[libunwind][MIPS]: Add support for unwinding in O32 and N64 processes.

This supports the soft-float ABI only and has been tested with both clang
and gcc on FreeBSD.

Reviewed By: sdardis, compnerd

Differential Revision: https://reviews.llvm.org/D38110

llvm-svn: 320528

2 files changed, 54 insertions, 0 deletions

diff --git a/libunwind/include/__libunwind_config.h b/libunwind/include/__libunwind_config.h
index 5e3cf274242..69a49961a6e 100644
--- a/libunwind/include/__libunwind_config.h
+++ b/libunwind/include/__libunwind_config.h
@@ -21,6 +21,7 @@
 #define _LIBUNWIND_HIGHEST_DWARF_REGISTER_ARM64     95
 #define _LIBUNWIND_HIGHEST_DWARF_REGISTER_ARM       287
 #define _LIBUNWIND_HIGHEST_DWARF_REGISTER_OR1K      31
+#define _LIBUNWIND_HIGHEST_DWARF_REGISTER_MIPS      65
 
 #if defined(_LIBUNWIND_IS_NATIVE_ONLY)
 # if defined(__i386__)
@@ -63,6 +64,19 @@
 #  define _LIBUNWIND_CONTEXT_SIZE 16
 #  define _LIBUNWIND_CURSOR_SIZE 24
 #  define _LIBUNWIND_HIGHEST_DWARF_REGISTER _LIBUNWIND_HIGHEST_DWARF_REGISTER_OR1K
+# elif defined(__mips__)
+#  if defined(_ABIO32) && defined(__mips_soft_float)
+#    define _LIBUNWIND_TARGET_MIPS_O32 1
+#    define _LIBUNWIND_CONTEXT_SIZE 18
+#    define _LIBUNWIND_CURSOR_SIZE 24
+#  elif defined(_ABI64) && defined(__mips_soft_float)
+#    define _LIBUNWIND_TARGET_MIPS_N64 1
+#    define _LIBUNWIND_CONTEXT_SIZE 35
+#    define _LIBUNWIND_CURSOR_SIZE 47
+#  else
+#    error "Unsupported MIPS ABI and/or environment"
+#  endif
+#  define _LIBUNWIND_HIGHEST_DWARF_REGISTER _LIBUNWIND_HIGHEST_DWARF_REGISTER_MIPS
 # else
 #  error "Unsupported architecture."
 # endif
@@ -73,6 +87,8 @@
 # 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_N64 1
 # define _LIBUNWIND_CONTEXT_SIZE 128
 # define _LIBUNWIND_CURSOR_SIZE 140
 # define _LIBUNWIND_HIGHEST_DWARF_REGISTER 287
diff --git a/libunwind/include/libunwind.h b/libunwind/include/libunwind.h
index ece30976aba..9011d55460c 100644
--- a/libunwind/include/libunwind.h
+++ b/libunwind/include/libunwind.h
@@ -563,4 +563,42 @@ enum {
   UNW_OR1K_R31 = 31,
 };
 
+// MIPS registers
+enum {
+  UNW_MIPS_R0  = 0,
+  UNW_MIPS_R1  = 1,
+  UNW_MIPS_R2  = 2,
+  UNW_MIPS_R3  = 3,
+  UNW_MIPS_R4  = 4,
+  UNW_MIPS_R5  = 5,
+  UNW_MIPS_R6  = 6,
+  UNW_MIPS_R7  = 7,
+  UNW_MIPS_R8  = 8,
+  UNW_MIPS_R9  = 9,
+  UNW_MIPS_R10 = 10,
+  UNW_MIPS_R11 = 11,
+  UNW_MIPS_R12 = 12,
+  UNW_MIPS_R13 = 13,
+  UNW_MIPS_R14 = 14,
+  UNW_MIPS_R15 = 15,
+  UNW_MIPS_R16 = 16,
+  UNW_MIPS_R17 = 17,
+  UNW_MIPS_R18 = 18,
+  UNW_MIPS_R19 = 19,
+  UNW_MIPS_R20 = 20,
+  UNW_MIPS_R21 = 21,
+  UNW_MIPS_R22 = 22,
+  UNW_MIPS_R23 = 23,
+  UNW_MIPS_R24 = 24,
+  UNW_MIPS_R25 = 25,
+  UNW_MIPS_R26 = 26,
+  UNW_MIPS_R27 = 27,
+  UNW_MIPS_R28 = 28,
+  UNW_MIPS_R29 = 29,
+  UNW_MIPS_R30 = 30,
+  UNW_MIPS_R31 = 31,
+  UNW_MIPS_HI = 64,
+  UNW_MIPS_LO = 65,
+};
+
 #endif