1/* Generate information regarding function declarations and definitions based 2 on information stored in GCC's tree structure. This code implements the 3 -aux-info option. 4 Copyright (C) 1989, 1991, 1994, 1995, 1997, 1998, 5 1999, 2000, 2003, 2004 Free Software Foundation, Inc. 6 Contributed by Ron Guilmette (rfg@segfault.us.com). 7 8This file is part of GCC. 9 10GCC is free software; you can redistribute it and/or modify it under 11the terms of the GNU General Public License as published by the Free 12Software Foundation; either version 2, or (at your option) any later 13version. 14 15GCC is distributed in the hope that it will be useful, but WITHOUT ANY 16WARRANTY; without even the implied warranty of MERCHANTABILITY or 17FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 18for more details. 19 20You should have received a copy of the GNU General Public License 21along with GCC; see the file COPYING. If not, write to the Free 22Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 2302110-1301, USA. */ 24 25#include "config.h" 26#include "system.h" 27#include "coretypes.h" 28#include "tm.h" 29#include "flags.h" 30#include "tree.h" 31#include "c-tree.h" 32#include "toplev.h" 33 34enum formals_style_enum { 35 ansi, 36 k_and_r_names, 37 k_and_r_decls 38}; 39typedef enum formals_style_enum formals_style; 40 41 42static const char *data_type; 43 44static char *affix_data_type (const char *) ATTRIBUTE_MALLOC; 45static const char *gen_formal_list_for_type (tree, formals_style); 46static int deserves_ellipsis (tree); 47static const char *gen_formal_list_for_func_def (tree, formals_style); 48static const char *gen_type (const char *, tree, formals_style); 49static const char *gen_decl (tree, int, formals_style); 50 51/* Given a string representing an entire type or an entire declaration 52 which only lacks the actual "data-type" specifier (at its left end), 53 affix the data-type specifier to the left end of the given type 54 specification or object declaration. 55 56 Because of C language weirdness, the data-type specifier (which normally 57 goes in at the very left end) may have to be slipped in just to the 58 right of any leading "const" or "volatile" qualifiers (there may be more 59 than one). Actually this may not be strictly necessary because it seems 60 that GCC (at least) accepts `<data-type> const foo;' and treats it the 61 same as `const <data-type> foo;' but people are accustomed to seeing 62 `const char *foo;' and *not* `char const *foo;' so we try to create types 63 that look as expected. */ 64 65static char * 66affix_data_type (const char *param) 67{ 68 char *const type_or_decl = ASTRDUP (param); 69 char *p = type_or_decl; 70 char *qualifiers_then_data_type; 71 char saved; 72 73 /* Skip as many leading const's or volatile's as there are. */ 74 75 for (;;) 76 { 77 if (!strncmp (p, "volatile ", 9)) 78 { 79 p += 9; 80 continue; 81 } 82 if (!strncmp (p, "const ", 6)) 83 { 84 p += 6; 85 continue; 86 } 87 break; 88 } 89 90 /* p now points to the place where we can insert the data type. We have to 91 add a blank after the data-type of course. */ 92 93 if (p == type_or_decl) 94 return concat (data_type, " ", type_or_decl, NULL); 95 96 saved = *p; 97 *p = '\0'; 98 qualifiers_then_data_type = concat (type_or_decl, data_type, NULL); 99 *p = saved; 100 return reconcat (qualifiers_then_data_type, 101 qualifiers_then_data_type, " ", p, NULL); 102} 103 104/* Given a tree node which represents some "function type", generate the 105 source code version of a formal parameter list (of some given style) for 106 this function type. Return the whole formal parameter list (including 107 a pair of surrounding parens) as a string. Note that if the style 108 we are currently aiming for is non-ansi, then we just return a pair 109 of empty parens here. */ 110 111static const char * 112gen_formal_list_for_type (tree fntype, formals_style style) 113{ 114 const char *formal_list = ""; 115 tree formal_type; 116 117 if (style != ansi) 118 return "()"; 119 120 formal_type = TYPE_ARG_TYPES (fntype); 121 while (formal_type && TREE_VALUE (formal_type) != void_type_node) 122 { 123 const char *this_type; 124 125 if (*formal_list) 126 formal_list = concat (formal_list, ", ", NULL); 127 128 this_type = gen_type ("", TREE_VALUE (formal_type), ansi); 129 formal_list 130 = ((strlen (this_type)) 131 ? concat (formal_list, affix_data_type (this_type), NULL) 132 : concat (formal_list, data_type, NULL)); 133 134 formal_type = TREE_CHAIN (formal_type); 135 } 136 137 /* If we got to here, then we are trying to generate an ANSI style formal 138 parameters list. 139 140 New style prototyped ANSI formal parameter lists should in theory always 141 contain some stuff between the opening and closing parens, even if it is 142 only "void". 143 144 The brutal truth though is that there is lots of old K&R code out there 145 which contains declarations of "pointer-to-function" parameters and 146 these almost never have fully specified formal parameter lists associated 147 with them. That is, the pointer-to-function parameters are declared 148 with just empty parameter lists. 149 150 In cases such as these, protoize should really insert *something* into 151 the vacant parameter lists, but what? It has no basis on which to insert 152 anything in particular. 153 154 Here, we make life easy for protoize by trying to distinguish between 155 K&R empty parameter lists and new-style prototyped parameter lists 156 that actually contain "void". In the latter case we (obviously) want 157 to output the "void" verbatim, and that what we do. In the former case, 158 we do our best to give protoize something nice to insert. 159 160 This "something nice" should be something that is still valid (when 161 re-compiled) but something that can clearly indicate to the user that 162 more typing information (for the parameter list) should be added (by 163 hand) at some convenient moment. 164 165 The string chosen here is a comment with question marks in it. */ 166 167 if (!*formal_list) 168 { 169 if (TYPE_ARG_TYPES (fntype)) 170 /* assert (TREE_VALUE (TYPE_ARG_TYPES (fntype)) == void_type_node); */ 171 formal_list = "void"; 172 else 173 formal_list = "/* ??? */"; 174 } 175 else 176 { 177 /* If there were at least some parameters, and if the formals-types-list 178 petered out to a NULL (i.e. without being terminated by a 179 void_type_node) then we need to tack on an ellipsis. */ 180 if (!formal_type) 181 formal_list = concat (formal_list, ", ...", NULL); 182 } 183 184 return concat (" (", formal_list, ")", NULL); 185} 186 187/* For the generation of an ANSI prototype for a function definition, we have 188 to look at the formal parameter list of the function's own "type" to 189 determine if the function's formal parameter list should end with an 190 ellipsis. Given a tree node, the following function will return nonzero 191 if the "function type" parameter list should end with an ellipsis. */ 192 193static int 194deserves_ellipsis (tree fntype) 195{ 196 tree formal_type; 197 198 formal_type = TYPE_ARG_TYPES (fntype); 199 while (formal_type && TREE_VALUE (formal_type) != void_type_node) 200 formal_type = TREE_CHAIN (formal_type); 201 202 /* If there were at least some parameters, and if the formals-types-list 203 petered out to a NULL (i.e. without being terminated by a void_type_node) 204 then we need to tack on an ellipsis. */ 205 206 return (!formal_type && TYPE_ARG_TYPES (fntype)); 207} 208 209/* Generate a parameter list for a function definition (in some given style). 210 211 Note that this routine has to be separate (and different) from the code that 212 generates the prototype parameter lists for function declarations, because 213 in the case of a function declaration, all we have to go on is a tree node 214 representing the function's own "function type". This can tell us the types 215 of all of the formal parameters for the function, but it cannot tell us the 216 actual *names* of each of the formal parameters. We need to output those 217 parameter names for each function definition. 218 219 This routine gets a pointer to a tree node which represents the actual 220 declaration of the given function, and this DECL node has a list of formal 221 parameter (variable) declarations attached to it. These formal parameter 222 (variable) declaration nodes give us the actual names of the formal 223 parameters for the given function definition. 224 225 This routine returns a string which is the source form for the entire 226 function formal parameter list. */ 227 228static const char * 229gen_formal_list_for_func_def (tree fndecl, formals_style style) 230{ 231 const char *formal_list = ""; 232 tree formal_decl; 233 234 formal_decl = DECL_ARGUMENTS (fndecl); 235 while (formal_decl) 236 { 237 const char *this_formal; 238 239 if (*formal_list && ((style == ansi) || (style == k_and_r_names))) 240 formal_list = concat (formal_list, ", ", NULL); 241 this_formal = gen_decl (formal_decl, 0, style); 242 if (style == k_and_r_decls) 243 formal_list = concat (formal_list, this_formal, "; ", NULL); 244 else 245 formal_list = concat (formal_list, this_formal, NULL); 246 formal_decl = TREE_CHAIN (formal_decl); 247 } 248 if (style == ansi) 249 { 250 if (!DECL_ARGUMENTS (fndecl)) 251 formal_list = concat (formal_list, "void", NULL); 252 if (deserves_ellipsis (TREE_TYPE (fndecl))) 253 formal_list = concat (formal_list, ", ...", NULL); 254 } 255 if ((style == ansi) || (style == k_and_r_names)) 256 formal_list = concat (" (", formal_list, ")", NULL); 257 return formal_list; 258} 259 260/* Generate a string which is the source code form for a given type (t). This 261 routine is ugly and complex because the C syntax for declarations is ugly 262 and complex. This routine is straightforward so long as *no* pointer types, 263 array types, or function types are involved. 264 265 In the simple cases, this routine will return the (string) value which was 266 passed in as the "ret_val" argument. Usually, this starts out either as an 267 empty string, or as the name of the declared item (i.e. the formal function 268 parameter variable). 269 270 This routine will also return with the global variable "data_type" set to 271 some string value which is the "basic" data-type of the given complete type. 272 This "data_type" string can be concatenated onto the front of the returned 273 string after this routine returns to its caller. 274 275 In complicated cases involving pointer types, array types, or function 276 types, the C declaration syntax requires an "inside out" approach, i.e. if 277 you have a type which is a "pointer-to-function" type, you need to handle 278 the "pointer" part first, but it also has to be "innermost" (relative to 279 the declaration stuff for the "function" type). Thus, is this case, you 280 must prepend a "(*" and append a ")" to the name of the item (i.e. formal 281 variable). Then you must append and prepend the other info for the 282 "function type" part of the overall type. 283 284 To handle the "innermost precedence" rules of complicated C declarators, we 285 do the following (in this routine). The input parameter called "ret_val" 286 is treated as a "seed". Each time gen_type is called (perhaps recursively) 287 some additional strings may be appended or prepended (or both) to the "seed" 288 string. If yet another (lower) level of the GCC tree exists for the given 289 type (as in the case of a pointer type, an array type, or a function type) 290 then the (wrapped) seed is passed to a (recursive) invocation of gen_type() 291 this recursive invocation may again "wrap" the (new) seed with yet more 292 declarator stuff, by appending, prepending (or both). By the time the 293 recursion bottoms out, the "seed value" at that point will have a value 294 which is (almost) the complete source version of the declarator (except 295 for the data_type info). Thus, this deepest "seed" value is simply passed 296 back up through all of the recursive calls until it is given (as the return 297 value) to the initial caller of the gen_type() routine. All that remains 298 to do at this point is for the initial caller to prepend the "data_type" 299 string onto the returned "seed". */ 300 301static const char * 302gen_type (const char *ret_val, tree t, formals_style style) 303{ 304 tree chain_p; 305 306 /* If there is a typedef name for this type, use it. */ 307 if (TYPE_NAME (t) && TREE_CODE (TYPE_NAME (t)) == TYPE_DECL) 308 data_type = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (t))); 309 else 310 { 311 switch (TREE_CODE (t)) 312 { 313 case POINTER_TYPE: 314 if (TYPE_READONLY (t)) 315 ret_val = concat ("const ", ret_val, NULL); 316 if (TYPE_VOLATILE (t)) 317 ret_val = concat ("volatile ", ret_val, NULL); 318 319 ret_val = concat ("*", ret_val, NULL); 320 321 if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE || TREE_CODE (TREE_TYPE (t)) == FUNCTION_TYPE) 322 ret_val = concat ("(", ret_val, ")", NULL); 323 324 ret_val = gen_type (ret_val, TREE_TYPE (t), style); 325 326 return ret_val; 327 328 case ARRAY_TYPE: 329 if (!COMPLETE_TYPE_P (t) || TREE_CODE (TYPE_SIZE (t)) != INTEGER_CST) 330 ret_val = gen_type (concat (ret_val, "[]", NULL), 331 TREE_TYPE (t), style); 332 else if (int_size_in_bytes (t) == 0) 333 ret_val = gen_type (concat (ret_val, "[0]", NULL), 334 TREE_TYPE (t), style); 335 else 336 { 337 int size = (int_size_in_bytes (t) / int_size_in_bytes (TREE_TYPE (t))); 338 char buff[10]; 339 sprintf (buff, "[%d]", size); 340 ret_val = gen_type (concat (ret_val, buff, NULL), 341 TREE_TYPE (t), style); 342 } 343 break; 344 345 case FUNCTION_TYPE: 346 ret_val = gen_type (concat (ret_val, 347 gen_formal_list_for_type (t, style), 348 NULL), 349 TREE_TYPE (t), style); 350 break; 351 352 case IDENTIFIER_NODE: 353 data_type = IDENTIFIER_POINTER (t); 354 break; 355 356 /* The following three cases are complicated by the fact that a 357 user may do something really stupid, like creating a brand new 358 "anonymous" type specification in a formal argument list (or as 359 part of a function return type specification). For example: 360 361 int f (enum { red, green, blue } color); 362 363 In such cases, we have no name that we can put into the prototype 364 to represent the (anonymous) type. Thus, we have to generate the 365 whole darn type specification. Yuck! */ 366 367 case RECORD_TYPE: 368 if (TYPE_NAME (t)) 369 data_type = IDENTIFIER_POINTER (TYPE_NAME (t)); 370 else 371 { 372 data_type = ""; 373 chain_p = TYPE_FIELDS (t); 374 while (chain_p) 375 { 376 data_type = concat (data_type, gen_decl (chain_p, 0, ansi), 377 NULL); 378 chain_p = TREE_CHAIN (chain_p); 379 data_type = concat (data_type, "; ", NULL); 380 } 381 data_type = concat ("{ ", data_type, "}", NULL); 382 } 383 data_type = concat ("struct ", data_type, NULL); 384 break; 385 386 case UNION_TYPE: 387 if (TYPE_NAME (t)) 388 data_type = IDENTIFIER_POINTER (TYPE_NAME (t)); 389 else 390 { 391 data_type = ""; 392 chain_p = TYPE_FIELDS (t); 393 while (chain_p) 394 { 395 data_type = concat (data_type, gen_decl (chain_p, 0, ansi), 396 NULL); 397 chain_p = TREE_CHAIN (chain_p); 398 data_type = concat (data_type, "; ", NULL); 399 } 400 data_type = concat ("{ ", data_type, "}", NULL); 401 } 402 data_type = concat ("union ", data_type, NULL); 403 break; 404 405 case ENUMERAL_TYPE: 406 if (TYPE_NAME (t)) 407 data_type = IDENTIFIER_POINTER (TYPE_NAME (t)); 408 else 409 { 410 data_type = ""; 411 chain_p = TYPE_VALUES (t); 412 while (chain_p) 413 { 414 data_type = concat (data_type, 415 IDENTIFIER_POINTER (TREE_PURPOSE (chain_p)), NULL); 416 chain_p = TREE_CHAIN (chain_p); 417 if (chain_p) 418 data_type = concat (data_type, ", ", NULL); 419 } 420 data_type = concat ("{ ", data_type, " }", NULL); 421 } 422 data_type = concat ("enum ", data_type, NULL); 423 break; 424 425 case TYPE_DECL: 426 data_type = IDENTIFIER_POINTER (DECL_NAME (t)); 427 break; 428 429 case INTEGER_TYPE: 430 data_type = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (t))); 431 /* Normally, `unsigned' is part of the deal. Not so if it comes 432 with a type qualifier. */ 433 if (TYPE_UNSIGNED (t) && TYPE_QUALS (t)) 434 data_type = concat ("unsigned ", data_type, NULL); 435 break; 436 437 case REAL_TYPE: 438 data_type = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (t))); 439 break; 440 441 case VOID_TYPE: 442 data_type = "void"; 443 break; 444 445 case ERROR_MARK: 446 data_type = "[ERROR]"; 447 break; 448 449 default: 450 gcc_unreachable (); 451 } 452 } 453 if (TYPE_READONLY (t)) 454 ret_val = concat ("const ", ret_val, NULL); 455 if (TYPE_VOLATILE (t)) 456 ret_val = concat ("volatile ", ret_val, NULL); 457 if (TYPE_RESTRICT (t)) 458 ret_val = concat ("restrict ", ret_val, NULL); 459 return ret_val; 460} 461 462/* Generate a string (source) representation of an entire entity declaration 463 (using some particular style for function types). 464 465 The given entity may be either a variable or a function. 466 467 If the "is_func_definition" parameter is nonzero, assume that the thing 468 we are generating a declaration for is a FUNCTION_DECL node which is 469 associated with a function definition. In this case, we can assume that 470 an attached list of DECL nodes for function formal arguments is present. */ 471 472static const char * 473gen_decl (tree decl, int is_func_definition, formals_style style) 474{ 475 const char *ret_val; 476 477 if (DECL_NAME (decl)) 478 ret_val = IDENTIFIER_POINTER (DECL_NAME (decl)); 479 else 480 ret_val = ""; 481 482 /* If we are just generating a list of names of formal parameters, we can 483 simply return the formal parameter name (with no typing information 484 attached to it) now. */ 485 486 if (style == k_and_r_names) 487 return ret_val; 488 489 /* Note that for the declaration of some entity (either a function or a 490 data object, like for instance a parameter) if the entity itself was 491 declared as either const or volatile, then const and volatile properties 492 are associated with just the declaration of the entity, and *not* with 493 the `type' of the entity. Thus, for such declared entities, we have to 494 generate the qualifiers here. */ 495 496 if (TREE_THIS_VOLATILE (decl)) 497 ret_val = concat ("volatile ", ret_val, NULL); 498 if (TREE_READONLY (decl)) 499 ret_val = concat ("const ", ret_val, NULL); 500 501 data_type = ""; 502 503 /* For FUNCTION_DECL nodes, there are two possible cases here. First, if 504 this FUNCTION_DECL node was generated from a function "definition", then 505 we will have a list of DECL_NODE's, one for each of the function's formal 506 parameters. In this case, we can print out not only the types of each 507 formal, but also each formal's name. In the second case, this 508 FUNCTION_DECL node came from an actual function declaration (and *not* 509 a definition). In this case, we do nothing here because the formal 510 argument type-list will be output later, when the "type" of the function 511 is added to the string we are building. Note that the ANSI-style formal 512 parameter list is considered to be a (suffix) part of the "type" of the 513 function. */ 514 515 if (TREE_CODE (decl) == FUNCTION_DECL && is_func_definition) 516 { 517 ret_val = concat (ret_val, gen_formal_list_for_func_def (decl, ansi), 518 NULL); 519 520 /* Since we have already added in the formals list stuff, here we don't 521 add the whole "type" of the function we are considering (which 522 would include its parameter-list info), rather, we only add in 523 the "type" of the "type" of the function, which is really just 524 the return-type of the function (and does not include the parameter 525 list info). */ 526 527 ret_val = gen_type (ret_val, TREE_TYPE (TREE_TYPE (decl)), style); 528 } 529 else 530 ret_val = gen_type (ret_val, TREE_TYPE (decl), style); 531 532 ret_val = affix_data_type (ret_val); 533 534 if (TREE_CODE (decl) != FUNCTION_DECL && C_DECL_REGISTER (decl)) 535 ret_val = concat ("register ", ret_val, NULL); 536 if (TREE_PUBLIC (decl)) 537 ret_val = concat ("extern ", ret_val, NULL); 538 if (TREE_CODE (decl) == FUNCTION_DECL && !TREE_PUBLIC (decl)) 539 ret_val = concat ("static ", ret_val, NULL); 540 541 return ret_val; 542} 543 544extern FILE *aux_info_file; 545 546/* Generate and write a new line of info to the aux-info (.X) file. This 547 routine is called once for each function declaration, and once for each 548 function definition (even the implicit ones). */ 549 550void 551gen_aux_info_record (tree fndecl, int is_definition, int is_implicit, 552 int is_prototyped) 553{ 554 if (flag_gen_aux_info) 555 { 556 static int compiled_from_record = 0; 557 expanded_location xloc = expand_location (DECL_SOURCE_LOCATION (fndecl)); 558 559 /* Each output .X file must have a header line. Write one now if we 560 have not yet done so. */ 561 562 if (!compiled_from_record++) 563 { 564 /* The first line tells which directory file names are relative to. 565 Currently, -aux-info works only for files in the working 566 directory, so just use a `.' as a placeholder for now. */ 567 fprintf (aux_info_file, "/* compiled from: . */\n"); 568 } 569 570 /* Write the actual line of auxiliary info. */ 571 572 fprintf (aux_info_file, "/* %s:%d:%c%c */ %s;", 573 xloc.file, xloc.line, 574 (is_implicit) ? 'I' : (is_prototyped) ? 'N' : 'O', 575 (is_definition) ? 'F' : 'C', 576 gen_decl (fndecl, is_definition, ansi)); 577 578 /* If this is an explicit function declaration, we need to also write 579 out an old-style (i.e. K&R) function header, just in case the user 580 wants to run unprotoize. */ 581 582 if (is_definition) 583 { 584 fprintf (aux_info_file, " /*%s %s*/", 585 gen_formal_list_for_func_def (fndecl, k_and_r_names), 586 gen_formal_list_for_func_def (fndecl, k_and_r_decls)); 587 } 588 589 fprintf (aux_info_file, "\n"); 590 } 591} 592