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       {                                                         \
  37         rtx func = DECL_RTL (current_function_decl);            \
  38         const char *name = XSTR (XEXP (func, 0), 0);            \
  39         fprintf (file, "\t.stabn 68,0,%d,L$M%d-%s\nL$M%d:\n",   \
  40                  line, counter,                                 \
  41                  (* targetm.strip_name_encoding) (name),        \
  42                  counter);                                      \
  43       }                                                         \
  44     else                                                        \
  45       fprintf (file, "\t.stabn 68,0,%d,0\n", line);             \
  46     last_function_decl = current_function_decl;                 \
  47   }
  48
  49 /* gdb needs a null N_SO at the end of each file for scattered loading.  */
  50
  51 #undef  DBX_OUTPUT_MAIN_SOURCE_FILE_END
  52 #define DBX_OUTPUT_MAIN_SOURCE_FILE_END(FILE, FILENAME) \
  53   text_section (); \
  54   fputs ("\t.SPACE $TEXT$\n\t.NSUBSPA $CODE$,QUAD=0,ALIGN=8,ACCESS=44,CODE_ONLY\n", FILE); \
  55   fprintf (FILE,                                                        \
  56            "\t.stabs \"\",%d,0,0,L$text_end0000\nL$text_end0000:\n", N_SO)
  57
  58 /* Select a format to encode pointers in exception handling data.  CODE
  59    is 0 for data, 1 for code labels, 2 for function pointers.  GLOBAL is
  60    true if the symbol may be affected by dynamic relocations.  Because
  61    the HP assembler does auto alignment, it is necessary to use
  62    DW_EH_PE_aligned instead of the default DW_EH_PE_absptr.  */
  63
  64 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
  65   (TARGET_GAS ? DW_EH_PE_absptr : DW_EH_PE_aligned)
  66
  67 /* HPUX has a program 'chatr' to list the dependencies of dynamically
  68    linked executables and shared libraries.  */
  69 #define LDD_SUFFIX "chatr"
  70 /* Look for lines like "dynamic   /usr/lib/X11R5/libX11.sl"
  71    or "static    /usr/lib/X11R5/libX11.sl".
  72
  73    HPUX 10.20 also has lines like "static branch prediction ..."
  74    so we filter that out explicitly.
  75
  76    We also try to bound our search for libraries with marker
  77    lines.  What a pain.  */
  78 #define PARSE_LDD_OUTPUT(PTR)                                   \
  79 do {                                                            \
  80   static int in_shlib_list = 0;                                 \
  81   while (*PTR == ' ') PTR++;                                    \
  82   if (strncmp (PTR, "shared library list:",                     \
  83                sizeof ("shared library list:") - 1) == 0)       \
  84     {                                                           \
  85       PTR = 0;                                                  \
  86       in_shlib_list = 1;                                        \
  87     }                                                           \
  88   else if (strncmp (PTR, "shared library binding:",             \
  89                     sizeof ("shared library binding:") - 1) == 0)\
  90     {                                                           \
  91       PTR = 0;                                                  \
  92       in_shlib_list = 0;                                        \
  93     }                                                           \
  94   else if (strncmp (PTR, "static branch prediction disabled",   \
  95                     sizeof ("static branch prediction disabled") - 1) == 0)\
  96     {                                                           \
  97       PTR = 0;                                                  \
  98       in_shlib_list = 0;                                        \
  99     }                                                           \
 100   else if (in_shlib_list                                        \
 101            &&  strncmp (PTR, "dynamic", sizeof ("dynamic") - 1) == 0) \
 102     {                                                           \
 103       PTR += sizeof ("dynamic") - 1;                            \
 104       while (*p == ' ') PTR++;                                  \
 105     }                                                           \
 106   else if (in_shlib_list                                        \
 107            && strncmp (PTR, "static", sizeof ("static") - 1) == 0) \
 108     {                                                           \
 109       PTR += sizeof ("static") - 1;                             \
 110       while (*p == ' ') PTR++;                                  \
 111     }                                                           \
 112   else                                                          \
 113     PTR = 0;                                                    \
 114 } while (0)
 115
 116 /* Output the label for a function definition.  */
 117 #ifndef HP_FP_ARG_DESCRIPTOR_REVERSED
 118 #define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)    \
 119   do { fprintf (FILE, ",ARGW%d=FR", (ARG0));            \
 120        fprintf (FILE, ",ARGW%d=FU", (ARG1));} while (0)
 121 #define DFMODE_RETURN_STRING ",RTNVAL=FU"
 122 #define SFMODE_RETURN_STRING ",RTNVAL=FR"
 123 #else
 124 #define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)    \
 125   do { fprintf (FILE, ",ARGW%d=FU", (ARG0));            \
 126        fprintf (FILE, ",ARGW%d=FR", (ARG1));} while (0)
 127 #define DFMODE_RETURN_STRING ",RTNVAL=FR"
 128 #define SFMODE_RETURN_STRING ",RTNVAL=FU"
 129 #endif
 130
 131 \f
 132 /* NAME refers to the function's name.  If we are placing each function into
 133    its own section, we need to switch to the section for this function.  Note
 134    that the section name will have a "." prefix.  */
 135 #define ASM_OUTPUT_FUNCTION_PREFIX(FILE, NAME) \
 136   {                                                                     \
 137     const char *name = (*targetm.strip_name_encoding) (NAME);           \
 138     if (TARGET_GAS && in_section == in_text)                            \
 139       fputs ("\t.NSUBSPA $CODE$,QUAD=0,ALIGN=8,ACCESS=44,CODE_ONLY\n", FILE); \
 140     else if (TARGET_GAS)                                                \
 141       fprintf (FILE,                                                    \
 142                "\t.SUBSPA .%s\n", name);                                \
 143   }
 144
 145 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
 146     do { tree fntype = TREE_TYPE (TREE_TYPE (DECL));                    \
 147          tree tree_type = TREE_TYPE (DECL);                             \
 148          tree parm;                                                     \
 149          int i;                                                         \
 150          if (TREE_PUBLIC (DECL) || TARGET_GAS)                          \
 151            {                                                            \
 152              if (TREE_PUBLIC (DECL))                                    \
 153                {                                                        \
 154                  fputs ("\t.EXPORT ", FILE);                            \
 155                  assemble_name (FILE, NAME);                            \
 156                  fputs (",ENTRY,PRIV_LEV=3", FILE);                     \
 157                }                                                        \
 158              else                                                       \
 159                {                                                        \
 160                  fputs ("\t.PARAM ", FILE);                             \
 161                  assemble_name (FILE, NAME);                            \
 162                  fputs (",PRIV_LEV=3", FILE);                           \
 163                }                                                        \
 164              for (parm = DECL_ARGUMENTS (DECL), i = 0; parm && i < 4;   \
 165                   parm = TREE_CHAIN (parm))                             \
 166                {                                                        \
 167                  if (TYPE_MODE (DECL_ARG_TYPE (parm)) == SFmode         \
 168                      && ! TARGET_SOFT_FLOAT)                            \
 169                    fprintf (FILE, ",ARGW%d=FR", i++);                   \
 170                  else if (TYPE_MODE (DECL_ARG_TYPE (parm)) == DFmode    \
 171                           && ! TARGET_SOFT_FLOAT)                       \
 172                    {                                                    \
 173                      if (i <= 2)                                        \
 174                        {                                                \
 175                          if (i == 1) i++;                               \
 176                          ASM_DOUBLE_ARG_DESCRIPTORS (FILE, i++, i++);   \
 177                        }                                                \
 178                      else                                               \
 179                        break;                                           \
 180                    }                                                    \
 181                  else                                                   \
 182                    {                                                    \
 183                      int arg_size =                                     \
 184                        FUNCTION_ARG_SIZE (TYPE_MODE (DECL_ARG_TYPE (parm)),\
 185                                           DECL_ARG_TYPE (parm));        \
 186                      /* Passing structs by invisible reference uses     \
 187                         one general register.  */                       \
 188                      if (arg_size > 2                                   \
 189                          || TREE_ADDRESSABLE (DECL_ARG_TYPE (parm)))    \
 190                        arg_size = 1;                                    \
 191                      if (arg_size == 2 && i <= 2)                       \
 192                        {                                                \
 193                          if (i == 1) i++;                               \
 194                          fprintf (FILE, ",ARGW%d=GR", i++);             \
 195                          fprintf (FILE, ",ARGW%d=GR", i++);             \
 196                        }                                                \
 197                      else if (arg_size == 1)                            \
 198                        fprintf (FILE, ",ARGW%d=GR", i++);               \
 199                      else                                               \
 200                        i += arg_size;                                   \
 201                    }                                                    \
 202                }                                                        \
 203              /* anonymous args */                                       \
 204              if (TYPE_ARG_TYPES (tree_type) != 0                        \
 205                  && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (tree_type)))\
 206                      != void_type_node))                                \
 207                {                                                        \
 208                  for (; i < 4; i++)                                     \
 209                    fprintf (FILE, ",ARGW%d=GR", i);                     \
 210                }                                                        \
 211              if (TYPE_MODE (fntype) == DFmode && ! TARGET_SOFT_FLOAT)   \
 212                fputs (DFMODE_RETURN_STRING, FILE);                      \
 213              else if (TYPE_MODE (fntype) == SFmode && ! TARGET_SOFT_FLOAT) \
 214                fputs (SFMODE_RETURN_STRING, FILE);                      \
 215              else if (fntype != void_type_node)                         \
 216                fputs (",RTNVAL=GR", FILE);                              \
 217              fputs ("\n", FILE);                                        \
 218            }} while (0)
 219
 220 #define TARGET_ASM_FILE_START pa_som_file_start
 221
 222 /* Output before code.  */
 223
 224 /* Supposedly the assembler rejects the command if there is no tab!  */
 225 #define TEXT_SECTION_ASM_OP "\t.SPACE $TEXT$\n\t.SUBSPA $CODE$\n"
 226
 227 /* Output before read-only data.  */
 228
 229 /* Supposedly the assembler rejects the command if there is no tab!  */
 230 #define READONLY_DATA_ASM_OP "\t.SPACE $TEXT$\n\t.SUBSPA $LIT$\n"
 231
 232 #define EXTRA_SECTIONS in_readonly_data
 233
 234 #define EXTRA_SECTION_FUNCTIONS                                         \
 235 extern void readonly_data PARAMS ((void));                              \
 236 void                                                                    \
 237 readonly_data ()                                                        \
 238 {                                                                       \
 239   if (in_section != in_readonly_data)                                   \
 240     {                                                                   \
 241       in_section = in_readonly_data;                                    \
 242       fprintf (asm_out_file, "%s\n", READONLY_DATA_ASM_OP);             \
 243     }                                                                   \
 244 }
 245
 246 /* FIXME: HPUX ld generates incorrect GOT entries for "T" fixups
 247    which reference data within the $TEXT$ space (for example constant
 248    strings in the $LIT$ subspace).
 249
 250    The assemblers (GAS and HP as) both have problems with handling
 251    the difference of two symbols which is the other correct way to
 252    reference constant data during PIC code generation.
 253
 254    So, there's no way to reference constant data which is in the
 255    $TEXT$ space during PIC generation.  Instead place all constant
 256    data into the $PRIVATE$ subspace (this reduces sharing, but it
 257    works correctly).  */
 258
 259 #define READONLY_DATA_SECTION (flag_pic ? data_section : readonly_data)
 260
 261 /* Output before writable data.  */
 262
 263 /* Supposedly the assembler rejects the command if there is no tab!  */
 264 #define DATA_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $DATA$\n"
 265
 266 /* Output before uninitialized data.  */
 267
 268 #define BSS_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $BSS$\n"
 269
 270 /* We must not have a reference to an external symbol defined in a
 271    shared library in a readonly section, else the SOM linker will
 272    complain.
 273
 274    So, we force exception information into the data section.  */
 275 #define TARGET_ASM_EXCEPTION_SECTION data_section
 276
 277 /* This is how to output a command to make the user-level label named NAME
 278    defined for reference from other files.
 279
 280    We call assemble_name, which in turn sets TREE_SYMBOL_REFERENCED.  This
 281    macro will restore the original value of TREE_SYMBOL_REFERENCED to avoid
 282    placing useless function definitions in the output file.
 283
 284    Also note that the SOM based tools need the symbol imported as a CODE
 285    symbol, while the ELF based tools require the symbol to be imported as
 286    an ENTRY symbol.  What a crock.  */
 287
 288 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME)   \
 289   do { int save_referenced;                                     \
 290        save_referenced = TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (DECL)); \
 291        fputs ("\t.IMPORT ", FILE);                              \
 292        assemble_name (FILE, NAME);                              \
 293        if (FUNCTION_NAME_P (NAME))                              \
 294          fputs (",CODE\n", FILE);                               \
 295        else                                                     \
 296          fputs (",DATA\n", FILE);                               \
 297        TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (DECL)) = save_referenced; \
 298      } while (0)
 299
 300 /* The bogus HP assembler requires ALL external references to be
 301    "imported", even library calls. They look a bit different, so
 302    here's this macro.
 303
 304    Also note not all libcall names are passed to pa_encode_section_info
 305    (__main for example).  To make sure all libcall names have section
 306    info recorded in them, we do it here.  We must also ensure that
 307    we don't import a libcall that has been previously exported since
 308    the HP assembler may change an ENTRY symbol to a CODE symbol.  */
 309
 310 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, RTL) \
 311   do { const char *name;                                                \
 312        tree id;                                                         \
 313                                                                         \
 314        if (!function_label_operand (RTL, VOIDmode))                     \
 315          hppa_encode_label (RTL);                                       \
 316                                                                         \
 317        name = (*targetm.strip_name_encoding) (XSTR ((RTL), 0));         \
 318        id = maybe_get_identifier (name);                                \
 319        if (! id || ! TREE_SYMBOL_REFERENCED (id))                       \
 320          {                                                              \
 321            fputs ("\t.IMPORT ", FILE);                                  \
 322            assemble_name (FILE, XSTR ((RTL), 0));                       \
 323            fputs (",CODE\n", FILE);                                     \
 324          }                                                              \
 325      } while (0)
 326
 327 /* We want __gcc_plt_call to appear in every program built by
 328    gcc, so we make a reference to it out of __main.
 329    We use the asm statement to fool the optimizer into not
 330    removing the dead (but important) initialization of
 331    REFERENCE.  */
 332
 333 #define DO_GLOBAL_DTORS_BODY                    \
 334 do {                                            \
 335   extern void __gcc_plt_call ();                \
 336   void (*reference)() = &__gcc_plt_call;        \
 337   func_ptr *p;                                  \
 338   __asm__ ("" : : "r" (reference));             \
 339   for (p = __DTOR_LIST__ + 1; *p; )             \
 340     (*p++) ();                                  \
 341 } while (0)
 342
 343 /* The .align directive in the HP assembler allows up to a 32 alignment.  */
 344 #define MAX_OFILE_ALIGNMENT 32768
 345
 346 /* The SOM linker hardcodes paths into binaries.  As a result, dotdots
 347    must be removed from library prefixes to prevent binaries from depending
 348    on the location of the GCC tool directory.  The downside is GCC
 349    cannot be moved after installation using a symlink.  */
 350 #define ALWAYS_STRIP_DOTDOT 1
 351
 352 /* Aggregates with a single float or double field should be passed and
 353    returned in the general registers.  */
 354 #define MEMBER_TYPE_FORCES_BLK(FIELD, MODE) (MODE==SFmode || MODE==DFmode)
 355
 356 /* If GAS supports weak, we can support weak when we have working linker
 357    support for secondary definitions and are generating code for GAS.  */
 358 #ifdef HAVE_GAS_WEAK
 359 #define SUPPORTS_WEAK (TARGET_SOM_SDEF && TARGET_GAS)
 360 #else
 361 #define SUPPORTS_WEAK 0
 362 #endif
 363
 364 /* We can support one only if we support weak.  */
 365 #define SUPPORTS_ONE_ONLY SUPPORTS_WEAK
 366
 367 /* Use weak (secondary definitions) to make one only declarations.  */
 368 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
 369
 370 /* This is how we tell the assembler that a symbol is weak.  The SOM
 371    weak implementation uses the secondary definition (sdef) flag.
 372
 373    The behavior of sdef symbols is similar to ELF weak symbols in that
 374    multiple definitions can occur without incurring a link error.
 375    However, they differ in the following ways:
 376      1) Undefined sdef symbols are not allowed.
 377      2) The linker searches for undefined sdef symbols and will load an
 378         archive library member to resolve an undefined sdef symbol.
 379      3) The exported symbol from a shared library is a primary symbol
 380         rather than a sdef symbol.  Thus, more care is needed in the
 381         ordering of libraries.
 382
 383    It appears that the linker discards extra copies of "weak" functions
 384    when linking shared libraries, independent of whether or not they
 385    are in their own section.  In linking final executables, -Wl,-O can
 386    be used to remove dead procedures.  Thus, support for named sections
 387    is not needed and in previous testing caused problems with various
 388    HP tools.  */
 389 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 390   do { fputs ("\t.weak\t", FILE);                               \
 391        assemble_name (FILE, NAME);                              \
 392        fputc ('\n', FILE);                                      \
 393        if (! FUNCTION_NAME_P (NAME))                            \
 394          {                                                      \
 395            fputs ("\t.EXPORT ", FILE);                          \
 396            assemble_name (FILE, NAME);                          \
 397            fputs (",DATA\n", FILE);                             \
 398          }                                                      \
 399   } while (0)
 400
 401 /* We can't handle weak aliases, and therefore can't support pragma weak.
 402    Suppress the use of pragma weak in gthr-dce.h and gthr-posix.h.  */
 403 #define GTHREAD_USE_WEAK 0