gcc/config/arm/netbsd.h

   1 /* NetBSD/arm (RiscBSD) version.
   2    Copyright (C) 1993, 1994, 1997, 1998 Free Software Foundation, Inc.
   3    Contributed by Mark Brinicombe (amb@physig.ph.kcl.ac.uk)
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU CC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 /* Run-time Target Specification.  */
  23 #define TARGET_VERSION fputs (" (ARM/NetBSD)", stderr);
  24
  25 /* This is used in ASM_FILE_START.  */
  26 #define ARM_OS_NAME "NetBSD"
  27
  28 /* Unsigned chars produces much better code than signed.  */
  29 #define DEFAULT_SIGNED_CHAR  0
  30
  31 /* Since we always use GAS as our assembler we support stabs.  */
  32 #define DBX_DEBUGGING_INFO 1
  33
  34 /*#undef ASM_DECLARE_FUNCTION_NAME*/
  35
  36 /* ARM6 family default cpu.  */
  37 #define SUBTARGET_CPU_DEFAULT TARGET_CPU_arm6
  38
  39 /* Default is to use APCS-32 mode.  */
  40 #define TARGET_DEFAULT (ARM_FLAG_APCS_32 | ARM_FLAG_SOFT_FLOAT)
  41
  42 #include "arm/aout.h"
  43
  44 /* This gets redefined in config/netbsd.h.  */
  45 #undef TARGET_MEM_FUNCTIONS
  46
  47 #include <netbsd.h>
  48
  49 /* Until they use ELF or something that handles dwarf2 unwinds
  50    and initialization stuff better.  */
  51 #undef DWARF2_UNWIND_INFO
  52
  53 /* Some defines for CPP.
  54    arm32 is the NetBSD port name, so we always define arm32 and __arm32__.  */
  55 #undef CPP_PREDEFINES
  56 #define CPP_PREDEFINES "\
  57 -Dunix -Driscbsd -Darm32 -D__arm32__ -D__arm__ -D__NetBSD__ \
  58 -Asystem(unix) -Asystem(NetBSD) -Acpu(arm) -Amachine(arm)"
  59
  60 /* Define _POSIX_SOURCE if necessary.  */
  61 #undef CPP_SPEC
  62 #define CPP_SPEC "\
  63 %(cpp_cpu_arch) %(cpp_apcs_pc) %(cpp_float) %(cpp_endian) \
  64 %{posix:-D_POSIX_SOURCE} \
  65 "
  66
  67 /* Because TARGET_DEFAULT sets ARM_FLAG_APCS_32 */
  68 #undef CPP_APCS_PC_DEFAULT_SPEC
  69 #define CPP_APCS_PC_DEFAULT_SPEC "-D__APCS_32__"
  70
  71 /* Because TARGET_DEFAULT sets ARM_FLAG_SOFT_FLOAT */
  72 #undef CPP_FLOAT_DEFAULT_SPEC
  73 #define CPP_FLOAT_DEFAULT_SPEC "-D__SOFTFP__"
  74
  75 /* Pass -X to the linker so that it will strip symbols starting with 'L' */
  76 #undef LINK_SPEC
  77 #define LINK_SPEC "\
  78 -X %{!nostdlib:%{!r*:%{!e*:-e start}}} -dc -dp %{R*} \
  79 %{static:-Bstatic} %{assert*} \
  80 "
  81
  82 #undef SIZE_TYPE
  83 #define SIZE_TYPE "unsigned int"
  84
  85 #undef PTRDIFF_TYPE
  86 #define PTRDIFF_TYPE "int"
  87
  88 #undef WCHAR_TYPE
  89 #define WCHAR_TYPE "int"
  90
  91 #undef WCHAR_UNSIGNED
  92 #define WCHAR_UNSIGNED 0
  93
  94 #undef WCHAR_TYPE_SIZE
  95 #define WCHAR_TYPE_SIZE 32
  96
  97 #define HANDLE_SYSV_PRAGMA
  98
  99 /* We don't have any limit on the length as out debugger is GDB.  */
 100 #undef DBX_CONTIN_LENGTH
 101
 102 /* NetBSD does its profiling differently to the Acorn compiler. We
 103    don't need a word following the mcount call; and to skip it
 104    requires either an assembly stub or use of fomit-frame-pointer when
 105    compiling the profiling functions.  Since we break Acorn CC
 106    compatibility below a little more won't hurt.  */
 107
 108 #undef FUNCTION_PROFILER
 109 #define FUNCTION_PROFILER(STREAM,LABELNO)                                   \
 110 {                                                                           \
 111   fprintf(STREAM, "\tmov\t%sip, %slr\n", REGISTER_PREFIX, REGISTER_PREFIX); \
 112   fprintf(STREAM, "\tbl\tmcount\n");                                        \
 113 }
 114
 115 /* On the ARM `@' introduces a comment, so we must use something else
 116    for .type directives.  */
 117 #undef TYPE_OPERAND_FMT
 118 #define TYPE_OPERAND_FMT "%%%s"
 119
 120 /* NetBSD uses the old PCC style aggregate returning conventions. */
 121 #undef DEFAULT_PCC_STRUCT_RETURN
 122 #define DEFAULT_PCC_STRUCT_RETURN 1
 123
 124 /* Although not normally relevant (since by default, all aggregates
 125    are returned in memory) compiling some parts of libc requires
 126    non-APCS style struct returns.  */
 127 #undef RETURN_IN_MEMORY
 128
 129 /* VERY BIG NOTE : Change of structure alignment for RiscBSD.
 130    There are consequences you should be aware of...
 131
 132    Normally GCC/arm uses a structure alignment of 32 for compatibility
 133    with armcc.  This means that structures are padded to a word
 134    boundary.  However this causes problems with bugged NetBSD kernel
 135    code (possibly userland code as well - I have not checked every
 136    binary).  The nature of this bugged code is to rely on sizeof()
 137    returning the correct size of various structures rounded to the
 138    nearest byte (SCSI and ether code are two examples, the vm system
 139    is another).  This code breaks when the structure alignment is 32
 140    as sizeof() will report a word=rounded size.  By changing the
 141    structure alignment to 8. GCC will conform to what is expected by
 142    NetBSD.
 143
 144    This has several side effects that should be considered.
 145    1. Structures will only be aligned to the size of the largest member.
 146       i.e. structures containing only bytes will be byte aligned.
 147            structures containing shorts will be half word alinged.
 148            structures containing ints will be word aligned.
 149
 150       This means structures should be padded to a word boundary if
 151       alignment of 32 is required for byte structures etc.
 152
 153    2. A potential performance penalty may exist if strings are no longer
 154       word aligned.  GCC will not be able to use word load/stores to copy
 155       short strings.
 156
 157    This modification is not encouraged but with the present state of the
 158    NetBSD source tree it is currently the only solution that meets the
 159    requirements.  */
 160 #undef  DEFAULT_STRUCTURE_SIZE_BOUNDARY
 161 #define DEFAULT_STRUCTURE_SIZE_BOUNDARY 8