Don't loop endlessly for MachO files with 0 ncmds
llvm-svn: 225271
diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
index 1373dba..e476976 100644
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -236,6 +236,9 @@
DataInCodeLoadCmd(nullptr), DyldInfoLoadCmd(nullptr),
UuidLoadCmd(nullptr), HasPageZeroSegment(false) {
uint32_t LoadCommandCount = this->getHeader().ncmds;
+ if (LoadCommandCount == 0)
+ return;
+
MachO::LoadCommandType SegmentLoadType = is64Bit() ?
MachO::LC_SEGMENT_64 : MachO::LC_SEGMENT;
diff --git a/llvm/test/Object/Inputs/macho-zero-ncmds b/llvm/test/Object/Inputs/macho-zero-ncmds
new file mode 100644
index 0000000..0505419
--- /dev/null
+++ b/llvm/test/Object/Inputs/macho-zero-ncmds
Binary files differ
diff --git a/llvm/test/Object/objdump-macho-quirks.test b/llvm/test/Object/objdump-macho-quirks.test
new file mode 100644
index 0000000..eeee153
--- /dev/null
+++ b/llvm/test/Object/objdump-macho-quirks.test
@@ -0,0 +1,9 @@
+RUN: llvm-objdump -private-headers %p/Inputs/macho-zero-ncmds \
+RUN: | FileCheck %s -check-prefix A
+
+// Check that we don't get an infinite loop if ncmds = 0
+A: file format Mach-O 64-bit unknown
+A: Mach header
+A: magic cputype cpusubtype caps filetype ncmds sizeofcmds flags
+A: MH_MAGIC_64 0x00 OBJECT 0 0 0x00000000
+
diff --git a/llvm/tools/llvm-objdump/MachODump.cpp b/llvm/tools/llvm-objdump/MachODump.cpp
index 36db9ad..935696b 100644
--- a/llvm/tools/llvm-objdump/MachODump.cpp
+++ b/llvm/tools/llvm-objdump/MachODump.cpp
@@ -4204,6 +4204,8 @@
static void PrintLoadCommands(const MachOObjectFile *Obj, uint32_t ncmds,
uint32_t filetype, uint32_t cputype,
bool verbose) {
+ if (ncmds == 0)
+ return;
StringRef Buf = Obj->getData();
MachOObjectFile::LoadCommandInfo Command = Obj->getFirstLoadCommandInfo();
for (unsigned i = 0;; ++i) {