gcc/config/pa/som.h

   1 /* Definitions for SOM assembler support.
   2    Copyright (C) 1999, 2001, 2002, 2003, 2004, 2005 Free Software Foundation,
   3    Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC 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 GCC 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 GCC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22 /* So we can conditionalize small amounts of code in pa.c or pa.md.  */
  23 #undef TARGET_SOM
  24 #define TARGET_SOM 1
  25
  26 /* We do not use BINCL stabs in SOM.
  27    ??? If it does not hurt, we probably should to avoid useless divergence
  28    from other embedded stabs implementations.  */
  29 #undef DBX_USE_BINCL
  30
  31 #define DBX_LINES_FUNCTION_RELATIVE 1
  32
  33 /* gdb needs a null N_SO at the end of each file for scattered loading.  */
  34
  35 #define DBX_OUTPUT_NULL_N_SO_AT_MAIN_SOURCE_FILE_END
  36
  37 /* HPUX has a program 'chatr' to list the dependencies of dynamically
  38    linked executables and shared libraries.  */
  39 #define LDD_SUFFIX "chatr"
  40 /* Look for lines like "dynamic   /usr/lib/X11R5/libX11.sl"
  41    or "static    /usr/lib/X11R5/libX11.sl".
  42
  43    HPUX 10.20 also has lines like "static branch prediction ..."
  44    so we filter that out explicitly.
  45
  46    We also try to bound our search for libraries with marker
  47    lines.  What a pain.  */
  48 #define PARSE_LDD_OUTPUT(PTR)                                   \
  49 do {                                                            \
  50   static int in_shlib_list = 0;                                 \
  51   while (*PTR == ' ') PTR++;                                    \
  52   if (strncmp (PTR, "shared library list:",                     \
  53                sizeof ("shared library list:") - 1) == 0)       \
  54     {                                                           \
  55       PTR = 0;                                                  \
  56       in_shlib_list = 1;                                        \
  57     }                                                           \
  58   else if (strncmp (PTR, "shared library binding:",             \
  59                     sizeof ("shared library binding:") - 1) == 0)\
  60     {                                                           \
  61       PTR = 0;                                                  \
  62       in_shlib_list = 0;                                        \
  63     }                                                           \
  64   else if (strncmp (PTR, "static branch prediction disabled",   \
  65                     sizeof ("static branch prediction disabled") - 1) == 0)\
  66     {                                                           \
  67       PTR = 0;                                                  \
  68       in_shlib_list = 0;                                        \
  69     }                                                           \
  70   else if (in_shlib_list                                        \
  71            &&  strncmp (PTR, "dynamic", sizeof ("dynamic") - 1) == 0) \
  72     {                                                           \
  73       PTR += sizeof ("dynamic") - 1;                            \
  74       while (*p == ' ') PTR++;                                  \
  75     }                                                           \
  76   else if (in_shlib_list                                        \
  77            && strncmp (PTR, "static", sizeof ("static") - 1) == 0) \
  78     {                                                           \
  79       PTR += sizeof ("static") - 1;                             \
  80       while (*p == ' ') PTR++;                                  \
  81     }                                                           \
  82   else                                                          \
  83     PTR = 0;                                                    \
  84 } while (0)
  85
  86 /* Output the label for a function definition.  */
  87 #ifndef HP_FP_ARG_DESCRIPTOR_REVERSED
  88 #define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)    \
  89   do { fprintf (FILE, ",ARGW%d=FR", (ARG0));            \
  90        fprintf (FILE, ",ARGW%d=FU", (ARG1));} while (0)
  91 #define DFMODE_RETURN_STRING ",RTNVAL=FU"
  92 #define SFMODE_RETURN_STRING ",RTNVAL=FR"
  93 #else
  94 #define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)    \
  95   do { fprintf (FILE, ",ARGW%d=FU", (ARG0));            \
  96        fprintf (FILE, ",ARGW%d=FR", (ARG1));} while (0)
  97 #define DFMODE_RETURN_STRING ",RTNVAL=FR"
  98 #define SFMODE_RETURN_STRING ",RTNVAL=FU"
  99 #endif
 100
 101 \f
 102 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
 103     do { tree fntype = TREE_TYPE (TREE_TYPE (DECL));                    \
 104          tree tree_type = TREE_TYPE (DECL);                             \
 105          tree parm;                                                     \
 106          int i;                                                         \
 107          if (TREE_PUBLIC (DECL) || TARGET_GAS)                          \
 108            {                                                            \
 109              if (TREE_PUBLIC (DECL))                                    \
 110                {                                                        \
 111                  fputs ("\t.EXPORT ", FILE);                            \
 112                  assemble_name (FILE, NAME);                            \
 113                  fputs (",ENTRY,PRIV_LEV=3", FILE);                     \
 114                }                                                        \
 115              else                                                       \
 116                {                                                        \
 117                  fputs ("\t.PARAM ", FILE);                             \
 118                  assemble_name (FILE, NAME);                            \
 119                  fputs (",PRIV_LEV=3", FILE);                           \
 120                }                                                        \
 121              for (parm = DECL_ARGUMENTS (DECL), i = 0; parm && i < 4;   \
 122                   parm = TREE_CHAIN (parm))                             \
 123                {                                                        \
 124                  if (TYPE_MODE (DECL_ARG_TYPE (parm)) == SFmode         \
 125                      && ! TARGET_SOFT_FLOAT)                            \
 126                    fprintf (FILE, ",ARGW%d=FR", i++);                   \
 127                  else if (TYPE_MODE (DECL_ARG_TYPE (parm)) == DFmode    \
 128                           && ! TARGET_SOFT_FLOAT)                       \
 129                    {                                                    \
 130                      if (i <= 2)                                        \
 131                        {                                                \
 132                          if (i == 1) i++;                               \
 133                          ASM_DOUBLE_ARG_DESCRIPTORS (FILE, i++, i++);   \
 134                        }                                                \
 135                      else                                               \
 136                        break;                                           \
 137                    }                                                    \
 138                  else                                                   \
 139                    {                                                    \
 140                      int arg_size =                                     \
 141                        FUNCTION_ARG_SIZE (TYPE_MODE (DECL_ARG_TYPE (parm)),\
 142                                           DECL_ARG_TYPE (parm));        \
 143                      /* Passing structs by invisible reference uses     \
 144                         one general register.  */                       \
 145                      if (arg_size > 2                                   \
 146                          || TREE_ADDRESSABLE (DECL_ARG_TYPE (parm)))    \
 147                        arg_size = 1;                                    \
 148                      if (arg_size == 2 && i <= 2)                       \
 149                        {                                                \
 150                          if (i == 1) i++;                               \
 151                          fprintf (FILE, ",ARGW%d=GR", i++);             \
 152                          fprintf (FILE, ",ARGW%d=GR", i++);             \
 153                        }                                                \
 154                      else if (arg_size == 1)                            \
 155                        fprintf (FILE, ",ARGW%d=GR", i++);               \
 156                      else                                               \
 157                        i += arg_size;                                   \
 158                    }                                                    \
 159                }                                                        \
 160              /* anonymous args */                                       \
 161              if (TYPE_ARG_TYPES (tree_type) != 0                        \
 162                  && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (tree_type)))\
 163                      != void_type_node))                                \
 164                {                                                        \
 165                  for (; i < 4; i++)                                     \
 166                    fprintf (FILE, ",ARGW%d=GR", i);                     \
 167                }                                                        \
 168              if (TYPE_MODE (fntype) == DFmode && ! TARGET_SOFT_FLOAT)   \
 169                fputs (DFMODE_RETURN_STRING, FILE);                      \
 170              else if (TYPE_MODE (fntype) == SFmode && ! TARGET_SOFT_FLOAT) \
 171                fputs (SFMODE_RETURN_STRING, FILE);                      \
 172              else if (fntype != void_type_node)                         \
 173                fputs (",RTNVAL=GR", FILE);                              \
 174              fputs ("\n", FILE);                                        \
 175            }} while (0)
 176
 177 #define TARGET_ASM_FILE_START pa_som_file_start
 178
 179 /* String to output before text.  */
 180 #define TEXT_SECTION_ASM_OP som_text_section_asm_op ()
 181
 182 /* String to output before writable data.  */
 183 #define DATA_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $DATA$\n"
 184
 185 /* String to output before uninitialized data.  */
 186 #define BSS_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $BSS$\n"
 187
 188 /* FIXME: HPUX ld generates incorrect GOT entries for "T" fixups
 189    which reference data within the $TEXT$ space (for example constant
 190    strings in the $LIT$ subspace).
 191
 192    The assemblers (GAS and HP as) both have problems with handling
 193    the difference of two symbols which is the other correct way to
 194    reference constant data during PIC code generation.
 195
 196    So, there's no way to reference constant data which is in the
 197    $TEXT$ space during PIC generation.  Instead place all constant
 198    data into the $PRIVATE$ subspace (this reduces sharing, but it
 199    works correctly).  */
 200 #define READONLY_DATA_SECTION \
 201   (flag_pic ? data_section : som_readonly_data_section)
 202
 203 /* We must not have a reference to an external symbol defined in a
 204    shared library in a readonly section, else the SOM linker will
 205    complain.
 206
 207    So, we force exception information into the data section.  */
 208 #define TARGET_ASM_EXCEPTION_SECTION data_section
 209
 210 /* This is how to output a command to make the user-level label
 211    named NAME defined for reference from other files.  We use
 212    assemble_name_raw instead of assemble_name since a symbol in
 213    a .IMPORT directive that isn't otherwise referenced is not
 214    placed in the symbol table of the assembled object.
 215
 216    Failure to import a function reference can cause the HP linker
 217    to segmentation fault!
 218
 219    Note that the SOM based tools need the symbol imported as a
 220    CODE symbol, while the ELF based tools require the symbol to
 221    be imported as an ENTRY symbol.  */
 222
 223 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME) \
 224   pa_hpux_asm_output_external ((FILE), (DECL), (NAME))
 225 #define ASM_OUTPUT_EXTERNAL_REAL(FILE, DECL, NAME) \
 226   do { fputs ("\t.IMPORT ", FILE);                                      \
 227        assemble_name_raw (FILE, NAME);                                  \
 228        if (FUNCTION_NAME_P (NAME))                                      \
 229          fputs (",CODE\n", FILE);                                       \
 230        else                                                             \
 231          fputs (",DATA\n", FILE);                                       \
 232      } while (0)
 233
 234 /* The bogus HP assembler requires ALL external references to be
 235    "imported", even library calls.  They look a bit different, so
 236    here's this macro.
 237
 238    Also note not all libcall names are passed to pa_encode_section_info
 239    (__main for example).  To make sure all libcall names have section
 240    info recorded in them, we do it here.
 241
 242    We must also ensure that a libcall that has been previously
 243    exported is not subsequently imported since the HP assembler may
 244    change the type from an ENTRY to a CODE symbol.  This would make
 245    the symbol local.  We are forced to use the identifier node
 246    associated with the real assembler name for this check as the
 247    symbol_ref available in ASM_DECLARE_FUNCTION_NAME is not the
 248    same as the one used here.  As a result, we can't use flags
 249    in the symbol_ref for this check.  The identifier check assumes
 250    assemble_external_libcall is called before the symbol is used.  */
 251
 252 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, RTL) \
 253   do { const char *name;                                                \
 254        tree id;                                                         \
 255                                                                         \
 256        if (!function_label_operand (RTL, VOIDmode))                     \
 257          hppa_encode_label (RTL);                                       \
 258                                                                         \
 259        name = targetm.strip_name_encoding (XSTR ((RTL), 0));            \
 260        id = maybe_get_identifier (name);                                \
 261        if (!id || !TREE_SYMBOL_REFERENCED (id))                         \
 262          {                                                              \
 263            fputs ("\t.IMPORT ", FILE);                                  \
 264            assemble_name_raw (FILE, XSTR ((RTL), 0));                   \
 265            fputs (",CODE\n", FILE);                                     \
 266          }                                                              \
 267      } while (0)
 268
 269 /* We want __gcc_plt_call to appear in every program built by
 270    gcc, so we make a reference to it out of __main.
 271    We use the asm statement to fool the optimizer into not
 272    removing the dead (but important) initialization of
 273    REFERENCE.  */
 274
 275 #define DO_GLOBAL_DTORS_BODY                    \
 276 do {                                            \
 277   extern void __gcc_plt_call (void);            \
 278   void (*reference)(void) = &__gcc_plt_call;    \
 279   func_ptr *p;                                  \
 280   __asm__ ("" : : "r" (reference));             \
 281   for (p = __DTOR_LIST__ + 1; *p; )             \
 282     (*p++) ();                                  \
 283 } while (0)
 284
 285 /* This macro specifies the biggest alignment supported by the object
 286    file format of this machine.
 287
 288    The .align directive in the HP assembler allows alignments up to 4096
 289    bytes.  However, the maximum alignment of a global common symbol is 8
 290    bytes for objects smaller than the page size (4096 bytes).  For larger
 291    objects, the linker provides an alignment of 32 bytes.  Unfortunately,
 292    this macro doesn't provide a mechanism to test for common symbols.  */
 293 #define MAX_OFILE_ALIGNMENT 32768
 294
 295 /* The SOM linker hardcodes paths into binaries.  As a result, dotdots
 296    must be removed from library prefixes to prevent binaries from depending
 297    on the location of the GCC tool directory.  The downside is GCC
 298    cannot be moved after installation using a symlink.  */
 299 #define ALWAYS_STRIP_DOTDOT 1
 300
 301 /* If GAS supports weak, we can support weak when we have working linker
 302    support for secondary definitions and are generating code for GAS.  */
 303 #ifdef HAVE_GAS_WEAK
 304 #define SUPPORTS_WEAK (TARGET_SOM_SDEF && TARGET_GAS)
 305 #else
 306 #define SUPPORTS_WEAK 0
 307 #endif
 308
 309 /* CVS GAS as of 4/28/04 supports a comdat parameter for the .nsubspa
 310    directive.  This provides one-only linkage semantics even though we
 311    don't have weak support.  */
 312 #ifdef HAVE_GAS_NSUBSPA_COMDAT
 313 #define SUPPORTS_SOM_COMDAT (TARGET_GAS)
 314 #else
 315 #define SUPPORTS_SOM_COMDAT 0
 316 #endif
 317
 318 /* We can support one only if we support weak or comdat.  */
 319 #define SUPPORTS_ONE_ONLY (SUPPORTS_WEAK || SUPPORTS_SOM_COMDAT)
 320
 321 /* We use DECL_COMMON for uninitialized one-only variables as we don't
 322    have linkonce .bss.  We use SOM secondary definitions or comdat for
 323    initialized variables and functions.  */
 324 #define MAKE_DECL_ONE_ONLY(DECL) \
 325   do {                                                                  \
 326     if (TREE_CODE (DECL) == VAR_DECL                                    \
 327         && (DECL_INITIAL (DECL) == 0                                    \
 328             || DECL_INITIAL (DECL) == error_mark_node))                 \
 329       DECL_COMMON (DECL) = 1;                                           \
 330     else if (SUPPORTS_WEAK)                                             \
 331       DECL_WEAK (DECL) = 1;                                             \
 332   } while (0)
 333
 334 /* This is how we tell the assembler that a symbol is weak.  The SOM
 335    weak implementation uses the secondary definition (sdef) flag.
 336
 337    The behavior of sdef symbols is similar to ELF weak symbols in that
 338    multiple definitions can occur without incurring a link error.
 339    However, they differ in the following ways:
 340      1) Undefined sdef symbols are not allowed.
 341      2) The linker searches for undefined sdef symbols and will load an
 342         archive library member to resolve an undefined sdef symbol.
 343      3) The exported symbol from a shared library is a primary symbol
 344         rather than a sdef symbol.  Thus, more care is needed in the
 345         ordering of libraries.
 346
 347    It appears that the linker discards extra copies of "weak" functions
 348    when linking shared libraries, independent of whether or not they
 349    are in their own section.  In linking final executables, -Wl,-O can
 350    be used to remove dead procedures.  Thus, support for named sections
 351    is not needed and in previous testing caused problems with various
 352    HP tools.  */
 353 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 354   do { fputs ("\t.weak\t", FILE);                               \
 355        assemble_name (FILE, NAME);                              \
 356        fputc ('\n', FILE);                                      \
 357        targetm.asm_out.globalize_label (FILE, NAME);            \
 358   } while (0)
 359
 360 /* We can't handle weak aliases, and therefore can't support pragma weak.
 361    Suppress the use of pragma weak in gthr-dce.h and gthr-posix.h.  */
 362 #define GTHREAD_USE_WEAK 0