/* Intel 386 target-dependent stuff.
Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
- 1997, 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+ 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software
+ Foundation, Inc.
This file is part of GDB.
subl %edx, %edx
subl %eax, %eax
+ Because of the symmetry, there are actually two ways to
+ encode these instructions; with opcode bytes 0x29 and 0x2b
+ for `subl' and opcode bytes 0x31 and 0x33 for `xorl'.
+
Make sure we only skip these instructions if we later see the
`movl %esp, %ebp' that actually sets up the frame. */
- while (op == 0x29 || op == 0x31)
+ while (op == 0x29 || op == 0x2b || op == 0x31 || op == 0x33)
{
op = read_memory_unsigned_integer (pc + skip + 2, 1);
switch (op)
#define LOW_RETURN_REGNUM I386_EAX_REGNUM /* %eax */
#define HIGH_RETURN_REGNUM I386_EDX_REGNUM /* %edx */
-/* Extract from an array REGBUF containing the (raw) register state, a
- function return value of TYPE, and copy that, in virtual format,
- into VALBUF. */
+/* Read, for architecture GDBARCH, a function return value of TYPE
+ from REGCACHE, and copy that into VALBUF. */
static void
-i386_extract_return_value (struct type *type, struct regcache *regcache,
- void *valbuf)
+i386_extract_return_value (struct gdbarch *gdbarch, struct type *type,
+ struct regcache *regcache, void *valbuf)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
int len = TYPE_LENGTH (type);
char buf[I386_MAX_REGISTER_SIZE];
- if (TYPE_CODE (type) == TYPE_CODE_STRUCT
- && TYPE_NFIELDS (type) == 1)
- {
- i386_extract_return_value (TYPE_FIELD_TYPE (type, 0), regcache, valbuf);
- return;
- }
-
if (TYPE_CODE (type) == TYPE_CODE_FLT)
{
if (tdep->st0_regnum < 0)
}
}
-/* Write into the appropriate registers a function return value stored
- in VALBUF of type TYPE, given in virtual format. */
+/* Write, for architecture GDBARCH, a function return value of TYPE
+ from VALBUF into REGCACHE. */
static void
-i386_store_return_value (struct type *type, struct regcache *regcache,
- const void *valbuf)
+i386_store_return_value (struct gdbarch *gdbarch, struct type *type,
+ struct regcache *regcache, const void *valbuf)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
int len = TYPE_LENGTH (type);
/* Define I387_ST0_REGNUM such that we use the proper definitions
for the architecture. */
#define I387_ST0_REGNUM I386_ST0_REGNUM
- if (TYPE_CODE (type) == TYPE_CODE_STRUCT
- && TYPE_NFIELDS (type) == 1)
- {
- i386_store_return_value (TYPE_FIELD_TYPE (type, 0), regcache, valbuf);
- return;
- }
-
if (TYPE_CODE (type) == TYPE_CODE_FLT)
{
ULONGEST fstat;
#undef I387_ST0_REGNUM
}
-
-/* Extract from REGCACHE, which contains the (raw) register state, the
- address in which a function should return its structure value, as a
- CORE_ADDR. */
-
-static CORE_ADDR
-i386_extract_struct_value_address (struct regcache *regcache)
-{
- char buf[4];
-
- regcache_cooked_read (regcache, I386_EAX_REGNUM, buf);
- return extract_unsigned_integer (buf, 4);
-}
\f
/* This is the variable that is set with "set struct-convention", and
};
static const char *struct_convention = default_struct_convention;
+/* Return non-zero if TYPE, which is assumed to be a structure or
+ union type, should be returned in registers for architecture
+ GDBARCH. */
+
static int
-i386_use_struct_convention (int gcc_p, struct type *type)
+i386_reg_struct_return_p (struct gdbarch *gdbarch, struct type *type)
{
- enum struct_return struct_return;
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ enum type_code code = TYPE_CODE (type);
+ int len = TYPE_LENGTH (type);
- if (struct_convention == default_struct_convention)
- struct_return = gdbarch_tdep (current_gdbarch)->struct_return;
- else if (struct_convention == pcc_struct_convention)
- struct_return = pcc_struct_return;
- else
- struct_return = reg_struct_return;
+ gdb_assert (code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION);
- return generic_use_struct_convention (struct_return == reg_struct_return,
- type);
+ if (struct_convention == pcc_struct_convention
+ || (struct_convention == default_struct_convention
+ && tdep->struct_return == pcc_struct_return))
+ return 0;
+
+ return (len == 1 || len == 2 || len == 4 || len == 8);
+}
+
+/* Determine, for architecture GDBARCH, how a return value of TYPE
+ should be returned. If it is supposed to be returned in registers,
+ and READBUF is non-zero, read the appropriate value from REGCACHE,
+ and copy it into READBUF. If WRITEBUF is non-zero, write the value
+ from WRITEBUF into REGCACHE. */
+
+static enum return_value_convention
+i386_return_value (struct gdbarch *gdbarch, struct type *type,
+ struct regcache *regcache, void *readbuf,
+ const void *writebuf)
+{
+ enum type_code code = TYPE_CODE (type);
+
+ if ((code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION)
+ && !i386_reg_struct_return_p (gdbarch, type))
+ return RETURN_VALUE_STRUCT_CONVENTION;
+
+ /* This special case is for structures consisting of a single
+ `float' or `double' member. These structures are returned in
+ %st(0). For these structures, we call ourselves recursively,
+ changing TYPE into the type of the first member of the structure.
+ Since that should work for all structures that have only one
+ member, we don't bother to check the member's type here. */
+ if (code == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1)
+ {
+ type = check_typedef (TYPE_FIELD_TYPE (type, 0));
+ return i386_return_value (gdbarch, type, regcache, readbuf, writebuf);
+ }
+
+ if (readbuf)
+ i386_extract_return_value (gdbarch, type, regcache, readbuf);
+ if (writebuf)
+ i386_store_return_value (gdbarch, type, regcache, writebuf);
+
+ return RETURN_VALUE_REGISTER_CONVENTION;
}
\f
to register cache REGCACHE. If REGNUM is -1, do this for all
registers in REGSET. */
-static void
+void
i386_supply_gregset (const struct regset *regset, struct regcache *regcache,
int regnum, const void *gregs, size_t len)
{
set_gdbarch_register_to_value (gdbarch, i386_register_to_value);
set_gdbarch_value_to_register (gdbarch, i386_value_to_register);
- set_gdbarch_extract_return_value (gdbarch, i386_extract_return_value);
- set_gdbarch_store_return_value (gdbarch, i386_store_return_value);
- set_gdbarch_extract_struct_value_address (gdbarch,
- i386_extract_struct_value_address);
- set_gdbarch_use_struct_convention (gdbarch, i386_use_struct_convention);
+ set_gdbarch_return_value (gdbarch, i386_return_value);
set_gdbarch_skip_prologue (gdbarch, i386_skip_prologue);
set_gdbarch_breakpoint_from_pc (gdbarch, i386_breakpoint_from_pc);
set_gdbarch_decr_pc_after_break (gdbarch, 1);
- set_gdbarch_function_start_offset (gdbarch, 0);
set_gdbarch_frame_args_skip (gdbarch, 8);
set_gdbarch_pc_in_sigtramp (gdbarch, i386_pc_in_sigtramp);
projects / deliverable / binutils-gdb.git / blobdiff