Don't read one command past the end.

Thanks to Evgeniy Stepanov for reporting this.

It might be a good idea to add a command iterator abstraction to MachO.h, but
this fixes the bug for now.

llvm-svn: 179848

4 files changed, 16 insertions, 4 deletions

diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
index f5910dd95d7..d26eb2ce611 100644
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -405,7 +405,7 @@ MachOObjectFile::MachOObjectFile(MemoryBuffer *Object,
     macho::LCT_Segment64 : macho::LCT_Segment;
 
   MachOObjectFile::LoadCommandInfo Load = getFirstLoadCommandInfo();
-  for (unsigned I = 0; I < LoadCommandCount; ++I) {
+  for (unsigned I = 0; ; ++I) {
     if (Load.C.Type == macho::LCT_Symtab) {
       assert(!SymtabLoadCmd && "Multiple symbol tables");
       SymtabLoadCmd = Load.Ptr;
@@ -418,7 +418,11 @@ MachOObjectFile::MachOObjectFile(MemoryBuffer *Object,
         Sections.push_back(reinterpret_cast<const char*>(Sec));
       }
     }
-    Load = getNextLoadCommandInfo(Load);
+
+    if (I == LoadCommandCount - 1)
+      break;
+    else
+      Load = getNextLoadCommandInfo(Load);
   }
 }
 
diff --git a/llvm/test/Object/ARM/objdump-thumb.test b/llvm/test/Object/ARM/objdump-thumb.test
new file mode 100644
index 00000000000..9c92a27782d
--- /dev/null
+++ b/llvm/test/Object/ARM/objdump-thumb.test
@@ -0,0 +1,4 @@
+RUN: llvm-objdump -d -macho -triple=thumbv7-apple-ios \
+RUN: %p/../Inputs/macho-text.thumb | FileCheck %s
+
+CHECK: 0:	00 bf                                        	nop
diff --git a/llvm/test/Object/Inputs/macho-text.thumb b/llvm/test/Object/Inputs/macho-text.thumb
new file mode 100644
index 00000000000..b29428a7878
--- /dev/null
+++ b/llvm/test/Object/Inputs/macho-text.thumb
diff --git a/llvm/tools/llvm-objdump/MachODump.cpp b/llvm/tools/llvm-objdump/MachODump.cpp
index e4d9ce24985..d78d7f31a6c 100644
--- a/llvm/tools/llvm-objdump/MachODump.cpp
+++ b/llvm/tools/llvm-objdump/MachODump.cpp
@@ -205,7 +205,7 @@ getSectionsAndSymbols(const macho::Header Header,
 
   MachOObjectFile::LoadCommandInfo Command =
     MachOObj->getFirstLoadCommandInfo();
-  for (unsigned i = 0; i != Header.NumLoadCommands; ++i) {
+  for (unsigned i = 0; ; ++i) {
     if (Command.C.Type == macho::LCT_FunctionStarts) {
       // We found a function starts segment, parse the addresses for later
       // consumption.
@@ -214,7 +214,11 @@ getSectionsAndSymbols(const macho::Header Header,
 
       MachOObj->ReadULEB128s(LLC.DataOffset, FoundFns);
     }
-    Command = MachOObj->getNextLoadCommandInfo(Command);
+
+    if (i == Header.NumLoadCommands - 1)
+      break;
+    else
+      Command = MachOObj->getNextLoadCommandInfo(Command);
   }
 }