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Re: [Patch] New gdbarch method "dwarf_cfa_op" and migrate SPARC to it
Thanks for the review.
On 21/04/17 20:37, Pedro Alves wrote:
On 04/21/2017 03:56 PM, Jiong Wang wrote:
Doesn't the Aarch64 version of the opcode have its own
name, like DW_CFA_GNU_Aarch64_whatever, even if it reuses the
opcode number? I think that would help a lot going forward
if it had one. E.g., it'd avoid confusion, allow for easier
searching, etc.
AArch64 do have a name for it, "DW_CFA_AARCH64_negate_ra_state",
I will add it to gcc/include/dwarf2.def later once it's used and will request
a sync from GCC to Bintuils.
On the patch, I think it would be better if in execute_cfa_program:
case DW_CFA_GNU_window_save:
- /* This is SPARC-specific code, and contains hard-coded
- constants for the register numbering scheme used by
you removed "case CFA_GNU_window_save:" too, and moved the
gdbarch_dwarf_cfa_op call to the default case.
Done.
Then make the hook return a boolean indication about whether it /recognized the
opcode, and make the caller throw an error if the hook returns
false.
Done.
And make that error call be a regular "error()" call instead
of the current internal_error call. The internal error is bogus
here because we reach that with an unrecognized opcode that comes
from a binary, i.e., input, not a gdb bug.
Done.
Replace the gdb_assert in sparc_dwarf_cfa_op by returning false for
unrecognized opcodes, and likewise change default_dwarf_cfa_op
to return false instead of calling error itself.
Done.
Add a comment at the hook call site about letting the backend
handle vendor-specific opcodes, and generalize a bit the comment
describing the hook in gdbarch.sh in that direction as well.
Done.
Maybe rename to hook from dwarf_cfa_op to something like:
execute_dwarf_cfa_vendor_op
Done with above name.
Ok for master? thanks
gdb/
2017-04-25 Jiong Wang <jiong.wang@arm.com>
* gdbarch.sh: New gdbarch method execute_dwarf_cfa_vendor_op.
* gdbarch.c: Regenerated.
* gdbarch.h: Regenerated.
* dwarf2-frame.c (dwarf2_frame_state_alloc_regs): Made the
visibility external.
(execute_cfa_program): Call execute_dwarf_cfa_vendor_op for CFI
between DW_CFA_lo_user and DW_CFA_high_user inclusive.
(enum cfa_how_kind): Move to ...
(struct dwarf2_frame_state_reg_info): Likewise.
(struct dwarf2_frame_state): Likewise.
* dwarf2-frame.h: ... here.
(dwarf2_frame_state_alloc_regs): New declaration.
* sparc-tdep.c (sparc_execute_dwarf_cfa_vendor_op): New function.
(sparc32_gdbarch_init): Register execute_dwarf_cfa_vendor_op hook.
diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c
index 3b22e51..b1cec80 100644
--- a/gdb/arch-utils.c
+++ b/gdb/arch-utils.c
@@ -204,6 +204,15 @@ default_adjust_dwarf2_line (CORE_ADDR addr, int rel)
return addr;
}
+/* See arch-utils.h. */
+
+bool
+default_execute_dwarf_cfa_vendor_op (struct gdbarch *gdbarch, gdb_byte op,
+ struct dwarf2_frame_state *fs)
+{
+ return false;
+}
+
int
cannot_register_not (struct gdbarch *gdbarch, int regnum)
{
diff --git a/gdb/arch-utils.h b/gdb/arch-utils.h
index 4d7b499..967a4b1 100644
--- a/gdb/arch-utils.h
+++ b/gdb/arch-utils.h
@@ -25,6 +25,7 @@ struct frame_info;
struct minimal_symbol;
struct type;
struct gdbarch_info;
+struct dwarf2_frame_state;
template <size_t bp_size, const gdb_byte *break_insn>
struct bp_manipulation
@@ -130,6 +131,11 @@ CORE_ADDR default_adjust_dwarf2_addr (CORE_ADDR pc);
CORE_ADDR default_adjust_dwarf2_line (CORE_ADDR addr, int rel);
+/* Default DWARF vendor CFI handler. */
+
+bool default_execute_dwarf_cfa_vendor_op (struct gdbarch *gdbarch, gdb_byte op,
+ struct dwarf2_frame_state *fs);
+
/* Version of cannot_fetch_register() / cannot_store_register() that
always fails. */
diff --git a/gdb/dwarf2-frame.c b/gdb/dwarf2-frame.c
index f8dd1df..1bdddeb 100644
--- a/gdb/dwarf2-frame.c
+++ b/gdb/dwarf2-frame.c
@@ -165,58 +165,6 @@ static CORE_ADDR read_encoded_value (struct comp_unit *unit, gdb_byte encoding,
CORE_ADDR func_base);
-enum cfa_how_kind
-{
- CFA_UNSET,
- CFA_REG_OFFSET,
- CFA_EXP
-};
-
-struct dwarf2_frame_state_reg_info
-{
- struct dwarf2_frame_state_reg *reg;
- int num_regs;
-
- LONGEST cfa_offset;
- ULONGEST cfa_reg;
- enum cfa_how_kind cfa_how;
- const gdb_byte *cfa_exp;
-
- /* Used to implement DW_CFA_remember_state. */
- struct dwarf2_frame_state_reg_info *prev;
-};
-
-/* Structure describing a frame state. */
-
-struct dwarf2_frame_state
-{
- /* Each register save state can be described in terms of a CFA slot,
- another register, or a location expression. */
- struct dwarf2_frame_state_reg_info regs;
-
- /* The PC described by the current frame state. */
- CORE_ADDR pc;
-
- /* Initial register set from the CIE.
- Used to implement DW_CFA_restore. */
- struct dwarf2_frame_state_reg_info initial;
-
- /* The information we care about from the CIE. */
- LONGEST data_align;
- ULONGEST code_align;
- ULONGEST retaddr_column;
-
- /* Flags for known producer quirks. */
-
- /* The ARM compilers, in DWARF2 mode, assume that DW_CFA_def_cfa
- and DW_CFA_def_cfa_offset takes a factored offset. */
- int armcc_cfa_offsets_sf;
-
- /* The ARM compilers, in DWARF2 or DWARF3 mode, may assume that
- the CFA is defined as REG - OFFSET rather than REG + OFFSET. */
- int armcc_cfa_offsets_reversed;
-};
-
/* Store the length the expression for the CFA in the `cfa_reg' field,
which is unused in that case. */
#define cfa_exp_len cfa_reg
@@ -224,7 +172,7 @@ struct dwarf2_frame_state
/* Assert that the register set RS is large enough to store gdbarch_num_regs
columns. If necessary, enlarge the register set. */
-static void
+void
dwarf2_frame_state_alloc_regs (struct dwarf2_frame_state_reg_info *rs,
int num_regs)
{
@@ -672,31 +620,6 @@ bad CFI data; mismatched DW_CFA_restore_state at %s"),
/* cfa_how deliberately not set. */
break;
- case DW_CFA_GNU_window_save:
- /* This is SPARC-specific code, and contains hard-coded
- constants for the register numbering scheme used by
- GCC. Rather than having a architecture-specific
- operation that's only ever used by a single
- architecture, we provide the implementation here.
- Incidentally that's what GCC does too in its
- unwinder. */
- {
- int size = register_size (gdbarch, 0);
-
- dwarf2_frame_state_alloc_regs (&fs->regs, 32);
- for (reg = 8; reg < 16; reg++)
- {
- fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG;
- fs->regs.reg[reg].loc.reg = reg + 16;
- }
- for (reg = 16; reg < 32; reg++)
- {
- fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
- fs->regs.reg[reg].loc.offset = (reg - 16) * size;
- }
- }
- break;
-
case DW_CFA_GNU_args_size:
/* Ignored. */
insn_ptr = safe_read_uleb128 (insn_ptr, insn_end, &utmp);
@@ -713,8 +636,17 @@ bad CFI data; mismatched DW_CFA_restore_state at %s"),
break;
default:
- internal_error (__FILE__, __LINE__,
- _("Unknown CFI encountered."));
+ if (insn >= DW_CFA_lo_user && insn <= DW_CFA_hi_user)
+ {
+ /* Handle vendor-specific CFI for different architectures. */
+ if (!gdbarch_execute_dwarf_cfa_vendor_op (gdbarch, insn, fs))
+ error (_("Call Frame Instruction %d in vendor extension "
+ "space is not handled on this architecture."),
+ insn);
+ }
+ else
+ internal_error (__FILE__, __LINE__,
+ _("Unknown CFI encountered."));
}
}
}
diff --git a/gdb/dwarf2-frame.h b/gdb/dwarf2-frame.h
index 2ada436..9e8668e 100644
--- a/gdb/dwarf2-frame.h
+++ b/gdb/dwarf2-frame.h
@@ -82,6 +82,58 @@ struct dwarf2_frame_state_reg
enum dwarf2_frame_reg_rule how;
};
+enum cfa_how_kind
+{
+ CFA_UNSET,
+ CFA_REG_OFFSET,
+ CFA_EXP
+};
+
+struct dwarf2_frame_state_reg_info
+{
+ struct dwarf2_frame_state_reg *reg;
+ int num_regs;
+
+ LONGEST cfa_offset;
+ ULONGEST cfa_reg;
+ enum cfa_how_kind cfa_how;
+ const gdb_byte *cfa_exp;
+
+ /* Used to implement DW_CFA_remember_state. */
+ struct dwarf2_frame_state_reg_info *prev;
+};
+
+/* Structure describing a frame state. */
+
+struct dwarf2_frame_state
+{
+ /* Each register save state can be described in terms of a CFA slot,
+ another register, or a location expression. */
+ struct dwarf2_frame_state_reg_info regs;
+
+ /* The PC described by the current frame state. */
+ CORE_ADDR pc;
+
+ /* Initial register set from the CIE.
+ Used to implement DW_CFA_restore. */
+ struct dwarf2_frame_state_reg_info initial;
+
+ /* The information we care about from the CIE. */
+ LONGEST data_align;
+ ULONGEST code_align;
+ ULONGEST retaddr_column;
+
+ /* Flags for known producer quirks. */
+
+ /* The ARM compilers, in DWARF2 mode, assume that DW_CFA_def_cfa
+ and DW_CFA_def_cfa_offset takes a factored offset. */
+ int armcc_cfa_offsets_sf;
+
+ /* The ARM compilers, in DWARF2 or DWARF3 mode, may assume that
+ the CFA is defined as REG - OFFSET rather than REG + OFFSET. */
+ int armcc_cfa_offsets_reversed;
+};
+
/* Set the architecture-specific register state initialization
function for GDBARCH to INIT_REG. */
@@ -120,6 +172,12 @@ extern const struct frame_base *
CORE_ADDR dwarf2_frame_cfa (struct frame_info *this_frame);
+/* Assert that the register set RS is large enough to store gdbarch_num_regs
+ columns. If necessary, enlarge the register set. */
+
+void dwarf2_frame_state_alloc_regs (struct dwarf2_frame_state_reg_info *rs,
+ int num_regs);
+
/* Find the CFA information for PC.
Return 1 if a register is used for the CFA, or 0 if another
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index 5664325..41c0866 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -275,6 +275,7 @@ struct gdbarch
int have_nonsteppable_watchpoint;
gdbarch_address_class_type_flags_ftype *address_class_type_flags;
gdbarch_address_class_type_flags_to_name_ftype *address_class_type_flags_to_name;
+ gdbarch_execute_dwarf_cfa_vendor_op_ftype *execute_dwarf_cfa_vendor_op;
gdbarch_address_class_name_to_type_flags_ftype *address_class_name_to_type_flags;
gdbarch_register_reggroup_p_ftype *register_reggroup_p;
gdbarch_fetch_pointer_argument_ftype *fetch_pointer_argument;
@@ -436,6 +437,7 @@ gdbarch_alloc (const struct gdbarch_info *info,
gdbarch->make_symbol_special = default_make_symbol_special;
gdbarch->adjust_dwarf2_addr = default_adjust_dwarf2_addr;
gdbarch->adjust_dwarf2_line = default_adjust_dwarf2_line;
+ gdbarch->execute_dwarf_cfa_vendor_op = default_execute_dwarf_cfa_vendor_op;
gdbarch->register_reggroup_p = default_register_reggroup_p;
gdbarch->skip_permanent_breakpoint = default_skip_permanent_breakpoint;
gdbarch->displaced_step_hw_singlestep = default_displaced_step_hw_singlestep;
@@ -634,6 +636,7 @@ verify_gdbarch (struct gdbarch *gdbarch)
/* Skip verify of have_nonsteppable_watchpoint, invalid_p == 0 */
/* Skip verify of address_class_type_flags, has predicate. */
/* Skip verify of address_class_type_flags_to_name, has predicate. */
+ /* Skip verify of execute_dwarf_cfa_vendor_op, invalid_p == 0 */
/* Skip verify of address_class_name_to_type_flags, has predicate. */
/* Skip verify of register_reggroup_p, invalid_p == 0 */
/* Skip verify of fetch_pointer_argument, has predicate. */
@@ -975,6 +978,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
"gdbarch_dump: elfcore_write_linux_prpsinfo = <%s>\n",
host_address_to_string (gdbarch->elfcore_write_linux_prpsinfo));
fprintf_unfiltered (file,
+ "gdbarch_dump: execute_dwarf_cfa_vendor_op = <%s>\n",
+ host_address_to_string (gdbarch->execute_dwarf_cfa_vendor_op));
+ fprintf_unfiltered (file,
"gdbarch_dump: fast_tracepoint_valid_at = <%s>\n",
host_address_to_string (gdbarch->fast_tracepoint_valid_at));
fprintf_unfiltered (file,
@@ -3523,6 +3529,23 @@ set_gdbarch_address_class_type_flags_to_name (struct gdbarch *gdbarch,
gdbarch->address_class_type_flags_to_name = address_class_type_flags_to_name;
}
+bool
+gdbarch_execute_dwarf_cfa_vendor_op (struct gdbarch *gdbarch, gdb_byte op, struct dwarf2_frame_state *fs)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->execute_dwarf_cfa_vendor_op != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_execute_dwarf_cfa_vendor_op called\n");
+ return gdbarch->execute_dwarf_cfa_vendor_op (gdbarch, op, fs);
+}
+
+void
+set_gdbarch_execute_dwarf_cfa_vendor_op (struct gdbarch *gdbarch,
+ gdbarch_execute_dwarf_cfa_vendor_op_ftype execute_dwarf_cfa_vendor_op)
+{
+ gdbarch->execute_dwarf_cfa_vendor_op = execute_dwarf_cfa_vendor_op;
+}
+
int
gdbarch_address_class_name_to_type_flags_p (struct gdbarch *gdbarch)
{
diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index 4845f23..7617908 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -827,6 +827,13 @@ typedef const char * (gdbarch_address_class_type_flags_to_name_ftype) (struct gd
extern const char * gdbarch_address_class_type_flags_to_name (struct gdbarch *gdbarch, int type_flags);
extern void set_gdbarch_address_class_type_flags_to_name (struct gdbarch *gdbarch, gdbarch_address_class_type_flags_to_name_ftype *address_class_type_flags_to_name);
+/* Execute vendor-specific DWARF Call Frame Instruction. OP is the instruction.
+ FS are passed from the generic execute_cfa_program function. */
+
+typedef bool (gdbarch_execute_dwarf_cfa_vendor_op_ftype) (struct gdbarch *gdbarch, gdb_byte op, struct dwarf2_frame_state *fs);
+extern bool gdbarch_execute_dwarf_cfa_vendor_op (struct gdbarch *gdbarch, gdb_byte op, struct dwarf2_frame_state *fs);
+extern void set_gdbarch_execute_dwarf_cfa_vendor_op (struct gdbarch *gdbarch, gdbarch_execute_dwarf_cfa_vendor_op_ftype *execute_dwarf_cfa_vendor_op);
+
/* Return the appropriate type_flags for the supplied address class.
This function should return 1 if the address class was recognized and
type_flags was set, zero otherwise. */
diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index a42dc43..fa85f7c 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -708,6 +708,9 @@ v:int:cannot_step_breakpoint:::0:0::0
v:int:have_nonsteppable_watchpoint:::0:0::0
F:int:address_class_type_flags:int byte_size, int dwarf2_addr_class:byte_size, dwarf2_addr_class
M:const char *:address_class_type_flags_to_name:int type_flags:type_flags
+# Execute vendor-specific DWARF Call Frame Instruction. OP is the instruction.
+# FS are passed from the generic execute_cfa_program function.
+m:bool:execute_dwarf_cfa_vendor_op:gdb_byte op, struct dwarf2_frame_state *fs:op, fs::default_execute_dwarf_cfa_vendor_op::0
# Return the appropriate type_flags for the supplied address class.
# This function should return 1 if the address class was recognized and
diff --git a/gdb/sparc-tdep.c b/gdb/sparc-tdep.c
index 078907a..73152ce 100644
--- a/gdb/sparc-tdep.c
+++ b/gdb/sparc-tdep.c
@@ -20,6 +20,7 @@
#include "defs.h"
#include "arch-utils.h"
#include "dis-asm.h"
+#include "dwarf2.h"
#include "dwarf2-frame.h"
#include "floatformat.h"
#include "frame.h"
@@ -1536,6 +1537,34 @@ sparc32_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
}
}
+/* Implement the execute_dwarf_cfa_vendor_op method. */
+
+static bool
+sparc_execute_dwarf_cfa_vendor_op (struct gdbarch *gdbarch, gdb_byte op,
+ struct dwarf2_frame_state *fs)
+{
+ /* Only DW_CFA_GNU_window_save is expected on SPARC. */
+ if (op != DW_CFA_GNU_window_save)
+ return false;
+
+ uint64_t reg;
+ int size = register_size (gdbarch, 0);
+
+ dwarf2_frame_state_alloc_regs (&fs->regs, 32);
+ for (reg = 8; reg < 16; reg++)
+ {
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG;
+ fs->regs.reg[reg].loc.reg = reg + 16;
+ }
+ for (reg = 16; reg < 32; reg++)
+ {
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
+ fs->regs.reg[reg].loc.offset = (reg - 16) * size;
+ }
+
+ return true;
+}
+
/* The SPARC Architecture doesn't have hardware single-step support,
and most operating systems don't implement it either, so we provide
@@ -1801,6 +1830,9 @@ sparc32_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
/* Hook in the DWARF CFI frame unwinder. */
dwarf2_frame_set_init_reg (gdbarch, sparc32_dwarf2_frame_init_reg);
+ /* Register DWARF vendor CFI handler. */
+ set_gdbarch_execute_dwarf_cfa_vendor_op (gdbarch,
+ sparc_execute_dwarf_cfa_vendor_op);
/* FIXME: kettenis/20050423: Don't enable the unwinder until the
StackGhost issues have been resolved. */