gdb/

* frame.c (frame_unwind_register): Throw an error if unwinding the
	register failed.
	* get_prev_frame_1 (get_prev_frame_1): Ask the unwinder if there's
	an unwind stop reason.
	(frame_stop_reason_string): Handle UNWIND_UNAVAILABLE.
	* frame.h (enum unwind_stop_reason) <UNWIND_OUTERMOST,
	UNWIND_UNAVAILABLE>: New.
	* inline-frame.c (inline_frame_unwind): Install
	default_frame_unwind_stop_reason.
	* frame-unwind.c: Include "exceptions.h".
	(frame_unwind_find_by_frame): Swallow NOT_AVAILABLE_ERROR errors.
	(default_frame_unwind_stop_reason): New.
	* frame-unwind.h (frame_unwind_stop_reason_ftype): New typedef.
	(default_frame_unwind_stop_reason): Declare.
	(struct frame_unwind) <stop_reason>: New function pointer.

	* dummy-frame.c: Install default_frame_unwind_stop_reason.
	* dwarf2-frame.c: Include exceptions.h.
	(struct dwarf2_frame_cache) <unavailable_retaddr>: New field.
	(dwarf2_frame_cache): Swallow NOT_AVAILABLE_ERROR errors when
	computing the CFA.  If such an error was thrown, set
	unavailable_retaddr.
	(dwarf2_frame_unwind_stop_reason): New.
	(dwarf2_frame_this_id): Don't build a frame id if the CFA was
	unavailable.
	(dwarf2_frame_unwind): Install dwarf2_frame_unwind_stop_reason.
	(dwarf2_signal_frame_unwind): Ditto.

	* amd64-tdep.c: Include "exceptions.h".
	(struct amd64_frame_cache): New field "base_p".
	(amd64_init_frame_cache): Clear it.
	(amd64_frame_cache_1): New, factored out from amd64_frame_cache.
	Avoid reading registers with functions that throw if the register
	is not necessary to compute the frame base.
	(amd64_frame_cache): Reimplement wrapping amd64_frame_cache_1, and
	swallowing NOT_AVAILABLE_ERROR.
	(amd64_frame_unwind_stop_reason): New.
	(amd64_frame_this_id): Don't build a frame id if the frame base
	was unavailable.
	(amd64_frame_unwind): Install amd64_frame_unwind_stop_reason.
	(amd64_sigtramp_frame_cache): Swallow NOT_AVAILABLE_ERROR, and set
	base_p if the frame base was computable.
	(amd64_sigtramp_frame_unwind_stop_reason): New.
	(amd64_sigtramp_frame_this_id): Don't build a frame id if the
	frame base was unavailable.
	(amd64_sigtramp_frame_unwind): Install
	amd64_sigtramp_frame_unwind_stop_reason.
	(amd64_epilogue_frame_cache): Swallow NOT_AVAILABLE_ERROR, and set
	base_p if the frame base was computable.
	(amd64_epilogue_frame_unwind_stop_reason): New.
	(amd64_epilogue_frame_this_id): Don't build a frame id if the
	frame base was unavailable.
	(amd64_epilogue_frame_unwind): Install
	amd64_epilogue_frame_unwind_stop_reason.
	* i386-tdep.c: Include "exceptions.h".
	(struct i386_frame_cache): New field "base_p".
	(i386_init_frame_cache): Clear it.
	(i386_frame_cache_1): New, factored out from amd64_frame_cache.
	Avoid reading registers with functions that throw if the register
	is not necessary to compute the frame base.
	(i386_frame_cache): Reimplement wrapping amd64_frame_cache_1, and
	swallowing NOT_AVAILABLE_ERROR.
	(i386_frame_unwind_stop_reason): New.
	(i386_frame_this_id): Don't build a frame id if the frame base was
	unavailable.
	(i386_frame_prev_register): Handle unavailable SP.
	(i386_frame_unwind): Install i386_frame_unwind_stop_reason.
	(i386_epilogue_frame_cache): Swallow NOT_AVAILABLE_ERROR, and set
	base_p if the frame base was computable.
	(i386_epilogue_frame_unwind_stop_reason): New.
	(i386_epilogue_frame_this_id): Don't build a frame id if the frame
	base was unavailable.
	(i386_epilogue_frame_unwind): Install
	i386_epilogue_frame_unwind_stop_reason.
	(i386_sigtramp_frame_cache): Swallow NOT_AVAILABLE_ERROR, and set
	base_p if the frame base was computable.
	(i386_sigtramp_frame_unwind_stop_reason): New.
	(i386_sigtramp_frame_this_id): Don't build a frame id if the frame
	base was unavailable.
	(i386_sigtramp_frame_unwind): Install
	i386_sigtramp_frame_unwind_stop_reason.
	* sentinel-frame.c (sentinel_frame_prev_register): Use the value
	type's size, not the register's.
	(sentinel_frame_unwind): Install default_frame_unwind_stop_reason.

	* alpha-mdebug-tdep.c (alpha_mdebug_frame_unwind): Install
	default_frame_unwind_stop_reason.
	* alpha-tdep.c (alpha_sigtramp_frame_unwind)
	(alpha_heuristic_frame_unwind): Ditto.
	* amd64obsd-tdep.c (amd64obsd_trapframe_unwind): Ditto.
	* arm-tdep.c (arm_prologue_unwind, arm_stub_unwind): Ditto.
	* avr-tdep.c (avr_frame_unwind): Ditto.
	* cris-tdep.c (cris_sigtramp_frame_unwind, cris_frame_unwind):
	Ditto.
	* frv-linux-tdep.c (frv_linux_sigtramp_frame_unwind): Ditto.
	* frv-tdep.c (frv_frame_unwind): Ditto.
	* h8300-tdep.c (h8300_frame_unwind): Ditto.
	* hppa-hpux-tdep.c (hppa_hpux_sigtramp_frame_unwind): Ditto.
	* hppa-linux-tdep.c (hppa_linux_sigtramp_frame_unwind): Ditto.
	* hppa-tdep.c (hppa_frame_unwind, hppa_fallback_frame_unwind)
	(hppa_stub_frame_unwind): Ditto.
	* i386obsd-tdep.c (i386obsd_trapframe_unwind): Ditto.
	* ia64-tdep.c (ia64_frame_unwind, ia64_sigtramp_frame_unwind)
	(ia64_libunwind_frame_unwind)
	(ia64_libunwind_sigtramp_frame_unwind): Ditto.
	* iq2000-tdep.c (iq2000_frame_unwind): Ditto.
	* lm32-tdep.c (lm32_frame_unwind): Ditto.
	* m32c-tdep.c (m32c_unwind): Ditto.
	* m32r-linux-tdep.c (m32r_linux_sigtramp_frame_unwind): Ditto.
	* m32r-tdep.c (m32r_frame_unwind): Ditto.
	* m68hc11-tdep.c (m68hc11_frame_unwind): Ditto.
	* m68k-tdep.c (m68k_frame_unwind): Ditto.
	* m68klinux-tdep.c (m68k_linux_sigtramp_frame_unwind): Ditto.
	* m88k-tdep.c (m88k_frame_unwind): Ditto.
	* mep-tdep.c (mep_frame_unwind): Ditto.
	* microblaze-tdep.c (microblaze_frame_unwind): Ditto.
	* mips-tdep.c (mips_insn16_frame_unwind, mips_insn32_frame_unwind)
	(mips_stub_frame_unwind): Ditto.
	* mn10300-tdep.c (mn10300_frame_unwind): Ditto.
	* moxie-tdep.c (moxie_frame_unwind): Ditto.
	* mt-tdep.c (mt_frame_unwind): Ditto.
	* ppc-linux-tdep.c (ppu2spu_unwind): Ditto.
	* ppcobsd-tdep.c (ppcobsd_sigtramp_frame_unwind): Ditto.
	* rs6000-tdep.c (rs6000_frame_unwind): Ditto.
	* s390-tdep.c (s390_frame_unwind, s390_stub_frame_unwind)
	(s390_sigtramp_frame_unwind): Ditto.
	* score-tdep.c (score_prologue_unwind): Ditto.
	* sh-tdep.c (sh_frame_unwind): Ditto.
	* sh64-tdep.c (sh64_frame_unwind): Ditto.
	* sparc-sol2-tdep.c (sparc32_sol2_sigtramp_frame_unwind): Ditto.
	* sparc-tdep.c (sparc32_frame_unwind): Ditto.
	* sparc64-sol2-tdep.c (sparc64_sol2_sigtramp_frame_unwind): Ditto.
	* sparc64-tdep.c (sparc64_frame_unwind): Ditto.
	* sparc64fbsd-tdep.c (sparc64fbsd_sigtramp_frame_unwind): Ditto.
	* sparc64nbsd-tdep.c (sparc64nbsd_sigcontext_frame_unwind): Ditto.
	* sparc64obsd-tdep.c (sparc64obsd_frame_unwind)
	(sparc64obsd_trapframe_unwind): Ditto.
	* sparcnbsd-tdep.c (sparc32nbsd_sigcontext_frame_unwind): Ditto.
	* sparcobsd-tdep.c (sparc32obsd_sigtramp_frame_unwind): Ditto.
	* spu-tdep.c (spu_frame_unwind, spu2ppu_unwind): Ditto.
	* v850-tdep.c (v850_frame_unwind): Ditto.
	* vax-tdep.c (vax_frame_unwind): Ditto.
	* vaxobsd-tdep.c (vaxobsd_sigtramp_frame_unwind): Ditto.
	* xstormy16-tdep.c (frame_unwind xstormy16_frame_unwind): Ditto.
	* xtensa-tdep.c (xtensa_unwind): Ditto.

gdb/amd64-tdep.c

@@ -38,7 +38,7 @@
 #include "symfile.h"
 #include "disasm.h"
 #include "gdb_assert.h"
-
+#include "exceptions.h"
 #include "amd64-tdep.h"
 #include "i387-tdep.h"
 
@@ -1635,6 +1635,7 @@ struct amd64_frame_cache
 {
   /* Base address.  */
   CORE_ADDR base;
+  int base_p;
   CORE_ADDR sp_offset;
   CORE_ADDR pc;
 
@@ -1656,6 +1657,7 @@ amd64_init_frame_cache (struct amd64_frame_cache *cache)
 
   /* Base address.  */
   cache->base = 0;
+  cache->base_p = 0;
   cache->sp_offset = -8;
   cache->pc = 0;
 
@@ -1913,33 +1915,20 @@ amd64_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
 
 /* Normal frames.  */
 
-static struct amd64_frame_cache *
-amd64_frame_cache (struct frame_info *this_frame, void **this_cache)
+static void
+amd64_frame_cache_1 (struct frame_info *this_frame,
+		     struct amd64_frame_cache *cache)
 {
   struct gdbarch *gdbarch = get_frame_arch (this_frame);
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
-  struct amd64_frame_cache *cache;
   gdb_byte buf[8];
   int i;
 
-  if (*this_cache)
-    return *this_cache;
-
-  cache = amd64_alloc_frame_cache ();
-  *this_cache = cache;
-
   cache->pc = get_frame_func (this_frame);
   if (cache->pc != 0)
     amd64_analyze_prologue (gdbarch, cache->pc, get_frame_pc (this_frame),
 			    cache);
 
-  if (cache->saved_sp_reg != -1)
-    {
-      /* Stack pointer has been saved.  */
-      get_frame_register (this_frame, cache->saved_sp_reg, buf);
-      cache->saved_sp = extract_unsigned_integer(buf, 8, byte_order);
-    }
-
   if (cache->frameless_p)
     {
       /* We didn't find a valid frame.  If we're at the start of a
@@ -1951,6 +1940,10 @@ amd64_frame_cache (struct frame_info *this_frame, void **this_cache)
 
       if (cache->saved_sp_reg != -1)
 	{
+	  /* Stack pointer has been saved.  */
+	  get_frame_register (this_frame, cache->saved_sp_reg, buf);
+	  cache->saved_sp = extract_unsigned_integer (buf, 8, byte_order);
+
 	  /* We're halfway aligning the stack.  */
 	  cache->base = ((cache->saved_sp - 8) & 0xfffffffffffffff0LL) - 8;
 	  cache->saved_regs[AMD64_RIP_REGNUM] = cache->saved_sp - 8;
@@ -1988,9 +1981,48 @@ amd64_frame_cache (struct frame_info *this_frame, void **this_cache)
     if (cache->saved_regs[i] != -1)
       cache->saved_regs[i] += cache->base;
 
+  cache->base_p = 1;
+}
+
+static struct amd64_frame_cache *
+amd64_frame_cache (struct frame_info *this_frame, void **this_cache)
+{
+  volatile struct gdb_exception ex;
+  struct amd64_frame_cache *cache;
+
+  if (*this_cache)
+    return *this_cache;
+
+  cache = amd64_alloc_frame_cache ();
+  *this_cache = cache;
+
+  TRY_CATCH (ex, RETURN_MASK_ERROR)
+    {
+      amd64_frame_cache_1 (this_frame, cache);
+    }
+  if (ex.reason < 0 && ex.error != NOT_AVAILABLE_ERROR)
+    throw_exception (ex);
+
   return cache;
 }
 
+static enum unwind_stop_reason
+amd64_frame_unwind_stop_reason (struct frame_info *this_frame,
+				void **this_cache)
+{
+  struct amd64_frame_cache *cache =
+    amd64_frame_cache (this_frame, this_cache);
+
+  if (!cache->base_p)
+    return UNWIND_UNAVAILABLE;
+
+  /* This marks the outermost frame.  */
+  if (cache->base == 0)
+    return UNWIND_OUTERMOST;
+
+  return UNWIND_NO_REASON;
+}
+
 static void
 amd64_frame_this_id (struct frame_info *this_frame, void **this_cache,
 		     struct frame_id *this_id)
@@ -1998,6 +2030,9 @@ amd64_frame_this_id (struct frame_info *this_frame, void **this_cache,
   struct amd64_frame_cache *cache =
     amd64_frame_cache (this_frame, this_cache);
 
+  if (!cache->base_p)
+    return;
+
   /* This marks the outermost frame.  */
   if (cache->base == 0)
     return;
@@ -2028,6 +2063,7 @@ amd64_frame_prev_register (struct frame_info *this_frame, void **this_cache,
 static const struct frame_unwind amd64_frame_unwind =
 {
   NORMAL_FRAME,
+  amd64_frame_unwind_stop_reason,
   amd64_frame_this_id,
   amd64_frame_prev_register,
   NULL,
@@ -2047,6 +2083,7 @@ amd64_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache)
   struct gdbarch *gdbarch = get_frame_arch (this_frame);
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+  volatile struct gdb_exception ex;
   struct amd64_frame_cache *cache;
   CORE_ADDR addr;
   gdb_byte buf[8];
@@ -2057,20 +2094,40 @@ amd64_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache)
 
   cache = amd64_alloc_frame_cache ();
 
-  get_frame_register (this_frame, AMD64_RSP_REGNUM, buf);
-  cache->base = extract_unsigned_integer (buf, 8, byte_order) - 8;
+  TRY_CATCH (ex, RETURN_MASK_ERROR)
+    {
+      get_frame_register (this_frame, AMD64_RSP_REGNUM, buf);
+      cache->base = extract_unsigned_integer (buf, 8, byte_order) - 8;
 
-  addr = tdep->sigcontext_addr (this_frame);
-  gdb_assert (tdep->sc_reg_offset);
-  gdb_assert (tdep->sc_num_regs <= AMD64_NUM_SAVED_REGS);
-  for (i = 0; i < tdep->sc_num_regs; i++)
-    if (tdep->sc_reg_offset[i] != -1)
-      cache->saved_regs[i] = addr + tdep->sc_reg_offset[i];
+      addr = tdep->sigcontext_addr (this_frame);
+      gdb_assert (tdep->sc_reg_offset);
+      gdb_assert (tdep->sc_num_regs <= AMD64_NUM_SAVED_REGS);
+      for (i = 0; i < tdep->sc_num_regs; i++)
+	if (tdep->sc_reg_offset[i] != -1)
+	  cache->saved_regs[i] = addr + tdep->sc_reg_offset[i];
+
+      cache->base_p = 1;
+    }
+  if (ex.reason < 0 && ex.error != NOT_AVAILABLE_ERROR)
+    throw_exception (ex);
 
   *this_cache = cache;
   return cache;
 }
 
+static enum unwind_stop_reason
+amd64_sigtramp_frame_unwind_stop_reason (struct frame_info *this_frame,
+					 void **this_cache)
+{
+  struct amd64_frame_cache *cache =
+    amd64_sigtramp_frame_cache (this_frame, this_cache);
+
+  if (!cache->base_p)
+    return UNWIND_UNAVAILABLE;
+
+  return UNWIND_NO_REASON;
+}
+
 static void
 amd64_sigtramp_frame_this_id (struct frame_info *this_frame,
 			      void **this_cache, struct frame_id *this_id)
@@ -2078,6 +2135,9 @@ amd64_sigtramp_frame_this_id (struct frame_info *this_frame,
   struct amd64_frame_cache *cache =
     amd64_sigtramp_frame_cache (this_frame, this_cache);
 
+  if (!cache->base_p)
+    return;
+
   (*this_id) = frame_id_build (cache->base + 16, get_frame_pc (this_frame));
 }
 
@@ -2124,6 +2184,7 @@ amd64_sigtramp_frame_sniffer (const struct frame_unwind *self,
 static const struct frame_unwind amd64_sigtramp_frame_unwind =
 {
   SIGTRAMP_FRAME,
+  amd64_sigtramp_frame_unwind_stop_reason,
   amd64_sigtramp_frame_this_id,
   amd64_sigtramp_frame_prev_register,
   NULL,
@@ -2185,6 +2246,7 @@ amd64_epilogue_frame_cache (struct frame_info *this_frame, void **this_cache)
 {
   struct gdbarch *gdbarch = get_frame_arch (this_frame);
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+  volatile struct gdb_exception ex;
   struct amd64_frame_cache *cache;
   gdb_byte buf[8];
 
@@ -2194,23 +2256,43 @@ amd64_epilogue_frame_cache (struct frame_info *this_frame, void **this_cache)
   cache = amd64_alloc_frame_cache ();
   *this_cache = cache;
 
-  /* Cache base will be %esp plus cache->sp_offset (-8).  */
-  get_frame_register (this_frame, AMD64_RSP_REGNUM, buf);
-  cache->base = extract_unsigned_integer (buf, 8, 
-					  byte_order) + cache->sp_offset;
+  TRY_CATCH (ex, RETURN_MASK_ERROR)
+    {
+      /* Cache base will be %esp plus cache->sp_offset (-8).  */
+      get_frame_register (this_frame, AMD64_RSP_REGNUM, buf);
+      cache->base = extract_unsigned_integer (buf, 8,
+					      byte_order) + cache->sp_offset;
 
-  /* Cache pc will be the frame func.  */
-  cache->pc = get_frame_pc (this_frame);
+      /* Cache pc will be the frame func.  */
+      cache->pc = get_frame_pc (this_frame);
 
-  /* The saved %esp will be at cache->base plus 16.  */
-  cache->saved_sp = cache->base + 16;
+      /* The saved %esp will be at cache->base plus 16.  */
+      cache->saved_sp = cache->base + 16;
 
-  /* The saved %eip will be at cache->base plus 8.  */
-  cache->saved_regs[AMD64_RIP_REGNUM] = cache->base + 8;
+      /* The saved %eip will be at cache->base plus 8.  */
+      cache->saved_regs[AMD64_RIP_REGNUM] = cache->base + 8;
+
+      cache->base_p = 1;
+    }
+  if (ex.reason < 0 && ex.error != NOT_AVAILABLE_ERROR)
+    throw_exception (ex);
 
   return cache;
 }
 
+static enum unwind_stop_reason
+amd64_epilogue_frame_unwind_stop_reason (struct frame_info *this_frame,
+					 void **this_cache)
+{
+  struct amd64_frame_cache *cache
+    = amd64_epilogue_frame_cache (this_frame, this_cache);
+
+  if (!cache->base_p)
+    return UNWIND_UNAVAILABLE;
+
+  return UNWIND_NO_REASON;
+}
+
 static void
 amd64_epilogue_frame_this_id (struct frame_info *this_frame,
 			      void **this_cache,
@@ -2219,12 +2301,16 @@ amd64_epilogue_frame_this_id (struct frame_info *this_frame,
   struct amd64_frame_cache *cache = amd64_epilogue_frame_cache (this_frame,
 							       this_cache);
 
+  if (!cache->base_p)
+    return;
+
   (*this_id) = frame_id_build (cache->base + 8, cache->pc);
 }
 
 static const struct frame_unwind amd64_epilogue_frame_unwind =
 {
   NORMAL_FRAME,
+  amd64_epilogue_frame_unwind_stop_reason,
   amd64_epilogue_frame_this_id,
   amd64_frame_prev_register,
   NULL,