gcc/config/pa/som.h

   1 /* Definitions for SOM assembler support.
   2    Copyright (C) 1999-2024 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.cc or pa.md.  */
  21 #undef TARGET_SOM
  22 #define TARGET_SOM 1
  23
  24 /* HPUX has a program 'chatr' to list the dependencies of dynamically
  25    linked executables and shared libraries.  */
  26 #define LDD_SUFFIX "chatr"
  27 /* Look for lines like "dynamic   /usr/lib/X11R5/libX11.sl"
  28    or "static    /usr/lib/X11R5/libX11.sl".
  29
  30    HPUX 10.20 also has lines like "static branch prediction ..."
  31    so we filter that out explicitly.
  32
  33    We also try to bound our search for libraries with marker
  34    lines.  What a pain.  */
  35 #define PARSE_LDD_OUTPUT(PTR)                                   \
  36 do {                                                            \
  37   static int in_shlib_list = 0;                                 \
  38   while (*PTR == ' ') PTR++;                                    \
  39   if (startswith (PTR, "shared library list:"))                 \
  40     {                                                           \
  41       PTR = 0;                                                  \
  42       in_shlib_list = 1;                                        \
  43     }                                                           \
  44   else if (startswith (PTR, "shared library binding:"))         \
  45     {                                                           \
  46       PTR = 0;                                                  \
  47       in_shlib_list = 0;                                        \
  48     }                                                           \
  49   else if (startswith (PTR, "static branch prediction disabled")) \
  50     {                                                           \
  51       PTR = 0;                                                  \
  52       in_shlib_list = 0;                                        \
  53     }                                                           \
  54   else if (in_shlib_list                                        \
  55            && startswith (PTR, "dynamic"))                      \
  56     {                                                           \
  57       PTR += sizeof ("dynamic") - 1;                            \
  58       while (*p == ' ') PTR++;                                  \
  59     }                                                           \
  60   else if (in_shlib_list                                        \
  61            && startswith (PTR, "static"))                       \
  62     {                                                           \
  63       PTR += sizeof ("static") - 1;                             \
  64       while (*p == ' ') PTR++;                                  \
  65     }                                                           \
  66   else                                                          \
  67     PTR = 0;                                                    \
  68 } while (0)
  69
  70 /* Output the label for a function definition.  */
  71 #ifndef HP_FP_ARG_DESCRIPTOR_REVERSED
  72 #define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)    \
  73   do { fprintf (FILE, ",ARGW%d=FR", (ARG0));            \
  74        fprintf (FILE, ",ARGW%d=FU", (ARG1));} while (0)
  75 #define DFMODE_RETURN_STRING ",RTNVAL=FU"
  76 #define SFMODE_RETURN_STRING ",RTNVAL=FR"
  77 #else
  78 #define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)    \
  79   do { fprintf (FILE, ",ARGW%d=FU", (ARG0));            \
  80        fprintf (FILE, ",ARGW%d=FR", (ARG1));} while (0)
  81 #define DFMODE_RETURN_STRING ",RTNVAL=FR"
  82 #define SFMODE_RETURN_STRING ",RTNVAL=FU"
  83 #endif
  84
  85 \f
  86 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
  87     do { tree tree_type = TREE_TYPE (DECL);                             \
  88          tree fntype = TREE_TYPE (tree_type);                           \
  89          tree parm;                                                     \
  90          int i;                                                         \
  91          if (TREE_PUBLIC (DECL) || TARGET_GAS)                          \
  92            {                                                            \
  93              if (TREE_PUBLIC (DECL))                                    \
  94                {                                                        \
  95                  fputs ("\t.EXPORT ", FILE);                            \
  96                  assemble_name (FILE, NAME);                            \
  97                  fputs (",ENTRY,PRIV_LEV=3", FILE);                     \
  98                }                                                        \
  99              else                                                       \
 100                {                                                        \
 101                  fputs ("\t.PARAM ", FILE);                             \
 102                  assemble_name (FILE, NAME);                            \
 103                  fputs (",PRIV_LEV=3", FILE);                           \
 104                }                                                        \
 105              for (parm = DECL_ARGUMENTS (DECL), i = 0; parm && i < 4;   \
 106                   parm = DECL_CHAIN (parm))                             \
 107                {                                                        \
 108                  tree type = DECL_ARG_TYPE (parm);                      \
 109                  machine_mode mode = TYPE_MODE (type);                  \
 110                  if (!AGGREGATE_TYPE_P (type)                           \
 111                      && mode == SFmode && ! TARGET_SOFT_FLOAT)          \
 112                    fprintf (FILE, ",ARGW%d=FR", i++);                   \
 113                  else if (!AGGREGATE_TYPE_P (type)                      \
 114                           && mode == DFmode && ! TARGET_SOFT_FLOAT)     \
 115                    {                                                    \
 116                      if (i <= 2)                                        \
 117                        {                                                \
 118                          if (i == 1) i++;                               \
 119                          ASM_DOUBLE_ARG_DESCRIPTORS (FILE, i++, i++);   \
 120                        }                                                \
 121                      else                                               \
 122                        break;                                           \
 123                    }                                                    \
 124                  else                                                   \
 125                    {                                                    \
 126                      int arg_size = pa_function_arg_size (mode, type);  \
 127                      /* Passing structs by invisible reference uses     \
 128                         one general register.  */                       \
 129                      if (arg_size > 2 || TREE_ADDRESSABLE (type))       \
 130                        arg_size = 1;                                    \
 131                      if (arg_size == 2 && i <= 2)                       \
 132                        {                                                \
 133                          if (i == 1) i++;                               \
 134                          fprintf (FILE, ",ARGW%d=GR", i++);             \
 135                          fprintf (FILE, ",ARGW%d=GR", i++);             \
 136                        }                                                \
 137                      else if (arg_size == 1)                            \
 138                        fprintf (FILE, ",ARGW%d=GR", i++);               \
 139                      else                                               \
 140                        i += arg_size;                                   \
 141                    }                                                    \
 142                }                                                        \
 143              /* anonymous args */                                       \
 144              if (stdarg_p (tree_type))                                  \
 145                {                                                        \
 146                  for (; i < 4; i++)                                     \
 147                    fprintf (FILE, ",ARGW%d=GR", i);                     \
 148                }                                                        \
 149              if (!AGGREGATE_TYPE_P (fntype)                             \
 150                  && TYPE_MODE (fntype) == DFmode                        \
 151                  && ! TARGET_SOFT_FLOAT)                                \
 152                fputs (DFMODE_RETURN_STRING, FILE);                      \
 153              else if (!AGGREGATE_TYPE_P (fntype)                        \
 154                       && TYPE_MODE (fntype) == SFmode                   \
 155                       && ! TARGET_SOFT_FLOAT)                           \
 156                fputs (SFMODE_RETURN_STRING, FILE);                      \
 157              else if (fntype != void_type_node)                         \
 158                fputs (",RTNVAL=GR", FILE);                              \
 159              fputs ("\n", FILE);                                        \
 160            }} while (0)
 161
 162 #define TARGET_ASM_FILE_START pa_som_file_start
 163 #define TARGET_ASM_INIT_SECTIONS pa_som_asm_init_sections
 164
 165 /* String to output before writable data.  */
 166 #define DATA_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $DATA$\n"
 167
 168 /* String to output before uninitialized data.  */
 169 #define BSS_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $BSS$\n"
 170
 171 /* This is how to output a command to make the user-level label
 172    named NAME defined for reference from other files.  We use
 173    assemble_name_raw instead of assemble_name since a symbol in
 174    a .IMPORT directive that isn't otherwise referenced is not
 175    placed in the symbol table of the assembled object.
 176
 177    Failure to import a function reference can cause the HP linker
 178    to segmentation fault!
 179
 180    Note that the SOM based tools need the symbol imported as a
 181    CODE symbol, while the ELF based tools require the symbol to
 182    be imported as an ENTRY symbol.  */
 183
 184 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME) \
 185   pa_hpux_asm_output_external ((FILE), (DECL), (NAME))
 186 #define ASM_OUTPUT_EXTERNAL_REAL(FILE, DECL, NAME) \
 187   do { fputs ("\t.IMPORT ", FILE);                                      \
 188        assemble_name_raw (FILE, NAME);                                  \
 189        if (FUNCTION_NAME_P (NAME))                                      \
 190          fputs (",CODE\n", FILE);                                       \
 191        else                                                             \
 192          fputs (",DATA\n", FILE);                                       \
 193      } while (0)
 194
 195 /* The bogus HP assembler requires ALL external references to be
 196    "imported", even library calls.  They look a bit different, so
 197    here's this macro.
 198
 199    Also note not all libcall names are passed to pa_encode_section_info
 200    (__main for example).  To make sure all libcall names have section
 201    info recorded in them, we do it here.
 202
 203    We must also ensure that a libcall that has been previously
 204    exported is not subsequently imported since the HP assembler may
 205    change the type from an ENTRY to a CODE symbol.  This would make
 206    the symbol local.  We are forced to use the identifier node
 207    associated with the real assembler name for this check as the
 208    symbol_ref available in ASM_DECLARE_FUNCTION_NAME is not the
 209    same as the one used here.  As a result, we can't use flags
 210    in the symbol_ref for this check.  The identifier check assumes
 211    assemble_external_libcall is called before the symbol is used.  */
 212
 213 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, RTL) \
 214   do { const char *name;                                                \
 215        tree id;                                                         \
 216                                                                         \
 217        if (!function_label_operand (RTL, VOIDmode))                     \
 218          pa_encode_label (RTL);                                         \
 219                                                                         \
 220        name = targetm.strip_name_encoding (XSTR ((RTL), 0));            \
 221        id = maybe_get_identifier (name);                                \
 222        if (!id || !TREE_SYMBOL_REFERENCED (id))                         \
 223          {                                                              \
 224            fputs ("\t.IMPORT ", FILE);                                  \
 225            assemble_name_raw (FILE, XSTR ((RTL), 0));                   \
 226            fputs (",CODE\n", FILE);                                     \
 227          }                                                              \
 228      } while (0)
 229
 230 /* We want __gcc_plt_call to appear in every program built by
 231    gcc, so we make a reference to it out of __main.
 232    We use the asm statement to fool the optimizer into not
 233    removing the dead (but important) initialization of
 234    REFERENCE.  */
 235
 236 #define DO_GLOBAL_DTORS_BODY                    \
 237 do {                                            \
 238   extern void __gcc_plt_call (void);            \
 239   void (*reference)(void) = &__gcc_plt_call;    \
 240   func_ptr *p;                                  \
 241   __asm__ ("" : : "r" (reference));             \
 242   for (p = __DTOR_LIST__ + 1; *p; )             \
 243     (*p++) ();                                  \
 244 } while (0)
 245
 246 /* This macro specifies the biggest alignment supported by the object
 247    file format of this machine.
 248
 249    The .align directive in the HP assembler allows alignments up to 4096
 250    bytes.  However, the maximum alignment of a global common symbol is 8
 251    bytes for objects smaller than the page size (4096 bytes).  For larger
 252    objects, the linker provides an alignment of 32 bytes.  Unfortunately,
 253    this macro doesn't provide a mechanism to test for common symbols.  */
 254 #define MAX_OFILE_ALIGNMENT 32768
 255
 256 /* The SOM linker hardcodes paths into binaries.  As a result, dotdots
 257    must be removed from library prefixes to prevent binaries from depending
 258    on the location of the GCC tool directory.  The downside is GCC
 259    cannot be moved after installation using a symlink.  */
 260 #undef TARGET_ALWAYS_STRIP_DOTDOT
 261 #define TARGET_ALWAYS_STRIP_DOTDOT true
 262
 263 /* If GAS supports weak, we can support weak when we have working linker
 264    support for secondary definitions and are generating code for GAS.
 265    This is primarily for one-only support as SOM doesn't allow undefined
 266    weak symbols or weak aliases.  */
 267 #ifdef HAVE_GAS_WEAK
 268 #define TARGET_SUPPORTS_WEAK (TARGET_SOM_SDEF && TARGET_GAS)
 269 #else
 270 #define TARGET_SUPPORTS_WEAK 0
 271 #endif
 272
 273 /* CVS GAS as of 4/28/04 supports a comdat parameter for the .nsubspa
 274    directive.  This provides one-only linkage semantics even though we
 275    don't have weak support.  */
 276 #ifdef HAVE_GAS_NSUBSPA_COMDAT
 277 #define SUPPORTS_SOM_COMDAT (TARGET_GAS)
 278 #else
 279 #define SUPPORTS_SOM_COMDAT 0
 280 #endif
 281
 282 /* We can support one only if we support weak or comdat.  */
 283 #define SUPPORTS_ONE_ONLY (TARGET_SUPPORTS_WEAK || SUPPORTS_SOM_COMDAT)
 284
 285 /* We use DECL_COMMON for uninitialized one-only variables as we don't
 286    have linkonce .bss.  We use SOM secondary definitions or comdat for
 287    initialized variables and functions.  */
 288 #define MAKE_DECL_ONE_ONLY(DECL) \
 289   do {                                                                  \
 290     if (VAR_P (DECL)                                    \
 291         && (DECL_INITIAL (DECL) == 0                                    \
 292             || DECL_INITIAL (DECL) == error_mark_node))                 \
 293       DECL_COMMON (DECL) = 1;                                           \
 294     else if (TARGET_SUPPORTS_WEAK)                                      \
 295       DECL_WEAK (DECL) = 1;                                             \
 296   } while (0)
 297
 298 /* This is how we tell the assembler that a symbol is weak.  The SOM
 299    weak implementation uses the secondary definition (sdef) flag.
 300
 301    The behavior of sdef symbols is similar to ELF weak symbols in that
 302    multiple definitions can occur without incurring a link error.
 303    However, they differ in the following ways:
 304      1) Undefined sdef symbols are not allowed.
 305      2) The linker searches for undefined sdef symbols and will load an
 306         archive library member to resolve an undefined sdef symbol.
 307      3) The exported symbol from a shared library is a primary symbol
 308         rather than a sdef symbol.  Thus, more care is needed in the
 309         ordering of libraries.
 310
 311    It appears that the linker discards extra copies of "weak" functions
 312    when linking shared libraries, independent of whether or not they
 313    are in their own section.  In linking final executables, -Wl,-O can
 314    be used to remove dead procedures.  Thus, support for named sections
 315    is not needed and in previous testing caused problems with various
 316    HP tools.  */
 317 #if defined HAVE_GAS_WEAK
 318 #define ASM_WEAKEN_DECL(FILE,DECL,NAME,VALUE) \
 319   do                                                                    \
 320     {                                                                   \
 321       if ((VALUE) != NULL)                                              \
 322         error_at (DECL_SOURCE_LOCATION (DECL),                          \
 323                   "weak aliases are not supported");                    \
 324       fputs ("\t.weak\t", FILE);                                        \
 325       assemble_name (FILE, NAME);                                       \
 326       fputc ('\n', FILE);                                               \
 327                                                                         \
 328       /* Import external objects.  */                                   \
 329       if (DECL_EXTERNAL (DECL))                                         \
 330         {                                                               \
 331           fputs ("\t.IMPORT ", FILE);                                   \
 332           assemble_name (FILE, NAME);                                   \
 333           if (TREE_CODE (DECL) == FUNCTION_DECL)                        \
 334             fputs (",CODE\n", FILE);                                    \
 335           else                                                          \
 336             fputs (",DATA\n", FILE);                                    \
 337         }                                                               \
 338       /* Functions are globalized by ASM_DECLARE_FUNCTION_NAME.  */     \
 339       else if (TREE_CODE (DECL) != FUNCTION_DECL)                       \
 340         {                                                               \
 341           fputs ("\t.EXPORT ", FILE);                                   \
 342           assemble_name (FILE, NAME);                                   \
 343           fputs (",DATA\n", FILE);                                      \
 344         }                                                               \
 345     }                                                                   \
 346   while (0)
 347 #endif
 348
 349 /* Although gas accepts .weakref, it doesn't provide the correct symbol
 350    type for function references.  For now, we use ASM_WEAKEN_DECL instead.
 351    We have to undefine HAVE_GAS_WEAKREF to prevent default.h from defining
 352    ASM_OUTPUT_WEAKREF.  */
 353 #undef HAVE_GAS_WEAKREF
 354
 355 /* We can't handle weak aliases, and therefore can't support pragma weak.
 356    Suppress the use of pragma weak in gthr-dce.h and gthr-posix.h.  */
 357 #define GTHREAD_USE_WEAK 0
 358
 359 /* Shared library suffix.  Collect2 strips the version string after
 360    this suffix when generating constructor/destructor names.  */
 361 #define SHLIB_SUFFIX ".sl"
 362
 363 /* We don't have named sections.  */
 364 #define TARGET_HAVE_NAMED_SECTIONS false
 365
 366 #define TARGET_ASM_TM_CLONE_TABLE_SECTION pa_som_tm_clone_table_section
 367
 368 /* Generate specially named labels to identify DWARF 2 frame unwind
 369    information.  */
 370 #define EH_FRAME_THROUGH_COLLECT2