157031 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../MachO/ARM/llvm-objdump-macho-stripped.s   |  5 +++
 tools/llvm-objdump/MachODump.cpp              | 31 +++++++++++++++++--
 2 files changed, 34 insertions(+), 2 deletions(-)
 create mode 100644 test/MC/MachO/ARM/llvm-objdump-macho-stripped.s

diff --git a/test/MC/MachO/ARM/llvm-objdump-macho-stripped.s b/test/MC/MachO/ARM/llvm-objdump-macho-stripped.s
new file mode 100644
index 00000000000..7fcec529947
--- /dev/null
+++ b/test/MC/MachO/ARM/llvm-objdump-macho-stripped.s
@@ -0,0 +1,5 @@
+@ RUN: llvm-mc -triple=thumbv7-apple-ios -filetype=obj -o - < %s | llvm-objdump -d -macho -triple=thumbv7-apple-ios - | FileCheck %s
+	nop
+# CHECK:        0:	00 bf                                        	nop
+# We are checking that disassembly happens when there are no symbols.
+# rdar://11460289
diff --git a/tools/llvm-objdump/MachODump.cpp b/tools/llvm-objdump/MachODump.cpp
index 60c33f27892..5e175a004d4 100644
--- a/tools/llvm-objdump/MachODump.cpp
+++ b/tools/llvm-objdump/MachODump.cpp
@@ -286,8 +286,10 @@ void llvm::DisassembleInputMachO(StringRef Filename) {
 
   // Read and register the symbol table data.
   InMemoryStruct<macho::SymtabLoadCommand> SymtabLC;
-  MachOObj->ReadSymtabLoadCommand(*SymtabLCI, SymtabLC);
-  MachOObj->RegisterStringTable(*SymtabLC);
+  if (SymtabLCI) {
+    MachOObj->ReadSymtabLoadCommand(*SymtabLCI, SymtabLC);
+    MachOObj->RegisterStringTable(*SymtabLC);
+  }
 
   std::vector<SectionRef> Sections;
   std::vector<SymbolRef> Symbols;
@@ -498,6 +500,31 @@ void llvm::DisassembleInputMachO(StringRef Filename) {
             InstrAnalysis.get(), Start, DebugOut, FunctionMap, Functions);
       }
     }
+    if (!CFG && !symbolTableWorked) {
+      // Reading the symbol table didn't work, disassemble the whole section. 
+      uint64_t SectAddress;
+      Sections[SectIdx].getAddress(SectAddress);
+      uint64_t SectSize;
+      Sections[SectIdx].getSize(SectSize);
+      uint64_t InstSize;
+      for (uint64_t Index = 0; Index < SectSize; Index += InstSize) {
+	MCInst Inst;
+
+	if (DisAsm->getInstruction(Inst, InstSize, memoryObject, Index,
+				   DebugOut, nulls())) {
+	  outs() << format("%8" PRIx64 ":\t", SectAddress + Index);
+
+	  DumpBytes(StringRef(Bytes.data() + Index, InstSize));
+	  IP->printInst(&Inst, outs(), "");
+
+	  outs() << "\n";
+	} else {
+	  errs() << "llvm-objdump: warning: invalid instruction encoding\n";
+	  if (InstSize == 0)
+	    InstSize = 1; // skip illegible bytes
+	}
+      }
+    }
 
     if (CFG) {
       if (!symbolTableWorked) {
-- 
2.34.1