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Diffstat (limited to 'gdb/rs6000-lynx178-tdep.c')
| -rw-r--r-- | gdb/rs6000-lynx178-tdep.c | 422 |
1 files changed, 422 insertions, 0 deletions
diff --git a/gdb/rs6000-lynx178-tdep.c b/gdb/rs6000-lynx178-tdep.c new file mode 100644 index 0000000..92a6bc2 --- /dev/null +++ b/gdb/rs6000-lynx178-tdep.c @@ -0,0 +1,422 @@ +/* Copyright (C) 2012 Free Software Foundation, Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#include "defs.h" +#include "osabi.h" +#include "regcache.h" +#include "gdbcore.h" +#include "gdbtypes.h" +#include "infcall.h" +#include "ppc-tdep.h" +#include "value.h" +#include "xcoffread.h" + +/* Implement the "push_dummy_call" gdbarch method. */ + +static CORE_ADDR +rs6000_lynx178_push_dummy_call (struct gdbarch *gdbarch, + struct value *function, + struct regcache *regcache, CORE_ADDR bp_addr, + int nargs, struct value **args, CORE_ADDR sp, + int struct_return, CORE_ADDR struct_addr) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + int ii; + int len = 0; + int argno; /* current argument number */ + int argbytes; /* current argument byte */ + gdb_byte tmp_buffer[50]; + int f_argno = 0; /* current floating point argno */ + int wordsize = gdbarch_tdep (gdbarch)->wordsize; + CORE_ADDR func_addr = find_function_addr (function, NULL); + + struct value *arg = 0; + struct type *type; + + ULONGEST saved_sp; + + /* The calling convention this function implements assumes the + processor has floating-point registers. We shouldn't be using it + on PPC variants that lack them. */ + gdb_assert (ppc_floating_point_unit_p (gdbarch)); + + /* The first eight words of ther arguments are passed in registers. + Copy them appropriately. */ + ii = 0; + + /* If the function is returning a `struct', then the first word + (which will be passed in r3) is used for struct return address. + In that case we should advance one word and start from r4 + register to copy parameters. */ + if (struct_return) + { + regcache_raw_write_unsigned (regcache, tdep->ppc_gp0_regnum + 3, + struct_addr); + ii++; + } + + /* 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. */ + + gdb_assert (len <= 8); + + regcache_cooked_write (regcache, + tdep->ppc_fp0_regnum + 1 + f_argno, + value_contents (arg)); + ++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. */ + int adj = gdbarch_byte_order (gdbarch) + == BFD_ENDIAN_BIG ? reg_size - len : 0; + 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 = align_down (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 += align_up (len - argbytes, 4); + jj = argno + 1; + } + else + jj = argno; + + for (; jj < nargs; ++jj) + { + struct value *val = args[jj]; + + space += align_up (TYPE_LENGTH (value_type (val)), 4); + } + + /* Add location required for the rest of the parameters. */ + space = align_up (space, 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 += align_up (len - argbytes, 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 += align_up (len, 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); + + target_store_registers (regcache, -1); + return sp; +} + +/* Implement the "return_value" gdbarch method. */ + +static enum return_value_convention +rs6000_lynx178_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; +} + +/* PowerPC Lynx178 OSABI sniffer. */ + +static enum gdb_osabi +rs6000_lynx178_osabi_sniffer (bfd *abfd) +{ + if (bfd_get_flavour (abfd) != bfd_target_xcoff_flavour) + return GDB_OSABI_UNKNOWN; + + /* The only noticeable difference between Lynx178 XCOFF files and + AIX XCOFF files comes from the fact that there are no shared + libraries on Lynx178. So if the number of import files is + different from zero, it cannot be a Lynx178 binary. */ + if (xcoff_get_n_import_files (abfd) != 0) + return GDB_OSABI_UNKNOWN; + + return GDB_OSABI_LYNXOS178; +} + +/* Callback for powerpc-lynx178 initialization. */ + +static void +rs6000_lynx178_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch) +{ + set_gdbarch_push_dummy_call (gdbarch, rs6000_lynx178_push_dummy_call); + set_gdbarch_return_value (gdbarch, rs6000_lynx178_return_value); + set_gdbarch_long_double_bit (gdbarch, 8 * TARGET_CHAR_BIT); +} + +/* -Wmissing-prototypes. */ +extern initialize_file_ftype _initialize_rs6000_lynx178_tdep; + +void +_initialize_rs6000_lynx178_tdep (void) +{ + gdbarch_register_osabi_sniffer (bfd_arch_rs6000, + bfd_target_xcoff_flavour, + rs6000_lynx178_osabi_sniffer); + gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_LYNXOS178, + rs6000_lynx178_init_osabi); +} + |