Implements parsing and emitting of .cfi_window_save in MC.

llvm-svn: 191431

llvm/include/llvm/MC/MCDwarf.h

@@ -290,7 +290,8 @@ public:
     OpEscape,
     OpRestore,
     OpUndefined,
-    OpRegister
+    OpRegister,
+    OpWindowSave
   };
 
 private:
@@ -364,6 +365,11 @@ public:
     return MCCFIInstruction(OpRegister, L, Register1, Register2);
   }
 
+  /// \brief .cfi_window_save SPARC register window is saved.
+  static MCCFIInstruction createWindowSave(MCSymbol *L) {
+    return MCCFIInstruction(OpWindowSave, L, 0, 0, "");
+  }
+
   /// \brief .cfi_restore says that the rule for Register is now the same as it
   /// was at the beginning of the function, after all initial instructions added
   /// by .cfi_startproc were executed.

llvm/include/llvm/MC/MCStreamer.h

@@ -578,6 +578,7 @@ public:
   virtual void EmitCFISignalFrame();
   virtual void EmitCFIUndefined(int64_t Register);
   virtual void EmitCFIRegister(int64_t Register1, int64_t Register2);
+  virtual void EmitCFIWindowSave();
 
   virtual void EmitWin64EHStartProc(const MCSymbol *Symbol);
   virtual void EmitWin64EHEndProc();

llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp

@@ -185,5 +185,8 @@ void AsmPrinter::emitCFIInstruction(const MCCFIInstruction &Inst) const {
   case MCCFIInstruction::OpOffset:
     OutStreamer.EmitCFIOffset(Inst.getRegister(), Inst.getOffset());
     break;
+  case MCCFIInstruction::OpWindowSave:
+    OutStreamer.EmitCFIWindowSave();
+    break;
   }
 }

llvm/lib/MC/MCAsmStreamer.cpp

@@ -229,6 +229,7 @@ public:
   virtual void EmitCFISignalFrame();
   virtual void EmitCFIUndefined(int64_t Register);
   virtual void EmitCFIRegister(int64_t Register1, int64_t Register2);
+  virtual void EmitCFIWindowSave();
 
   virtual void EmitWin64EHStartProc(const MCSymbol *Symbol);
   virtual void EmitWin64EHEndProc();
@@ -1098,6 +1099,16 @@ void MCAsmStreamer::EmitCFIRegister(int64_t Register1, int64_t Register2) {
   EmitEOL();
 }
 
+void MCAsmStreamer::EmitCFIWindowSave() {
+  MCStreamer::EmitCFIWindowSave();
+
+  if (!UseCFI)
+    return;
+
+  OS << "\t.cfi_window_save";
+  EmitEOL();
+}
+
 void MCAsmStreamer::EmitWin64EHStartProc(const MCSymbol *Symbol) {
   MCStreamer::EmitWin64EHStartProc(Symbol);
 

llvm/lib/MC/MCDwarf.cpp

@@ -959,6 +959,10 @@ void FrameEmitterImpl::EmitCFIInstruction(MCStreamer &Streamer,
     Streamer.EmitULEB128IntValue(Reg2);
     return;
   }
+  case MCCFIInstruction::OpWindowSave: {
+    Streamer.EmitIntValue(dwarf::DW_CFA_GNU_window_save, 1);
+    return;
+  }
   case MCCFIInstruction::OpUndefined: {
     unsigned Reg = Instr.getRegister();
     if (VerboseAsm) {

llvm/lib/MC/MCParser/AsmParser.cpp

@@ -355,7 +355,7 @@ private:
     DK_CFI_OFFSET, DK_CFI_REL_OFFSET, DK_CFI_PERSONALITY, DK_CFI_LSDA,
     DK_CFI_REMEMBER_STATE, DK_CFI_RESTORE_STATE, DK_CFI_SAME_VALUE,
     DK_CFI_RESTORE, DK_CFI_ESCAPE, DK_CFI_SIGNAL_FRAME, DK_CFI_UNDEFINED,
-    DK_CFI_REGISTER,
+    DK_CFI_REGISTER, DK_CFI_WINDOW_SAVE,
     DK_MACROS_ON, DK_MACROS_OFF, DK_MACRO, DK_ENDM, DK_ENDMACRO, DK_PURGEM,
     DK_SLEB128, DK_ULEB128
   };
@@ -384,6 +384,7 @@ private:
 
   // .cfi directives
   bool parseDirectiveCFIRegister(SMLoc DirectiveLoc);
+  bool parseDirectiveCFIWindowSave();
   bool parseDirectiveCFISections();
   bool parseDirectiveCFIStartProc();
   bool parseDirectiveCFIEndProc();
@@ -1469,6 +1470,8 @@ bool AsmParser::parseStatement(ParseStatementInfo &Info) {
       return parseDirectiveCFIUndefined(IDLoc);
     case DK_CFI_REGISTER:
       return parseDirectiveCFIRegister(IDLoc);
+    case DK_CFI_WINDOW_SAVE:
+      return parseDirectiveCFIWindowSave();
     case DK_MACROS_ON:
     case DK_MACROS_OFF:
       return parseDirectiveMacrosOnOff(IDVal);
@@ -2827,6 +2830,13 @@ bool AsmParser::parseDirectiveCFIRegister(SMLoc DirectiveLoc) {
   return false;
 }
 
+/// parseDirectiveCFIWindowSave
+/// ::= .cfi_window_save
+bool AsmParser::parseDirectiveCFIWindowSave() {
+  getStreamer().EmitCFIWindowSave();
+  return false;
+}
+
 /// parseDirectiveCFIAdjustCfaOffset
 /// ::= .cfi_adjust_cfa_offset adjustment
 bool AsmParser::parseDirectiveCFIAdjustCfaOffset() {
@@ -3820,6 +3830,7 @@ void AsmParser::initializeDirectiveKindMap() {
   DirectiveKindMap[".cfi_signal_frame"] = DK_CFI_SIGNAL_FRAME;
   DirectiveKindMap[".cfi_undefined"] = DK_CFI_UNDEFINED;
   DirectiveKindMap[".cfi_register"] = DK_CFI_REGISTER;
+  DirectiveKindMap[".cfi_window_save"] = DK_CFI_WINDOW_SAVE;
   DirectiveKindMap[".macros_on"] = DK_MACROS_ON;
   DirectiveKindMap[".macros_off"] = DK_MACROS_OFF;
   DirectiveKindMap[".macro"] = DK_MACRO;

llvm/lib/MC/MCStreamer.cpp

@@ -399,6 +399,14 @@ void MCStreamer::EmitCFIRegister(int64_t Register1, int64_t Register2) {
   CurFrame->Instructions.push_back(Instruction);
 }
 
+void MCStreamer::EmitCFIWindowSave() {
+  MCSymbol *Label = EmitCFICommon();
+  MCCFIInstruction Instruction =
+    MCCFIInstruction::createWindowSave(Label);
+  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
+  CurFrame->Instructions.push_back(Instruction);
+}
+
 void MCStreamer::setCurrentW64UnwindInfo(MCWin64EHUnwindInfo *Frame) {
   W64UnwindInfos.push_back(Frame);
   CurrentW64UnwindInfo = W64UnwindInfos.back();

llvm/test/MC/AsmParser/cfi-window-save.s

@@ -0,0 +1,15 @@
+# RUN: llvm-mc -filetype=asm -triple x86_64-pc-linux-gnu <%s | FileCheck %s
+
+# Should use SPARC as the target to test this. However, SPARC does not support
+# asm parsing yet.
+
+# CHECK: .cfi_window_save
+
+
+f:
+        .cfi_startproc
+        nop
+        .cfi_window_save
+        nop
+        .cfi_endproc
+

llvm/test/MC/ELF/cfi-window-save.s

@@ -0,0 +1,51 @@
+// RUN: llvm-mc -filetype=obj -triple x86_64-pc-linux-gnu %s -o - | llvm-readobj -s -sr -sd | FileCheck %s
+
+# Should use SPARC as the target to test this. However, SPARC does not
+# use MC yet.
+
+f:
+        .cfi_startproc
+        nop
+        .cfi_window_save
+        nop
+        .cfi_endproc
+
+// CHECK:        Section {
+// CHECK:          Name: .eh_frame
+// CHECK-NEXT:     Type: SHT_PROGBITS
+// CHECK-NEXT:     Flags [
+// CHECK-NEXT:       SHF_ALLOC
+// CHECK-NEXT:     ]
+// CHECK-NEXT:     Address: 0x0
+// CHECK-NEXT:     Offset: 0x48
+// CHECK-NEXT:     Size: 48
+// CHECK-NEXT:     Link: 0
+// CHECK-NEXT:     Info: 0
+// CHECK-NEXT:     AddressAlignment: 8
+// CHECK-NEXT:     EntrySize: 0
+// CHECK-NEXT:     Relocations [
+// CHECK-NEXT:     ]
+// CHECK-NEXT:     SectionData (
+// CHECK-NEXT:       0000: 14000000 00000000 017A5200 01781001
+// CHECK-NEXT:       0010: 1B0C0708 90010000 14000000 1C000000
+// CHECK-NEXT:       0020: 00000000 02000000 00412D00 00000000
+// CHECK-NEXT:     )
+// CHECK-NEXT:   }
+
+// CHECK:        Section {
+// CHECK:          Name: .rela.eh_frame
+// CHECK-NEXT:     Type: SHT_RELA
+// CHECK-NEXT:     Flags [
+// CHECK-NEXT:     ]
+// CHECK-NEXT:     Address: 0x0
+// CHECK-NEXT:     Offset: 0x390
+// CHECK-NEXT:     Size: 24
+// CHECK-NEXT:     Link: 7
+// CHECK-NEXT:     Info: 4
+// CHECK-NEXT:     AddressAlignment: 8
+// CHECK-NEXT:     EntrySize: 24
+// CHECK-NEXT:     Relocations [
+// CHECK-NEXT:       0x20 R_X86_64_PC32 .text 0x0
+// CHECK-NEXT:     ]
+// CHECK:        }
+