From ed0b17172ebb1d8ef290709f622ec0da3078a34b Mon Sep 17 00:00:00 2001
From: Chris Bieneman <beanz@apple.com>
Date: Thu, 12 May 2016 17:44:48 +0000
Subject: [PATCH] [yaml2obj] Support for dumping mach_header from yaml

With this change obj2yaml and yaml2obj can now round-trip mach_headers.

This change also adds ObjectYAML/MachO tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269314 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/ObjectYAML/MachO/mach_header.yaml    | 23 ++++++++++
 test/ObjectYAML/MachO/mach_header_64.yaml | 23 ++++++++++
 test/ObjectYAML/lit.local.cfg             |  1 +
 tools/yaml2obj/yaml2macho.cpp             | 70 +++++++++++++++++++++++++++++--
 4 files changed, 114 insertions(+), 3 deletions(-)
 create mode 100644 test/ObjectYAML/MachO/mach_header.yaml
 create mode 100644 test/ObjectYAML/MachO/mach_header_64.yaml
 create mode 100644 test/ObjectYAML/lit.local.cfg

diff --git a/test/ObjectYAML/MachO/mach_header.yaml b/test/ObjectYAML/MachO/mach_header.yaml
new file mode 100644
index 00000000000..722a00be6f8
--- /dev/null
+++ b/test/ObjectYAML/MachO/mach_header.yaml
@@ -0,0 +1,23 @@
+# RUN: yaml2obj -format=macho %s | obj2yaml | FileCheck %s
+
+--- !mach-o
+FileHeader:      
+  magic:           0xFEEDFACE
+  cputype:         0x00000007
+  cpusubtype:      0x80000003
+  filetype:        0x00000002
+  ncmds:           0
+  sizeofcmds:      0
+  flags:           0x00218085
+...
+
+# CHECK: --- !mach-o
+# CHECK: FileHeader:      
+# CHECK:   magic:           0xFEEDFACE
+# CHECK:   cputype:         0x00000007
+# CHECK:   cpusubtype:      0x80000003
+# CHECK:   filetype:        0x00000002
+# CHECK:   ncmds:           0
+# CHECK:   sizeofcmds:      0
+# CHECK:   flags:           0x00218085
+# CHECK: ...
diff --git a/test/ObjectYAML/MachO/mach_header_64.yaml b/test/ObjectYAML/MachO/mach_header_64.yaml
new file mode 100644
index 00000000000..a9ea82e1a84
--- /dev/null
+++ b/test/ObjectYAML/MachO/mach_header_64.yaml
@@ -0,0 +1,23 @@
+# RUN: yaml2obj -format=macho %s | obj2yaml | FileCheck %s
+
+--- !mach-o
+FileHeader:      
+  magic:           0xFEEDFACF
+  cputype:         0x01000007
+  cpusubtype:      0x80000003
+  filetype:        0x00000002
+  ncmds:           0
+  sizeofcmds:      0
+  flags:           0x00218085
+...
+
+# CHECK: --- !mach-o
+# CHECK: FileHeader:      
+# CHECK:   magic:           0xFEEDFACF
+# CHECK:   cputype:         0x01000007
+# CHECK:   cpusubtype:      0x80000003
+# CHECK:   filetype:        0x00000002
+# CHECK:   ncmds:           0
+# CHECK:   sizeofcmds:      0
+# CHECK:   flags:           0x00218085
+# CHECK: ...
diff --git a/test/ObjectYAML/lit.local.cfg b/test/ObjectYAML/lit.local.cfg
new file mode 100644
index 00000000000..8169b9f95e1
--- /dev/null
+++ b/test/ObjectYAML/lit.local.cfg
@@ -0,0 +1 @@
+config.suffixes = ['.yaml']
diff --git a/tools/yaml2obj/yaml2macho.cpp b/tools/yaml2obj/yaml2macho.cpp
index 09a94ce2a40..ae391cc087b 100644
--- a/tools/yaml2obj/yaml2macho.cpp
+++ b/tools/yaml2obj/yaml2macho.cpp
@@ -13,11 +13,75 @@
 //===----------------------------------------------------------------------===//
 
 #include "yaml2obj.h"
+#include "llvm/ObjectYAML/MachOYAML.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/MachO.h"
+#include "llvm/Support/YAMLTraits.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 
-int yaml2macho(llvm::yaml::Input &YIn, llvm::raw_ostream &Out) {
-  errs() << "yaml2obj: Mach-O not implemented yet!\n";
-  return 1;
+namespace {
+
+class MachOWriter {
+public:
+  MachOWriter(MachOYAML::Object &Obj) : Obj(Obj) {
+    is64Bit = Obj.Header.magic == MachO::MH_MAGIC_64 ||
+              Obj.Header.magic == MachO::MH_CIGAM_64;
+    bzero(&Header64, sizeof(MachO::mach_header_64));
+  }
+
+  Error writeMachO(raw_ostream &OS);
+
+private:
+  Error writeHeader(raw_ostream &OS);
+
+  MachOYAML::Object Obj;
+  bool is64Bit;
+
+  union {
+    MachO::mach_header_64 Header64;
+    MachO::mach_header Header;
+  };
+};
+
+Error MachOWriter::writeMachO(raw_ostream &OS) {
+  if (auto Err = writeHeader(OS))
+    return Err;
+  return Error::success();
+}
+
+Error MachOWriter::writeHeader(raw_ostream &OS) {
+  Header.magic = Obj.Header.magic;
+  Header.cputype = Obj.Header.cputype;
+  Header.cpusubtype = Obj.Header.cpusubtype;
+  Header.filetype = Obj.Header.filetype;
+  Header.ncmds = Obj.Header.ncmds;
+  Header.sizeofcmds = Obj.Header.sizeofcmds;
+  Header.flags = Obj.Header.flags;
+
+  if (is64Bit)
+    OS.write((const char *)&Header64, sizeof(MachO::mach_header_64));
+  else
+    OS.write((const char *)&Header, sizeof(MachO::mach_header));
+
+  return Error::success();
+}
+
+} // end anonymous namespace
+
+int yaml2macho(yaml::Input &YIn, raw_ostream &Out) {
+  MachOYAML::Object Doc;
+  YIn >> Doc;
+  if (YIn.error()) {
+    errs() << "yaml2obj: Failed to parse YAML file!\n";
+    return 1;
+  }
+
+  MachOWriter Writer(Doc);
+  if (auto Err = Writer.writeMachO(Out)) {
+    errs() << toString(std::move(Err));
+    return 1;
+  }
+  return 0;
 }
-- 
2.11.0