[Sparc] Add Sparc V8 support

[dcederman]

Summary

Adds the register class implementation for Sparc.
Adds support for DW_CFA_GNU_window_save.
Adds save and restore context functionality.

On Sparc the return address is the address of the call instruction, so an offset needs to be added when returning to skip the call instruction and its delay slot. If the function returns a struct it is also necessary to skip one extra instruction.

[mclow.lists]

In general, this looks reasonable. No being a sparc expert, I don't know if it's correct, but it fits in with the existing libunwind structure.

src/DwarfParser.hpp

687

Should this be wrapped in #ifdef _LIBUNWIND_TARGET_SPARC ?

[dcederman]

src/DwarfParser.hpp

687

Yes, it probably should. I will fix that.

[dcederman]

Only include DW_CFA_GNU_window_save support when compiling for Sparc.

[mstorsjo]

src/UnwindLevel1.c

495 ↗

(On Diff #178460)

How widely is this builtin available, e.g. on older versions of clang or in gcc?

[dcederman]

src/UnwindLevel1.c

495 ↗

(On Diff #178460)

Looks like it has been available since 1997 for GCC and 2009 for Clang. But looking into it I think it would be better to follow the same approach as aarch64 and modify the return address in stepWithDwarf instead, without using the builtin. That would also allow for better handling of functions that returns structs.

[dcederman]

This update does not use __builtin_extract_return_addr in _Unwind_GetIP. Instead it modifies the return address in stepWithDwarf, similar to aarch64. It also checks if the instruction at the return address is an unimp instruction. If it is, that means that the function is returning a struct and that we should skip one extra instruction.

[dcederman]

I have been using this Sparc version of libunwind when running the libc++ testsuite and have not had any problems related to libunwind. Does anyone have any additional comments or is it ok to commit?

[compnerd]

src/DwarfParser.hpp

701

Could you put this before the execution of the op please?

src/Registers.hpp

3339

I guess as long as we don't care about async exceptions where the %o7 is being twiddled around for a call or being used as a temporary, this should be okay (IIRC, %o7 needs to be saved before call on SPARC).

3374

Spurious empty line.

3389

Spurious empty line

src/UnwindRegistersRestore.S

1023

Indentation is off

src/UnwindRegistersSave.S

974

Indentation is off

[mclow.lists]

If Saleem is happy with this, then I'm good too.

[dcederman]

Thanks for the review!

src/DwarfParser.hpp

701

Sure. But for the other ops the trace printout is placed after the op, so this would break that pattern?

src/UnwindRegistersRestore.S

1023

The extra space is a convention used when writing Sparc assembly to indicate that the instruction is in the delay slot of the previous instruction.

[dcederman]

Removed empty lines and moved the trace message to before the operation.

[mgorny]

This commit is causing regression when building with -DLIBUNWIND_ENABLE_CROSS_UNWINDING=ON:

FAILED: src/CMakeFiles/unwind_objects.dir/libunwind.cpp.o
/usr/bin/c++  -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I../include -fvisibility-inlines-hidden -Werror=date-time -std=c++11 -w -fdiagnostics-color -ffunction-sections -fdata-sections -std=c++11 -fPIC   -Werror=return-type -W -Wall -Wchar-subscripts -Wconversion -Wmissing-braces -Wno-unused-function -Wshadow -Wsign-compare -Wsign-conversion -Wstrict-aliasing=2 -Wstrict-overflow=4 -Wunused-parameter -Wunused-variable -Wwrite-strings -Wundef -Wno-error -pedantic -D_DEBUG -fno-exceptions -funwind-tables  -fstrict-aliasing -fno-rtti -MD -MT src/CMakeFiles/unwind_objects.dir/libunwind.cpp.o -MF src/CMakeFiles/unwind_objects.dir/libunwind.cpp.o.d -o src/CMakeFiles/unwind_objects.dir/libunwind.cpp.o -c ../src/libunwind.cpp
In file included from ../src/EHHeaderParser.hpp:18:0,
                 from ../src/AddressSpace.hpp:43,
                 from ../src/libunwind.cpp:28:
../src/DwarfParser.hpp: In instantiation of 'static bool libunwind::CFI_Parser<A>::parseInstructions(A&, libunwind::CFI_Parser<A>::pint_t, libunwind::CFI_Parser<A>::pint_t, const libunwind::CFI_Parser<A>::CIE_Info&, libunwind::CFI_Parser<A>::pint_t, libunwind::CFI_Parser<A>::PrologInfoStackEntry*&, libunwind::CFI_Parser<A>::PrologInfo*) [with A = libunwind::LocalAddressSpace; libunwind::CFI_Parser<A>::pint_t = long unsigned int]':
../src/DwarfParser.hpp:363:27:   required from 'static bool libunwind::CFI_Parser<A>::parseFDEInstructions(A&, const libunwind::CFI_Parser<A>::FDE_Info&, const libunwind::CFI_Parser<A>::CIE_Info&, libunwind::CFI_Parser<A>::pint_t, libunwind::CFI_Parser<A>::PrologInfo*) [with A = libunwind::LocalAddressSpace; libunwind::CFI_Parser<A>::pint_t = long unsigned int]'
../src/UnwindCursor.hpp:1874:46:   required from 'void libunwind::UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool) [with A = libunwind::LocalAddressSpace; R = libunwind::Registers_x86_64]'
../src/libunwind.cpp:407:1:   required from here
../src/DwarfParser.hpp:689:5: error: duplicate case value
     case DW_CFA_GNU_window_save:
     ^~~~
../src/DwarfParser.hpp:682:5: note: previously used here
     case DW_CFA_AARCH64_negate_ra_state:
     ^~~~
ninja: build stopped: subcommand failed.

[jyknight]

In D55763#1351165, @mgorny wrote:

This commit is causing regression when building with -DLIBUNWIND_ENABLE_CROSS_UNWINDING=ON:

I think the patch should be reverted until this can be fixed -- as DW_CFA_GNU_window_save and DW_CFA_AARCH64_negate_ra_state are the same constant, the two cases will need to be merged, and disambiguated by the target architecture.

[jgorbe]

I reverted this patch on r350787

[mgorny]

Thank you.

[dcederman]

For me native support is enough, so I removed the Sparc define from the !_LIBUNWIND_IS_NATIVE_ONLY section. That should make it compile with -DLIBUNWIND_ENABLE_CROSS_UNWINDING=ON.

I did not see an easy way to get information about the correct architecture in parseInstructions(). If someone has a suggestion on how to best provide this information (extend the Register class with a getArch() function?) I could try it out in a subsequent patch.

[jyknight]

In D55763#1352608, @dcederman wrote:

For me native support is enough, so I removed the Sparc define from the !_LIBUNWIND_IS_NATIVE_ONLY section. That should make it compile with -DLIBUNWIND_ENABLE_CROSS_UNWINDING=ON.

I did not see an easy way to get information about the correct architecture in parseInstructions(). If someone has a suggestion on how to best provide this information (extend the Register class with a getArch() function?) I could try it out in a subsequent patch.

I think an enum with a value for each Registers_* type, and a function in each such type to return its enum-value. Then pass that enum value as an arg to parseFDEInstructions.

[dcederman]

Added functionality to be able to differ between DW_CFA_AARCH64_negate_ra_state and DW_CFA_GNU_window_save.

[mgorny]

src/DwarfParser.hpp

682

Could you add a static_assert that verifies that the constants indeed have the same value?

[dcederman]

Added assert to verify that DW_CFA_AARCH64_negate_ra_state and DW_CFA_GNU_window_save have the same value.

[jyknight]

src/DwarfInstructions.hpp

209

I think this architecture conditional ought to be outside of the entire if block checking UNW_ARM64_RA_SIGN_STATE. LGTM other than this.

[mgorny]

src/DwarfParser.hpp

684

/var/tmp/portage/sys-libs/llvm-libunwind-9999/work/llvm-libunwind-9999/src/DwarfParser.hpp:686:75: error: macro "static_assert" requires 2 argument
s, but only 1 given                                                                                                                                
     static_assert(DW_CFA_AARCH64_negate_ra_state == DW_CFA_GNU_window_save);                                                                      
                                                                           ^

[dcederman]

Added message to static_assert and moved the AArch64 check one step up.

[mgorny]

Thanks, builds fine now.

[dcederman]

It seems that warnings are disabled by default for libunwind? Or I did something wrong when running cmake. Enabling warnings got me list of things I will have to fix before committing.

Thanks for all comments and have a nice weekend everyone!

[dcederman]

Fixed warnings related to sign and unused parameters.

include/__libunwind_config.h

 #define _LIBUNWIND_HIGHEST_DWARF_REGISTER_X86       8
 #define _LIBUNWIND_HIGHEST_DWARF_REGISTER_X86_64    32
 #define _LIBUNWIND_HIGHEST_DWARF_REGISTER_PPC       112
 #define _LIBUNWIND_HIGHEST_DWARF_REGISTER_PPC64     116
 #define _LIBUNWIND_HIGHEST_DWARF_REGISTER_ARM64     95
 #define _LIBUNWIND_HIGHEST_DWARF_REGISTER_ARM       287
 #define _LIBUNWIND_HIGHEST_DWARF_REGISTER_OR1K      32
 #define _LIBUNWIND_HIGHEST_DWARF_REGISTER_MIPS      65
+#define _LIBUNWIND_HIGHEST_DWARF_REGISTER_SPARC     31
 
 #if defined(_LIBUNWIND_IS_NATIVE_ONLY)
 # if defined(__i386__)
 #  define _LIBUNWIND_TARGET_I386
 #  define _LIBUNWIND_CONTEXT_SIZE 8
 #  define _LIBUNWIND_CURSOR_SIZE 15
 #  define _LIBUNWIND_HIGHEST_DWARF_REGISTER _LIBUNWIND_HIGHEST_DWARF_REGISTER_X86
 # elif defined(__x86_64__)

 #    else
 #      define _LIBUNWIND_CONTEXT_SIZE 35
 #      define _LIBUNWIND_CURSOR_SIZE 47
 #    endif
 #  else
 #    error "Unsupported MIPS ABI and/or environment"
 #  endif
 #  define _LIBUNWIND_HIGHEST_DWARF_REGISTER _LIBUNWIND_HIGHEST_DWARF_REGISTER_MIPS
+# elif defined(__sparc__)
+  #define _LIBUNWIND_TARGET_SPARC 1
+  #define _LIBUNWIND_HIGHEST_DWARF_REGISTER _LIBUNWIND_HIGHEST_DWARF_REGISTER_SPARC
+  #define _LIBUNWIND_CONTEXT_SIZE 16
+  #define _LIBUNWIND_CURSOR_SIZE 23
 # else
 #  error "Unsupported architecture."
 # endif
 #else // !_LIBUNWIND_IS_NATIVE_ONLY
 # define _LIBUNWIND_TARGET_I386
 # define _LIBUNWIND_TARGET_X86_64 1
 # define _LIBUNWIND_TARGET_PPC 1
 # define _LIBUNWIND_TARGET_PPC64 1
 # define _LIBUNWIND_TARGET_AARCH64 1
 # define _LIBUNWIND_TARGET_ARM 1
 # define _LIBUNWIND_TARGET_OR1K 1
 # define _LIBUNWIND_TARGET_MIPS_O32 1
 # define _LIBUNWIND_TARGET_MIPS_NEWABI 1
+# define _LIBUNWIND_TARGET_SPARC 1
 # define _LIBUNWIND_CONTEXT_SIZE 167
 # define _LIBUNWIND_CURSOR_SIZE 179
 # define _LIBUNWIND_HIGHEST_DWARF_REGISTER 287
 #endif // _LIBUNWIND_IS_NATIVE_ONLY
 
 #endif // ____LIBUNWIND_CONFIG_H__

include/libunwind.h

enum {
   UNW_MIPS_F28 = 60,
   UNW_MIPS_F29 = 61,
   UNW_MIPS_F30 = 62,
   UNW_MIPS_F31 = 63,
   UNW_MIPS_HI = 64,
   UNW_MIPS_LO = 65,
 };
 
+// SPARC registers
+enum {
+  UNW_SPARC_G0 = 0,
+  UNW_SPARC_G1 = 1,
+  UNW_SPARC_G2 = 2,
+  UNW_SPARC_G3 = 3,
+  UNW_SPARC_G4 = 4,
+  UNW_SPARC_G5 = 5,
+  UNW_SPARC_G6 = 6,
+  UNW_SPARC_G7 = 7,
+  UNW_SPARC_O0 = 8,
+  UNW_SPARC_O1 = 9,
+  UNW_SPARC_O2 = 10,
+  UNW_SPARC_O3 = 11,
+  UNW_SPARC_O4 = 12,
+  UNW_SPARC_O5 = 13,
+  UNW_SPARC_O6 = 14,
+  UNW_SPARC_O7 = 15,
+  UNW_SPARC_L0 = 16,
+  UNW_SPARC_L1 = 17,
+  UNW_SPARC_L2 = 18,
+  UNW_SPARC_L3 = 19,
+  UNW_SPARC_L4 = 20,
+  UNW_SPARC_L5 = 21,
+  UNW_SPARC_L6 = 22,
+  UNW_SPARC_L7 = 23,
+  UNW_SPARC_I0 = 24,
+  UNW_SPARC_I1 = 25,
+  UNW_SPARC_I2 = 26,
+  UNW_SPARC_I3 = 27,
+  UNW_SPARC_I4 = 28,
+  UNW_SPARC_I5 = 29,
+  UNW_SPARC_I6 = 30,
+  UNW_SPARC_I7 = 31,
+};
+
 #endif

src/DwarfInstructions.hpp

 #if defined(_LIBUNWIND_TARGET_AARCH64)
       // If the target is aarch64 then the return address may have been signed
       // using the v8.3 pointer authentication extensions. The original
       // return address needs to be authenticated before the return address is
       // restored. autia1716 is used instead of autia as autia1716 assembles
       // to a NOP on pre-v8.3a architectures.
       if (prolog.savedRegisters[UNW_ARM64_RA_SIGN_STATE].value) {
 #if !defined(_LIBUNWIND_IS_NATIVE_ONLY)
         return UNW_ECROSSRASIGNING;
 #else
         register unsigned long long x17 __asm("x17") = returnAddress;
         register unsigned long long x16 __asm("x16") = cfa;
 
         // These are the autia1716/autib1716 instructions. The hint instructions
         // are used here as gcc does not assemble autia1716/autib1716 for pre
         // armv8.3a targets.
         if (cieInfo.addressesSignedWithBKey)
           asm("hint 0xe" : "+r"(x17) : "r"(x16)); // autib1716
         else
           asm("hint 0xc" : "+r"(x17) : "r"(x16)); // autia1716
         returnAddress = x17;
 #endif
       }
 #endif
 
+#if defined(_LIBUNWIND_TARGET_SPARC)
+      // Skip call site instruction and delay slot
+      returnAddress += 8;
+      // Skip unimp instruction if function returns a struct
+      if ((addressSpace.get32(returnAddress) & 0xC1C00000) == 0)
+        returnAddress += 4;
+#endif
+
       // Return address is address after call site instruction, so setting IP to
       // that does simualates a return.
       newRegisters.setIP(returnAddress);
 
       // Simulate the step by replacing the register set with the new ones.
       registers = newRegisters;
 
       return UNW_STEP_SUCCESS;

src/DwarfParser.hpp

case DW_CFA_GNU_negative_offset_extended:
                                                     * cieInfo.dataAlignFactor;
       results->savedRegisters[reg].location = kRegisterInCFA;
       results->savedRegisters[reg].value = -offset;
       _LIBUNWIND_TRACE_DWARF(
           "DW_CFA_GNU_negative_offset_extended(%" PRId64 ")\n", offset);
       break;
 
 #if defined(_LIBUNWIND_TARGET_AARCH64)
     case DW_CFA_AARCH64_negate_ra_state:
       results->savedRegisters[UNW_ARM64_RA_SIGN_STATE].value ^= 0x1;
       _LIBUNWIND_TRACE_DWARF("DW_CFA_AARCH64_negate_ra_state\n");
       break;
 #endif
 
+#if defined(_LIBUNWIND_TARGET_SPARC)
+    case DW_CFA_GNU_window_save:
+      _LIBUNWIND_TRACE_DWARF("DW_CFA_GNU_window_save()\n");
+      for (reg = UNW_SPARC_O0; reg <= UNW_SPARC_O7; reg++) {
+        results->savedRegisters[reg].location = kRegisterInRegister;
+        results->savedRegisters[reg].value =
+            (reg - UNW_SPARC_O0) + UNW_SPARC_I0;
+      }
+
+      for (reg = UNW_SPARC_L0; reg <= UNW_SPARC_I7; reg++) {
+        results->savedRegisters[reg].location = kRegisterInCFA;
+        results->savedRegisters[reg].value = (reg - UNW_SPARC_L0) * 4;
+      }
+      break;
+#endif
+
     default:
       operand = opcode & 0x3F;
       switch (opcode & 0xC0) {
       case DW_CFA_offset:
         reg = operand;
         if (reg > kMaxRegisterNumber) {
           _LIBUNWIND_LOG("malformed DW_CFA_offset DWARF unwind, reg (%" PRIu64
                          ") out of range",

src/Registers.hpp

case UNW_MIPS_HI:
     return "$hi";
   case UNW_MIPS_LO:
     return "$lo";
   default:
     return "unknown register";
   }
 }
 #endif // _LIBUNWIND_TARGET_MIPS_NEWABI
+
+#if defined(_LIBUNWIND_TARGET_SPARC)
+/// Registers_sparc holds the register state of a thread in a 32-bit Sparc
+/// process.
+class _LIBUNWIND_HIDDEN Registers_sparc {
+public:
+  Registers_sparc();
+  Registers_sparc(const void *registers);
+
+  bool        validRegister(int num) const;
+  uint32_t    getRegister(int num) const;
+  void        setRegister(int num, uint32_t value);
+  bool        validFloatRegister(int num) const;
+  double      getFloatRegister(int num) const;
+  void        setFloatRegister(int num, double value);
+  bool        validVectorRegister(int num) const;
+  v128        getVectorRegister(int num) const;
+  void        setVectorRegister(int num, v128 value);
+  static const char *getRegisterName(int num);
+  void        jumpto();
+  static int  lastDwarfRegNum() { return _LIBUNWIND_HIGHEST_DWARF_REGISTER_SPARC; }
+
+  uint64_t  getSP() const         { return _registers.__regs[UNW_SPARC_O6]; }
+  void      setSP(uint32_t value) { _registers.__regs[UNW_SPARC_O6] = value; }
+  uint64_t  getIP() const         { return _registers.__regs[UNW_SPARC_O7]; }
+  void      setIP(uint32_t value) { _registers.__regs[UNW_SPARC_O7] = value; }
+
+private:
+  struct sparc_thread_state_t {
+    unsigned int __regs[32];
+  };
+
+  sparc_thread_state_t _registers;
+};
+
+inline Registers_sparc::Registers_sparc(const void *registers) {
+  static_assert((check_fit<Registers_sparc, unw_context_t>::does_fit),
+                "sparc registers do not fit into unw_context_t");
+  memcpy(&_registers, static_cast<const uint8_t *>(registers),
+         sizeof(_registers));
+}
+
+inline Registers_sparc::Registers_sparc() {
+  memset(&_registers, 0, sizeof(_registers));
+}
+
+inline bool Registers_sparc::validRegister(int regNum) const {
+  if (regNum == UNW_REG_IP)
+    return true;
+  if (regNum == UNW_REG_SP)
+    return true;
+  if (regNum < 0)
+    return false;
+  if (regNum <= UNW_SPARC_I7)
+    return true;
+  return false;
+}
+
+inline uint32_t Registers_sparc::getRegister(int regNum) const {
+  if ((UNW_SPARC_G0 <= regNum) && (regNum <= UNW_SPARC_I7)) {
+    return _registers.__regs[regNum];
+  }
+
+  switch (regNum) {
+  case UNW_REG_IP:
+    return _registers.__regs[UNW_SPARC_O7];
+  case UNW_REG_SP:
+    return _registers.__regs[UNW_SPARC_O6];
+  }
+  _LIBUNWIND_ABORT("unsupported sparc register");
+}
+
+inline void Registers_sparc::setRegister(int regNum, uint32_t value) {
+  if ((UNW_SPARC_G0 <= regNum) && (regNum <= UNW_SPARC_I7)) {
+    _registers.__regs[regNum] = value;
+    return;
+  }
+
+  switch (regNum) {
+  case UNW_REG_IP:
+    _registers.__regs[UNW_SPARC_O7] = value;
+    return;
+  case UNW_REG_SP:
+    _registers.__regs[UNW_SPARC_O6] = value;
+    return;
+  }
+  _LIBUNWIND_ABORT("unsupported sparc register");
+}
+
+inline bool Registers_sparc::validFloatRegister(int regNum) const {
+  return false;
+}
+
+inline double Registers_sparc::getFloatRegister(int regNum) const {
+  _LIBUNWIND_ABORT("no Sparc float registers");
+}
+
+inline void Registers_sparc::setFloatRegister(int regNum, double value) {
+  _LIBUNWIND_ABORT("no Sparc float registers");
+}
+
+inline bool Registers_sparc::validVectorRegister(int regNum) const {
+  return false;
+}
+
+inline v128 Registers_sparc::getVectorRegister(int regNum) const {
+  _LIBUNWIND_ABORT("no Sparc vector registers");
+}
+
+inline void Registers_sparc::setVectorRegister(int regNum, v128 value) {
+  _LIBUNWIND_ABORT("no Sparc vector registers");
+}
+
+inline const char *Registers_sparc::getRegisterName(int regNum) {
+  switch (regNum) {
+  case UNW_REG_IP:
+    return "pc";
+  case UNW_SPARC_G0:
+    return "g0";
+  case UNW_SPARC_G1:
+    return "g1";
+  case UNW_SPARC_G2:
+    return "g2";
+  case UNW_SPARC_G3:
+    return "g3";
+  case UNW_SPARC_G4:
+    return "g4";
+  case UNW_SPARC_G5:
+    return "g5";
+  case UNW_SPARC_G6:
+    return "g6";
+  case UNW_SPARC_G7:
+    return "g7";
+  case UNW_SPARC_O0:
+    return "o0";
+  case UNW_SPARC_O1:
+    return "o1";
+  case UNW_SPARC_O2:
+    return "o2";
+  case UNW_SPARC_O3:
+    return "o3";
+  case UNW_SPARC_O4:
+    return "o4";
+  case UNW_SPARC_O5:
+    return "o5";
+  case UNW_REG_SP:
+  case UNW_SPARC_O6:
+    return "sp";
+  case UNW_SPARC_O7:
+    return "o7";
+  case UNW_SPARC_L0:
+    return "l0";
+  case UNW_SPARC_L1:
+    return "l1";
+  case UNW_SPARC_L2:
+    return "l2";
+  case UNW_SPARC_L3:
+    return "l3";
+  case UNW_SPARC_L4:
+    return "l4";
+  case UNW_SPARC_L5:
+    return "l5";
+  case UNW_SPARC_L6:
+    return "l6";
+  case UNW_SPARC_L7:
+    return "l7";
+  case UNW_SPARC_I0:
+    return "i0";
+  case UNW_SPARC_I1:
+    return "i1";
+  case UNW_SPARC_I2:
+    return "i2";
+  case UNW_SPARC_I3:
+    return "i3";
+  case UNW_SPARC_I4:
+    return "i4";
+  case UNW_SPARC_I5:
+    return "i5";
+  case UNW_SPARC_I6:
+    return "fp";
+  case UNW_SPARC_I7:
+    return "i7";
+  default:
+    return "unknown register";
+  }
+}
+#endif // _LIBUNWIND_TARGET_SPARC
+
 } // namespace libunwind
 
 #endif // __REGISTERS_HPP__

src/UnwindCursor.hpp

 #endif
 
 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
   int stepWithCompactEncoding(Registers_mips_newabi &) {
     return UNW_EINVAL;
   }
 #endif
 
+#if defined(_LIBUNWIND_TARGET_SPARC)
+  int stepWithCompactEncoding(Registers_sparc &) { return UNW_EINVAL; }
+#endif
+
   bool compactSaysUseDwarf(uint32_t *offset=NULL) const {
     R dummy;
     return compactSaysUseDwarf(dummy, offset);
   }
 
 #if defined(_LIBUNWIND_TARGET_X86_64)
   bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const {
     if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) {
#if defined(_LIBUNWIND_TARGET_MIPS_O32)
   }
 #endif
 
 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
   bool compactSaysUseDwarf(Registers_mips_newabi &, uint32_t *) const {
     return true;
   }
 #endif
+
+#if defined(_LIBUNWIND_TARGET_SPARC)
+  bool compactSaysUseDwarf(Registers_sparc &, uint32_t *) const { return true; }
+#endif
+
 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
 
 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
   compact_unwind_encoding_t dwarfEncoding() const {
     R dummy;
     return dwarfEncoding(dummy);
   }
 
#if defined (_LIBUNWIND_TARGET_MIPS_O32)
   }
 #endif
 
 #if defined (_LIBUNWIND_TARGET_MIPS_NEWABI)
   compact_unwind_encoding_t dwarfEncoding(Registers_mips_newabi &) const {
     return 0;
   }
 #endif
+
+#if defined(_LIBUNWIND_TARGET_SPARC)
+  compact_unwind_encoding_t dwarfEncoding(Registers_sparc &) const { return 0; }
+#endif
+
 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
 
 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
   // For runtime environments using SEH unwind data without Windows runtime
   // support.
   pint_t getLastPC() const { /* FIXME: Implement */ return 0; }
   void setLastPC(pint_t pc) { /* FIXME: Implement */ }
   RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {

src/UnwindRegistersRestore.S

#endif
   ld    $30, (8 * 30)($4)
   // load new pc into ra
   ld    $31, (8 * 32)($4)
   // jump to ra, load a0 in the delay slot
   jr    $31
   ld    $4, (8 * 4)($4)
   .set pop
 
+#elif defined(__sparc__)
+
+//
+// void libunwind::Registers_sparc_o32::jumpto()
+//
+// On entry:
+//  thread_state pointer is in o0
+//
+DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind15Registers_sparc6jumptoEv)
+  ta 3
+  ldd [%o0 + 64],  %l0
+  ldd [%o0 + 72],  %l2
+  ldd [%o0 + 80],  %l4
+  ldd [%o0 + 88],  %l6
+  ldd [%o0 + 96],  %i0
+  ldd [%o0 + 104], %i2
+  ldd [%o0 + 112], %i4
+  ldd [%o0 + 120], %i6
+  ld  [%o0 + 60],  %o7
+  jmp %o7
+   nop
+
 #endif
 
 #endif /* !defined(__USING_SJLJ_EXCEPTIONS__) */
 
 NO_EXEC_STACK_DIRECTIVE
 

src/UnwindRegistersSave.S

DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
   l.sw     112(r3), r28
   l.sw     116(r3), r29
   l.sw     120(r3), r30
   l.sw     124(r3), r31
   # store ra to pc
   l.sw     128(r3), r9
   # zero epcr
   l.sw     132(r3), r0
-#endif
 
+#elif defined(__sparc__)
+
+#
+# extern int unw_getcontext(unw_context_t* thread_state)
+#
+# On entry:
+#  thread_state pointer is in o0
+#
+DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+  ta 3
+  add %o7, 8, %o7
+  std %g0, [%o0 +   0]
+  std %g2, [%o0 +   8]
+  std %g4, [%o0 +  16]
+  std %g6, [%o0 +  24]
+  std %o0, [%o0 +  32]
+  std %o2, [%o0 +  40]
+  std %o4, [%o0 +  48]
+  std %o6, [%o0 +  56]
+  std %l0, [%o0 +  64]
+  std %l2, [%o0 +  72]
+  std %l4, [%o0 +  80]
+  std %l6, [%o0 +  88]
+  std %i0, [%o0 +  96]
+  std %i2, [%o0 + 104]
+  std %i4, [%o0 + 112]
+  std %i6, [%o0 + 120]
+  jmp %o7
+   clr %o0                   // return UNW_ESUCCESS
+#endif
 #endif /* !defined(__USING_SJLJ_EXCEPTIONS__) */
 
 NO_EXEC_STACK_DIRECTIVE
-

src/assembly.h

 #define EXPORT_SYMBOL(name)
 #else
 #define EXPORT_SYMBOL(name) EXPORT_SYMBOL2(name)
 #endif
 #define HIDDEN_SYMBOL(name)
 
 #define NO_EXEC_STACK_DIRECTIVE
 
+#elif defined(__sparc__)
+
 #else
 
 #error Unsupported target
 
 #endif
 
 #define DEFINE_LIBUNWIND_FUNCTION(name)                   \
   .globl SYMBOL_NAME(name) SEPARATOR                      \

src/libunwind.cpp

 #elif defined(__or1k__)
 # define REGISTER_KIND Registers_or1k
 #elif defined(__mips__) && defined(_ABIO32) && _MIPS_SIM == _ABIO32
 # define REGISTER_KIND Registers_mips_o32
 #elif defined(__mips64)
 # define REGISTER_KIND Registers_mips_newabi
 #elif defined(__mips__)
 # warning The MIPS architecture is not supported with this ABI and environment!
+#elif defined(__sparc__)
+# define REGISTER_KIND Registers_sparc
 #else
 # error Architecture not supported
 #endif
   // Use "placement new" to allocate UnwindCursor in the cursor buffer.
   new ((void *)cursor) UnwindCursor<LocalAddressSpace, REGISTER_KIND>(
                                  context, LocalAddressSpace::sThisAddressSpace);
 #undef REGISTER_KIND
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;