ARM: suuport .tlsdescseq directive

This enhances the ARMAsmParser to handle .tlsdescseq directives.  This is a
slightly special relocation.  We must be able to generate them, but not consume
them in assembly.  The relocation is meant to assist the linker in generating a
TLS descriptor sequence.  The ELF target streamer is enhanced to append
additional fixups into the current segment and that is used to emit the new
R_ARM_TLS_DESCSEQ relocations.

llvm-svn: 200448

1 files changed, 19 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
index efee318a047..c2e3503278b 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
@@ -139,6 +139,8 @@ class ARMTargetAsmStreamer : public ARMTargetStreamer {
   virtual void emitInst(uint32_t Inst, char Suffix = '\0');
   virtual void finishAttributeSection();
 
+  virtual void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE);
+
 public:
   ARMTargetAsmStreamer(MCStreamer &S, formatted_raw_ostream &OS,
                        MCInstPrinter &InstPrinter, bool VerboseAsm);
@@ -241,6 +243,10 @@ void ARMTargetAsmStreamer::emitFPU(unsigned FPU) {
 }
 void ARMTargetAsmStreamer::finishAttributeSection() {
 }
+void
+ARMTargetAsmStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
+  OS << "\t.tlsdescseq\t" << S->getSymbol().getName();
+}
 
 void ARMTargetAsmStreamer::emitInst(uint32_t Inst, char Suffix) {
   OS << "\t.inst";
@@ -397,6 +403,8 @@ private:
   virtual void emitInst(uint32_t Inst, char Suffix = '\0');
   virtual void finishAttributeSection();
 
+  virtual void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE);
+
   size_t calculateContentSize() const;
 
 public:
@@ -605,6 +613,8 @@ private:
   void SwitchToExTabSection(const MCSymbol &FnStart);
   void SwitchToExIdxSection(const MCSymbol &FnStart);
 
+  void EmitFixup(const MCExpr *Expr, MCFixupKind Kind);
+
   bool IsThumb;
   int64_t MappingSymbolCounter;
 
@@ -953,6 +963,10 @@ void ARMTargetELFStreamer::finishAttributeSection() {
   Contents.clear();
   FPU = ARM::INVALID_FPU;
 }
+void
+ARMTargetELFStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
+  getStreamer().EmitFixup(S, FK_Data_4);
+}
 void ARMTargetELFStreamer::emitInst(uint32_t Inst, char Suffix) {
   getStreamer().emitInst(Inst, Suffix);
 }
@@ -1011,6 +1025,11 @@ inline void ARMELFStreamer::SwitchToExIdxSection(const MCSymbol &FnStart) {
                     SectionKind::getDataRel(),
                     FnStart);
 }
+void ARMELFStreamer::EmitFixup(const MCExpr *Expr, MCFixupKind Kind) {
+  MCDataFragment *Frag = getOrCreateDataFragment();
+  Frag->getFixups().push_back(MCFixup::Create(Frag->getContents().size(), Expr,
+                                              Kind));
+}
 
 void ARMELFStreamer::Reset() {
   ExTab = NULL;