gcc/config/pa/som.h

   1 /* Definitions for SOM assembler support.
   2    Copyright (C) 1999, 2001, 2002, 2003 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 /* So we can conditionalize small amounts of code in pa.c or pa.md.  */
  22 #undef TARGET_SOM
  23 #define TARGET_SOM 1
  24
  25 /* We do not use BINCL stabs in SOM.
  26    ??? If it does not hurt, we probably should to avoid useless divergence
  27    from other embedded stabs implementations.  */
  28 #undef DBX_USE_BINCL
  29
  30 /* We make the first line stab special to avoid adding several
  31    gross hacks to GAS.  */
  32 #undef  ASM_OUTPUT_SOURCE_LINE
  33 #define ASM_OUTPUT_SOURCE_LINE(file, line, counter)     \
  34   { static tree last_function_decl = NULL;              \
  35     if (current_function_decl == last_function_decl)    \
  36       fprintf (file, "\t.stabn 68,0,%d,L$M%d-%s\nL$M%d:\n",     \
  37                line, counter,                   \
  38                XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0) + 1, \
  39                counter);                                \
  40     else                                                \
  41       fprintf (file, "\t.stabn 68,0,%d,0\n", line);     \
  42     last_function_decl = current_function_decl;         \
  43   }
  44
  45 /* gdb needs a null N_SO at the end of each file for scattered loading.  */
  46
  47 #undef  DBX_OUTPUT_MAIN_SOURCE_FILE_END
  48 #define DBX_OUTPUT_MAIN_SOURCE_FILE_END(FILE, FILENAME) \
  49   text_section (); \
  50   fputs ("\t.SPACE $TEXT$\n\t.NSUBSPA $CODE$,QUAD=0,ALIGN=8,ACCESS=44,CODE_ONLY\n", FILE); \
  51   fprintf (FILE,                                                        \
  52            "\t.stabs \"\",%d,0,0,L$text_end0000\nL$text_end0000:\n", N_SO)
  53
  54 /* Select a format to encode pointers in exception handling data.  CODE
  55    is 0 for data, 1 for code labels, 2 for function pointers.  GLOBAL is
  56    true if the symbol may be affected by dynamic relocations.  Because
  57    the HP assembler does auto alignment, it is necessary to use
  58    DW_EH_PE_aligned instead of the default DW_EH_PE_absptr.  */
  59
  60 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
  61   (TARGET_GAS ? DW_EH_PE_absptr : DW_EH_PE_aligned)
  62
  63 /* HPUX has a program 'chatr' to list the dependencies of dynamically
  64    linked executables and shared libraries.  */
  65 #define LDD_SUFFIX "chatr"
  66 /* Look for lines like "dynamic   /usr/lib/X11R5/libX11.sl"
  67    or "static    /usr/lib/X11R5/libX11.sl".
  68
  69    HPUX 10.20 also has lines like "static branch prediction ..."
  70    so we filter that out explicitly.
  71
  72    We also try to bound our search for libraries with marker
  73    lines.  What a pain.  */
  74 #define PARSE_LDD_OUTPUT(PTR)                                   \
  75 do {                                                            \
  76   static int in_shlib_list = 0;                                 \
  77   while (*PTR == ' ') PTR++;                                    \
  78   if (strncmp (PTR, "shared library list:",                     \
  79                sizeof ("shared library list:") - 1) == 0)       \
  80     {                                                           \
  81       PTR = 0;                                                  \
  82       in_shlib_list = 1;                                        \
  83     }                                                           \
  84   else if (strncmp (PTR, "shared library binding:",             \
  85                     sizeof ("shared library binding:") - 1) == 0)\
  86     {                                                           \
  87       PTR = 0;                                                  \
  88       in_shlib_list = 0;                                        \
  89     }                                                           \
  90   else if (strncmp (PTR, "static branch prediction disabled",   \
  91                     sizeof ("static branch prediction disabled") - 1) == 0)\
  92     {                                                           \
  93       PTR = 0;                                                  \
  94       in_shlib_list = 0;                                        \
  95     }                                                           \
  96   else if (in_shlib_list                                        \
  97            &&  strncmp (PTR, "dynamic", sizeof ("dynamic") - 1) == 0) \
  98     {                                                           \
  99       PTR += sizeof ("dynamic") - 1;                            \
 100       while (*p == ' ') PTR++;                                  \
 101     }                                                           \
 102   else if (in_shlib_list                                        \
 103            && strncmp (PTR, "static", sizeof ("static") - 1) == 0) \
 104     {                                                           \
 105       PTR += sizeof ("static") - 1;                             \
 106       while (*p == ' ') PTR++;                                  \
 107     }                                                           \
 108   else                                                          \
 109     PTR = 0;                                                    \
 110 } while (0)
 111
 112 /* Output the label for a function definition.  */
 113 #ifndef HP_FP_ARG_DESCRIPTOR_REVERSED
 114 #define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)    \
 115   do { fprintf (FILE, ",ARGW%d=FR", (ARG0));            \
 116        fprintf (FILE, ",ARGW%d=FU", (ARG1));} while (0)
 117 #define DFMODE_RETURN_STRING ",RTNVAL=FU"
 118 #define SFMODE_RETURN_STRING ",RTNVAL=FR"
 119 #else
 120 #define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)    \
 121   do { fprintf (FILE, ",ARGW%d=FU", (ARG0));            \
 122        fprintf (FILE, ",ARGW%d=FR", (ARG1));} while (0)
 123 #define DFMODE_RETURN_STRING ",RTNVAL=FR"
 124 #define SFMODE_RETURN_STRING ",RTNVAL=FU"
 125 #endif
 126
 127 \f
 128 /* NAME refers to the function's name.  If we are placing each function into
 129    its own section, we need to switch to the section for this function.  Note
 130    that the section name will have a "." prefix.  */
 131 #define ASM_OUTPUT_FUNCTION_PREFIX(FILE, NAME) \
 132   {                                                                     \
 133     const char *name = (*targetm.strip_name_encoding) (NAME);           \
 134     if (TARGET_GAS && in_section == in_text)                            \
 135       fputs ("\t.NSUBSPA $CODE$,QUAD=0,ALIGN=8,ACCESS=44,CODE_ONLY\n", FILE); \
 136     else if (TARGET_GAS)                                                \
 137       fprintf (FILE,                                                    \
 138                "\t.SUBSPA .%s\n", name);                                \
 139   }
 140
 141 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
 142     do { tree fntype = TREE_TYPE (TREE_TYPE (DECL));                    \
 143          tree tree_type = TREE_TYPE (DECL);                             \
 144          tree parm;                                                     \
 145          int i;                                                         \
 146          if (TREE_PUBLIC (DECL) || TARGET_GAS)                          \
 147            {                                                            \
 148              if (TREE_PUBLIC (DECL))                                    \
 149                {                                                        \
 150                  fputs ("\t.EXPORT ", FILE);                            \
 151                  assemble_name (FILE, NAME);                            \
 152                  fputs (",ENTRY,PRIV_LEV=3", FILE);                     \
 153                }                                                        \
 154              else                                                       \
 155                {                                                        \
 156                  fputs ("\t.PARAM ", FILE);                             \
 157                  assemble_name (FILE, NAME);                            \
 158                  fputs (",PRIV_LEV=3", FILE);                           \
 159                }                                                        \
 160              for (parm = DECL_ARGUMENTS (DECL), i = 0; parm && i < 4;   \
 161                   parm = TREE_CHAIN (parm))                             \
 162                {                                                        \
 163                  if (TYPE_MODE (DECL_ARG_TYPE (parm)) == SFmode         \
 164                      && ! TARGET_SOFT_FLOAT)                            \
 165                    fprintf (FILE, ",ARGW%d=FR", i++);                   \
 166                  else if (TYPE_MODE (DECL_ARG_TYPE (parm)) == DFmode    \
 167                           && ! TARGET_SOFT_FLOAT)                       \
 168                    {                                                    \
 169                      if (i <= 2)                                        \
 170                        {                                                \
 171                          if (i == 1) i++;                               \
 172                          ASM_DOUBLE_ARG_DESCRIPTORS (FILE, i++, i++);   \
 173                        }                                                \
 174                      else                                               \
 175                        break;                                           \
 176                    }                                                    \
 177                  else                                                   \
 178                    {                                                    \
 179                      int arg_size =                                     \
 180                        FUNCTION_ARG_SIZE (TYPE_MODE (DECL_ARG_TYPE (parm)),\
 181                                           DECL_ARG_TYPE (parm));        \
 182                      /* Passing structs by invisible reference uses     \
 183                         one general register.  */                       \
 184                      if (arg_size > 2                                   \
 185                          || TREE_ADDRESSABLE (DECL_ARG_TYPE (parm)))    \
 186                        arg_size = 1;                                    \
 187                      if (arg_size == 2 && i <= 2)                       \
 188                        {                                                \
 189                          if (i == 1) i++;                               \
 190                          fprintf (FILE, ",ARGW%d=GR", i++);             \
 191                          fprintf (FILE, ",ARGW%d=GR", i++);             \
 192                        }                                                \
 193                      else if (arg_size == 1)                            \
 194                        fprintf (FILE, ",ARGW%d=GR", i++);               \
 195                      else                                               \
 196                        i += arg_size;                                   \
 197                    }                                                    \
 198                }                                                        \
 199              /* anonymous args */                                       \
 200              if (TYPE_ARG_TYPES (tree_type) != 0                        \
 201                  && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (tree_type)))\
 202                      != void_type_node))                                \
 203                {                                                        \
 204                  for (; i < 4; i++)                                     \
 205                    fprintf (FILE, ",ARGW%d=GR", i);                     \
 206                }                                                        \
 207              if (TYPE_MODE (fntype) == DFmode && ! TARGET_SOFT_FLOAT)   \
 208                fputs (DFMODE_RETURN_STRING, FILE);                      \
 209              else if (TYPE_MODE (fntype) == SFmode && ! TARGET_SOFT_FLOAT) \
 210                fputs (SFMODE_RETURN_STRING, FILE);                      \
 211              else if (fntype != void_type_node)                         \
 212                fputs (",RTNVAL=GR", FILE);                              \
 213              fputs ("\n", FILE);                                        \
 214            }} while (0)
 215
 216 #define TARGET_ASM_FILE_START pa_som_file_start
 217
 218 /* Output before code.  */
 219
 220 /* Supposedly the assembler rejects the command if there is no tab!  */
 221 #define TEXT_SECTION_ASM_OP "\t.SPACE $TEXT$\n\t.SUBSPA $CODE$\n"
 222
 223 /* Output before read-only data.  */
 224
 225 /* Supposedly the assembler rejects the command if there is no tab!  */
 226 #define READONLY_DATA_ASM_OP "\t.SPACE $TEXT$\n\t.SUBSPA $LIT$\n"
 227
 228 #define EXTRA_SECTIONS in_readonly_data
 229
 230 #define EXTRA_SECTION_FUNCTIONS                                         \
 231 extern void readonly_data PARAMS ((void));                              \
 232 void                                                                    \
 233 readonly_data ()                                                        \
 234 {                                                                       \
 235   if (in_section != in_readonly_data)                                   \
 236     {                                                                   \
 237       in_section = in_readonly_data;                                    \
 238       fprintf (asm_out_file, "%s\n", READONLY_DATA_ASM_OP);             \
 239     }                                                                   \
 240 }
 241
 242 /* FIXME: HPUX ld generates incorrect GOT entries for "T" fixups
 243    which reference data within the $TEXT$ space (for example constant
 244    strings in the $LIT$ subspace).
 245
 246    The assemblers (GAS and HP as) both have problems with handling
 247    the difference of two symbols which is the other correct way to
 248    reference constant data during PIC code generation.
 249
 250    So, there's no way to reference constant data which is in the
 251    $TEXT$ space during PIC generation.  Instead place all constant
 252    data into the $PRIVATE$ subspace (this reduces sharing, but it
 253    works correctly).  */
 254
 255 #define READONLY_DATA_SECTION (flag_pic ? data_section : readonly_data)
 256
 257 /* Output before writable data.  */
 258
 259 /* Supposedly the assembler rejects the command if there is no tab!  */
 260 #define DATA_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $DATA$\n"
 261
 262 /* Output before uninitialized data.  */
 263
 264 #define BSS_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $BSS$\n"
 265
 266 /* We must not have a reference to an external symbol defined in a
 267    shared library in a readonly section, else the SOM linker will
 268    complain.
 269
 270    So, we force exception information into the data section.  */
 271 #define TARGET_ASM_EXCEPTION_SECTION data_section
 272
 273 /* This is how to output a command to make the user-level label named NAME
 274    defined for reference from other files.
 275
 276    We call assemble_name, which in turn sets TREE_SYMBOL_REFERENCED.  This
 277    macro will restore the original value of TREE_SYMBOL_REFERENCED to avoid
 278    placing useless function definitions in the output file.
 279
 280    Also note that the SOM based tools need the symbol imported as a CODE
 281    symbol, while the ELF based tools require the symbol to be imported as
 282    an ENTRY symbol.  What a crock.  */
 283
 284 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME)   \
 285   do { int save_referenced;                                     \
 286        save_referenced = TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (DECL)); \
 287        fputs ("\t.IMPORT ", FILE);                              \
 288        assemble_name (FILE, NAME);                              \
 289        if (FUNCTION_NAME_P (NAME))                              \
 290          fputs (",CODE\n", FILE);                               \
 291        else                                                     \
 292          fputs (",DATA\n", FILE);                               \
 293        TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (DECL)) = save_referenced; \
 294      } while (0)
 295
 296 /* The bogus HP assembler requires ALL external references to be
 297    "imported", even library calls. They look a bit different, so
 298    here's this macro.
 299
 300    Also note not all libcall names are passed to pa_encode_section_info
 301    (__main for example).  To make sure all libcall names have section
 302    info recorded in them, we do it here.  We must also ensure that
 303    we don't import a libcall that has been previously exported since
 304    the HP assembler may change an ENTRY symbol to a CODE symbol.  */
 305
 306 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, RTL) \
 307   do { const char *name;                                                \
 308        tree id;                                                         \
 309                                                                         \
 310        if (!function_label_operand (RTL, VOIDmode))                     \
 311          hppa_encode_label (RTL);                                       \
 312                                                                         \
 313        name = (*targetm.strip_name_encoding) (XSTR ((RTL), 0));         \
 314        id = maybe_get_identifier (name);                                \
 315        if (! id || ! TREE_SYMBOL_REFERENCED (id))                       \
 316          {                                                              \
 317            fputs ("\t.IMPORT ", FILE);                                  \
 318            assemble_name (FILE, XSTR ((RTL), 0));                       \
 319            fputs (",CODE\n", FILE);                                     \
 320          }                                                              \
 321      } while (0)
 322
 323 /* We want __gcc_plt_call to appear in every program built by
 324    gcc, so we make a reference to it out of __main.
 325    We use the asm statement to fool the optimizer into not
 326    removing the dead (but important) initialization of
 327    REFERENCE.  */
 328
 329 #define DO_GLOBAL_DTORS_BODY                    \
 330 do {                                            \
 331   extern void __gcc_plt_call ();                \
 332   void (*reference)() = &__gcc_plt_call;        \
 333   func_ptr *p;                                  \
 334   __asm__ ("" : : "r" (reference));             \
 335   for (p = __DTOR_LIST__ + 1; *p; )             \
 336     (*p++) ();                                  \
 337 } while (0)
 338
 339 /* The .align directive in the HP assembler allows up to a 32 alignment.  */
 340 #define MAX_OFILE_ALIGNMENT 32768
 341
 342 /* The SOM linker hardcodes paths into binaries.  As a result, dotdots
 343    must be removed from library prefixes to prevent binaries from depending
 344    on the location of the GCC tool directory.  The downside is GCC
 345    cannot be moved after installation using a symlink.  */
 346 #define ALWAYS_STRIP_DOTDOT 1
 347
 348 /* Aggregates with a single float or double field should be passed and
 349    returned in the general registers.  */
 350 #define MEMBER_TYPE_FORCES_BLK(FIELD, MODE) (MODE==SFmode || MODE==DFmode)
 351
 352 /* If GAS supports weak, we can support weak when we have working linker
 353    support for secondary definitions and are generating code for GAS.  */
 354 #ifdef HAVE_GAS_WEAK
 355 #define SUPPORTS_WEAK (TARGET_SOM_SDEF && TARGET_GAS)
 356 #else
 357 #define SUPPORTS_WEAK 0
 358 #endif
 359
 360 /* We can support one only if we support weak.  */
 361 #define SUPPORTS_ONE_ONLY SUPPORTS_WEAK
 362
 363 /* Use weak (secondary definitions) to make one only declarations.  */
 364 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
 365
 366 /* This is how we tell the assembler that a symbol is weak.  The SOM
 367    weak implementation uses the secondary definition (sdef) flag.
 368
 369    The behavior of sdef symbols is similar to ELF weak symbols in that
 370    multiple definitions can occur without incurring a link error.
 371    However, they differ in the following ways:
 372      1) Undefined sdef symbols are not allowed.
 373      2) The linker searches for undefined sdef symbols and will load an
 374         archive library member to resolve an undefined sdef symbol.
 375      3) The exported symbol from a shared library is a primary symbol
 376         rather than a sdef symbol.  Thus, more care is needed in the
 377         ordering of libraries.
 378
 379    It appears that the linker discards extra copies of "weak" functions
 380    when linking shared libraries, independent of whether or not they
 381    are in their own section.  In linking final executables, -Wl,-O can
 382    be used to remove dead procedures.  Thus, support for named sections
 383    is not needed and in previous testing caused problems with various
 384    HP tools.  */
 385 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 386   do { fputs ("\t.weak\t", FILE);                               \
 387        assemble_name (FILE, NAME);                              \
 388        fputc ('\n', FILE);                                      \
 389        if (! FUNCTION_NAME_P (NAME))                            \
 390          {                                                      \
 391            fputs ("\t.EXPORT ", FILE);                          \
 392            assemble_name (FILE, NAME);                          \
 393            fputs (",DATA\n", FILE);                             \
 394          }                                                      \
 395   } while (0)
 396
 397 /* We can't handle weak aliases, and therefore can't support pragma weak.
 398    Suppress the use of pragma weak in gthr-dce.h and gthr-posix.h.  */
 399 #define GTHREAD_USE_WEAK 0