[4/6,ARM] Add support for systems that don't support ucontext.h

diff --git a/include/libunwind-arm.h b/include/libunwind-arm.h
index 492331e..cba380f 100644
--- a/include/libunwind-arm.h
+++ b/include/libunwind-arm.h
@@ -30,7 +30,7 @@  extern "C" {
 #endif
 
 #include <inttypes.h>
-#include <ucontext.h>
+#include <stddef.h>
 
 #define UNW_TARGET	arm
 #define UNW_TARGET_ARM	1
@@ -250,8 +250,14 @@  typedef struct unw_tdep_save_loc
   }
 unw_tdep_save_loc_t;
 
-/* On ARM, we can directly use ucontext_t as the unwind context.  */
-typedef ucontext_t unw_tdep_context_t;
+/* On ARM, we define our own unw_tdep_context instead of using ucontext_t.
+   This allows us to support systems that don't support getcontext and
+   therefore do not define ucontext_t.  */
+typedef struct unw_tdep_context
+  {
+    unsigned long regs[16];
+  }
+unw_tdep_context_t;
 
 /* There is no getcontext() on ARM.  Use a stub version which only saves GP
    registers.  FIXME: Not ideal, may not be sufficient for all libunwind
@@ -259,8 +265,7 @@  typedef ucontext_t unw_tdep_context_t;
 #ifndef __thumb__
 #define unw_tdep_getcontext(uc) (({					\
   unw_tdep_context_t *unw_ctx = (uc);					\
-  register int unw_base asm ("r0")					\
-    = (int) (&unw_ctx->uc_mcontext.arm_r0);				\
+  register unsigned long *unw_base asm ("r0") = unw_ctx->regs;		\
   __asm__ __volatile__ (						\
     "stmia %[base], {r0-r15}"						\
     : : [base] "r" (unw_base) : "memory");				\
@@ -268,8 +273,7 @@  typedef ucontext_t unw_tdep_context_t;
 #else /* __thumb__ */
 #define unw_tdep_getcontext(uc) (({					\
   unw_tdep_context_t *unw_ctx = (uc);					\
-  register int unw_base asm ("r0")					\
-    = (int) (&unw_ctx->uc_mcontext.arm_r0);				\
+  register unsigned long *unw_base asm ("r0") = unw_ctx->regs;		\
   __asm__ __volatile__ (						\
     ".align 2\nbx pc\nnop\n.code 32\n"					\
     "stmia %[base], {r0-r15}\n"						\
diff --git a/include/tdep-arm/libunwind_i.h b/include/tdep-arm/libunwind_i.h
index 7a5a394..a6c515d 100644
--- a/include/tdep-arm/libunwind_i.h
+++ b/include/tdep-arm/libunwind_i.h
@@ -274,7 +274,7 @@  extern void arm_put_unwind_info (unw_addr_space_t as,
 extern int tdep_search_unwind_table (unw_addr_space_t as, unw_word_t ip,
 				     unw_dyn_info_t *di, unw_proc_info_t *pi,
 				     int need_unwind_info, void *arg);
-extern void *tdep_uc_addr (ucontext_t *uc, int reg);
+extern void *tdep_uc_addr (unw_tdep_context_t *uc, int reg);
 extern int tdep_get_elf_image (struct elf_image *ei, pid_t pid, unw_word_t ip,
 			       unsigned long *segbase, unsigned long *mapoff,
 			       char *path, size_t pathlen);
diff --git a/src/arm/Gglobal.c b/src/arm/Gglobal.c
index 473a0b8..54dcd9d 100644
--- a/src/arm/Gglobal.c
+++ b/src/arm/Gglobal.c
@@ -22,7 +22,6 @@  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
 
-#include <ucontext.h>
 #include "unwind_i.h"
 #include "dwarf_i.h"
 
@@ -37,7 +36,10 @@  HIDDEN int unwi_unwind_method = UNW_ARM_METHOD_ALL;
 
 HIDDEN uint8_t dwarf_to_unw_regnum_map[16] =
   {
-    R0, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15
+    /* 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 */
+    UNW_ARM_R0, UNW_ARM_R1, UNW_ARM_R2, UNW_ARM_R3, UNW_ARM_R4, UNW_ARM_R5,
+    UNW_ARM_R6, UNW_ARM_R7, UNW_ARM_R8, UNW_ARM_R9, UNW_ARM_R10, UNW_ARM_R11,
+    UNW_ARM_R12, UNW_ARM_R13, UNW_ARM_R14, UNW_ARM_R15
   };
 
 HIDDEN void
diff --git a/src/arm/Ginit.c b/src/arm/Ginit.c
index b1e5228..b6fabca 100644
--- a/src/arm/Ginit.c
+++ b/src/arm/Ginit.c
@@ -39,39 +39,18 @@  static struct unw_addr_space local_addr_space;
 PROTECTED unw_addr_space_t unw_local_addr_space = &local_addr_space;
 
 static inline void *
-uc_addr (ucontext_t *uc, int reg)
+uc_addr (unw_tdep_context_t *uc, int reg)
 {
-  void *addr;
-
-  switch (reg)
-    {
-    case UNW_ARM_R0:  addr = &uc->uc_mcontext.arm_r0; break;
-    case UNW_ARM_R1:  addr = &uc->uc_mcontext.arm_r1; break;
-    case UNW_ARM_R2:  addr = &uc->uc_mcontext.arm_r2; break;
-    case UNW_ARM_R3:  addr = &uc->uc_mcontext.arm_r3; break;
-    case UNW_ARM_R4:  addr = &uc->uc_mcontext.arm_r4; break;
-    case UNW_ARM_R5:  addr = &uc->uc_mcontext.arm_r5; break;
-    case UNW_ARM_R6:  addr = &uc->uc_mcontext.arm_r6; break;
-    case UNW_ARM_R7:  addr = &uc->uc_mcontext.arm_r7; break;
-    case UNW_ARM_R8:  addr = &uc->uc_mcontext.arm_r8; break;
-    case UNW_ARM_R9:  addr = &uc->uc_mcontext.arm_r9; break;
-    case UNW_ARM_R10: addr = &uc->uc_mcontext.arm_r10; break;
-    case UNW_ARM_R11: addr = &uc->uc_mcontext.arm_fp; break;
-    case UNW_ARM_R12: addr = &uc->uc_mcontext.arm_ip; break;
-    case UNW_ARM_R13: addr = &uc->uc_mcontext.arm_sp; break;
-    case UNW_ARM_R14: addr = &uc->uc_mcontext.arm_lr; break;
-    case UNW_ARM_R15: addr = &uc->uc_mcontext.arm_pc; break;
-
-    default:
-      addr = NULL;
-    }
-  return addr;
+  if (reg >= UNW_ARM_R0 && reg < UNW_ARM_R0 + 16)
+    return &uc->regs[reg - UNW_ARM_R0];
+  else
+    return NULL;
 }
 
 # ifdef UNW_LOCAL_ONLY
 
 HIDDEN void *
-tdep_uc_addr (ucontext_t *uc, int reg)
+tdep_uc_addr (unw_tdep_context_t *uc, int reg)
 {
   return uc_addr (uc, reg);
 }
@@ -115,7 +94,7 @@  access_reg (unw_addr_space_t as, unw_regnum_t reg, unw_word_t *val, int write,
 	    void *arg)
 {
   unw_word_t *addr;
-  ucontext_t *uc = arg;
+  unw_tdep_context_t *uc = arg;
 
   if (unw_is_fpreg (reg))
     goto badreg;
@@ -145,7 +124,7 @@  static int
 access_fpreg (unw_addr_space_t as, unw_regnum_t reg, unw_fpreg_t *val,
 	      int write, void *arg)
 {
-  ucontext_t *uc = arg;
+  unw_tdep_context_t *uc = arg;
   unw_fpreg_t *addr;
 
   if (!unw_is_fpreg (reg))
diff --git a/src/arm/Ginit_local.c b/src/arm/Ginit_local.c
index b0f73cd..87d07a3 100644
--- a/src/arm/Ginit_local.c
+++ b/src/arm/Ginit_local.c
@@ -29,7 +29,7 @@  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
 #ifdef UNW_REMOTE_ONLY
 
 PROTECTED int
-unw_init_local (unw_cursor_t *cursor, ucontext_t *uc)
+unw_init_local (unw_cursor_t *cursor, unw_context_t *uc)
 {
   return -UNW_EINVAL;
 }
@@ -37,7 +37,7 @@  unw_init_local (unw_cursor_t *cursor, ucontext_t *uc)
 #else /* !UNW_REMOTE_ONLY */
 
 PROTECTED int
-unw_init_local (unw_cursor_t *cursor, ucontext_t *uc)
+unw_init_local (unw_cursor_t *cursor, unw_context_t *uc)
 {
   struct cursor *c = (struct cursor *) cursor;
 
diff --git a/src/arm/Gresume.c b/src/arm/Gresume.c
index f496e99..da45dec 100644
--- a/src/arm/Gresume.c
+++ b/src/arm/Gresume.c
@@ -33,23 +33,23 @@  arm_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
 {
 #ifdef __linux__
   struct cursor *c = (struct cursor *) cursor;
-  ucontext_t *uc = c->dwarf.as_arg;
+  unw_tdep_context_t *uc = c->dwarf.as_arg;
 
   if (c->sigcontext_format == ARM_SCF_NONE)
     {
       /* Since there are no signals involved here we restore the non scratch
 	 registers only.  */
       unsigned long regs[10];
-      regs[0] = uc->uc_mcontext.arm_r4;
-      regs[1] = uc->uc_mcontext.arm_r5;
-      regs[2] = uc->uc_mcontext.arm_r6;
-      regs[3] = uc->uc_mcontext.arm_r7;
-      regs[4] = uc->uc_mcontext.arm_r8;
-      regs[5] = uc->uc_mcontext.arm_r9;
-      regs[6] = uc->uc_mcontext.arm_r10;
-      regs[7] = uc->uc_mcontext.arm_fp;
-      regs[8] = uc->uc_mcontext.arm_sp;
-      regs[9] = uc->uc_mcontext.arm_lr;
+      regs[0] = uc->regs[4];
+      regs[1] = uc->regs[5];
+      regs[2] = uc->regs[6];
+      regs[3] = uc->regs[7];
+      regs[4] = uc->regs[8];
+      regs[5] = uc->regs[9];
+      regs[6] = uc->regs[10];
+      regs[7] = uc->regs[11]; /* FP */
+      regs[8] = uc->regs[13]; /* SP */
+      regs[9] = uc->regs[14]; /* LR */
 
       asm __volatile__ (
 	"ldmia %0, {r4-r12, lr}\n"
@@ -63,22 +63,22 @@  arm_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
       /* In case a signal frame is involved, we're using its trampoline which
 	 calls sigreturn.  */
       struct sigcontext *sc = (struct sigcontext *) c->sigcontext_addr;
-      sc->arm_r0 = uc->uc_mcontext.arm_r0;
-      sc->arm_r1 = uc->uc_mcontext.arm_r1;
-      sc->arm_r2 = uc->uc_mcontext.arm_r2;
-      sc->arm_r3 = uc->uc_mcontext.arm_r3;
-      sc->arm_r4 = uc->uc_mcontext.arm_r4;
-      sc->arm_r5 = uc->uc_mcontext.arm_r5;
-      sc->arm_r6 = uc->uc_mcontext.arm_r6;
-      sc->arm_r7 = uc->uc_mcontext.arm_r7;
-      sc->arm_r8 = uc->uc_mcontext.arm_r8;
-      sc->arm_r9 = uc->uc_mcontext.arm_r9;
-      sc->arm_r10 = uc->uc_mcontext.arm_r10;
-      sc->arm_fp = uc->uc_mcontext.arm_fp;
-      sc->arm_ip = uc->uc_mcontext.arm_ip;
-      sc->arm_sp = uc->uc_mcontext.arm_sp;
-      sc->arm_lr = uc->uc_mcontext.arm_lr;
-      sc->arm_pc = uc->uc_mcontext.arm_pc;
+      sc->arm_r0 = uc->regs[0];
+      sc->arm_r1 = uc->regs[1];
+      sc->arm_r2 = uc->regs[2];
+      sc->arm_r3 = uc->regs[3];
+      sc->arm_r4 = uc->regs[4];
+      sc->arm_r5 = uc->regs[5];
+      sc->arm_r6 = uc->regs[6];
+      sc->arm_r7 = uc->regs[7];
+      sc->arm_r8 = uc->regs[8];
+      sc->arm_r9 = uc->regs[9];
+      sc->arm_r10 = uc->regs[10];
+      sc->arm_fp = uc->regs[11]; /* FP */
+      sc->arm_ip = uc->regs[12]; /* IP */
+      sc->arm_sp = uc->regs[13]; /* SP */
+      sc->arm_lr = uc->regs[14]; /* LR */
+      sc->arm_pc = uc->regs[15]; /* PC */
       /* clear the ITSTATE bits.  */
       sc->arm_cpsr &= 0xf9ff03ffUL;
 
diff --git a/src/arm/init.h b/src/arm/init.h
index 767dbdc..676c340 100644
--- a/src/arm/init.h
+++ b/src/arm/init.h
@@ -29,26 +29,26 @@  common_init (struct cursor *c, unsigned use_prev_instr)
 {
   int ret, i;
 
-  c->dwarf.loc[R0] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R0);
-  c->dwarf.loc[R1] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R1);
-  c->dwarf.loc[R2] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R2);
-  c->dwarf.loc[R3] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R3);
-  c->dwarf.loc[R4] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R4);
-  c->dwarf.loc[R5] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R5);
-  c->dwarf.loc[R6] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R6);
-  c->dwarf.loc[R7] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R7);
-  c->dwarf.loc[R8] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R8);
-  c->dwarf.loc[R9] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R9);
-  c->dwarf.loc[R10] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R10);
-  c->dwarf.loc[R11] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R11);
-  c->dwarf.loc[R12] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R12);
-  c->dwarf.loc[R13] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R13);
-  c->dwarf.loc[R14] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R14);
-  c->dwarf.loc[R15] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R15);
-  for (i = R15 + 1; i < DWARF_NUM_PRESERVED_REGS; ++i)
+  c->dwarf.loc[UNW_ARM_R0] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R0);
+  c->dwarf.loc[UNW_ARM_R1] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R1);
+  c->dwarf.loc[UNW_ARM_R2] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R2);
+  c->dwarf.loc[UNW_ARM_R3] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R3);
+  c->dwarf.loc[UNW_ARM_R4] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R4);
+  c->dwarf.loc[UNW_ARM_R5] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R5);
+  c->dwarf.loc[UNW_ARM_R6] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R6);
+  c->dwarf.loc[UNW_ARM_R7] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R7);
+  c->dwarf.loc[UNW_ARM_R8] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R8);
+  c->dwarf.loc[UNW_ARM_R9] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R9);
+  c->dwarf.loc[UNW_ARM_R10] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R10);
+  c->dwarf.loc[UNW_ARM_R11] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R11);
+  c->dwarf.loc[UNW_ARM_R12] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R12);
+  c->dwarf.loc[UNW_ARM_R13] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R13);
+  c->dwarf.loc[UNW_ARM_R14] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R14);
+  c->dwarf.loc[UNW_ARM_R15] = DWARF_REG_LOC (&c->dwarf, UNW_ARM_R15);
+  for (i = UNW_ARM_R15 + 1; i < DWARF_NUM_PRESERVED_REGS; ++i)
     c->dwarf.loc[i] = DWARF_NULL_LOC;
 
-  ret = dwarf_get (&c->dwarf, c->dwarf.loc[R15], &c->dwarf.ip);
+  ret = dwarf_get (&c->dwarf, c->dwarf.loc[UNW_ARM_R15], &c->dwarf.ip);
   if (ret < 0)
     return ret;