[SystemZ][z/OS] Initial code to generate assembly files on z/OS

- This patch consists of the bare basic code needed in order to generate some assembly for the z/OS target.
- Only the .text and the .bss sections are added for now.
- The relevant MCSectionGOFF/Symbol interfaces have been added. This enables us to print out the GOFF machine code sections.
- This patch enables us to add simple lit tests wherever possible, and contribute to the testing coverage for the z/OS target
- Further improvements and additions will be made in future patches.

Reviewed By: tmatheson

Differential Revision: https://reviews.llvm.org/D106380

1 files changed, 22 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 8d8838f..add34ec 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -48,6 +48,7 @@
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCSectionCOFF.h"
 #include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCSectionGOFF.h"
 #include "llvm/MC/MCSectionMachO.h"
 #include "llvm/MC/MCSectionWasm.h"
 #include "llvm/MC/MCSectionXCOFF.h"
@@ -2521,3 +2522,24 @@ MCSection *TargetLoweringObjectFileXCOFF::getSectionForTOCEntry(
           TM.getCodeModel() == CodeModel::Large ? XCOFF::XMC_TE : XCOFF::XMC_TC,
           XCOFF::XTY_SD));
 }
+
+//===----------------------------------------------------------------------===//
+//                                  GOFF
+//===----------------------------------------------------------------------===//
+TargetLoweringObjectFileGOFF::TargetLoweringObjectFileGOFF()
+    : TargetLoweringObjectFile() {}
+
+MCSection *TargetLoweringObjectFileGOFF::getExplicitSectionGlobal(
+    const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
+  return SelectSectionForGlobal(GO, Kind, TM);
+}
+
+MCSection *TargetLoweringObjectFileGOFF::SelectSectionForGlobal(
+    const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
+  auto *Symbol = TM.getSymbol(GO);
+  if (Kind.isBSS())
+    return getContext().getGOFFSection(Symbol->getName(),
+                                       SectionKind::getBSS());
+
+  return getContext().getObjectFileInfo()->getTextSection();
+}