CORE_ADDR cur_sp = cache->sp;
struct gdbarch *gdbarch = get_frame_arch (this_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- int j;
+ int first = 1;
+
+ /* There are at least 3 possibilities to share an unwind info entry:
+ 1. Two different runtime_function entries (in .pdata) can point to the
+ same unwind info entry. There is no such indication while unwinding,
+ so we don't really care about that case. We suppose this scheme is
+ used to save memory when the unwind entries are exactly the same.
+ 2. Chained unwind_info entries, with no unwind codes (no prologue).
+ There is a major difference with the previous case: the pc range for
+ the function is different (in case 1, the pc range comes from the
+ runtime_function entry; in case 2, the pc range for the chained entry
+ comes from the first unwind entry). Case 1 cannot be used instead as
+ the pc is not in the prologue. This case is officially documented.
+ (There might be unwind code in the first unwind entry to handle
+ additional unwinding). GCC (at least until gcc 5.0) doesn't chain
+ entries.
+ 3. Undocumented unwind info redirection. Hard to know the exact purpose,
+ so it is considered as a memory optimization of case 2.
+ */
- for (j = 0; ; j++)
+ if (unwind_info & 1)
+ {
+ /* Unofficially documented unwind info redirection, when UNWIND_INFO
+ address is odd (http://www.codemachine.com/article_x64deepdive.html).
+ */
+ struct external_pex64_runtime_function d;
+ CORE_ADDR sa, ea;
+
+ if (target_read_memory (cache->image_base + (unwind_info & ~1),
+ (gdb_byte *) &d, sizeof (d)) != 0)
+ return;
+
+ cache->start_rva
+ = extract_unsigned_integer (d.rva_BeginAddress, 4, byte_order);
+ cache->end_rva
+ = extract_unsigned_integer (d.rva_EndAddress, 4, byte_order);
+ unwind_info
+ = extract_unsigned_integer (d.rva_UnwindData, 4, byte_order);
+ }
+
+ while (1)
{
struct external_pex64_unwind_info ex_ui;
/* There are at most 256 16-bit unwind insns. */
unsigned char codes_count;
unsigned char frame_reg;
unsigned char frame_off;
+ CORE_ADDR start;
/* Read and decode header. */
if (target_read_memory (cache->image_base + unwind_info,
&& PEX64_UWI_VERSION (ex_ui.Version_Flags) != 2)
return;
- if (j == 0
- && (cache->pc >=
- cache->image_base + cache->start_rva + ex_ui.SizeOfPrologue))
+ start = cache->image_base + cache->start_rva;
+ if (first
+ && !(cache->pc >= start && cache->pc < start + ex_ui.SizeOfPrologue))
{
- /* Not in the prologue. We want to detect if the PC points to an
- epilogue. If so, the epilogue detection+decoding function is
+ /* We want to detect if the PC points to an epilogue. This needs
+ to be checked only once, and an epilogue can be anywhere but in
+ the prologue. If so, the epilogue detection+decoding function is
sufficient. Otherwise, the unwinder will consider that the PC
is in the body of the function and will need to decode unwind
info. */
{
int reg;
- if (frame_debug)
- fprintf_unfiltered
- (gdb_stdlog, " op #%u: off=0x%02x, insn=0x%02x\n",
- (unsigned) (p - insns), p[0], p[1]);
-
- /* Virtually execute the operation. */
- if (cache->pc >= cache->image_base + cache->start_rva + p[0])
+ /* Virtually execute the operation if the pc is after the
+ corresponding instruction (that does matter in case of break
+ within the prologue). Note that for chained info (!first), the
+ prologue has been fully executed. */
+ if (cache->pc >= start + p[0] || cache->pc < start)
{
+ if (frame_debug)
+ fprintf_unfiltered
+ (gdb_stdlog, " op #%u: off=0x%02x, insn=0x%02x\n",
+ (unsigned) (p - insns), p[0], p[1]);
+
/* If there is no frame registers defined, the current value of
rsp is used instead. */
if (frame_reg == 0)
save_addr = cur_sp;
+ reg = -1;
+
switch (PEX64_UNWCODE_CODE (p[1]))
{
case UWOP_PUSH_NONVOL:
case UWOP_SAVE_NONVOL:
reg = amd64_windows_w2gdb_regnum[PEX64_UNWCODE_INFO (p[1])];
cache->prev_reg_addr[reg] = save_addr
- - 8 * extract_unsigned_integer (p + 2, 2, byte_order);
+ + 8 * extract_unsigned_integer (p + 2, 2, byte_order);
break;
case UWOP_SAVE_NONVOL_FAR:
reg = amd64_windows_w2gdb_regnum[PEX64_UNWCODE_INFO (p[1])];
cache->prev_reg_addr[reg] = save_addr
- - 8 * extract_unsigned_integer (p + 2, 4, byte_order);
+ + 8 * extract_unsigned_integer (p + 2, 4, byte_order);
break;
case UWOP_SAVE_XMM128:
cache->prev_xmm_addr[PEX64_UNWCODE_INFO (p[1])] =
default:
return;
}
+
+ /* Display address where the register was saved. */
+ if (frame_debug && reg >= 0)
+ fprintf_unfiltered
+ (gdb_stdlog, " [reg %s at %s]\n",
+ gdbarch_register_name (gdbarch, reg),
+ paddress (gdbarch, cache->prev_reg_addr[reg]));
}
/* Adjust with the length of the opcode. */
}
}
if (PEX64_UWI_FLAGS (ex_ui.Version_Flags) != UNW_FLAG_CHAININFO)
- break;
+ {
+ /* End of unwind info. */
+ break;
+ }
else
{
/* Read the chained unwind info. */
struct external_pex64_runtime_function d;
CORE_ADDR chain_vma;
+ /* Not anymore the first entry. */
+ first = 0;
+
+ /* Stay aligned on word boundary. */
chain_vma = cache->image_base + unwind_info
+ sizeof (ex_ui) + ((codes_count + 1) & ~1) * 2;
if (target_read_memory (chain_vma, (gdb_byte *) &d, sizeof (d)) != 0)
return;
+ /* Decode begin/end. This may be different from .pdata index, as
+ an unwind info may be shared by several functions (in particular
+ if many functions have the same prolog and handler. */
cache->start_rva =
extract_unsigned_integer (d.rva_BeginAddress, 4, byte_order);
cache->end_rva =
"amd64_windows_find_unwind_data: image_base=%s, unwind_data=%s\n",
paddress (gdbarch, base), paddress (gdbarch, *unwind_info));
- if (*unwind_info & 1)
- {
- /* Unofficially documented unwind info redirection, when UNWIND_INFO
- address is odd (http://www.codemachine.com/article_x64deepdive.html).
- */
- struct external_pex64_runtime_function d;
- CORE_ADDR sa, ea;
-
- if (target_read_memory (base + (*unwind_info & ~1),
- (gdb_byte *) &d, sizeof (d)) != 0)
- return -1;
-
- *start_rva =
- extract_unsigned_integer (d.rva_BeginAddress, 4, byte_order);
- *end_rva = extract_unsigned_integer (d.rva_EndAddress, 4, byte_order);
- *unwind_info =
- extract_unsigned_integer (d.rva_UnwindData, 4, byte_order);
-
- }
return 0;
}
projects / binutils-gdb.git / commitdiff