#endif /* GET_LONGJMP_TARGET */
+/* These registers are used for returning integers (and on some
+ targets also for returning `struct' and `union' values when their
+ size and alignment match an integer type. */
+#define LOW_RETURN_REGNUM 0 /* %eax */
+#define HIGH_RETURN_REGNUM 2 /* %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. */
+
void
-i386_extract_return_value (type, regbuf, valbuf)
- struct type *type;
- char regbuf[REGISTER_BYTES];
- char *valbuf;
+i386_extract_return_value (struct type *type, char *regbuf, char *valbuf)
{
- /* On AIX, i386 GNU/Linux and DJGPP, floating point values are
- returned in floating point registers. */
- /* FIXME: cagney/2000-02-29: This function needs to be rewritten
- using multi-arch. Please don't keep adding to this #ifdef
- spaghetti. */
-#if defined(I386_AIX_TARGET) || defined(I386_GNULINUX_TARGET) || defined(I386_DJGPP_TARGET)
+ int len = TYPE_LENGTH (type);
+
if (TYPE_CODE_FLT == TYPE_CODE (type))
{
- double d;
- /* 387 %st(0), gcc uses this */
- floatformat_to_double (&floatformat_i387_ext,
-#if defined(FPDATA_REGNUM)
- ®buf[REGISTER_BYTE (FPDATA_REGNUM)],
-#else /* !FPDATA_REGNUM */
- ®buf[REGISTER_BYTE (FP0_REGNUM)],
-#endif /* FPDATA_REGNUM */
-
- &d);
- store_floating (valbuf, TYPE_LENGTH (type), d);
+ if (NUM_FREGS == 0)
+ {
+ warning ("Cannot find floating-point return value.");
+ memset (valbuf, 0, len);
+ }
+
+ /* Floating-point return values can be found in %st(0). */
+ if (len == TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT
+ && TARGET_LONG_DOUBLE_FORMAT == &floatformat_i387_ext)
+ {
+ /* Copy straight over, but take care of the padding. */
+ memcpy (valbuf, ®buf[REGISTER_BYTE (FP0_REGNUM)],
+ FPU_REG_RAW_SIZE);
+ memset (valbuf + FPU_REG_RAW_SIZE, 0, len - FPU_REG_RAW_SIZE);
+ }
+ else
+ {
+ /* Convert the extended floating-point number found in
+ %st(0) to the desired type. This is probably not exactly
+ how it would happen on the target itself, but it is the
+ best we can do. */
+ DOUBLEST val;
+ floatformat_to_doublest (&floatformat_i387_ext,
+ ®buf[REGISTER_BYTE (FP0_REGNUM)], &val);
+ store_floating (valbuf, TYPE_LENGTH (type), val);
+ }
}
else
-#endif /* I386_AIX_TARGET || I386_GNULINUX_TARGET || I386_DJGPP_TARGET */
{
-#if defined(LOW_RETURN_REGNUM)
- int len = TYPE_LENGTH (type);
int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM);
int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM);
if (len <= low_size)
- memcpy (valbuf, regbuf + REGISTER_BYTE (LOW_RETURN_REGNUM), len);
+ memcpy (valbuf, ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], len);
else if (len <= (low_size + high_size))
{
memcpy (valbuf,
- regbuf + REGISTER_BYTE (LOW_RETURN_REGNUM),
- low_size);
+ ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], low_size);
memcpy (valbuf + low_size,
- regbuf + REGISTER_BYTE (HIGH_RETURN_REGNUM),
- len - low_size);
+ ®buf[REGISTER_BYTE (HIGH_RETURN_REGNUM)], len - low_size);
}
else
- error ("GDB bug: i386-tdep.c (i386_extract_return_value): Don't know how to find a return value %d bytes long", len);
-#else /* !LOW_RETURN_REGNUM */
- memcpy (valbuf, regbuf, TYPE_LENGTH (type));
-#endif /* LOW_RETURN_REGNUM */
+ internal_error ("Cannot extract return value of %d bytes long.", len);
}
}
}
#endif /* I386V4_SIGTRAMP_SAVED_PC */
-#ifdef I386_LINUX_SIGTRAMP
-
-/* When the i386 Linux kernel calls a signal handler, the return
- address points to a bit of code on the stack. This function
- returns whether the PC appears to be within this bit of code.
-
- The instruction sequence is
- pop %eax
- mov $0x77,%eax
- int $0x80
- or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80.
-
- Checking for the code sequence should be somewhat reliable, because
- the effect is to call the system call sigreturn. This is unlikely
- to occur anywhere other than a signal trampoline.
-
- It kind of sucks that we have to read memory from the process in
- order to identify a signal trampoline, but there doesn't seem to be
- any other way. The IN_SIGTRAMP macro in tm-linux.h arranges to
- only call us if no function name could be identified, which should
- be the case since the code is on the stack. */
-
-#define LINUX_SIGTRAMP_INSN0 (0x58) /* pop %eax */
-#define LINUX_SIGTRAMP_OFFSET0 (0)
-#define LINUX_SIGTRAMP_INSN1 (0xb8) /* mov $NNNN,%eax */
-#define LINUX_SIGTRAMP_OFFSET1 (1)
-#define LINUX_SIGTRAMP_INSN2 (0xcd) /* int */
-#define LINUX_SIGTRAMP_OFFSET2 (6)
-
-static const unsigned char linux_sigtramp_code[] =
-{
- LINUX_SIGTRAMP_INSN0, /* pop %eax */
- LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77,%eax */
- LINUX_SIGTRAMP_INSN2, 0x80 /* int $0x80 */
-};
-
-#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
-
-/* If PC is in a sigtramp routine, return the address of the start of
- the routine. Otherwise, return 0. */
-
-static CORE_ADDR
-i386_linux_sigtramp_start (pc)
- CORE_ADDR pc;
-{
- unsigned char buf[LINUX_SIGTRAMP_LEN];
-
- /* We only recognize a signal trampoline if PC is at the start of
- one of the three instructions. We optimize for finding the PC at
- the start, as will be the case when the trampoline is not the
- first frame on the stack. We assume that in the case where the
- PC is not at the start of the instruction sequence, there will be
- a few trailing readable bytes on the stack. */
-
- if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
- return 0;
-
- if (buf[0] != LINUX_SIGTRAMP_INSN0)
- {
- int adjust;
-
- switch (buf[0])
- {
- case LINUX_SIGTRAMP_INSN1:
- adjust = LINUX_SIGTRAMP_OFFSET1;
- break;
- case LINUX_SIGTRAMP_INSN2:
- adjust = LINUX_SIGTRAMP_OFFSET2;
- break;
- default:
- return 0;
- }
-
- pc -= adjust;
-
- if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
- return 0;
- }
-
- if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
- return 0;
-
- return pc;
-}
-
-/* Return whether PC is in a Linux sigtramp routine. */
-
-int
-i386_linux_sigtramp (pc)
- CORE_ADDR pc;
-{
- return i386_linux_sigtramp_start (pc) != 0;
-}
-
-/* Assuming FRAME is for a Linux sigtramp routine, return the saved
- program counter. The Linux kernel will set up a sigcontext
- structure immediately before the sigtramp routine on the stack. */
-
-CORE_ADDR
-i386_linux_sigtramp_saved_pc (frame)
- struct frame_info *frame;
-{
- CORE_ADDR pc;
-
- pc = i386_linux_sigtramp_start (frame->pc);
- if (pc == 0)
- error ("i386_linux_sigtramp_saved_pc called when no sigtramp");
- return read_memory_integer ((pc
- - LINUX_SIGCONTEXT_SIZE
- + LINUX_SIGCONTEXT_PC_OFFSET),
- 4);
-}
-
-/* Assuming FRAME is for a Linux sigtramp routine, return the saved
- stack pointer. The Linux kernel will set up a sigcontext structure
- immediately before the sigtramp routine on the stack. */
-
-CORE_ADDR
-i386_linux_sigtramp_saved_sp (frame)
- struct frame_info *frame;
-{
- CORE_ADDR pc;
-
- pc = i386_linux_sigtramp_start (frame->pc);
- if (pc == 0)
- error ("i386_linux_sigtramp_saved_sp called when no sigtramp");
- return read_memory_integer ((pc
- - LINUX_SIGCONTEXT_SIZE
- + LINUX_SIGCONTEXT_SP_OFFSET),
- 4);
-}
-
-#endif /* I386_LINUX_SIGTRAMP */
#ifdef STATIC_TRANSFORM_NAME
/* SunPRO encodes the static variables. This is not related to C++ mangling,