[Sparc] Add Sparc V8 support

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

Adds getArch() function to each Registers_ class to be able to separate
between DW_CFA_AARCH64_negate_ra_state and DW_CFA_GNU_window_save which
are both represented by the same constant.

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 on Sparc V8.

Reviewers: jyknight, mclow.lists, mstorsjo, compnerd

Reviewed By: jyknight, compnerd

Subscribers: jgorbe, mgorny, christof, llvm-commits, fedor.sergeev, JDevlieghere, ldionne, libcxx-commits

Differential Revision: https://reviews.llvm.org/D55763

llvm-svn: 351044

2 files changed, 43 insertions, 0 deletions

diff --git a/libunwind/include/__libunwind_config.h b/libunwind/include/__libunwind_config.h
index 54509495c38a..a8e30de13a6a 100644
--- a/libunwind/include/__libunwind_config.h
+++ b/libunwind/include/__libunwind_config.h
@@ -23,6 +23,7 @@
 #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__)
@@ -113,6 +114,11 @@
 #    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
@@ -126,6 +132,7 @@
 # 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
diff --git a/libunwind/include/libunwind.h b/libunwind/include/libunwind.h
index d824c1318354..29c4aebde5ac 100644
--- a/libunwind/include/libunwind.h
+++ b/libunwind/include/libunwind.h
@@ -823,4 +823,40 @@ enum {
   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