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 /* Output at beginning of assembler file.  */
 217
 218 #define ASM_FILE_START(FILE) \
 219 do {  \
 220      if (TARGET_PA_20) \
 221        fputs("\t.LEVEL 2.0\n", FILE); \
 222      else if (TARGET_PA_11) \
 223        fputs("\t.LEVEL 1.1\n", FILE); \
 224      else \
 225        fputs("\t.LEVEL 1.0\n", FILE); \
 226      fputs ("\t.SPACE $PRIVATE$\n\
 227 \t.SUBSPA $DATA$,QUAD=1,ALIGN=8,ACCESS=31\n\
 228 \t.SUBSPA $BSS$,QUAD=1,ALIGN=8,ACCESS=31,ZERO,SORT=82\n\
 229 \t.SPACE $TEXT$\n\
 230 \t.SUBSPA $LIT$,QUAD=0,ALIGN=8,ACCESS=44\n\
 231 \t.SUBSPA $CODE$,QUAD=0,ALIGN=8,ACCESS=44,CODE_ONLY\n\
 232 \t.IMPORT $global$,DATA\n\
 233 \t.IMPORT $$dyncall,MILLICODE\n", FILE);\
 234      if (profile_flag)\
 235        fprintf (FILE, "\t.IMPORT _mcount, CODE\n");\
 236      if (write_symbols != NO_DEBUG) \
 237        output_file_directive ((FILE), main_input_filename); \
 238    } while (0)
 239
 240 /* Output before code.  */
 241
 242 /* Supposedly the assembler rejects the command if there is no tab!  */
 243 #define TEXT_SECTION_ASM_OP "\t.SPACE $TEXT$\n\t.SUBSPA $CODE$\n"
 244
 245 /* Output before read-only data.  */
 246
 247 /* Supposedly the assembler rejects the command if there is no tab!  */
 248 #define READONLY_DATA_ASM_OP "\t.SPACE $TEXT$\n\t.SUBSPA $LIT$\n"
 249
 250 #define EXTRA_SECTIONS in_readonly_data
 251
 252 #define EXTRA_SECTION_FUNCTIONS                                         \
 253 extern void readonly_data PARAMS ((void));                              \
 254 void                                                                    \
 255 readonly_data ()                                                        \
 256 {                                                                       \
 257   if (in_section != in_readonly_data)                                   \
 258     {                                                                   \
 259       in_section = in_readonly_data;                                    \
 260       fprintf (asm_out_file, "%s\n", READONLY_DATA_ASM_OP);             \
 261     }                                                                   \
 262 }
 263
 264 /* FIXME: HPUX ld generates incorrect GOT entries for "T" fixups
 265    which reference data within the $TEXT$ space (for example constant
 266    strings in the $LIT$ subspace).
 267
 268    The assemblers (GAS and HP as) both have problems with handling
 269    the difference of two symbols which is the other correct way to
 270    reference constant data during PIC code generation.
 271
 272    So, there's no way to reference constant data which is in the
 273    $TEXT$ space during PIC generation.  Instead place all constant
 274    data into the $PRIVATE$ subspace (this reduces sharing, but it
 275    works correctly).  */
 276
 277 #define READONLY_DATA_SECTION (flag_pic ? data_section : readonly_data)
 278
 279 /* Output before writable data.  */
 280
 281 /* Supposedly the assembler rejects the command if there is no tab!  */
 282 #define DATA_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $DATA$\n"
 283
 284 /* Output before uninitialized data.  */
 285
 286 #define BSS_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $BSS$\n"
 287
 288 /* We must not have a reference to an external symbol defined in a
 289    shared library in a readonly section, else the SOM linker will
 290    complain.
 291
 292    So, we force exception information into the data section.  */
 293 #define TARGET_ASM_EXCEPTION_SECTION data_section
 294
 295 /* This is how to output a command to make the user-level label named NAME
 296    defined for reference from other files.
 297
 298    We call assemble_name, which in turn sets TREE_SYMBOL_REFERENCED.  This
 299    macro will restore the original value of TREE_SYMBOL_REFERENCED to avoid
 300    placing useless function definitions in the output file.
 301
 302    Also note that the SOM based tools need the symbol imported as a CODE
 303    symbol, while the ELF based tools require the symbol to be imported as
 304    an ENTRY symbol.  What a crock.  */
 305
 306 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME)   \
 307   do { int save_referenced;                                     \
 308        save_referenced = TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (DECL)); \
 309        fputs ("\t.IMPORT ", FILE);                              \
 310        assemble_name (FILE, NAME);                              \
 311        if (FUNCTION_NAME_P (NAME))                              \
 312          fputs (",CODE\n", FILE);                               \
 313        else                                                     \
 314          fputs (",DATA\n", FILE);                               \
 315        TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (DECL)) = save_referenced; \
 316      } while (0)
 317
 318 /* The bogus HP assembler requires ALL external references to be
 319    "imported", even library calls. They look a bit different, so
 320    here's this macro.
 321
 322    Also note not all libcall names are passed to pa_encode_section_info
 323    (__main for example).  To make sure all libcall names have section
 324    info recorded in them, we do it here.  We must also ensure that
 325    we don't import a libcall that has been previously exported since
 326    the HP assembler may change an ENTRY symbol to a CODE symbol.  */
 327
 328 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, RTL) \
 329   do { const char *name;                                                \
 330        tree id;                                                         \
 331                                                                         \
 332        if (!function_label_operand (RTL, VOIDmode))                     \
 333          hppa_encode_label (RTL);                                       \
 334                                                                         \
 335        name = (*targetm.strip_name_encoding) (XSTR ((RTL), 0));         \
 336        id = maybe_get_identifier (name);                                \
 337        if (! id || ! TREE_SYMBOL_REFERENCED (id))                       \
 338          {                                                              \
 339            fputs ("\t.IMPORT ", FILE);                                  \
 340            assemble_name (FILE, XSTR ((RTL), 0));                       \
 341            fputs (",CODE\n", FILE);                                     \
 342          }                                                              \
 343      } while (0)
 344
 345 /* We want __gcc_plt_call to appear in every program built by
 346    gcc, so we make a reference to it out of __main.
 347    We use the asm statement to fool the optimizer into not
 348    removing the dead (but important) initialization of
 349    REFERENCE.  */
 350
 351 #define DO_GLOBAL_DTORS_BODY                    \
 352 do {                                            \
 353   extern void __gcc_plt_call ();                \
 354   void (*reference)() = &__gcc_plt_call;        \
 355   func_ptr *p;                                  \
 356   __asm__ ("" : : "r" (reference));             \
 357   for (p = __DTOR_LIST__ + 1; *p; )             \
 358     (*p++) ();                                  \
 359 } while (0)
 360
 361 /* The .align directive in the HP assembler allows up to a 32 alignment.  */
 362 #define MAX_OFILE_ALIGNMENT 32768
 363
 364 /* The SOM linker hardcodes paths into binaries.  As a result, dotdots
 365    must be removed from library prefixes to prevent binaries from depending
 366    on the location of the GCC tool directory.  The downside is GCC
 367    cannot be moved after installation using a symlink.  */
 368 #define ALWAYS_STRIP_DOTDOT 1
 369
 370 /* Aggregates with a single float or double field should be passed and
 371    returned in the general registers.  */
 372 #define MEMBER_TYPE_FORCES_BLK(FIELD, MODE) (MODE==SFmode || MODE==DFmode)
 373
 374 /* If GAS supports weak, we can support weak when we have working linker
 375    support for secondary definitions and are generating code for GAS.  */
 376 #ifdef HAVE_GAS_WEAK
 377 #define SUPPORTS_WEAK (TARGET_SOM_SDEF && TARGET_GAS)
 378 #else
 379 #define SUPPORTS_WEAK 0
 380 #endif
 381
 382 /* We can support one only if we support weak.  */
 383 #define SUPPORTS_ONE_ONLY SUPPORTS_WEAK
 384
 385 /* Use weak (secondary definitions) to make one only declarations.  */
 386 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
 387
 388 /* This is how we tell the assembler that a symbol is weak.  The SOM
 389    weak implementation uses the secondary definition (sdef) flag.
 390
 391    The behavior of sdef symbols is similar to ELF weak symbols in that
 392    multiple definitions can occur without incurring a link error.
 393    However, they differ in the following ways:
 394      1) Undefined sdef symbols are not allowed.
 395      2) The linker searches for undefined sdef symbols and will load an
 396         archive library member to resolve an undefined sdef symbol.
 397      3) The exported symbol from a shared library is a primary symbol
 398         rather than a sdef symbol.  Thus, more care is needed in the
 399         ordering of libraries.
 400
 401    It appears that the linker discards extra copies of "weak" functions
 402    when linking shared libraries, independent of whether or not they
 403    are in their own section.  In linking final executables, -Wl,-O can
 404    be used to remove dead procedures.  Thus, support for named sections
 405    is not needed and in previous testing caused problems with various
 406    HP tools.  */
 407 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 408   do { fputs ("\t.weak\t", FILE);                               \
 409        assemble_name (FILE, NAME);                              \
 410        fputc ('\n', FILE);                                      \
 411        if (! FUNCTION_NAME_P (NAME))                            \
 412          {                                                      \
 413            fputs ("\t.EXPORT ", FILE);                          \
 414            assemble_name (FILE, NAME);                          \
 415            fputs (",DATA\n", FILE);                             \
 416          }                                                      \
 417   } while (0)
 418
 419 /* We can't handle weak aliases, and therefore can't support pragma weak.
 420    Suppress the use of pragma weak in gthr-dce.h and gthr-posix.h.  */
 421 #define GTHREAD_USE_WEAK 0