[MC/Mach-O] Implement integrated assembler support for linker options.

 - Also, fixup syntax errors in LangRef and missing newline in the MCAsmStreamer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172837 91177308-0d34-0410-b5e6-96231b3b80d8

docs/LangRef.rst

@@ -2628,10 +2628,10 @@ For example, the following metadata section specifies two separate sets of
 linker options, presumably to link against ``libz`` and the ``Cocoa``
 framework::
 
-    !0 = metadata !{ i32 6, "Linker Options", 
+    !0 = metadata !{ i32 6, metadata !"Linker Options", 
        metadata !{
-          !metadata { metadata !"-lz" },
-          !metadata { metadata !"-framework", metadata !"Cocoa" } } }
+          metadata !{ metadata !"-lz" },
+          metadata !{ metadata !"-framework", metadata !"Cocoa" } } }
     !llvm.module.flags = !{ !0 }
 
 The metadata encoding as lists of lists of options, as opposed to a collapsed

lib/CodeGen/TargetLoweringObjectFileImpl.cpp

@@ -406,14 +406,14 @@ TargetLoweringObjectFileELF::InitializeELF(bool UseInitArray_) {
 //                                 MachO
 //===----------------------------------------------------------------------===//
 
-/// emitModuleFlags - Emit the module flags that specify the garbage collection
-/// information.
+/// emitModuleFlags - Perform code emission for module flags.
 void TargetLoweringObjectFileMachO::
 emitModuleFlags(MCStreamer &Streamer,
                 ArrayRef<Module::ModuleFlagEntry> ModuleFlags,
                 Mangler *Mang, const TargetMachine &TM) const {
   unsigned VersionVal = 0;
   unsigned ImageInfoFlags = 0;
+  MDNode *LinkerOptions = 0;
   StringRef SectionVal;
 
   for (ArrayRef<Module::ModuleFlagEntry>::iterator
@@ -427,14 +427,33 @@ emitModuleFlags(MCStreamer &Streamer,
     StringRef Key = MFE.Key->getString();
     Value *Val = MFE.Val;
 
-    if (Key == "Objective-C Image Info Version")
+    if (Key == "Objective-C Image Info Version") {
       VersionVal = cast<ConstantInt>(Val)->getZExtValue();
-    else if (Key == "Objective-C Garbage Collection" ||
-             Key == "Objective-C GC Only" ||
-             Key == "Objective-C Is Simulated")
+    } else if (Key == "Objective-C Garbage Collection" ||
+               Key == "Objective-C GC Only" ||
+               Key == "Objective-C Is Simulated") {
       ImageInfoFlags |= cast<ConstantInt>(Val)->getZExtValue();
-    else if (Key == "Objective-C Image Info Section")
+    } else if (Key == "Objective-C Image Info Section") {
       SectionVal = cast<MDString>(Val)->getString();
+    } else if (Key == "Linker Options") {
+      LinkerOptions = cast<MDNode>(Val);
+    }
+  }
+
+  // Emit the linker options if present.
+  if (LinkerOptions) {
+    for (unsigned i = 0, e = LinkerOptions->getNumOperands(); i != e; ++i) {
+      MDNode *MDOptions = cast<MDNode>(LinkerOptions->getOperand(i));
+      SmallVector<std::string, 4> StrOptions;
+
+      // Convert to strings.
+      for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) {
+        MDString *MDOption = cast<MDString>(MDOptions->getOperand(ii));
+        StrOptions.push_back(MDOption->getString());
+      }
+
+      Streamer.EmitLinkerOptions(StrOptions);
+    }
   }
 
   // The section is mandatory. If we don't have it, then we don't have GC info.

lib/MC/MCAsmStreamer.cpp

@@ -383,6 +383,7 @@ void MCAsmStreamer::EmitLinkerOptions(ArrayRef<std::string> Options) {
          ie = Options.end(); it != ie; ++it) {
     OS << ", " << '"' << *it << '"';
   }
+  OS << "\n";
 }
 
 void MCAsmStreamer::EmitDataRegion(MCDataRegionType Kind) {

test/MC/MachO/linker-options.ll

@@ -0,0 +1,35 @@
+; RUN: llc -O0 -mtriple=x86_64-apple-darwin -o - %s > %t
+; RUN: FileCheck --check-prefix=CHECK-ASM < %t %s
+
+; CHECK-ASM: .linker_option "-lz"
+; CHECK-ASM-NEXT: .linker_option "-framework", "Cocoa"
+
+; RUN: llc -O0 -mtriple=x86_64-apple-darwin -filetype=obj -o - %s | macho-dump > %t
+; RUN: FileCheck --check-prefix=CHECK-OBJ < %t %s
+
+; CHECK-OBJ: ('load_commands', [
+; CHECK-OBJ:   # Load Command 1
+; CHECK-OBJ:  (('command', 45)
+; CHECK-OBJ:   ('size', 16)
+; CHECK-OBJ:   ('count', 1)
+; CHECK-OBJ:   ('_strings', [
+; CHECK-OBJ: 	"-lz",
+; CHECK-OBJ:   ])
+; CHECK-OBJ:  ),
+; CHECK-OBJ:   # Load Command 2
+; CHECK-OBJ:  (('command', 45)
+; CHECK-OBJ:   ('size', 32)
+; CHECK-OBJ:   ('count', 2)
+; CHECK-OBJ:   ('_strings', [
+; CHECK-OBJ: 	"-framework",
+; CHECK-OBJ: 	"Cocoa",
+; CHECK-OBJ:   ])
+; CHECK-OBJ:  ),
+; CHECK-OBJ: ])
+
+!0 = metadata !{ i32 6, metadata !"Linker Options", 
+   metadata !{
+      metadata !{ metadata !"-lz" },
+      metadata !{ metadata !"-framework", metadata !"Cocoa" } } }
+
+!llvm.module.flags = !{ !0 }