gcc/fortran/trans.h

   1 /* Header for code translation functions
   2    Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
   3    Contributed by Paul Brook
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 #ifndef GFC_TRANS_H
  23 #define GFC_TRANS_H
  24
  25 /* Mangled symbols take the form __module__name.  */
  26 #define GFC_MAX_MANGLED_SYMBOL_LEN  (GFC_MAX_SYMBOL_LEN*2+4)
  27
  28 /* Struct for holding a block of statements.  It should be treated as an
  29    opaque entity and not modified directly.  This allows us to change the
  30    underlying representation of statement lists.  */
  31 typedef struct
  32 {
  33   tree head;
  34   unsigned int has_scope:1;
  35 }
  36 stmtblock_t;
  37
  38 /* a simplified expresson */
  39 typedef struct gfc_se
  40 {
  41   /* Code blocks to be executed before and after using the value.  */
  42   stmtblock_t pre;
  43   stmtblock_t post;
  44
  45   /* the result of the expression */
  46   tree expr;
  47
  48   /* The length of a character string value.  */
  49   tree string_length;
  50
  51   /* If set gfc_conv_variable will return an expression for the array
  52      descriptor. When set, want_pointer should also be set.
  53      If not set scalarizing variables will be substituted.  */
  54   unsigned descriptor_only:1;
  55
  56   /* When this is set gfc_conv_expr returns the address of a variable.  Only
  57      applies to EXPR_VARIABLE nodes.
  58      Also used by gfc_conv_array_parameter. When set this indicates a pointer
  59      to the descriptor should be returned, rather than the descriptor itself.
  60    */
  61   unsigned want_pointer:1;
  62
  63   /* An array function call returning without a temporary.  Also used for array
  64      pointer assignments.  */
  65   unsigned direct_byref:1;
  66
  67   /* Ignore absent optional arguments.  Used for some intrinsics.  */
  68   unsigned ignore_optional:1;
  69
  70   /* Scalarization parameters.  */
  71   struct gfc_se *parent;
  72   struct gfc_ss *ss;
  73   struct gfc_loopinfo *loop;
  74 }
  75 gfc_se;
  76
  77
  78 /* Scalarisation State chain.  Created by walking an expression tree before
  79    creating the scalarization loops. Then passed as part of a gfc_se structure
  80    to translate the expression inside the loop.  Note that these chains are
  81    terminated by gfc_se_terminator, not NULL.  A NULL pointer in a gfc_se
  82    indicates to gfc_conv_* that this is a scalar expression.
  83    Note that some member arrays correspond to scalarizer rank and others
  84    are the variable rank.  */
  85
  86 typedef struct gfc_ss_info
  87 {
  88   int dimen;
  89   /* The ref that holds information on this section.  */
  90   gfc_ref *ref;
  91   /* The descriptor of this array.  */
  92   tree descriptor;
  93   /* holds the pointer to the data array.  */
  94   tree data;
  95   /* To move some of the array index calculation out of the innermost loop.  */
  96   tree offset;
  97   tree saved_offset;
  98   tree stride0;
  99   /* Holds the SS for a subscript.  Indexed by actual dimension.  */
 100   struct gfc_ss *subscript[GFC_MAX_DIMENSIONS];
 101
 102   /* stride and delta are used to access this inside a scalarization loop.
 103      start is used in the calculation of these.  Indexed by scalarizer
 104      dimension.  */
 105   tree start[GFC_MAX_DIMENSIONS];
 106   tree stride[GFC_MAX_DIMENSIONS];
 107   tree delta[GFC_MAX_DIMENSIONS];
 108
 109   /* Translation from scalariser dimensions to actual dimensions.
 110      actual = dim[scalarizer]  */
 111   int dim[GFC_MAX_DIMENSIONS];
 112 }
 113 gfc_ss_info;
 114
 115 typedef enum
 116 {
 117   /* A scalar value.  This will be evaluated before entering the
 118      scalarization loop.  */
 119   GFC_SS_SCALAR,
 120
 121   /* Like GFC_SS_SCALAR except it evaluates a pointer the the expression.
 122      Used for elemental function parameters.  */
 123   GFC_SS_REFERENCE,
 124
 125   /* An array section.  Scalarization indices will be substituted during
 126      expression translation.  */
 127   GFC_SS_SECTION,
 128
 129   /* A non-elemental function call returning an array.  The call is executed
 130      before entering the scalarization loop, storing the result in a
 131      temporary.  This temporary is then used inside the scalarization loop.
 132      Simple assignments, eg. a(:) = fn() are handles without a temporary
 133      as a special case.  */
 134   GFC_SS_FUNCTION,
 135
 136   /* An array constructor.  The current implementation is sub-optimal in
 137      many cases.  It allocated a temporary, assigns the values to it, then
 138      uses this temporary inside the scalarization loop.  */
 139   GFC_SS_CONSTRUCTOR,
 140
 141   /* A vector subscript.  Only used as the SS chain for a subscript.
 142      Similar int format to a GFC_SS_SECTION.  */
 143   GFC_SS_VECTOR,
 144
 145   /* A temporary array allocated by the scalarizer.  Its rank can be less
 146      than that of the assignment expression.  */
 147   GFC_SS_TEMP,
 148
 149   /* An intrinsic function call.  Many intrinsic functions which map directly
 150      to library calls are created as GFC_SS_FUNCTION nodes.  */
 151   GFC_SS_INTRINSIC
 152 }
 153 gfc_ss_type;
 154
 155 /* SS structures can only belong to a single loopinfo.  They must be added
 156    otherwise they will not get freed.  */
 157 typedef struct gfc_ss
 158 {
 159   gfc_ss_type type;
 160   gfc_expr *expr;
 161   union
 162   {
 163     /* If type is GFC_SS_SCALAR or GFC_SS_REFERENCE.  */
 164     struct
 165     {
 166       tree expr;
 167       tree string_length;
 168     }
 169     scalar;
 170
 171     /* GFC_SS_TEMP.  */
 172     struct
 173     {
 174       /* The rank of the temporary.  May be less than the rank of the
 175          assigned expression.  */
 176       int dimen;
 177       tree type;
 178       tree string_length;
 179     }
 180     temp;
 181     /* All other types.  */
 182     gfc_ss_info info;
 183   }
 184   data;
 185
 186   /* All the SS in a loop and linked through loop_chain.  The SS for an
 187      expression are linked by the next pointer.  */
 188   struct gfc_ss *loop_chain;
 189   struct gfc_ss *next;
 190
 191   /* This is used by assignments requiring teporaries. The bits specify which
 192      loops the terms appear in.  This will be 1 for the RHS expressions,
 193      2 for the LHS expressions, and 3(=1|2) for the temporary.  */
 194   unsigned useflags:2;
 195 }
 196 gfc_ss;
 197 #define gfc_get_ss() gfc_getmem(sizeof(gfc_ss))
 198
 199 /* The contents of this aren't actualy used.  A NULL SS chain indicates a
 200    scalar expression, so this pointer is used to terminate SS chains.  */
 201 extern gfc_ss * const gfc_ss_terminator;
 202
 203 /* Holds information about an expression while it is being scalarized.  */
 204 typedef struct gfc_loopinfo
 205 {
 206   stmtblock_t pre;
 207   stmtblock_t post;
 208
 209   int dimen;
 210
 211   /* All the SS involved with this loop.  */
 212   gfc_ss *ss;
 213   /* The SS describing the teporary used in an assignment.  */
 214   gfc_ss *temp_ss;
 215
 216   /* The scalarization loop index variables.  */
 217   tree loopvar[GFC_MAX_DIMENSIONS];
 218
 219   /* The bounds of the scalarization loops.  */
 220   tree from[GFC_MAX_DIMENSIONS];
 221   tree to[GFC_MAX_DIMENSIONS];
 222   gfc_ss *specloop[GFC_MAX_DIMENSIONS];
 223
 224   /* The code member contains the code for the body of the next outer loop.  */
 225   stmtblock_t code[GFC_MAX_DIMENSIONS];
 226
 227   /* Order in which the dimensions should be looped, innermost first.  */
 228   int order[GFC_MAX_DIMENSIONS];
 229
 230   /* The number of dimensions for which a temporary is used.  */
 231   int temp_dim;
 232
 233   /* If set we don't need the loop variables.  */
 234   unsigned array_parameter:1;
 235 }
 236 gfc_loopinfo;
 237
 238
 239 /* Information about a symbol that has been shadowed by a temporary.  */
 240 typedef struct
 241 {
 242   symbol_attribute attr;
 243   tree decl;
 244 }
 245 gfc_saved_var;
 246
 247
 248 /* Advance the SS chain to the next term.  */
 249 void gfc_advance_se_ss_chain (gfc_se *);
 250
 251 /* Call this to initialise a gfc_se structure before use
 252    first parameter is structure to initialise, second is
 253    parent to get scalarization data from, or NULL.  */
 254 void gfc_init_se (gfc_se *, gfc_se *);
 255
 256 /* Create an artificial variable decl and add it to the current scope.  */
 257 tree gfc_create_var (tree, const char *);
 258 /* Like above but doesn't add it to the current scope.  */
 259 tree gfc_create_var_np (tree, const char *);
 260
 261 /* Store the result of an expression in a temp variable so it can be used
 262    repeatedly even if the original changes */
 263 void gfc_make_safe_expr (gfc_se * se);
 264
 265 /* Makes sure se is suitable for passing as a function string parameter.  */
 266 void gfc_conv_string_parameter (gfc_se * se);
 267
 268 /* Add an item to the end of TREE_LIST.  */
 269 tree gfc_chainon_list (tree, tree);
 270
 271 /* When using the gfc_conv_* make sure you understand what they do, ie.
 272    when a POST chain may be created, and what the retured expression may be
 273    used for.  Note that character strings have special handling.  This
 274    should not be a problem as most statements/operations only deal with
 275    numeric/logical types.  */
 276
 277 /* Entry point for expression translation.  */
 278 void gfc_conv_expr (gfc_se * se, gfc_expr * expr);
 279 /* Like gfc_conv_expr, but the POST block is guaranteed to be empty for
 280    numeric expressions.  */
 281 void gfc_conv_expr_val (gfc_se * se, gfc_expr * expr);
 282 /* Like gfc_conv_expr_val, but the value is also suitable for use in the lhs of
 283    an assignment.  */
 284 void gfc_conv_expr_lhs (gfc_se * se, gfc_expr * expr);
 285 /* Converts an expression so that it can be passed be reference.  */
 286 void gfc_conv_expr_reference (gfc_se * se, gfc_expr *);
 287 /* Equivalent to convert(type, gfc_conv_expr_val(se, expr)).  */
 288 void gfc_conv_expr_type (gfc_se * se, gfc_expr *, tree);
 289 /* If the value is not constant, Create a temporary and copy the value.  */
 290 tree gfc_evaluate_now (tree, stmtblock_t *);
 291
 292 /* Intrinsic function handling.  */
 293 void gfc_conv_intrinsic_function (gfc_se *, gfc_expr *);
 294
 295 /* Does an intrinsic map directly to an external library call.  */
 296 int gfc_is_intrinsic_libcall (gfc_expr *);
 297
 298 /* Also used to CALL subroutines.  */
 299 void gfc_conv_function_call (gfc_se *, gfc_symbol *, gfc_actual_arglist *);
 300 /* gfc_trans_* shouldn't call push/poplevel, use gfc_push/pop_scope */
 301
 302 /* Generate code for a scalar assignment.  */
 303 tree gfc_trans_scalar_assign (gfc_se *, gfc_se *, bt);
 304
 305 /* Translate COMMON blocks.  */
 306 void gfc_trans_common (gfc_namespace *);
 307
 308 /* Translate a derived type constructor. */
 309 void gfc_conv_structure (gfc_se *, gfc_expr *, int);
 310
 311 /* Return an expression which determines if a dummy parameter is present.  */
 312 tree gfc_conv_expr_present (gfc_symbol *);
 313
 314 /* Generate code to allocate a string temporary.  */
 315 tree gfc_conv_string_tmp (gfc_se *, tree, tree);
 316 /* Initialize a string length variable.  */
 317 void gfc_trans_init_string_length (gfc_charlen *, stmtblock_t *);
 318
 319 /* Add an expression to the end of a block.  */
 320 void gfc_add_expr_to_block (stmtblock_t *, tree);
 321 /* Add a block to the end of a block.  */
 322 void gfc_add_block_to_block (stmtblock_t *, stmtblock_t *);
 323 /* Add a MODIFY_EXPR to a block.  */
 324 void gfc_add_modify_expr (stmtblock_t *, tree, tree);
 325
 326 /* Initialize a statement block.  */
 327 void gfc_init_block (stmtblock_t *);
 328 /* Start a new satement block.  Like gfc_init_block but also starts a new
 329    variable scope.  */
 330 void gfc_start_block (stmtblock_t *);
 331 /* Finish a statement block.  Also closes the scope if the block was created
 332    with gfc_start_block.  */
 333 tree gfc_finish_block (stmtblock_t *);
 334 /* Merge the scope of a block with its parent.  */
 335 void gfc_merge_block_scope (stmtblock_t * block);
 336
 337 /* Return the backend label decl.  */
 338 tree gfc_get_label_decl (gfc_st_label *);
 339
 340 /* Return the decl for an external function.  */
 341 tree gfc_get_extern_function_decl (gfc_symbol *);
 342
 343 /* Return the decl for a function.  */
 344 tree gfc_get_function_decl (gfc_symbol *);
 345
 346 /* Build a CALL_EXPR.  */
 347 tree gfc_build_function_call (tree, tree);
 348
 349 /* Build an ADDR_EXPR.  */
 350 tree gfc_build_addr_expr (tree, tree);
 351
 352 /* Build an INDIRECT_REF.  */
 353 tree gfc_build_indirect_ref (tree);
 354
 355 /* Build an ARRAY_REF.  */
 356 tree gfc_build_array_ref (tree, tree);
 357
 358 /* Creates an label.  Decl is artificial if label_id == NULL_TREE.  */
 359 tree gfc_build_label_decl (tree);
 360
 361 /* Return the decl used to hold the function return value.
 362    Do not use if the function has an explicit result variable.  */
 363 tree gfc_get_fake_result_decl (gfc_symbol *);
 364
 365 /* Get the return label for the current function.  */
 366 tree gfc_get_return_label (void);
 367
 368 /* Add a decl to the binding level for the current function.  */
 369 void gfc_add_decl_to_function (tree);
 370
 371 /* Make prototypes for runtime library functions.  */
 372 void gfc_build_builtin_function_decls (void);
 373
 374 /* Return the variable decl for a symbol.  */
 375 tree gfc_get_symbol_decl (gfc_symbol *);
 376
 377 /* Substitute a temporary variable in place of the real one.  */
 378 void gfc_shadow_sym (gfc_symbol *, tree, gfc_saved_var *);
 379
 380 /* Restore the original variable.  */
 381 void gfc_restore_sym (gfc_symbol *, gfc_saved_var *);
 382
 383 /* Allocate the lang-spcific part of a decl node.  */
 384 void gfc_allocate_lang_decl (tree);
 385
 386 /* Advance along a TREE_CHAIN.  */
 387 tree gfc_advance_chain (tree, int);
 388
 389 /* Create a decl for a function.  */
 390 void gfc_build_function_decl (gfc_symbol *);
 391 /* Generate the code for a function.  */
 392 void gfc_generate_function_code (gfc_namespace *);
 393 /* Output a decl for a module variable.  */
 394 void gfc_generate_module_vars (gfc_namespace *);
 395
 396 /* Get and set the current location.  */
 397 void gfc_set_backend_locus (locus *);
 398 void gfc_get_backend_locus (locus *);
 399
 400 /* Handle static constructor functions.  */
 401 extern GTY(()) tree gfc_static_ctors;
 402 void gfc_generate_constructors (void);
 403
 404 /* Generate a runtime error check.  */
 405 void gfc_trans_runtime_check (tree, tree, stmtblock_t *);
 406
 407 /* Generate code for an assigment, includes scalarization.  */
 408 tree gfc_trans_assignment (gfc_expr *, gfc_expr *);
 409
 410 /* Generate code for an pointer assignment.  */
 411 tree gfc_trans_pointer_assignment (gfc_expr *, gfc_expr *);
 412
 413 /* Initialize function decls for library functions.  */
 414 void gfc_build_intrinsic_lib_fndecls (void);
 415 /* Create function decls for IO library functions.  */
 416 void gfc_build_io_library_fndecls (void);
 417 /* Build a function decl for a library function.  */
 418 tree gfc_build_library_function_decl (tree, tree, int, ...);
 419
 420 /* somewhere! */
 421 tree pushdecl (tree);
 422 tree pushdecl_top_level (tree);
 423 void pushlevel (int);
 424 tree poplevel (int, int, int);
 425 tree getdecls (void);
 426 tree gfc_truthvalue_conversion (tree);
 427
 428 /* Runtime library function decls.  */
 429 extern GTY(()) tree gfor_fndecl_internal_malloc;
 430 extern GTY(()) tree gfor_fndecl_internal_malloc64;
 431 extern GTY(()) tree gfor_fndecl_internal_free;
 432 extern GTY(()) tree gfor_fndecl_allocate;
 433 extern GTY(()) tree gfor_fndecl_allocate64;
 434 extern GTY(()) tree gfor_fndecl_deallocate;
 435 extern GTY(()) tree gfor_fndecl_pause_numeric;
 436 extern GTY(()) tree gfor_fndecl_pause_string;
 437 extern GTY(()) tree gfor_fndecl_stop_numeric;
 438 extern GTY(()) tree gfor_fndecl_stop_string;
 439 extern GTY(()) tree gfor_fndecl_select_string;
 440 extern GTY(()) tree gfor_fndecl_runtime_error;
 441 extern GTY(()) tree gfor_fndecl_in_pack;
 442 extern GTY(()) tree gfor_fndecl_in_unpack;
 443 extern GTY(()) tree gfor_fndecl_associated;
 444
 445 /* Math functions.  Many other math functions are handled in
 446    trans-intrinsic.c.  */
 447
 448 typedef struct gfc_powdecl_list GTY(())
 449 {
 450   tree integer;
 451   tree real;
 452   tree cmplx;
 453 }
 454 gfc_powdecl_list;
 455
 456 extern GTY(()) gfc_powdecl_list gfor_fndecl_math_powi[3][2];
 457 extern GTY(()) tree gfor_fndecl_math_cpowf;
 458 extern GTY(()) tree gfor_fndecl_math_cpow;
 459 extern GTY(()) tree gfor_fndecl_math_cabsf;
 460 extern GTY(()) tree gfor_fndecl_math_cabs;
 461 extern GTY(()) tree gfor_fndecl_math_sign4;
 462 extern GTY(()) tree gfor_fndecl_math_sign8;
 463 extern GTY(()) tree gfor_fndecl_math_ishftc4;
 464 extern GTY(()) tree gfor_fndecl_math_ishftc8;
 465 extern GTY(()) tree gfor_fndecl_math_exponent4;
 466 extern GTY(()) tree gfor_fndecl_math_exponent8;
 467
 468 /* String functions.  */
 469 extern GTY(()) tree gfor_fndecl_copy_string;
 470 extern GTY(()) tree gfor_fndecl_compare_string;
 471 extern GTY(()) tree gfor_fndecl_concat_string;
 472 extern GTY(()) tree gfor_fndecl_string_len_trim;
 473 extern GTY(()) tree gfor_fndecl_string_index;
 474 extern GTY(()) tree gfor_fndecl_string_scan;
 475 extern GTY(()) tree gfor_fndecl_string_verify;
 476 extern GTY(()) tree gfor_fndecl_string_trim;
 477 extern GTY(()) tree gfor_fndecl_string_repeat;
 478 extern GTY(()) tree gfor_fndecl_adjustl;
 479 extern GTY(()) tree gfor_fndecl_adjustr;
 480
 481 /* Other misc. runtime library functions.  */
 482 extern GTY(()) tree gfor_fndecl_size0;
 483 extern GTY(()) tree gfor_fndecl_size1;
 484
 485 /* Implemented in FORTRAN.  */
 486 extern GTY(()) tree gfor_fndecl_si_kind;
 487 extern GTY(()) tree gfor_fndecl_sr_kind;
 488
 489
 490 /* True if node is an integer constant.  */
 491 #define INTEGER_CST_P(node) (TREE_CODE(node) == INTEGER_CST)
 492
 493 /* G95-specific declaration information.  */
 494
 495 /* Array types only.  */
 496 struct lang_type                GTY(())
 497 {
 498   int rank;
 499   tree lbound[GFC_MAX_DIMENSIONS];
 500   tree ubound[GFC_MAX_DIMENSIONS];
 501   tree stride[GFC_MAX_DIMENSIONS];
 502   tree size;
 503   tree offset;
 504   tree dtype;
 505   tree dataptr_type;
 506 };
 507
 508 struct lang_decl                GTY(())
 509 {
 510   /* Dummy variables.  */
 511   tree saved_descriptor;
 512   /* Assigned integer nodes.  Stringlength is the IO format string's length.
 513      Addr is the address of the string or the target label. Stringlength is
 514      initialized to -2 and assiged to -1 when addr is assigned to the
 515      address of target label.  */
 516   tree stringlen;
 517   tree addr;
 518 };
 519
 520
 521 #define GFC_DECL_ASSIGN_ADDR(node) DECL_LANG_SPECIFIC(node)->addr
 522 #define GFC_DECL_STRING_LEN(node) DECL_LANG_SPECIFIC(node)->stringlen
 523 #define GFC_DECL_SAVED_DESCRIPTOR(node) \
 524   (DECL_LANG_SPECIFIC(node)->saved_descriptor)
 525 #define GFC_DECL_PACKED_ARRAY(node) DECL_LANG_FLAG_0(node)
 526 #define GFC_DECL_PARTIAL_PACKED_ARRAY(node) DECL_LANG_FLAG_1(node)
 527 #define GFC_DECL_ASSIGN(node) DECL_LANG_FLAG_2(node)
 528
 529 /* An array descriptor.  */
 530 #define GFC_DESCRIPTOR_TYPE_P(node) TYPE_LANG_FLAG_1(node)
 531 /* An array without a descriptor.  */
 532 #define GFC_ARRAY_TYPE_P(node) TYPE_LANG_FLAG_2(node)
 533 /* The GFC_TYPE_ARRAY_* members are present in both descriptor and
 534    descriptorless array types.  */
 535 #define GFC_TYPE_ARRAY_LBOUND(node, dim) \
 536   (TYPE_LANG_SPECIFIC(node)->lbound[dim])
 537 #define GFC_TYPE_ARRAY_UBOUND(node, dim) \
 538   (TYPE_LANG_SPECIFIC(node)->ubound[dim])
 539 #define GFC_TYPE_ARRAY_STRIDE(node, dim) \
 540   (TYPE_LANG_SPECIFIC(node)->stride[dim])
 541 #define GFC_TYPE_ARRAY_RANK(node) (TYPE_LANG_SPECIFIC(node)->rank)
 542 #define GFC_TYPE_ARRAY_SIZE(node) (TYPE_LANG_SPECIFIC(node)->size)
 543 #define GFC_TYPE_ARRAY_OFFSET(node) (TYPE_LANG_SPECIFIC(node)->offset)
 544 #define GFC_TYPE_ARRAY_DTYPE(node) (TYPE_LANG_SPECIFIC(node)->dtype)
 545 #define GFC_TYPE_ARRAY_DATAPTR_TYPE(node) \
 546   (TYPE_LANG_SPECIFIC(node)->dataptr_type)
 547
 548 /* I changed this from sorry(...) because it should not return.  */
 549 /* TODO: Remove gfc_todo_error before releasing version 1.0.  */
 550 #define gfc_todo_error(args...) fatal_error("gfc_todo: Not Implemented: " args)
 551
 552 /* Build an expression with void type.  */
 553 #define build1_v(code, arg) build(code, void_type_node, arg)
 554 #define build_v(code, args...) build(code, void_type_node, args)
 555
 556 /* flag for alternative return labels.  */
 557 extern int has_alternate_specifier;  /* for caller */
 558 #endif /* GFC_TRANS_H */