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* [binutils-gdb] gdb: LoongArch: Implement the push_dummy_call gdbarch method
@ 2022-07-07 9:10 Tiezhu Yang
0 siblings, 0 replies; only message in thread
From: Tiezhu Yang @ 2022-07-07 9:10 UTC (permalink / raw)
To: gdb-cvs
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=88de583569400f6c81caa6f943d1290d134ea48a
commit 88de583569400f6c81caa6f943d1290d134ea48a
Author: Tiezhu Yang <yangtiezhu@loongson.cn>
Date: Thu Jul 7 14:33:19 2022 +0800
gdb: LoongArch: Implement the push_dummy_call gdbarch method
According to "Procedure Calling Convention" in "LoongArch ELF ABI
specification" [1], implement the push_dummy_call gdbarch method
as clear as possible.
[1] https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html#_procedure_calling_convention
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Diff:
---
gdb/loongarch-tdep.c | 596 +++++++++++++++++++++++++++++++++++++++++++++++++++
gdb/loongarch-tdep.h | 2 +
2 files changed, 598 insertions(+)
diff --git a/gdb/loongarch-tdep.c b/gdb/loongarch-tdep.c
index 76480ce6c94..3add71b2a09 100644
--- a/gdb/loongarch-tdep.c
+++ b/gdb/loongarch-tdep.c
@@ -452,6 +452,599 @@ static const struct frame_unwind loongarch_frame_unwind = {
/*.prev_arch =*/nullptr,
};
+static void
+pass_in_gar (struct regcache *regcache, unsigned int gar, const gdb_byte *val)
+{
+ unsigned int regnum = LOONGARCH_ARG_REGNUM - gar + LOONGARCH_A0_REGNUM;
+ regcache->cooked_write (regnum, val);
+}
+
+static void
+pass_in_far (struct regcache *regcache, unsigned int far, const gdb_byte *val)
+{
+ unsigned int regnum = LOONGARCH_ARG_REGNUM - far + LOONGARCH_BADV_REGNUM + 1;
+ regcache->cooked_write (regnum, val);
+}
+
+static __attribute__((aligned(16))) gdb_byte buf[1024] = { 0 };
+static gdb_byte *addr = buf;
+
+static void
+pass_on_stack (struct regcache *regcache, const gdb_byte *val, size_t len, int align)
+{
+ align = align_up (align, 8);
+ if (align > 16)
+ align = 16;
+
+ CORE_ADDR align_addr = (CORE_ADDR) addr;
+ align_addr = align_up (align_addr, align);
+ addr = (gdb_byte *) align_addr;
+ memcpy (addr, val, len);
+ addr += len;
+}
+
+static unsigned int fixed_point_members = 0;
+static unsigned int floating_point_members = 0;
+static bool first_member_is_fixed_point = false;
+
+static void
+compute_struct_member (struct type *type)
+{
+ for (int i = 0; i < type->num_fields (); i++)
+ {
+ struct type *field_type = check_typedef (type->field (i).type ());
+
+ if (field_type->code () == TYPE_CODE_INT
+ || field_type->code () == TYPE_CODE_BOOL
+ || field_type->code () == TYPE_CODE_CHAR
+ || field_type->code () == TYPE_CODE_RANGE
+ || field_type->code () == TYPE_CODE_ENUM
+ || field_type->code () == TYPE_CODE_PTR)
+ {
+ fixed_point_members++;
+
+ if (floating_point_members == 0)
+ first_member_is_fixed_point = true;
+ }
+ else if (field_type->code () == TYPE_CODE_FLT)
+ floating_point_members++;
+ else if (field_type->code () == TYPE_CODE_STRUCT)
+ compute_struct_member (field_type);
+ else if (field_type->code () == TYPE_CODE_COMPLEX)
+ floating_point_members += 2;
+ }
+}
+
+/* Implement the push_dummy_call gdbarch method. */
+
+static CORE_ADDR
+loongarch_push_dummy_call (struct gdbarch *gdbarch,
+ struct value *function,
+ struct regcache *regcache,
+ CORE_ADDR bp_addr,
+ int nargs,
+ struct value **args,
+ CORE_ADDR sp,
+ function_call_return_method return_method,
+ CORE_ADDR struct_addr)
+{
+ int regsize = register_size (gdbarch, 0);
+ unsigned int gar = LOONGARCH_ARG_REGNUM;
+ unsigned int far = LOONGARCH_ARG_REGNUM;
+
+ if (return_method != return_method_normal)
+ pass_in_gar (regcache, gar--, (gdb_byte *) &struct_addr);
+
+ addr = buf;
+ for (int i = 0; i < nargs; i++)
+ {
+ struct value *arg = args[i];
+ const gdb_byte *val = value_contents (arg).data ();
+ struct type *type = check_typedef (value_type (arg));
+ size_t len = TYPE_LENGTH (type);
+ int align = type_align (type);
+ enum type_code code = type->code ();
+
+ switch (code)
+ {
+ case TYPE_CODE_INT:
+ case TYPE_CODE_BOOL:
+ case TYPE_CODE_CHAR:
+ case TYPE_CODE_RANGE:
+ case TYPE_CODE_ENUM:
+ case TYPE_CODE_PTR:
+ {
+ /* integer or pointer type is passed in GAR.
+ * If no GAR is available, it’s passed on the stack.
+ * When passed in registers or on the stack,
+ * the unsigned integer scalars are zero-extended to GRLEN bits,
+ * and the signed integer scalars are sign-extended. */
+ if (type->is_unsigned ())
+ {
+ ULONGEST data = extract_unsigned_integer (val, len, BFD_ENDIAN_LITTLE);
+ if (gar > 0)
+ pass_in_gar (regcache, gar--, (gdb_byte *) &data);
+ else
+ pass_on_stack (regcache, (gdb_byte *) &data, len, align);
+ }
+ else
+ {
+ LONGEST data = extract_signed_integer (val, len, BFD_ENDIAN_LITTLE);
+ if (gar > 0)
+ pass_in_gar (regcache, gar--, (gdb_byte *) &data);
+ else
+ pass_on_stack (regcache, (gdb_byte *) &data, len, align);
+ }
+ }
+ break;
+ case TYPE_CODE_FLT:
+ if (len == 2 * regsize)
+ {
+ /* long double type is passed in a pair of GAR,
+ * with the low-order GRLEN bits in the lower-numbered register
+ * and the high-order GRLEN bits in the higher-numbered register.
+ * If exactly one register is available,
+ * the low-order GRLEN bits are passed in the register
+ * and the high-order GRLEN bits are passed on the stack.
+ * If no GAR is available, it’s passed on the stack. */
+ if (gar >= 2)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_in_gar (regcache, gar--, val + regsize);
+ }
+ else if (gar == 1)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_on_stack (regcache, val + regsize, len - regsize, align);
+ }
+ else
+ {
+ pass_on_stack (regcache, val, len, align);
+ }
+ }
+ else
+ {
+ /* The other floating-point type is passed in FAR.
+ * If no FAR is available, it’s passed in GAR.
+ * If no GAR is available, it’s passed on the stack. */
+ if (far > 0)
+ pass_in_far (regcache, far--, val);
+ else if (gar > 0)
+ pass_in_gar (regcache, gar--, val);
+ else
+ pass_on_stack (regcache, val, len, align);
+ }
+ break;
+ case TYPE_CODE_STRUCT:
+ {
+ fixed_point_members = 0;
+ floating_point_members = 0;
+ first_member_is_fixed_point = false;
+ compute_struct_member (type);
+
+ if (len > 0 && len <= regsize)
+ {
+ /* The structure has only fixed-point members. */
+ if (fixed_point_members > 0 && floating_point_members == 0)
+ {
+ /* If there is an available GAR,
+ * the structure is passed through the GAR by value passing;
+ * If no GAR is available, it’s passed on the stack. */
+ if (gar > 0)
+ pass_in_gar (regcache, gar--, val);
+ else
+ pass_on_stack (regcache, val, len, align);
+ }
+ /* The structure has only floating-point members. */
+ else if (fixed_point_members == 0 && floating_point_members > 0)
+ {
+ /* One floating-point member.
+ * The argument is passed in a FAR.
+ * If no FAR is available, the value is passed in a GAR.
+ * if no GAR is available, the value is passed on the stack. */
+ if (floating_point_members == 1)
+ {
+ if (far > 0)
+ pass_in_far (regcache, far--, val);
+ else if (gar > 0)
+ pass_in_gar (regcache, gar--, val);
+ else
+ pass_on_stack (regcache, val, len, align);
+ }
+ /* Two floating-point members.
+ * The argument is passed in a pair of available FAR,
+ * with the low-order float member bits in the lower-numbered FAR
+ * and the high-order float member bits in the higher-numbered FAR.
+ * If the number of available FAR is less than 2, it’s passed in a GAR,
+ * and passed on the stack if no GAR is available. */
+ else if (floating_point_members == 2)
+ {
+ if (far >= 2)
+ {
+ pass_in_far (regcache, far--, val);
+ pass_in_far (regcache, far--, val + align);
+ }
+ else if (gar > 0)
+ {
+ pass_in_gar (regcache, gar--, val);
+ }
+ else
+ {
+ pass_on_stack (regcache, val, len, align);
+ }
+ }
+ }
+ /* The structure has both fixed-point and floating-point members. */
+ else if (fixed_point_members > 0 && floating_point_members > 0)
+ {
+ /* One float member and multiple fixed-point members.
+ * If there are available GAR, the structure is passed in a GAR,
+ * and passed on the stack if no GAR is available. */
+ if (floating_point_members == 1 && fixed_point_members > 1)
+ {
+ if (gar > 0)
+ pass_in_gar (regcache, gar--, val);
+ else
+ pass_on_stack (regcache, val, len, align);
+ }
+ /* One float member and only one fixed-point member.
+ * If one FAR and one GAR are available,
+ * the floating-point member of the structure is passed in the FAR,
+ * and the fixed-point member of the structure is passed in the GAR.
+ * If no floating-point register but one GAR is available, it’s passed in GAR;
+ * If no GAR is available, it’s passed on the stack. */
+ else if (floating_point_members == 1 && fixed_point_members == 1)
+ {
+ if (far > 0 && gar > 0)
+ {
+ if (first_member_is_fixed_point == false)
+ {
+ pass_in_far (regcache, far--, val);
+ pass_in_gar (regcache, gar--, val + align);
+ }
+ else
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_in_far (regcache, far--, val + align);
+ }
+ }
+ else
+ {
+ if (gar > 0)
+ pass_in_gar (regcache, gar--, val);
+ else
+ pass_on_stack (regcache, val, len, align);
+ }
+ }
+ }
+ }
+ else if (len > regsize && len <= 2 * regsize)
+ {
+ /* Only fixed-point members. */
+ if (fixed_point_members > 0 && floating_point_members == 0)
+ {
+ /* The argument is passed in a pair of available GAR,
+ * with the low-order bits in the lower-numbered GAR
+ * and the high-order bits in the higher-numbered GAR.
+ * If only one GAR is available,
+ * the low-order bits are in the GAR
+ * and the high-order bits are on the stack,
+ * and passed on the stack if no GAR is available. */
+ if (gar >= 2)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_in_gar (regcache, gar--, val + regsize);
+ }
+ else if (gar == 1)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_on_stack (regcache, val + regsize, len - regsize, align);
+ }
+ else
+ {
+ pass_on_stack (regcache, val, len, align);
+ }
+ }
+ /* Only floating-point members. */
+ else if (fixed_point_members == 0 && floating_point_members > 0)
+ {
+ /* The structure has one long double member
+ * or one double member and two adjacent float members
+ * or 3-4 float members.
+ * The argument is passed in a pair of available GAR,
+ * with the low-order bits in the lower-numbered GAR
+ * and the high-order bits in the higher-numbered GAR.
+ * If only one GAR is available,
+ * the low-order bits are in the GAR
+ * and the high-order bits are on the stack,
+ * and passed on the stack if no GAR is available. */
+ if ((len == 16 && floating_point_members == 1)
+ || (len == 16 && floating_point_members == 3)
+ || (len == 12 && floating_point_members == 3)
+ || (len == 16 && floating_point_members == 4))
+ {
+ if (gar >= 2)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_in_gar (regcache, gar--, val + regsize);
+ }
+ else if (gar == 1)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_on_stack (regcache, val + regsize, len - regsize, align);
+ }
+ else
+ {
+ pass_on_stack (regcache, val, len, align);
+ }
+ }
+ /* The structure with two double members
+ * is passed in a pair of available FAR,
+ * with the low-order bits in the lower-numbered FAR
+ * and the high-order bits in the higher-numbered FAR.
+ * If no a pair of available FAR,
+ * it’s passed in a pair of available GAR,
+ * with the low-order bits in the lower-numbered GAR
+ * and the high-order bits in the higher-numbered GAR.
+ * If only one GAR is available,
+ * the low-order bits are in the GAR
+ * and the high-order bits are on stack,
+ * and passed on the stack if no GAR is available.
+ * A structure with one double member and one float member is same. */
+ else if ((len == 16 && floating_point_members == 2)
+ || (len == 12 && floating_point_members == 2))
+ {
+ if (far >= 2)
+ {
+ pass_in_far (regcache, far--, val);
+ pass_in_far (regcache, far--, val + regsize);
+ }
+ else if (gar >= 2)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_in_gar (regcache, gar--, val + regsize);
+ }
+ else if (gar == 1)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_on_stack (regcache, val + regsize, len - regsize, align);
+ }
+ else
+ {
+ pass_on_stack (regcache, val, len, align);
+ }
+ }
+ }
+ /* Both fixed-point and floating-point members. */
+ else if (fixed_point_members > 0 && floating_point_members > 0)
+ {
+ /* The structure has one floating-point member and only one fixed-point member. */
+ if (floating_point_members == 1 && fixed_point_members == 1)
+ {
+ /* If one FAR and one GAR are available,
+ * the floating-point member of the structure is passed in the FAR,
+ * and the fixed-point member of the structure is passed in the GAR;
+ * If no floating-point registers but two GARs are available,
+ * it’s passed in the two GARs;
+ * If only one GAR is available,
+ * the low-order bits are in the GAR
+ * and the high-order bits are on the stack;
+ * And it’s passed on the stack if no GAR is available. */
+ if (far > 0 && gar > 0)
+ {
+ if (first_member_is_fixed_point == false)
+ {
+ pass_in_far (regcache, far--, val);
+ pass_in_gar (regcache, gar--, val + regsize);
+ }
+ else
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_in_far (regcache, far--, val + regsize);
+ }
+ }
+ else if (far == 0 && gar >= 2)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_in_gar (regcache, gar--, val + regsize);
+ }
+ else if (far == 0 && gar == 1)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_on_stack (regcache, val + regsize, len - regsize, align);
+ }
+ else if (far == 0 && gar == 0)
+ {
+ pass_on_stack (regcache, val, len, align);
+ }
+ }
+ else
+ {
+ /* The argument is passed in a pair of available GAR,
+ * with the low-order bits in the lower-numbered GAR
+ * and the high-order bits in the higher-numbered GAR.
+ * If only one GAR is available,
+ * the low-order bits are in the GAR
+ * and the high-order bits are on the stack,
+ * and passed on the stack if no GAR is available. */
+ if (gar >= 2)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_in_gar (regcache, gar--, val + regsize);
+ }
+ else if (gar == 1)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_on_stack (regcache, val + regsize, len - regsize, align);
+ }
+ else
+ {
+ pass_on_stack (regcache, val, len, align);
+ }
+ }
+ }
+ }
+ else if (len > 2 * regsize)
+ {
+ /* It’s passed by reference and are replaced in the argument list with the address.
+ * If there is an available GAR, the reference is passed in the GAR,
+ * and passed on the stack if no GAR is available. */
+ sp = align_down (sp - len, 16);
+ write_memory (sp, val, len);
+
+ if (gar > 0)
+ pass_in_gar (regcache, gar--, (const gdb_byte *) &sp);
+ else
+ pass_on_stack (regcache, (const gdb_byte*) &sp, len, regsize);
+ }
+ }
+ break;
+ case TYPE_CODE_UNION:
+ /* Union is passed in GAR or stack. */
+ if (len > 0 && len <= regsize)
+ {
+ /* The argument is passed in a GAR,
+ * or on the stack by value if no GAR is available. */
+ if (gar > 0)
+ pass_in_gar (regcache, gar--, val);
+ else
+ pass_on_stack (regcache, val, len, align);
+ }
+ else if (len > regsize && len <= 2 * regsize)
+ {
+ /* The argument is passed in a pair of available GAR,
+ * with the low-order bits in the lower-numbered GAR
+ * and the high-order bits in the higher-numbered GAR.
+ * If only one GAR is available,
+ * the low-order bits are in the GAR
+ * and the high-order bits are on the stack.
+ * The arguments are passed on the stack when no GAR is available. */
+ if (gar >= 2)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_in_gar (regcache, gar--, val + regsize);
+ }
+ else if (gar == 1)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_on_stack (regcache, val + regsize, len - regsize, align);
+ }
+ else
+ {
+ pass_on_stack (regcache, val, len, align);
+ }
+ }
+ else if (len > 2 * regsize)
+ {
+ /* It’s passed by reference and are replaced in the argument list with the address.
+ * If there is an available GAR, the reference is passed in the GAR,
+ * and passed on the stack if no GAR is available. */
+ sp = align_down (sp - len, 16);
+ write_memory (sp, val, len);
+
+ if (gar > 0)
+ pass_in_gar (regcache, gar--, (const gdb_byte *) &sp);
+ else
+ pass_on_stack (regcache, (const gdb_byte*) &sp, len, regsize);
+ }
+ break;
+ case TYPE_CODE_COMPLEX:
+ {
+ struct type *target_type = check_typedef (TYPE_TARGET_TYPE (type));
+ size_t target_len = TYPE_LENGTH (target_type);
+
+ if (target_len < regsize)
+ {
+ /* The complex with two float members
+ * is passed in a pair of available FAR,
+ * with the low-order float member bits in the lower-numbered FAR
+ * and the high-order float member bits in the higher-numbered FAR.
+ * If the number of available FAR is less than 2, it’s passed in a GAR,
+ * and passed on the stack if no GAR is available. */
+ if (far >= 2)
+ {
+ pass_in_far (regcache, far--, val);
+ pass_in_far (regcache, far--, val + align);
+ }
+ else if (gar > 0)
+ {
+ pass_in_gar (regcache, gar--, val);
+ }
+ else
+ {
+ pass_on_stack (regcache, val, len, align);
+ }
+ }
+ else if (target_len == regsize)
+ {
+ /* The complex with two double members
+ * is passed in a pair of available FAR,
+ * with the low-order bits in the lower-numbered FAR
+ * and the high-order bits in the higher-numbered FAR.
+ * If no a pair of available FAR,
+ * it’s passed in a pair of available GAR,
+ * with the low-order bits in the lower-numbered GAR
+ * and the high-order bits in the higher-numbered GAR.
+ * If only one GAR is available,
+ * the low-order bits are in the GAR
+ * and the high-order bits are on stack,
+ * and passed on the stack if no GAR is available. */
+ {
+ if (far >= 2)
+ {
+ pass_in_far (regcache, far--, val);
+ pass_in_far (regcache, far--, val + align);
+ }
+ else if (gar >= 2)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_in_gar (regcache, gar--, val + align);
+ }
+ else if (gar == 1)
+ {
+ pass_in_gar (regcache, gar--, val);
+ pass_on_stack (regcache, val + align, len - align, align);
+ }
+ else
+ {
+ pass_on_stack (regcache, val, len, align);
+ }
+ }
+ }
+ else if (target_len == 2 * regsize)
+ {
+ /* The complex with two long double members
+ * is passed by reference and are replaced in the argument list with the address.
+ * If there is an available GAR, the reference is passed in the GAR,
+ * and passed on the stack if no GAR is available. */
+ sp = align_down (sp - len, 16);
+ write_memory (sp, val, len);
+
+ if (gar > 0)
+ pass_in_gar (regcache, gar--, (const gdb_byte *) &sp);
+ else
+ pass_on_stack (regcache, (const gdb_byte*) &sp, regsize, regsize);
+ }
+ }
+ break;
+ default:
+ break;
+ }
+ }
+
+ if (addr > buf)
+ {
+ sp -= addr - buf;
+ sp = align_down (sp, 16);
+ write_memory (sp, buf, addr - buf);
+ }
+
+ regcache_cooked_write_unsigned (regcache, LOONGARCH_RA_REGNUM, bp_addr);
+ regcache_cooked_write_unsigned (regcache, LOONGARCH_SP_REGNUM, sp);
+
+ return sp;
+}
+
/* Implement the return_value gdbarch method. */
static enum return_value_convention
@@ -644,6 +1237,9 @@ loongarch_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
/* Finalise the target description registers. */
tdesc_use_registers (gdbarch, tdesc, std::move (tdesc_data));
+ /* Functions handling dummy frames. */
+ set_gdbarch_push_dummy_call (gdbarch, loongarch_push_dummy_call);
+
/* Return value info */
set_gdbarch_return_value (gdbarch, loongarch_return_value);
diff --git a/gdb/loongarch-tdep.h b/gdb/loongarch-tdep.h
index acf0191fd65..672bc2b80de 100644
--- a/gdb/loongarch-tdep.h
+++ b/gdb/loongarch-tdep.h
@@ -39,6 +39,8 @@ enum
LOONGARCH_PC_REGNUM = 33, /* Program Counter. */
LOONGARCH_BADV_REGNUM = 34, /* Bad Vaddr for Addressing Exception. */
LOONGARCH_LINUX_NUM_GREGSET = 45, /* 32 GPR, ORIG_A0, PC, BADV, RESERVED 10. */
+ LOONGARCH_ARG_REGNUM = 8, /* r4-r11: general-purpose argument registers.
+ f0-f7: floating-point argument registers. */
};
/* Register set definitions. */
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