Darwin: Add assembler directives to create version-min load commands.

Allow object files to be tagged with a version-min load command for iOS
or MacOSX.

Teach macho-dump to understand the version-min load commands for
testcases.

rdar://11337778

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204190 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 33 insertions, 0 deletions

diff --git a/include/llvm/MC/MCAssembler.h b/include/llvm/MC/MCAssembler.h
index c4b475ee03..4b519dd7c9 100644
--- a/include/llvm/MC/MCAssembler.h
+++ b/include/llvm/MC/MCAssembler.h
@@ -15,6 +15,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/ilist.h"
 #include "llvm/ADT/ilist_node.h"
+#include "llvm/MC/MCDirectives.h"
 #include "llvm/MC/MCFixup.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCSubtargetInfo.h"
@@ -840,6 +841,15 @@ public:
     const_data_region_iterator;
   typedef std::vector<DataRegionData>::iterator data_region_iterator;
 
+  /// MachO specific deployment target version info.
+  // A Major version of 0 indicates that no version information was supplied
+  // and so the corresponding load command should not be emitted.
+  typedef struct {
+    MCVersionMinType Kind;
+    unsigned Major;
+    unsigned Minor;
+    unsigned Update;
+  } VersionMinInfoType;
 private:
   MCAssembler(const MCAssembler&) LLVM_DELETED_FUNCTION;
   void operator=(const MCAssembler&) LLVM_DELETED_FUNCTION;
@@ -902,6 +912,8 @@ private:
   // Access to the flags is necessary in cases where assembler directives affect
   // which flags to be set.
   unsigned ELFHeaderEFlags;
+
+  VersionMinInfoType VersionMinInfo;
 private:
   /// Evaluate a fixup to a relocatable expression and the value which should be
   /// placed into the fixup.
@@ -983,6 +995,16 @@ public:
   unsigned getELFHeaderEFlags() const {return ELFHeaderEFlags;}
   void setELFHeaderEFlags(unsigned Flags) { ELFHeaderEFlags = Flags;}
 
+  /// MachO deployment target version information.
+  const VersionMinInfoType &getVersionMinInfo() const { return VersionMinInfo; }
+  void setVersionMinInfo(MCVersionMinType Kind, unsigned Major, unsigned Minor,
+                         unsigned Update) {
+    VersionMinInfo.Kind = Kind;
+    VersionMinInfo.Major = Major;
+    VersionMinInfo.Minor = Minor;
+    VersionMinInfo.Update = Update;
+  }
+
 public:
   /// Construct a new assembler instance.
   ///
diff --git a/include/llvm/MC/MCDirectives.h b/include/llvm/MC/MCDirectives.h
index 0461766c2f..f9d66e0b15 100644
--- a/include/llvm/MC/MCDirectives.h
+++ b/include/llvm/MC/MCDirectives.h
@@ -60,6 +60,11 @@ enum MCDataRegionType {
   MCDR_DataRegionEnd          ///< .end_data_region
 };
 
+enum MCVersionMinType {
+  MCVM_IOSVersionMin,         ///< .ios_version_min
+  MCVM_OSXVersionMin          ///< .macosx_version_min
+};
+
 } // end namespace llvm
 
 #endif
diff --git a/include/llvm/MC/MCStreamer.h b/include/llvm/MC/MCStreamer.h
index fc7a3b8648..37d18fbe43 100644
--- a/include/llvm/MC/MCStreamer.h
+++ b/include/llvm/MC/MCStreamer.h
@@ -386,6 +386,10 @@ public:
   /// EmitDataRegion - Note in the output the specified region @p Kind.
   virtual void EmitDataRegion(MCDataRegionType Kind) {}
 
+  /// EmitVersionMin - Specify the MachO minimum deployment target version.
+  virtual void EmitVersionMin(MCVersionMinType, unsigned Major, unsigned Minor,
+                              unsigned Update) {}
+
   /// EmitThumbFunc - Note in the output that the specified @p Func is
   /// a Thumb mode function (ARM target only).
   virtual void EmitThumbFunc(MCSymbol *Func) = 0;
diff --git a/include/llvm/Object/MachO.h b/include/llvm/Object/MachO.h
index 50296aed9b..34edec3ebf 100644
--- a/include/llvm/Object/MachO.h
+++ b/include/llvm/Object/MachO.h
@@ -178,6 +178,8 @@ public:
   getSegment64LoadCommand(const LoadCommandInfo &L) const;
   MachO::linker_options_command
   getLinkerOptionsLoadCommand(const LoadCommandInfo &L) const;
+  MachO::version_min_command
+  getVersionMinLoadCommand(const LoadCommandInfo &L) const;
 
   MachO::any_relocation_info getRelocation(DataRefImpl Rel) const;
   MachO::data_in_code_entry getDice(DataRefImpl Rel) const;