The ARM EH experiment worked!

Place the LSDA into the TEXT section for ARM platforms. This involves making the
encoding indirect, pcrel, and sdata4 instead of an absolute pointer. The
references to the type infos are then non-lazy pointers. Revision 98019 changed
the encoding of non-lazy pointers to add the symbol to the non-lazy pointer
definition if it's a local symbol (otherwise, it's external and set to '0' so
that the loader can adjust it to the real value). This paved the way for this
change to work on ARM.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98068 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 54 insertions, 0 deletions

diff --git a/lib/Target/ARM/ARMTargetObjectFile.cpp b/lib/Target/ARM/ARMTargetObjectFile.cpp
new file mode 100644
index 0000000..7463e30
--- /dev/null
+++ b/lib/Target/ARM/ARMTargetObjectFile.cpp
@@ -0,0 +1,54 @@
+//===-- llvm/Target/ARMTargetObjectFile.cpp - ARM Object Info Impl --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ARMTargetObjectFile.h"
+#include "ARMSubtarget.h"
+#include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCSectionMachO.h"
+#include "llvm/Support/Dwarf.h"
+#include "llvm/Target/TargetMachine.h"
+using namespace llvm;
+using namespace dwarf;
+
+//===----------------------------------------------------------------------===//
+//                               ELF Target
+//===----------------------------------------------------------------------===//
+
+void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
+                                        const TargetMachine &TM) {
+  TargetLoweringObjectFileELF::Initialize(Ctx, TM);
+
+  if (TM.getSubtarget<ARMSubtarget>().isAAPCS_ABI()) {
+    StaticCtorSection =
+      getELFSection(".init_array", MCSectionELF::SHT_INIT_ARRAY,
+                    MCSectionELF::SHF_WRITE | MCSectionELF::SHF_ALLOC,
+                    SectionKind::getDataRel());
+    StaticDtorSection =
+      getELFSection(".fini_array", MCSectionELF::SHT_FINI_ARRAY,
+                    MCSectionELF::SHF_WRITE | MCSectionELF::SHF_ALLOC,
+                    SectionKind::getDataRel());
+  }
+}
+
+//===----------------------------------------------------------------------===//
+//                              Mach-O Target
+//===----------------------------------------------------------------------===//
+
+void ARMMachOTargetObjectFile::Initialize(MCContext &Ctx,
+                                          const TargetMachine &TM) {
+  TargetLoweringObjectFileMachO::Initialize(Ctx, TM);
+
+  // Exception Handling.
+  LSDASection = getMachOSection("__TEXT", "__gcc_except_tab", 0,
+                                SectionKind::getReadOnlyWithRel());
+}
+
+unsigned ARMMachOTargetObjectFile::getTTypeEncoding() const {
+  return DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4;
+}