+
+/* effectively indirect call... gcc does...
+
+ return_val example( float, int);
+
+ eabi:
+ float in fp0, int in r3
+ offset of stack on overflow 8/16
+ for varargs, must go by type.
+ power open:
+ float in r3&r4, int in r5
+ offset of stack on overflow different
+ both:
+ return in r3 or f0. If no float, must study how gcc emulates floats;
+ pay attention to arg promotion.
+ User may have to cast\args to handle promotion correctly
+ since gdb won't know if prototype supplied or not. */
+
+ for (argno = 0, argbytes = 0; argno < nargs && ii < 8; ++ii)
+ {
+ int reg_size = register_size (gdbarch, ii + 3);
+
+ arg = args[argno];
+ type = check_typedef (value_type (arg));
+ len = TYPE_LENGTH (type);
+
+ if (TYPE_CODE (type) == TYPE_CODE_FLT)
+ {
+ /* Floating point arguments are passed in fpr's, as well as gpr's.
+ There are 13 fpr's reserved for passing parameters. At this point
+ there is no way we would run out of them.
+
+ Always store the floating point value using the register's
+ floating-point format. */
+ const int fp_regnum = tdep->ppc_fp0_regnum + 1 + f_argno;
+ gdb_byte reg_val[MAX_REGISTER_SIZE];
+ struct type *reg_type = register_type (gdbarch, fp_regnum);
+
+ gdb_assert (len <= 8);
+
+ convert_typed_floating (value_contents (arg), type,
+ reg_val, reg_type);
+ regcache_cooked_write (regcache, fp_regnum, reg_val);
+ ++f_argno;
+ }
+
+ if (len > reg_size)
+ {
+
+ /* Argument takes more than one register. */
+ while (argbytes < len)
+ {
+ gdb_byte word[MAX_REGISTER_SIZE];
+ memset (word, 0, reg_size);
+ memcpy (word,
+ ((char *) value_contents (arg)) + argbytes,
+ (len - argbytes) > reg_size
+ ? reg_size : len - argbytes);
+ regcache_cooked_write (regcache,
+ tdep->ppc_gp0_regnum + 3 + ii,
+ word);
+ ++ii, argbytes += reg_size;
+
+ if (ii >= 8)
+ goto ran_out_of_registers_for_arguments;
+ }
+ argbytes = 0;
+ --ii;
+ }
+ else
+ {
+ /* Argument can fit in one register. No problem. */
+ gdb_byte word[MAX_REGISTER_SIZE];
+
+ memset (word, 0, reg_size);
+ memcpy (word, value_contents (arg), len);
+ regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 3 +ii, word);
+ }
+ ++argno;
+ }
+
+ran_out_of_registers_for_arguments:
+
+ regcache_cooked_read_unsigned (regcache,
+ gdbarch_sp_regnum (gdbarch),
+ &saved_sp);
+
+ /* Location for 8 parameters are always reserved. */
+ sp -= wordsize * 8;
+
+ /* Another six words for back chain, TOC register, link register, etc. */
+ sp -= wordsize * 6;
+
+ /* Stack pointer must be quadword aligned. */
+ sp &= -16;
+
+ /* If there are more arguments, allocate space for them in
+ the stack, then push them starting from the ninth one. */
+
+ if ((argno < nargs) || argbytes)
+ {
+ int space = 0, jj;
+
+ if (argbytes)
+ {
+ space += ((len - argbytes + 3) & -4);
+ jj = argno + 1;
+ }
+ else
+ jj = argno;
+
+ for (; jj < nargs; ++jj)
+ {
+ struct value *val = args[jj];
+ space += ((TYPE_LENGTH (value_type (val))) + 3) & -4;
+ }
+
+ /* Add location required for the rest of the parameters. */
+ space = (space + 15) & -16;
+ sp -= space;
+
+ /* This is another instance we need to be concerned about
+ securing our stack space. If we write anything underneath %sp
+ (r1), we might conflict with the kernel who thinks he is free
+ to use this area. So, update %sp first before doing anything
+ else. */
+
+ regcache_raw_write_signed (regcache,
+ gdbarch_sp_regnum (gdbarch), sp);
+
+ /* If the last argument copied into the registers didn't fit there
+ completely, push the rest of it into stack. */
+
+ if (argbytes)
+ {
+ write_memory (sp + 24 + (ii * 4),
+ value_contents (arg) + argbytes,
+ len - argbytes);
+ ++argno;
+ ii += ((len - argbytes + 3) & -4) / 4;
+ }
+
+ /* Push the rest of the arguments into stack. */
+ for (; argno < nargs; ++argno)
+ {
+
+ arg = args[argno];
+ type = check_typedef (value_type (arg));
+ len = TYPE_LENGTH (type);
+
+
+ /* Float types should be passed in fpr's, as well as in the
+ stack. */
+ if (TYPE_CODE (type) == TYPE_CODE_FLT && f_argno < 13)
+ {
+
+ gdb_assert (len <= 8);
+
+ regcache_cooked_write (regcache,
+ tdep->ppc_fp0_regnum + 1 + f_argno,
+ value_contents (arg));
+ ++f_argno;
+ }
+
+ write_memory (sp + 24 + (ii * 4), value_contents (arg), len);
+ ii += ((len + 3) & -4) / 4;
+ }
+ }
+
+ /* Set the stack pointer. According to the ABI, the SP is meant to
+ be set _before_ the corresponding stack space is used. On AIX,
+ this even applies when the target has been completely stopped!
+ Not doing this can lead to conflicts with the kernel which thinks
+ that it still has control over this not-yet-allocated stack
+ region. */
+ regcache_raw_write_signed (regcache, gdbarch_sp_regnum (gdbarch), sp);
+
+ /* Set back chain properly. */
+ store_unsigned_integer (tmp_buffer, wordsize, byte_order, saved_sp);
+ write_memory (sp, tmp_buffer, wordsize);
+
+ /* Point the inferior function call's return address at the dummy's
+ breakpoint. */
+ regcache_raw_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr);
+
+ /* Set the TOC register value. */
+ regcache_raw_write_signed (regcache, tdep->ppc_toc_regnum,
+ solib_aix_get_toc_value (func_addr));
+
+ target_store_registers (regcache, -1);
+ return sp;
+}
+
+static enum return_value_convention
+rs6000_return_value (struct gdbarch *gdbarch, struct value *function,
+ struct type *valtype, struct regcache *regcache,
+ gdb_byte *readbuf, const gdb_byte *writebuf)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
+ /* The calling convention this function implements assumes the
+ processor has floating-point registers. We shouldn't be using it
+ on PowerPC variants that lack them. */
+ gdb_assert (ppc_floating_point_unit_p (gdbarch));
+
+ /* AltiVec extension: Functions that declare a vector data type as a
+ return value place that return value in VR2. */
+ if (TYPE_CODE (valtype) == TYPE_CODE_ARRAY && TYPE_VECTOR (valtype)
+ && TYPE_LENGTH (valtype) == 16)
+ {
+ if (readbuf)
+ regcache_cooked_read (regcache, tdep->ppc_vr0_regnum + 2, readbuf);
+ if (writebuf)
+ regcache_cooked_write (regcache, tdep->ppc_vr0_regnum + 2, writebuf);
+
+ return RETURN_VALUE_REGISTER_CONVENTION;
+ }
+
+ /* If the called subprogram returns an aggregate, there exists an
+ implicit first argument, whose value is the address of a caller-
+ allocated buffer into which the callee is assumed to store its
+ return value. All explicit parameters are appropriately
+ relabeled. */
+ if (TYPE_CODE (valtype) == TYPE_CODE_STRUCT
+ || TYPE_CODE (valtype) == TYPE_CODE_UNION
+ || TYPE_CODE (valtype) == TYPE_CODE_ARRAY)
+ return RETURN_VALUE_STRUCT_CONVENTION;
+
+ /* Scalar floating-point values are returned in FPR1 for float or
+ double, and in FPR1:FPR2 for quadword precision. Fortran
+ complex*8 and complex*16 are returned in FPR1:FPR2, and
+ complex*32 is returned in FPR1:FPR4. */
+ if (TYPE_CODE (valtype) == TYPE_CODE_FLT
+ && (TYPE_LENGTH (valtype) == 4 || TYPE_LENGTH (valtype) == 8))
+ {
+ struct type *regtype = register_type (gdbarch, tdep->ppc_fp0_regnum);
+ gdb_byte regval[8];
+
+ /* FIXME: kettenis/2007-01-01: Add support for quadword
+ precision and complex. */
+
+ if (readbuf)
+ {
+ regcache_cooked_read (regcache, tdep->ppc_fp0_regnum + 1, regval);
+ convert_typed_floating (regval, regtype, readbuf, valtype);
+ }
+ if (writebuf)
+ {
+ convert_typed_floating (writebuf, valtype, regval, regtype);
+ regcache_cooked_write (regcache, tdep->ppc_fp0_regnum + 1, regval);
+ }
+
+ return RETURN_VALUE_REGISTER_CONVENTION;
+ }
+
+ /* Values of the types int, long, short, pointer, and char (length
+ is less than or equal to four bytes), as well as bit values of
+ lengths less than or equal to 32 bits, must be returned right
+ justified in GPR3 with signed values sign extended and unsigned
+ values zero extended, as necessary. */
+ if (TYPE_LENGTH (valtype) <= tdep->wordsize)
+ {
+ if (readbuf)
+ {
+ ULONGEST regval;
+
+ /* For reading we don't have to worry about sign extension. */
+ regcache_cooked_read_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
+ ®val);
+ store_unsigned_integer (readbuf, TYPE_LENGTH (valtype), byte_order,
+ regval);
+ }
+ if (writebuf)
+ {
+ /* For writing, use unpack_long since that should handle any
+ required sign extension. */
+ regcache_cooked_write_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
+ unpack_long (valtype, writebuf));
+ }
+
+ return RETURN_VALUE_REGISTER_CONVENTION;
+ }
+
+ /* Eight-byte non-floating-point scalar values must be returned in
+ GPR3:GPR4. */
+
+ if (TYPE_LENGTH (valtype) == 8)
+ {
+ gdb_assert (TYPE_CODE (valtype) != TYPE_CODE_FLT);
+ gdb_assert (tdep->wordsize == 4);
+
+ if (readbuf)
+ {
+ gdb_byte regval[8];
+
+ regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 3, regval);
+ regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 4,
+ regval + 4);
+ memcpy (readbuf, regval, 8);
+ }
+ if (writebuf)
+ {
+ regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 3, writebuf);
+ regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 4,
+ writebuf + 4);
+ }
+
+ return RETURN_VALUE_REGISTER_CONVENTION;
+ }
+
+ return RETURN_VALUE_STRUCT_CONVENTION;
+}
+
+/* Support for CONVERT_FROM_FUNC_PTR_ADDR (ARCH, ADDR, TARG).
+
+ Usually a function pointer's representation is simply the address
+ of the function. On the RS/6000 however, a function pointer is
+ represented by a pointer to an OPD entry. This OPD entry contains
+ three words, the first word is the address of the function, the
+ second word is the TOC pointer (r2), and the third word is the
+ static chain value. Throughout GDB it is currently assumed that a
+ function pointer contains the address of the function, which is not
+ easy to fix. In addition, the conversion of a function address to
+ a function pointer would require allocation of an OPD entry in the
+ inferior's memory space, with all its drawbacks. To be able to
+ call C++ virtual methods in the inferior (which are called via
+ function pointers), find_function_addr uses this function to get the
+ function address from a function pointer. */
+
+/* Return real function address if ADDR (a function pointer) is in the data
+ space and is therefore a special function pointer. */
+
+static CORE_ADDR
+rs6000_convert_from_func_ptr_addr (struct gdbarch *gdbarch,
+ CORE_ADDR addr,
+ struct target_ops *targ)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ struct obj_section *s;
+
+ s = find_pc_section (addr);
+
+ /* Normally, functions live inside a section that is executable.
+ So, if ADDR points to a non-executable section, then treat it
+ as a function descriptor and return the target address iff
+ the target address itself points to a section that is executable. */
+ if (s && (s->the_bfd_section->flags & SEC_CODE) == 0)