1 /* Parse expressions for GDB.
3 Copyright (C) 1986, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
4 1997, 1998, 1999, 2000, 2001, 2004, 2005 Free Software Foundation, Inc.
6 Modified from expread.y by the Department of Computer Science at the
7 State University of New York at Buffalo, 1991.
9 This file is part of GDB.
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 2 of the License, or
14 (at your option) any later version.
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
21 You should have received a copy of the GNU General Public License
22 along with this program; if not, write to the Free Software
23 Foundation, Inc., 51 Franklin Street, Fifth Floor,
24 Boston, MA 02110-1301, USA. */
26 /* Parse an expression from text in a string,
27 and return the result as a struct expression pointer.
28 That structure contains arithmetic operations in reverse polish,
29 with constants represented by operations that are followed by special data.
30 See expression.h for the details of the format.
31 What is important here is that it can be built up sequentially
32 during the process of parsing; the lower levels of the tree always
33 come first in the result. */
38 #include "gdb_string.h"
42 #include "expression.h"
47 #include "parser-defs.h"
49 #include "symfile.h" /* for overlay functions */
50 #include "inferior.h" /* for NUM_PSEUDO_REGS. NOTE: replace
51 with "gdbarch.h" when appropriate. */
53 #include "gdb_assert.h"
58 /* Standard set of definitions for printing, dumping, prefixifying,
59 * and evaluating expressions. */
61 const struct exp_descriptor exp_descriptor_standard =
63 print_subexp_standard,
64 operator_length_standard,
66 dump_subexp_body_standard,
67 evaluate_subexp_standard
70 /* Global variables declared in parser-defs.h (and commented there). */
71 struct expression *expout;
74 struct block *expression_context_block;
75 CORE_ADDR expression_context_pc;
76 struct block *innermost_block;
78 union type_stack_elt *type_stack;
79 int type_stack_depth, type_stack_size;
85 /* A temporary buffer for identifiers, so we can null-terminate them.
87 We allocate this with xrealloc. parse_exp_1 used to allocate with
88 alloca, using the size of the whole expression as a conservative
89 estimate of the space needed. However, macro expansion can
90 introduce names longer than the original expression; there's no
91 practical way to know beforehand how large that might be. */
95 static int expressiondebug = 0;
97 show_expressiondebug (struct ui_file *file, int from_tty,
98 struct cmd_list_element *c, const char *value)
100 fprintf_filtered (file, _("Expression debugging is %s.\n"), value);
103 static void free_funcalls (void *ignore);
105 static void prefixify_expression (struct expression *);
107 static void prefixify_subexp (struct expression *, struct expression *, int,
110 static struct expression *parse_exp_in_context (char **, struct block *, int,
113 void _initialize_parse (void);
115 /* Data structure for saving values of arglist_len for function calls whose
116 arguments contain other function calls. */
120 struct funcall *next;
124 static struct funcall *funcall_chain;
126 /* Begin counting arguments for a function call,
127 saving the data about any containing call. */
134 new = (struct funcall *) xmalloc (sizeof (struct funcall));
135 new->next = funcall_chain;
136 new->arglist_len = arglist_len;
141 /* Return the number of arguments in a function call just terminated,
142 and restore the data for the containing function call. */
147 int val = arglist_len;
148 struct funcall *call = funcall_chain;
149 funcall_chain = call->next;
150 arglist_len = call->arglist_len;
155 /* Free everything in the funcall chain.
156 Used when there is an error inside parsing. */
159 free_funcalls (void *ignore)
161 struct funcall *call, *next;
163 for (call = funcall_chain; call; call = next)
170 /* This page contains the functions for adding data to the struct expression
171 being constructed. */
173 /* Add one element to the end of the expression. */
175 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
176 a register through here */
179 write_exp_elt (union exp_element expelt)
181 if (expout_ptr >= expout_size)
184 expout = (struct expression *)
185 xrealloc ((char *) expout, sizeof (struct expression)
186 + EXP_ELEM_TO_BYTES (expout_size));
188 expout->elts[expout_ptr++] = expelt;
192 write_exp_elt_opcode (enum exp_opcode expelt)
194 union exp_element tmp;
195 memset (&tmp, 0, sizeof (union exp_element));
203 write_exp_elt_sym (struct symbol *expelt)
205 union exp_element tmp;
206 memset (&tmp, 0, sizeof (union exp_element));
214 write_exp_elt_block (struct block *b)
216 union exp_element tmp;
217 memset (&tmp, 0, sizeof (union exp_element));
223 write_exp_elt_objfile (struct objfile *objfile)
225 union exp_element tmp;
226 memset (&tmp, 0, sizeof (union exp_element));
227 tmp.objfile = objfile;
232 write_exp_elt_longcst (LONGEST expelt)
234 union exp_element tmp;
235 memset (&tmp, 0, sizeof (union exp_element));
237 tmp.longconst = expelt;
243 write_exp_elt_dblcst (DOUBLEST expelt)
245 union exp_element tmp;
246 memset (&tmp, 0, sizeof (union exp_element));
248 tmp.doubleconst = expelt;
254 write_exp_elt_type (struct type *expelt)
256 union exp_element tmp;
257 memset (&tmp, 0, sizeof (union exp_element));
265 write_exp_elt_intern (struct internalvar *expelt)
267 union exp_element tmp;
268 memset (&tmp, 0, sizeof (union exp_element));
270 tmp.internalvar = expelt;
275 /* Add a string constant to the end of the expression.
277 String constants are stored by first writing an expression element
278 that contains the length of the string, then stuffing the string
279 constant itself into however many expression elements are needed
280 to hold it, and then writing another expression element that contains
281 the length of the string. I.E. an expression element at each end of
282 the string records the string length, so you can skip over the
283 expression elements containing the actual string bytes from either
284 end of the string. Note that this also allows gdb to handle
285 strings with embedded null bytes, as is required for some languages.
287 Don't be fooled by the fact that the string is null byte terminated,
288 this is strictly for the convenience of debugging gdb itself. Gdb
289 Gdb does not depend up the string being null terminated, since the
290 actual length is recorded in expression elements at each end of the
291 string. The null byte is taken into consideration when computing how
292 many expression elements are required to hold the string constant, of
297 write_exp_string (struct stoken str)
299 int len = str.length;
303 /* Compute the number of expression elements required to hold the string
304 (including a null byte terminator), along with one expression element
305 at each end to record the actual string length (not including the
306 null byte terminator). */
308 lenelt = 2 + BYTES_TO_EXP_ELEM (len + 1);
310 /* Ensure that we have enough available expression elements to store
313 if ((expout_ptr + lenelt) >= expout_size)
315 expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);
316 expout = (struct expression *)
317 xrealloc ((char *) expout, (sizeof (struct expression)
318 + EXP_ELEM_TO_BYTES (expout_size)));
321 /* Write the leading length expression element (which advances the current
322 expression element index), then write the string constant followed by a
323 terminating null byte, and then write the trailing length expression
326 write_exp_elt_longcst ((LONGEST) len);
327 strdata = (char *) &expout->elts[expout_ptr];
328 memcpy (strdata, str.ptr, len);
329 *(strdata + len) = '\0';
330 expout_ptr += lenelt - 2;
331 write_exp_elt_longcst ((LONGEST) len);
334 /* Add a bitstring constant to the end of the expression.
336 Bitstring constants are stored by first writing an expression element
337 that contains the length of the bitstring (in bits), then stuffing the
338 bitstring constant itself into however many expression elements are
339 needed to hold it, and then writing another expression element that
340 contains the length of the bitstring. I.E. an expression element at
341 each end of the bitstring records the bitstring length, so you can skip
342 over the expression elements containing the actual bitstring bytes from
343 either end of the bitstring. */
346 write_exp_bitstring (struct stoken str)
348 int bits = str.length; /* length in bits */
349 int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
353 /* Compute the number of expression elements required to hold the bitstring,
354 along with one expression element at each end to record the actual
355 bitstring length in bits. */
357 lenelt = 2 + BYTES_TO_EXP_ELEM (len);
359 /* Ensure that we have enough available expression elements to store
362 if ((expout_ptr + lenelt) >= expout_size)
364 expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);
365 expout = (struct expression *)
366 xrealloc ((char *) expout, (sizeof (struct expression)
367 + EXP_ELEM_TO_BYTES (expout_size)));
370 /* Write the leading length expression element (which advances the current
371 expression element index), then write the bitstring constant, and then
372 write the trailing length expression element. */
374 write_exp_elt_longcst ((LONGEST) bits);
375 strdata = (char *) &expout->elts[expout_ptr];
376 memcpy (strdata, str.ptr, len);
377 expout_ptr += lenelt - 2;
378 write_exp_elt_longcst ((LONGEST) bits);
381 /* Add the appropriate elements for a minimal symbol to the end of
382 the expression. The rationale behind passing in text_symbol_type and
383 data_symbol_type was so that Modula-2 could pass in WORD for
384 data_symbol_type. Perhaps it still is useful to have those types vary
385 based on the language, but they no longer have names like "int", so
386 the initial rationale is gone. */
388 static struct type *msym_text_symbol_type;
389 static struct type *msym_data_symbol_type;
390 static struct type *msym_unknown_symbol_type;
391 static struct type *msym_tls_symbol_type;
394 write_exp_msymbol (struct minimal_symbol *msymbol,
395 struct type *text_symbol_type,
396 struct type *data_symbol_type)
400 write_exp_elt_opcode (OP_LONG);
401 /* Let's make the type big enough to hold a 64-bit address. */
402 write_exp_elt_type (builtin_type_CORE_ADDR);
404 addr = SYMBOL_VALUE_ADDRESS (msymbol);
405 if (overlay_debugging)
406 addr = symbol_overlayed_address (addr, SYMBOL_BFD_SECTION (msymbol));
407 write_exp_elt_longcst ((LONGEST) addr);
409 write_exp_elt_opcode (OP_LONG);
411 if (SYMBOL_BFD_SECTION (msymbol)->flags & SEC_THREAD_LOCAL)
413 bfd *bfd = SYMBOL_BFD_SECTION (msymbol)->owner;
417 if (ofp->obfd == bfd)
420 write_exp_elt_opcode (UNOP_MEMVAL_TLS);
421 write_exp_elt_objfile (ofp);
422 write_exp_elt_type (msym_tls_symbol_type);
423 write_exp_elt_opcode (UNOP_MEMVAL_TLS);
427 write_exp_elt_opcode (UNOP_MEMVAL);
428 switch (msymbol->type)
432 case mst_solib_trampoline:
433 write_exp_elt_type (msym_text_symbol_type);
440 write_exp_elt_type (msym_data_symbol_type);
444 write_exp_elt_type (msym_unknown_symbol_type);
447 write_exp_elt_opcode (UNOP_MEMVAL);
450 /* Recognize tokens that start with '$'. These include:
452 $regname A native register name or a "standard
455 $variable A convenience variable with a name chosen
458 $digits Value history with index <digits>, starting
459 from the first value which has index 1.
461 $$digits Value history with index <digits> relative
462 to the last value. I.E. $$0 is the last
463 value, $$1 is the one previous to that, $$2
464 is the one previous to $$1, etc.
466 $ | $0 | $$0 The last value in the value history.
468 $$ An abbreviation for the second to the last
469 value in the value history, I.E. $$1
474 write_dollar_variable (struct stoken str)
476 struct symbol *sym = NULL;
477 struct minimal_symbol *msym = NULL;
479 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
480 and $$digits (equivalent to $<-digits> if you could type that). */
484 /* Double dollar means negate the number and add -1 as well.
485 Thus $$ alone means -1. */
486 if (str.length >= 2 && str.ptr[1] == '$')
493 /* Just dollars (one or two) */
497 /* Is the rest of the token digits? */
498 for (; i < str.length; i++)
499 if (!(str.ptr[i] >= '0' && str.ptr[i] <= '9'))
503 i = atoi (str.ptr + 1 + negate);
509 /* Handle tokens that refer to machine registers:
510 $ followed by a register name. */
511 i = frame_map_name_to_regnum (deprecated_selected_frame,
512 str.ptr + 1, str.length - 1);
514 goto handle_register;
516 /* On some systems, such as HP-UX and hppa-linux, certain system routines
517 have names beginning with $ or $$. Check for those, first. */
519 sym = lookup_symbol (copy_name (str), (struct block *) NULL,
520 VAR_DOMAIN, (int *) NULL, (struct symtab **) NULL);
523 write_exp_elt_opcode (OP_VAR_VALUE);
524 write_exp_elt_block (block_found); /* set by lookup_symbol */
525 write_exp_elt_sym (sym);
526 write_exp_elt_opcode (OP_VAR_VALUE);
529 msym = lookup_minimal_symbol (copy_name (str), NULL, NULL);
532 write_exp_msymbol (msym,
533 lookup_function_type (builtin_type_int),
538 /* Any other names starting in $ are debugger internal variables. */
540 write_exp_elt_opcode (OP_INTERNALVAR);
541 write_exp_elt_intern (lookup_internalvar (copy_name (str) + 1));
542 write_exp_elt_opcode (OP_INTERNALVAR);
545 write_exp_elt_opcode (OP_LAST);
546 write_exp_elt_longcst ((LONGEST) i);
547 write_exp_elt_opcode (OP_LAST);
550 write_exp_elt_opcode (OP_REGISTER);
551 write_exp_elt_longcst (i);
552 write_exp_elt_opcode (OP_REGISTER);
557 /* Parse a string that is possibly a namespace / nested class
558 specification, i.e., something of the form A::B::C::x. Input
559 (NAME) is the entire string; LEN is the current valid length; the
560 output is a string, TOKEN, which points to the largest recognized
561 prefix which is a series of namespaces or classes. CLASS_PREFIX is
562 another output, which records whether a nested class spec was
563 recognized (= 1) or a fully qualified variable name was found (=
564 0). ARGPTR is side-effected (if non-NULL) to point to beyond the
565 string recognized and consumed by this routine.
567 The return value is a pointer to the symbol for the base class or
568 variable if found, or NULL if not found. Callers must check this
569 first -- if NULL, the outputs may not be correct.
571 This function is used c-exp.y. This is used specifically to get
572 around HP aCC (and possibly other compilers), which insists on
573 generating names with embedded colons for namespace or nested class
576 (Argument LEN is currently unused. 1997-08-27)
578 Callers must free memory allocated for the output string TOKEN. */
580 static const char coloncolon[2] =
584 parse_nested_classes_for_hpacc (char *name, int len, char **token,
585 int *class_prefix, char **argptr)
587 /* Comment below comes from decode_line_1 which has very similar
588 code, which is called for "break" command parsing. */
590 /* We have what looks like a class or namespace
591 scope specification (A::B), possibly with many
592 levels of namespaces or classes (A::B::C::D).
594 Some versions of the HP ANSI C++ compiler (as also possibly
595 other compilers) generate class/function/member names with
596 embedded double-colons if they are inside namespaces. To
597 handle this, we loop a few times, considering larger and
598 larger prefixes of the string as though they were single
599 symbols. So, if the initially supplied string is
600 A::B::C::D::foo, we have to look up "A", then "A::B",
601 then "A::B::C", then "A::B::C::D", and finally
602 "A::B::C::D::foo" as single, monolithic symbols, because
603 A, B, C or D may be namespaces.
605 Note that namespaces can nest only inside other
606 namespaces, and not inside classes. So we need only
607 consider *prefixes* of the string; there is no need to look up
608 "B::C" separately as a symbol in the previous example. */
614 struct symbol *sym_class = NULL;
615 struct symbol *sym_var = NULL;
621 /* Check for HP-compiled executable -- in other cases
622 return NULL, and caller must default to standard GDB
625 if (!deprecated_hp_som_som_object_present)
626 return (struct symbol *) NULL;
630 /* Skip over whitespace and possible global "::" */
631 while (*p && (*p == ' ' || *p == '\t'))
633 if (p[0] == ':' && p[1] == ':')
635 while (*p && (*p == ' ' || *p == '\t'))
640 /* Get to the end of the next namespace or class spec. */
641 /* If we're looking at some non-token, fail immediately */
643 if (!(isalpha (*p) || *p == '$' || *p == '_'))
644 return (struct symbol *) NULL;
646 while (*p && (isalnum (*p) || *p == '$' || *p == '_'))
651 /* If we have the start of a template specification,
652 scan right ahead to its end */
653 q = find_template_name_end (p);
660 /* Skip over "::" and whitespace for next time around */
661 while (*p && (*p == ' ' || *p == '\t'))
663 if (p[0] == ':' && p[1] == ':')
665 while (*p && (*p == ' ' || *p == '\t'))
668 /* Done with tokens? */
669 if (!*p || !(isalpha (*p) || *p == '$' || *p == '_'))
672 tmp = (char *) alloca (prefix_len + end - start + 3);
675 memcpy (tmp, prefix, prefix_len);
676 memcpy (tmp + prefix_len, coloncolon, 2);
677 memcpy (tmp + prefix_len + 2, start, end - start);
678 tmp[prefix_len + 2 + end - start] = '\000';
682 memcpy (tmp, start, end - start);
683 tmp[end - start] = '\000';
687 prefix_len = strlen (prefix);
689 /* See if the prefix we have now is something we know about */
693 /* More tokens to process, so this must be a class/namespace */
694 sym_class = lookup_symbol (prefix, 0, STRUCT_DOMAIN,
695 0, (struct symtab **) NULL);
699 /* No more tokens, so try as a variable first */
700 sym_var = lookup_symbol (prefix, 0, VAR_DOMAIN,
701 0, (struct symtab **) NULL);
702 /* If failed, try as class/namespace */
704 sym_class = lookup_symbol (prefix, 0, STRUCT_DOMAIN,
705 0, (struct symtab **) NULL);
710 (t = check_typedef (SYMBOL_TYPE (sym_class)),
711 (TYPE_CODE (t) == TYPE_CODE_STRUCT
712 || TYPE_CODE (t) == TYPE_CODE_UNION))))
714 /* We found a valid token */
715 *token = (char *) xmalloc (prefix_len + 1);
716 memcpy (*token, prefix, prefix_len);
717 (*token)[prefix_len] = '\000';
721 /* No variable or class/namespace found, no more tokens */
723 return (struct symbol *) NULL;
726 /* Out of loop, so we must have found a valid token */
733 *argptr = done ? p : end;
735 return sym_var ? sym_var : sym_class; /* found */
739 find_template_name_end (char *p)
742 int just_seen_right = 0;
743 int just_seen_colon = 0;
744 int just_seen_space = 0;
746 if (!p || (*p != '<'))
757 /* In future, may want to allow these?? */
760 depth++; /* start nested template */
761 if (just_seen_colon || just_seen_right || just_seen_space)
762 return 0; /* but not after : or :: or > or space */
765 if (just_seen_colon || just_seen_right)
766 return 0; /* end a (nested?) template */
767 just_seen_right = 1; /* but not after : or :: */
768 if (--depth == 0) /* also disallow >>, insist on > > */
769 return ++p; /* if outermost ended, return */
772 if (just_seen_space || (just_seen_colon > 1))
773 return 0; /* nested class spec coming up */
774 just_seen_colon++; /* we allow :: but not :::: */
779 if (!((*p >= 'a' && *p <= 'z') || /* allow token chars */
780 (*p >= 'A' && *p <= 'Z') ||
781 (*p >= '0' && *p <= '9') ||
782 (*p == '_') || (*p == ',') || /* commas for template args */
783 (*p == '&') || (*p == '*') || /* pointer and ref types */
784 (*p == '(') || (*p == ')') || /* function types */
785 (*p == '[') || (*p == ']'))) /* array types */
800 /* Return a null-terminated temporary copy of the name
801 of a string token. */
804 copy_name (struct stoken token)
806 /* Make sure there's enough space for the token. */
807 if (namecopy_size < token.length + 1)
809 namecopy_size = token.length + 1;
810 namecopy = xrealloc (namecopy, token.length + 1);
813 memcpy (namecopy, token.ptr, token.length);
814 namecopy[token.length] = 0;
819 /* Reverse an expression from suffix form (in which it is constructed)
820 to prefix form (in which we can conveniently print or execute it). */
823 prefixify_expression (struct expression *expr)
826 sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts);
827 struct expression *temp;
828 int inpos = expr->nelts, outpos = 0;
830 temp = (struct expression *) alloca (len);
832 /* Copy the original expression into temp. */
833 memcpy (temp, expr, len);
835 prefixify_subexp (temp, expr, inpos, outpos);
838 /* Return the number of exp_elements in the postfix subexpression
839 of EXPR whose operator is at index ENDPOS - 1 in EXPR. */
842 length_of_subexp (struct expression *expr, int endpos)
846 operator_length (expr, endpos, &oplen, &args);
850 oplen += length_of_subexp (expr, endpos - oplen);
857 /* Sets *OPLENP to the length of the operator whose (last) index is
858 ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that
862 operator_length (struct expression *expr, int endpos, int *oplenp, int *argsp)
864 expr->language_defn->la_exp_desc->operator_length (expr, endpos,
868 /* Default value for operator_length in exp_descriptor vectors. */
871 operator_length_standard (struct expression *expr, int endpos,
872 int *oplenp, int *argsp)
876 enum f90_range_type range_type;
880 error (_("?error in operator_length_standard"));
882 i = (int) expr->elts[endpos - 1].opcode;
888 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
889 oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1);
912 case OP_F77_UNDETERMINED_ARGLIST:
914 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
917 case OP_OBJC_MSGCALL: /* Objective C message (method) call */
919 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
934 case UNOP_MEMVAL_TLS:
952 case STRUCTOP_STRUCT:
958 case OP_OBJC_NSSTRING: /* Objective C Foundation Class NSString constant */
959 case OP_OBJC_SELECTOR: /* Objective C "@selector" pseudo-op */
962 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
963 oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
967 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
968 oplen = (oplen + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
969 oplen = 4 + BYTES_TO_EXP_ELEM (oplen);
974 args = longest_to_int (expr->elts[endpos - 2].longconst);
975 args -= longest_to_int (expr->elts[endpos - 3].longconst);
981 case TERNOP_SLICE_COUNT:
986 case MULTI_SUBSCRIPT:
988 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
991 case BINOP_ASSIGN_MODIFY:
1005 range_type = longest_to_int (expr->elts[endpos - 2].longconst);
1008 case LOW_BOUND_DEFAULT:
1009 case HIGH_BOUND_DEFAULT:
1012 case BOTH_BOUND_DEFAULT:
1015 case NONE_BOUND_DEFAULT:
1023 args = 1 + (i < (int) BINOP_END);
1030 /* Copy the subexpression ending just before index INEND in INEXPR
1031 into OUTEXPR, starting at index OUTBEG.
1032 In the process, convert it from suffix to prefix form. */
1035 prefixify_subexp (struct expression *inexpr,
1036 struct expression *outexpr, int inend, int outbeg)
1042 enum exp_opcode opcode;
1044 operator_length (inexpr, inend, &oplen, &args);
1046 /* Copy the final operator itself, from the end of the input
1047 to the beginning of the output. */
1049 memcpy (&outexpr->elts[outbeg], &inexpr->elts[inend],
1050 EXP_ELEM_TO_BYTES (oplen));
1053 /* Find the lengths of the arg subexpressions. */
1054 arglens = (int *) alloca (args * sizeof (int));
1055 for (i = args - 1; i >= 0; i--)
1057 oplen = length_of_subexp (inexpr, inend);
1062 /* Now copy each subexpression, preserving the order of
1063 the subexpressions, but prefixifying each one.
1064 In this loop, inend starts at the beginning of
1065 the expression this level is working on
1066 and marches forward over the arguments.
1067 outbeg does similarly in the output. */
1068 for (i = 0; i < args; i++)
1072 prefixify_subexp (inexpr, outexpr, inend, outbeg);
1077 /* This page contains the two entry points to this file. */
1079 /* Read an expression from the string *STRINGPTR points to,
1080 parse it, and return a pointer to a struct expression that we malloc.
1081 Use block BLOCK as the lexical context for variable names;
1082 if BLOCK is zero, use the block of the selected stack frame.
1083 Meanwhile, advance *STRINGPTR to point after the expression,
1084 at the first nonwhite character that is not part of the expression
1085 (possibly a null character).
1087 If COMMA is nonzero, stop if a comma is reached. */
1090 parse_exp_1 (char **stringptr, struct block *block, int comma)
1092 return parse_exp_in_context (stringptr, block, comma, 0);
1095 /* As for parse_exp_1, except that if VOID_CONTEXT_P, then
1096 no value is expected from the expression. */
1098 static struct expression *
1099 parse_exp_in_context (char **stringptr, struct block *block, int comma,
1102 struct cleanup *old_chain;
1104 lexptr = *stringptr;
1108 type_stack_depth = 0;
1110 comma_terminates = comma;
1112 if (lexptr == 0 || *lexptr == 0)
1113 error_no_arg (_("expression to compute"));
1115 old_chain = make_cleanup (free_funcalls, 0 /*ignore*/);
1118 /* If no context specified, try using the current frame, if any. */
1121 block = get_selected_block (&expression_context_pc);
1123 /* Fall back to using the current source static context, if any. */
1127 struct symtab_and_line cursal = get_current_source_symtab_and_line ();
1129 block = BLOCKVECTOR_BLOCK (BLOCKVECTOR (cursal.symtab), STATIC_BLOCK);
1132 /* Save the context, if specified by caller, or found above. */
1136 expression_context_block = block;
1137 expression_context_pc = BLOCK_START (block);
1142 expout = (struct expression *)
1143 xmalloc (sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_size));
1144 expout->language_defn = current_language;
1145 make_cleanup (free_current_contents, &expout);
1147 if (current_language->la_parser ())
1148 current_language->la_error (NULL);
1150 discard_cleanups (old_chain);
1152 /* Record the actual number of expression elements, and then
1153 reallocate the expression memory so that we free up any
1156 expout->nelts = expout_ptr;
1157 expout = (struct expression *)
1158 xrealloc ((char *) expout,
1159 sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_ptr));;
1161 /* Convert expression from postfix form as generated by yacc
1162 parser, to a prefix form. */
1164 if (expressiondebug)
1165 dump_raw_expression (expout, gdb_stdlog,
1166 "before conversion to prefix form");
1168 prefixify_expression (expout);
1170 current_language->la_post_parser (&expout, void_context_p);
1172 if (expressiondebug)
1173 dump_prefix_expression (expout, gdb_stdlog);
1175 *stringptr = lexptr;
1179 /* Parse STRING as an expression, and complain if this fails
1180 to use up all of the contents of STRING. */
1183 parse_expression (char *string)
1185 struct expression *exp;
1186 exp = parse_exp_1 (&string, 0, 0);
1188 error (_("Junk after end of expression."));
1193 /* As for parse_expression, except that if VOID_CONTEXT_P, then
1194 no value is expected from the expression. */
1197 parse_expression_in_context (char *string, int void_context_p)
1199 struct expression *exp;
1200 exp = parse_exp_in_context (&string, 0, 0, void_context_p);
1201 if (*string != '\000')
1202 error (_("Junk after end of expression."));
1206 /* A post-parser that does nothing */
1209 null_post_parser (struct expression **exp, int void_context_p)
1213 /* Stuff for maintaining a stack of types. Currently just used by C, but
1214 probably useful for any language which declares its types "backwards". */
1217 check_type_stack_depth (void)
1219 if (type_stack_depth == type_stack_size)
1221 type_stack_size *= 2;
1222 type_stack = (union type_stack_elt *)
1223 xrealloc ((char *) type_stack, type_stack_size * sizeof (*type_stack));
1228 push_type (enum type_pieces tp)
1230 check_type_stack_depth ();
1231 type_stack[type_stack_depth++].piece = tp;
1235 push_type_int (int n)
1237 check_type_stack_depth ();
1238 type_stack[type_stack_depth++].int_val = n;
1242 push_type_address_space (char *string)
1244 push_type_int (address_space_name_to_int (string));
1250 if (type_stack_depth)
1251 return type_stack[--type_stack_depth].piece;
1258 if (type_stack_depth)
1259 return type_stack[--type_stack_depth].int_val;
1260 /* "Can't happen". */
1264 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1265 as modified by all the stuff on the stack. */
1267 follow_types (struct type *follow_type)
1271 int make_volatile = 0;
1272 int make_addr_space = 0;
1274 struct type *range_type;
1277 switch (pop_type ())
1282 follow_type = make_cv_type (make_const,
1283 TYPE_VOLATILE (follow_type),
1286 follow_type = make_cv_type (TYPE_CONST (follow_type),
1289 if (make_addr_space)
1290 follow_type = make_type_with_address_space (follow_type,
1292 make_const = make_volatile = 0;
1293 make_addr_space = 0;
1301 case tp_space_identifier:
1302 make_addr_space = pop_type_int ();
1305 follow_type = lookup_pointer_type (follow_type);
1307 follow_type = make_cv_type (make_const,
1308 TYPE_VOLATILE (follow_type),
1311 follow_type = make_cv_type (TYPE_CONST (follow_type),
1314 if (make_addr_space)
1315 follow_type = make_type_with_address_space (follow_type,
1317 make_const = make_volatile = 0;
1318 make_addr_space = 0;
1321 follow_type = lookup_reference_type (follow_type);
1323 follow_type = make_cv_type (make_const,
1324 TYPE_VOLATILE (follow_type),
1327 follow_type = make_cv_type (TYPE_CONST (follow_type),
1330 if (make_addr_space)
1331 follow_type = make_type_with_address_space (follow_type,
1333 make_const = make_volatile = 0;
1334 make_addr_space = 0;
1337 array_size = pop_type_int ();
1338 /* FIXME-type-allocation: need a way to free this type when we are
1341 create_range_type ((struct type *) NULL,
1342 builtin_type_int, 0,
1343 array_size >= 0 ? array_size - 1 : 0);
1345 create_array_type ((struct type *) NULL,
1346 follow_type, range_type);
1348 TYPE_ARRAY_UPPER_BOUND_TYPE (follow_type)
1349 = BOUND_CANNOT_BE_DETERMINED;
1352 /* FIXME-type-allocation: need a way to free this type when we are
1354 follow_type = lookup_function_type (follow_type);
1360 static void build_parse (void);
1366 msym_text_symbol_type =
1367 init_type (TYPE_CODE_FUNC, 1, 0, "<text variable, no debug info>", NULL);
1368 TYPE_TARGET_TYPE (msym_text_symbol_type) = builtin_type_int;
1369 msym_data_symbol_type =
1370 init_type (TYPE_CODE_INT, TARGET_INT_BIT / HOST_CHAR_BIT, 0,
1371 "<data variable, no debug info>", NULL);
1372 msym_unknown_symbol_type =
1373 init_type (TYPE_CODE_INT, 1, 0,
1374 "<variable (not text or data), no debug info>",
1377 msym_tls_symbol_type =
1378 init_type (TYPE_CODE_INT, TARGET_INT_BIT / HOST_CHAR_BIT, 0,
1379 "<thread local variable, no debug info>", NULL);
1382 /* This function avoids direct calls to fprintf
1383 in the parser generated debug code. */
1385 parser_fprintf (FILE *x, const char *y, ...)
1390 vfprintf_unfiltered (gdb_stderr, y, args);
1393 fprintf_unfiltered (gdb_stderr, " Unknown FILE used.\n");
1394 vfprintf_unfiltered (gdb_stderr, y, args);
1400 _initialize_parse (void)
1402 type_stack_size = 80;
1403 type_stack_depth = 0;
1404 type_stack = (union type_stack_elt *)
1405 xmalloc (type_stack_size * sizeof (*type_stack));
1409 /* FIXME - For the moment, handle types by swapping them in and out.
1410 Should be using the per-architecture data-pointer and a large
1412 DEPRECATED_REGISTER_GDBARCH_SWAP (msym_text_symbol_type);
1413 DEPRECATED_REGISTER_GDBARCH_SWAP (msym_data_symbol_type);
1414 DEPRECATED_REGISTER_GDBARCH_SWAP (msym_unknown_symbol_type);
1415 deprecated_register_gdbarch_swap (NULL, 0, build_parse);
1417 add_setshow_zinteger_cmd ("expression", class_maintenance,
1418 &expressiondebug, _("\
1419 Set expression debugging."), _("\
1420 Show expression debugging."), _("\
1421 When non-zero, the internal representation of expressions will be printed."),
1423 show_expressiondebug,
1424 &setdebuglist, &showdebuglist);