gcc/config/pa/som.h

   1 /* Definitions for SOM assembler support.
   2    Copyright (C) 1999-2020 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC 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 3, or (at your option)
   9 any later version.
  10
  11 GCC 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 GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 /* So we can conditionalize small amounts of code in pa.c or pa.md.  */
  21 #undef TARGET_SOM
  22 #define TARGET_SOM 1
  23
  24 /* We do not use BINCL stabs in SOM.
  25    ??? If it does not hurt, we probably should to avoid useless divergence
  26    from other embedded stabs implementations.  */
  27 #undef DBX_USE_BINCL
  28
  29 #define DBX_LINES_FUNCTION_RELATIVE 1
  30
  31 /* gdb needs a null N_SO at the end of each file for scattered loading.  */
  32
  33 #define DBX_OUTPUT_NULL_N_SO_AT_MAIN_SOURCE_FILE_END
  34
  35 /* HPUX has a program 'chatr' to list the dependencies of dynamically
  36    linked executables and shared libraries.  */
  37 #define LDD_SUFFIX "chatr"
  38 /* Look for lines like "dynamic   /usr/lib/X11R5/libX11.sl"
  39    or "static    /usr/lib/X11R5/libX11.sl".
  40
  41    HPUX 10.20 also has lines like "static branch prediction ..."
  42    so we filter that out explicitly.
  43
  44    We also try to bound our search for libraries with marker
  45    lines.  What a pain.  */
  46 #define PARSE_LDD_OUTPUT(PTR)                                   \
  47 do {                                                            \
  48   static int in_shlib_list = 0;                                 \
  49   while (*PTR == ' ') PTR++;                                    \
  50   if (strncmp (PTR, "shared library list:",                     \
  51                sizeof ("shared library list:") - 1) == 0)       \
  52     {                                                           \
  53       PTR = 0;                                                  \
  54       in_shlib_list = 1;                                        \
  55     }                                                           \
  56   else if (strncmp (PTR, "shared library binding:",             \
  57                     sizeof ("shared library binding:") - 1) == 0)\
  58     {                                                           \
  59       PTR = 0;                                                  \
  60       in_shlib_list = 0;                                        \
  61     }                                                           \
  62   else if (strncmp (PTR, "static branch prediction disabled",   \
  63                     sizeof ("static branch prediction disabled") - 1) == 0)\
  64     {                                                           \
  65       PTR = 0;                                                  \
  66       in_shlib_list = 0;                                        \
  67     }                                                           \
  68   else if (in_shlib_list                                        \
  69            &&  strncmp (PTR, "dynamic", sizeof ("dynamic") - 1) == 0) \
  70     {                                                           \
  71       PTR += sizeof ("dynamic") - 1;                            \
  72       while (*p == ' ') PTR++;                                  \
  73     }                                                           \
  74   else if (in_shlib_list                                        \
  75            && strncmp (PTR, "static", sizeof ("static") - 1) == 0) \
  76     {                                                           \
  77       PTR += sizeof ("static") - 1;                             \
  78       while (*p == ' ') PTR++;                                  \
  79     }                                                           \
  80   else                                                          \
  81     PTR = 0;                                                    \
  82 } while (0)
  83
  84 /* Output the label for a function definition.  */
  85 #ifndef HP_FP_ARG_DESCRIPTOR_REVERSED
  86 #define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)    \
  87   do { fprintf (FILE, ",ARGW%d=FR", (ARG0));            \
  88        fprintf (FILE, ",ARGW%d=FU", (ARG1));} while (0)
  89 #define DFMODE_RETURN_STRING ",RTNVAL=FU"
  90 #define SFMODE_RETURN_STRING ",RTNVAL=FR"
  91 #else
  92 #define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)    \
  93   do { fprintf (FILE, ",ARGW%d=FU", (ARG0));            \
  94        fprintf (FILE, ",ARGW%d=FR", (ARG1));} while (0)
  95 #define DFMODE_RETURN_STRING ",RTNVAL=FR"
  96 #define SFMODE_RETURN_STRING ",RTNVAL=FU"
  97 #endif
  98
  99 \f
 100 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
 101     do { tree tree_type = TREE_TYPE (DECL);                             \
 102          tree fntype = TREE_TYPE (tree_type);                           \
 103          tree parm;                                                     \
 104          int i;                                                         \
 105          if (TREE_PUBLIC (DECL) || TARGET_GAS)                          \
 106            {                                                            \
 107              if (TREE_PUBLIC (DECL))                                    \
 108                {                                                        \
 109                  fputs ("\t.EXPORT ", FILE);                            \
 110                  assemble_name (FILE, NAME);                            \
 111                  fputs (",ENTRY,PRIV_LEV=3", FILE);                     \
 112                }                                                        \
 113              else                                                       \
 114                {                                                        \
 115                  fputs ("\t.PARAM ", FILE);                             \
 116                  assemble_name (FILE, NAME);                            \
 117                  fputs (",PRIV_LEV=3", FILE);                           \
 118                }                                                        \
 119              for (parm = DECL_ARGUMENTS (DECL), i = 0; parm && i < 4;   \
 120                   parm = DECL_CHAIN (parm))                             \
 121                {                                                        \
 122                  tree type = DECL_ARG_TYPE (parm);                      \
 123                  machine_mode mode = TYPE_MODE (type);                  \
 124                  if (!AGGREGATE_TYPE_P (type)                           \
 125                      && mode == SFmode && ! TARGET_SOFT_FLOAT)          \
 126                    fprintf (FILE, ",ARGW%d=FR", i++);                   \
 127                  else if (!AGGREGATE_TYPE_P (type)                      \
 128                           && mode == DFmode && ! 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 = pa_function_arg_size (mode, type);  \
 141                      /* Passing structs by invisible reference uses     \
 142                         one general register.  */                       \
 143                      if (arg_size > 2 || TREE_ADDRESSABLE (type))       \
 144                        arg_size = 1;                                    \
 145                      if (arg_size == 2 && i <= 2)                       \
 146                        {                                                \
 147                          if (i == 1) i++;                               \
 148                          fprintf (FILE, ",ARGW%d=GR", i++);             \
 149                          fprintf (FILE, ",ARGW%d=GR", i++);             \
 150                        }                                                \
 151                      else if (arg_size == 1)                            \
 152                        fprintf (FILE, ",ARGW%d=GR", i++);               \
 153                      else                                               \
 154                        i += arg_size;                                   \
 155                    }                                                    \
 156                }                                                        \
 157              /* anonymous args */                                       \
 158              if (stdarg_p (tree_type))                                  \
 159                {                                                        \
 160                  for (; i < 4; i++)                                     \
 161                    fprintf (FILE, ",ARGW%d=GR", i);                     \
 162                }                                                        \
 163              if (!AGGREGATE_TYPE_P (fntype)                             \
 164                  && TYPE_MODE (fntype) == DFmode                        \
 165                  && ! TARGET_SOFT_FLOAT)                                \
 166                fputs (DFMODE_RETURN_STRING, FILE);                      \
 167              else if (!AGGREGATE_TYPE_P (fntype)                        \
 168                       && TYPE_MODE (fntype) == SFmode                   \
 169                       && ! TARGET_SOFT_FLOAT)                           \
 170                fputs (SFMODE_RETURN_STRING, FILE);                      \
 171              else if (fntype != void_type_node)                         \
 172                fputs (",RTNVAL=GR", FILE);                              \
 173              fputs ("\n", FILE);                                        \
 174            }} while (0)
 175
 176 #define TARGET_ASM_FILE_START pa_som_file_start
 177 #define TARGET_ASM_INIT_SECTIONS pa_som_asm_init_sections
 178
 179 /* String to output before writable data.  */
 180 #define DATA_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $DATA$\n"
 181
 182 /* String to output before uninitialized data.  */
 183 #define BSS_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $BSS$\n"
 184
 185 /* This is how to output a command to make the user-level label
 186    named NAME defined for reference from other files.  We use
 187    assemble_name_raw instead of assemble_name since a symbol in
 188    a .IMPORT directive that isn't otherwise referenced is not
 189    placed in the symbol table of the assembled object.
 190
 191    Failure to import a function reference can cause the HP linker
 192    to segmentation fault!
 193
 194    Note that the SOM based tools need the symbol imported as a
 195    CODE symbol, while the ELF based tools require the symbol to
 196    be imported as an ENTRY symbol.  */
 197
 198 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME) \
 199   pa_hpux_asm_output_external ((FILE), (DECL), (NAME))
 200 #define ASM_OUTPUT_EXTERNAL_REAL(FILE, DECL, NAME) \
 201   do { fputs ("\t.IMPORT ", FILE);                                      \
 202        assemble_name_raw (FILE, NAME);                                  \
 203        if (FUNCTION_NAME_P (NAME))                                      \
 204          fputs (",CODE\n", FILE);                                       \
 205        else                                                             \
 206          fputs (",DATA\n", FILE);                                       \
 207      } while (0)
 208
 209 /* The bogus HP assembler requires ALL external references to be
 210    "imported", even library calls.  They look a bit different, so
 211    here's this macro.
 212
 213    Also note not all libcall names are passed to pa_encode_section_info
 214    (__main for example).  To make sure all libcall names have section
 215    info recorded in them, we do it here.
 216
 217    We must also ensure that a libcall that has been previously
 218    exported is not subsequently imported since the HP assembler may
 219    change the type from an ENTRY to a CODE symbol.  This would make
 220    the symbol local.  We are forced to use the identifier node
 221    associated with the real assembler name for this check as the
 222    symbol_ref available in ASM_DECLARE_FUNCTION_NAME is not the
 223    same as the one used here.  As a result, we can't use flags
 224    in the symbol_ref for this check.  The identifier check assumes
 225    assemble_external_libcall is called before the symbol is used.  */
 226
 227 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, RTL) \
 228   do { const char *name;                                                \
 229        tree id;                                                         \
 230                                                                         \
 231        if (!function_label_operand (RTL, VOIDmode))                     \
 232          pa_encode_label (RTL);                                         \
 233                                                                         \
 234        name = targetm.strip_name_encoding (XSTR ((RTL), 0));            \
 235        id = maybe_get_identifier (name);                                \
 236        if (!id || !TREE_SYMBOL_REFERENCED (id))                         \
 237          {                                                              \
 238            fputs ("\t.IMPORT ", FILE);                                  \
 239            assemble_name_raw (FILE, XSTR ((RTL), 0));                   \
 240            fputs (",CODE\n", FILE);                                     \
 241          }                                                              \
 242      } while (0)
 243
 244 /* We want __gcc_plt_call to appear in every program built by
 245    gcc, so we make a reference to it out of __main.
 246    We use the asm statement to fool the optimizer into not
 247    removing the dead (but important) initialization of
 248    REFERENCE.  */
 249
 250 #define DO_GLOBAL_DTORS_BODY                    \
 251 do {                                            \
 252   extern void __gcc_plt_call (void);            \
 253   void (*reference)(void) = &__gcc_plt_call;    \
 254   func_ptr *p;                                  \
 255   __asm__ ("" : : "r" (reference));             \
 256   for (p = __DTOR_LIST__ + 1; *p; )             \
 257     (*p++) ();                                  \
 258 } while (0)
 259
 260 /* This macro specifies the biggest alignment supported by the object
 261    file format of this machine.
 262
 263    The .align directive in the HP assembler allows alignments up to 4096
 264    bytes.  However, the maximum alignment of a global common symbol is 8
 265    bytes for objects smaller than the page size (4096 bytes).  For larger
 266    objects, the linker provides an alignment of 32 bytes.  Unfortunately,
 267    this macro doesn't provide a mechanism to test for common symbols.  */
 268 #define MAX_OFILE_ALIGNMENT 32768
 269
 270 /* The SOM linker hardcodes paths into binaries.  As a result, dotdots
 271    must be removed from library prefixes to prevent binaries from depending
 272    on the location of the GCC tool directory.  The downside is GCC
 273    cannot be moved after installation using a symlink.  */
 274 #undef TARGET_ALWAYS_STRIP_DOTDOT
 275 #define TARGET_ALWAYS_STRIP_DOTDOT true
 276
 277 /* If GAS supports weak, we can support weak when we have working linker
 278    support for secondary definitions and are generating code for GAS.
 279    This is primarily for one-only support as SOM doesn't allow undefined
 280    weak symbols or weak aliases.  */
 281 #ifdef HAVE_GAS_WEAK
 282 #define TARGET_SUPPORTS_WEAK (TARGET_SOM_SDEF && TARGET_GAS)
 283 #else
 284 #define TARGET_SUPPORTS_WEAK 0
 285 #endif
 286
 287 /* CVS GAS as of 4/28/04 supports a comdat parameter for the .nsubspa
 288    directive.  This provides one-only linkage semantics even though we
 289    don't have weak support.  */
 290 #ifdef HAVE_GAS_NSUBSPA_COMDAT
 291 #define SUPPORTS_SOM_COMDAT (TARGET_GAS)
 292 #else
 293 #define SUPPORTS_SOM_COMDAT 0
 294 #endif
 295
 296 /* We can support one only if we support weak or comdat.  */
 297 #define SUPPORTS_ONE_ONLY (TARGET_SUPPORTS_WEAK || SUPPORTS_SOM_COMDAT)
 298
 299 /* We use DECL_COMMON for uninitialized one-only variables as we don't
 300    have linkonce .bss.  We use SOM secondary definitions or comdat for
 301    initialized variables and functions.  */
 302 #define MAKE_DECL_ONE_ONLY(DECL) \
 303   do {                                                                  \
 304     if (TREE_CODE (DECL) == VAR_DECL                                    \
 305         && (DECL_INITIAL (DECL) == 0                                    \
 306             || DECL_INITIAL (DECL) == error_mark_node))                 \
 307       DECL_COMMON (DECL) = 1;                                           \
 308     else if (TARGET_SUPPORTS_WEAK)                                      \
 309       DECL_WEAK (DECL) = 1;                                             \
 310   } while (0)
 311
 312 /* This is how we tell the assembler that a symbol is weak.  The SOM
 313    weak implementation uses the secondary definition (sdef) flag.
 314
 315    The behavior of sdef symbols is similar to ELF weak symbols in that
 316    multiple definitions can occur without incurring a link error.
 317    However, they differ in the following ways:
 318      1) Undefined sdef symbols are not allowed.
 319      2) The linker searches for undefined sdef symbols and will load an
 320         archive library member to resolve an undefined sdef symbol.
 321      3) The exported symbol from a shared library is a primary symbol
 322         rather than a sdef symbol.  Thus, more care is needed in the
 323         ordering of libraries.
 324
 325    It appears that the linker discards extra copies of "weak" functions
 326    when linking shared libraries, independent of whether or not they
 327    are in their own section.  In linking final executables, -Wl,-O can
 328    be used to remove dead procedures.  Thus, support for named sections
 329    is not needed and in previous testing caused problems with various
 330    HP tools.  */
 331 #if defined HAVE_GAS_WEAK
 332 #define ASM_WEAKEN_DECL(FILE,DECL,NAME,VALUE) \
 333   do                                                                    \
 334     {                                                                   \
 335       if ((VALUE) != NULL)                                              \
 336         error_at (DECL_SOURCE_LOCATION (DECL),                          \
 337                   "weak aliases are not supported");                    \
 338       fputs ("\t.weak\t", FILE);                                        \
 339       assemble_name (FILE, NAME);                                       \
 340       fputc ('\n', FILE);                                               \
 341                                                                         \
 342       /* Import external objects.  */                                   \
 343       if (DECL_EXTERNAL (DECL))                                         \
 344         {                                                               \
 345           fputs ("\t.IMPORT ", FILE);                                   \
 346           assemble_name (FILE, NAME);                                   \
 347           if (TREE_CODE (DECL) == FUNCTION_DECL)                        \
 348             fputs (",CODE\n", FILE);                                    \
 349           else                                                          \
 350             fputs (",DATA\n", FILE);                                    \
 351         }                                                               \
 352       /* Functions are globalized by ASM_DECLARE_FUNCTION_NAME.  */     \
 353       else if (TREE_CODE (DECL) != FUNCTION_DECL)                       \
 354         {                                                               \
 355           fputs ("\t.EXPORT ", FILE);                                   \
 356           assemble_name (FILE, NAME);                                   \
 357           fputs (",DATA\n", FILE);                                      \
 358         }                                                               \
 359     }                                                                   \
 360   while (0)
 361 #endif
 362
 363 /* Although gas accepts .weakref, it doesn't provide the correct symbol
 364    type for function references.  For now, we use ASM_WEAKEN_DECL instead.
 365    We have to undefine HAVE_GAS_WEAKREF to prevent default.h from defining
 366    ASM_OUTPUT_WEAKREF.  */
 367 #undef HAVE_GAS_WEAKREF
 368
 369 /* We can't handle weak aliases, and therefore can't support pragma weak.
 370    Suppress the use of pragma weak in gthr-dce.h and gthr-posix.h.  */
 371 #define GTHREAD_USE_WEAK 0
 372
 373 /* Shared library suffix.  Collect2 strips the version string after
 374    this suffix when generating constructor/destructor names.  */
 375 #define SHLIB_SUFFIX ".sl"
 376
 377 /* We don't have named sections.  */
 378 #define TARGET_HAVE_NAMED_SECTIONS false
 379
 380 #define TARGET_ASM_TM_CLONE_TABLE_SECTION pa_som_tm_clone_table_section
 381
 382 /* Generate specially named labels to identify DWARF 2 frame unwind
 383    information.  */
 384 #define EH_FRAME_THROUGH_COLLECT2