Re: [RFA/RFC Prec] Add Linux AMD64 process record support second version, (AMD64 Linux system call support) 3/3

Michael Snyder
2009-07-20T01:17:36Z

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Hui,

Here is an "epilogue unwinder" for the amd64. Please try it out.

If you update infrun.c now you will see most of your *-record.exp
testsuites broken by my recent change there. This will fix them.

Thanks,
Michael

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--- saveteawater3/amd64-tdep.c 2009-07-19 18:08:56.000000000 -0700
+++ ./amd64-tdep.c 2009-07-19 18:10:18.000000000 -0700
@@ -1887,6 +1887,89 @@ static const struct frame_base amd64_fra
amd64_frame_base_address
};

+/* Normal frames, but in a function epilogue. */
+
+/* The epilogue is defined here as the 'ret' instruction, which will
+ follow any instruction such as 'leave' or 'pop %ebp' that destroys
+ the function's stack frame. */
+
+static int
+amd64_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ gdb_byte insn;
+
+ if (target_read_memory (pc, &insn, 1))
+ return 0; /* Can't read memory at pc. */
+
+ if (insn != 0xc3) /* 'ret' instruction. */
+ return 0;
+
+ return 1;
+}
+
+static int
+amd64_epilogue_frame_sniffer (const struct frame_unwind *self,
+ struct frame_info *this_frame,
+ void **this_prologue_cache)
+{
+ if (frame_relative_level (this_frame) == 0)
+ return amd64_in_function_epilogue_p (get_frame_arch (this_frame),
+ get_frame_pc (this_frame));
+ else
+ return 0;
+}
+
+static struct amd64_frame_cache *
+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);
+ struct amd64_frame_cache *cache;
+ gdb_byte buf[4];
+
+ if (*this_cache)
+ return *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;
+
+ /* 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 %eip will be at cache->base plus 8. */
+ cache->saved_regs[AMD64_RIP_REGNUM] = cache->base + 8;
+
+ return cache;
+}
+
+static void
+amd64_epilogue_frame_this_id (struct frame_info *this_frame,
+ void **this_cache,
+ struct frame_id *this_id)
+{
+ struct amd64_frame_cache *cache = amd64_epilogue_frame_cache (this_frame,
+ this_cache);
+
+ (*this_id) = frame_id_build (cache->base + 8, cache->pc);
+}
+
+static const struct frame_unwind amd64_epilogue_frame_unwind =
+{
+ NORMAL_FRAME,
+ amd64_epilogue_frame_this_id,
+ amd64_frame_prev_register,
+ NULL,
+ amd64_epilogue_frame_sniffer
+};
+
static struct frame_id
amd64_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
{
@@ -2065,6 +2148,12 @@ amd64_init_abi (struct gdbarch_info info

set_gdbarch_dummy_id (gdbarch, amd64_dummy_id);

+ /* Hook the function epilogue frame unwinder. This unwinder is
+ appended to the list first, so that it supercedes the other
+ unwinders in function epilogues. */
+ frame_unwind_prepend_unwinder (gdbarch, &amd64_epilogue_frame_unwind);
+
+ /* Hook the prologue-based frame unwinders. */
frame_unwind_append_unwinder (gdbarch, &amd64_sigtramp_frame_unwind);
frame_unwind_append_unwinder (gdbarch, &amd64_frame_unwind);
frame_base_set_default (gdbarch, &amd64_frame_base);