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-rw-r--r--lib/Target/PowerPC/PPCTargetObjectFile.cpp57
1 files changed, 57 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/PPCTargetObjectFile.cpp b/lib/Target/PowerPC/PPCTargetObjectFile.cpp
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index 0000000000..90e4f15452
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+++ b/lib/Target/PowerPC/PPCTargetObjectFile.cpp
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+//===-- PPCTargetObjectFile.cpp - PPC Object Info -------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "PPCTargetObjectFile.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCSectionELF.h"
+#include "llvm/Target/Mangler.h"
+
+using namespace llvm;
+
+void
+PPC64LinuxTargetObjectFile::
+Initialize(MCContext &Ctx, const TargetMachine &TM) {
+ TargetLoweringObjectFileELF::Initialize(Ctx, TM);
+ InitializeELF(TM.Options.UseInitArray);
+}
+
+const MCSection * PPC64LinuxTargetObjectFile::
+SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
+ Mangler *Mang, const TargetMachine &TM) const {
+
+ const MCSection *DefaultSection =
+ TargetLoweringObjectFileELF::SelectSectionForGlobal(GV, Kind, Mang, TM);
+
+ if (DefaultSection != ReadOnlySection)
+ return DefaultSection;
+
+ // Here override ReadOnlySection to DataRelROSection for PPC64 SVR4 ABI
+ // when we have a constant that contains global relocations. This is
+ // necessary because of this ABI's handling of pointers to functions in
+ // a shared library. The address of a function is actually the address
+ // of a function descriptor, which resides in the .opd section. Generated
+ // code uses the descriptor directly rather than going via the GOT as some
+ // other ABIs do, which means that initialized function pointers must
+ // reference the descriptor. The linker must convert copy relocs of
+ // pointers to functions in shared libraries into dynamic relocations,
+ // because of an ordering problem with initialization of copy relocs and
+ // PLT entries. The dynamic relocation will be initialized by the dynamic
+ // linker, so we must use DataRelROSection instead of ReadOnlySection.
+ // For more information, see the description of ELIMINATE_COPY_RELOCS in
+ // GNU ld.
+ const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
+
+ if (GVar && GVar->isConstant() &&
+ (GVar->getInitializer()->getRelocationInfo() ==
+ Constant::GlobalRelocations))
+ return DataRelROSection;
+
+ return DefaultSection;
+}