1 /* Parse expressions for GDB.
2 Copyright (C) 1986, 89, 90, 91, 94, 98, 1999 Free Software Foundation, Inc.
3 Modified from expread.y by the Department of Computer Science at the
4 State University of New York at Buffalo, 1991.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
23 /* Parse an expression from text in a string,
24 and return the result as a struct expression pointer.
25 That structure contains arithmetic operations in reverse polish,
26 with constants represented by operations that are followed by special data.
27 See expression.h for the details of the format.
28 What is important here is that it can be built up sequentially
29 during the process of parsing; the lower levels of the tree always
30 come first in the result. */
35 #include "gdb_string.h"
39 #include "expression.h"
43 #include "parser-defs.h"
45 #include "symfile.h" /* for overlay functions */
47 /* Symbols which architectures can redefine. */
49 /* Some systems have routines whose names start with `$'. Giving this
50 macro a non-zero value tells GDB's expression parser to check for
51 such routines when parsing tokens that begin with `$'.
53 On HP-UX, certain system routines (millicode) have names beginning
54 with `$' or `$$'. For example, `$$dyncall' is a millicode routine
55 that handles inter-space procedure calls on PA-RISC. */
56 #ifndef SYMBOLS_CAN_START_WITH_DOLLAR
57 #define SYMBOLS_CAN_START_WITH_DOLLAR (0)
62 /* Global variables declared in parser-defs.h (and commented there). */
63 struct expression *expout;
66 struct block *expression_context_block;
67 struct block *innermost_block;
69 union type_stack_elt *type_stack;
70 int type_stack_depth, type_stack_size;
76 static int expressiondebug = 0;
78 extern int hp_som_som_object_present;
80 static void free_funcalls (void *ignore);
82 static void prefixify_expression (struct expression *);
85 prefixify_subexp (struct expression *, struct expression *, int, int);
87 void _initialize_parse (void);
89 /* Data structure for saving values of arglist_len for function calls whose
90 arguments contain other function calls. */
98 static struct funcall *funcall_chain;
100 /* Assign machine-independent names to certain registers
101 (unless overridden by the REGISTER_NAMES table) */
103 unsigned num_std_regs = 0;
104 struct std_regs *std_regs;
106 /* The generic method for targets to specify how their registers are
107 named. The mapping can be derived from three sources:
108 REGISTER_NAME; std_regs; or a target specific alias hook. */
111 target_map_name_to_register (str, len)
117 /* First try target specific aliases. We try these first because on some
118 systems standard names can be context dependent (eg. $pc on a
119 multiprocessor can be could be any of several PCs). */
120 #ifdef REGISTER_NAME_ALIAS_HOOK
121 i = REGISTER_NAME_ALIAS_HOOK (str, len);
126 /* Search architectural register name space. */
127 for (i = 0; i < NUM_REGS; i++)
128 if (REGISTER_NAME (i) && len == strlen (REGISTER_NAME (i))
129 && STREQN (str, REGISTER_NAME (i), len))
134 /* Try pseudo-registers, if any. */
135 for (i = NUM_REGS; i < NUM_REGS + NUM_PSEUDO_REGS; i++)
136 if (REGISTER_NAME (i) && len == strlen (REGISTER_NAME (i))
137 && STREQN (str, REGISTER_NAME (i), len))
142 /* Try standard aliases. */
143 for (i = 0; i < num_std_regs; i++)
144 if (std_regs[i].name && len == strlen (std_regs[i].name)
145 && STREQN (str, std_regs[i].name, len))
147 return std_regs[i].regnum;
153 /* Begin counting arguments for a function call,
154 saving the data about any containing call. */
159 register struct funcall *new;
161 new = (struct funcall *) xmalloc (sizeof (struct funcall));
162 new->next = funcall_chain;
163 new->arglist_len = arglist_len;
168 /* Return the number of arguments in a function call just terminated,
169 and restore the data for the containing function call. */
174 register int val = arglist_len;
175 register struct funcall *call = funcall_chain;
176 funcall_chain = call->next;
177 arglist_len = call->arglist_len;
182 /* Free everything in the funcall chain.
183 Used when there is an error inside parsing. */
186 free_funcalls (void *ignore)
188 register struct funcall *call, *next;
190 for (call = funcall_chain; call; call = next)
197 /* This page contains the functions for adding data to the struct expression
198 being constructed. */
200 /* Add one element to the end of the expression. */
202 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
203 a register through here */
206 write_exp_elt (expelt)
207 union exp_element expelt;
209 if (expout_ptr >= expout_size)
212 expout = (struct expression *)
213 xrealloc ((char *) expout, sizeof (struct expression)
214 + EXP_ELEM_TO_BYTES (expout_size));
216 expout->elts[expout_ptr++] = expelt;
220 write_exp_elt_opcode (expelt)
221 enum exp_opcode expelt;
223 union exp_element tmp;
231 write_exp_elt_sym (expelt)
232 struct symbol *expelt;
234 union exp_element tmp;
242 write_exp_elt_block (b)
245 union exp_element tmp;
251 write_exp_elt_longcst (expelt)
254 union exp_element tmp;
256 tmp.longconst = expelt;
262 write_exp_elt_dblcst (expelt)
265 union exp_element tmp;
267 tmp.doubleconst = expelt;
273 write_exp_elt_type (expelt)
276 union exp_element tmp;
284 write_exp_elt_intern (expelt)
285 struct internalvar *expelt;
287 union exp_element tmp;
289 tmp.internalvar = expelt;
294 /* Add a string constant to the end of the expression.
296 String constants are stored by first writing an expression element
297 that contains the length of the string, then stuffing the string
298 constant itself into however many expression elements are needed
299 to hold it, and then writing another expression element that contains
300 the length of the string. I.E. an expression element at each end of
301 the string records the string length, so you can skip over the
302 expression elements containing the actual string bytes from either
303 end of the string. Note that this also allows gdb to handle
304 strings with embedded null bytes, as is required for some languages.
306 Don't be fooled by the fact that the string is null byte terminated,
307 this is strictly for the convenience of debugging gdb itself. Gdb
308 Gdb does not depend up the string being null terminated, since the
309 actual length is recorded in expression elements at each end of the
310 string. The null byte is taken into consideration when computing how
311 many expression elements are required to hold the string constant, of
316 write_exp_string (str)
319 register int len = str.length;
321 register char *strdata;
323 /* Compute the number of expression elements required to hold the string
324 (including a null byte terminator), along with one expression element
325 at each end to record the actual string length (not including the
326 null byte terminator). */
328 lenelt = 2 + BYTES_TO_EXP_ELEM (len + 1);
330 /* Ensure that we have enough available expression elements to store
333 if ((expout_ptr + lenelt) >= expout_size)
335 expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);
336 expout = (struct expression *)
337 xrealloc ((char *) expout, (sizeof (struct expression)
338 + EXP_ELEM_TO_BYTES (expout_size)));
341 /* Write the leading length expression element (which advances the current
342 expression element index), then write the string constant followed by a
343 terminating null byte, and then write the trailing length expression
346 write_exp_elt_longcst ((LONGEST) len);
347 strdata = (char *) &expout->elts[expout_ptr];
348 memcpy (strdata, str.ptr, len);
349 *(strdata + len) = '\0';
350 expout_ptr += lenelt - 2;
351 write_exp_elt_longcst ((LONGEST) len);
354 /* Add a bitstring constant to the end of the expression.
356 Bitstring constants are stored by first writing an expression element
357 that contains the length of the bitstring (in bits), then stuffing the
358 bitstring constant itself into however many expression elements are
359 needed to hold it, and then writing another expression element that
360 contains the length of the bitstring. I.E. an expression element at
361 each end of the bitstring records the bitstring length, so you can skip
362 over the expression elements containing the actual bitstring bytes from
363 either end of the bitstring. */
366 write_exp_bitstring (str)
369 register int bits = str.length; /* length in bits */
370 register int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
372 register char *strdata;
374 /* Compute the number of expression elements required to hold the bitstring,
375 along with one expression element at each end to record the actual
376 bitstring length in bits. */
378 lenelt = 2 + BYTES_TO_EXP_ELEM (len);
380 /* Ensure that we have enough available expression elements to store
383 if ((expout_ptr + lenelt) >= expout_size)
385 expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);
386 expout = (struct expression *)
387 xrealloc ((char *) expout, (sizeof (struct expression)
388 + EXP_ELEM_TO_BYTES (expout_size)));
391 /* Write the leading length expression element (which advances the current
392 expression element index), then write the bitstring constant, and then
393 write the trailing length expression element. */
395 write_exp_elt_longcst ((LONGEST) bits);
396 strdata = (char *) &expout->elts[expout_ptr];
397 memcpy (strdata, str.ptr, len);
398 expout_ptr += lenelt - 2;
399 write_exp_elt_longcst ((LONGEST) bits);
402 /* Add the appropriate elements for a minimal symbol to the end of
403 the expression. The rationale behind passing in text_symbol_type and
404 data_symbol_type was so that Modula-2 could pass in WORD for
405 data_symbol_type. Perhaps it still is useful to have those types vary
406 based on the language, but they no longer have names like "int", so
407 the initial rationale is gone. */
409 static struct type *msym_text_symbol_type;
410 static struct type *msym_data_symbol_type;
411 static struct type *msym_unknown_symbol_type;
414 write_exp_msymbol (msymbol, text_symbol_type, data_symbol_type)
415 struct minimal_symbol *msymbol;
416 struct type *text_symbol_type;
417 struct type *data_symbol_type;
421 write_exp_elt_opcode (OP_LONG);
422 write_exp_elt_type (lookup_pointer_type (builtin_type_void));
424 addr = SYMBOL_VALUE_ADDRESS (msymbol);
425 if (overlay_debugging)
426 addr = symbol_overlayed_address (addr, SYMBOL_BFD_SECTION (msymbol));
427 write_exp_elt_longcst ((LONGEST) addr);
429 write_exp_elt_opcode (OP_LONG);
431 write_exp_elt_opcode (UNOP_MEMVAL);
432 switch (msymbol->type)
436 case mst_solib_trampoline:
437 write_exp_elt_type (msym_text_symbol_type);
444 write_exp_elt_type (msym_data_symbol_type);
448 write_exp_elt_type (msym_unknown_symbol_type);
451 write_exp_elt_opcode (UNOP_MEMVAL);
454 /* Recognize tokens that start with '$'. These include:
456 $regname A native register name or a "standard
459 $variable A convenience variable with a name chosen
462 $digits Value history with index <digits>, starting
463 from the first value which has index 1.
465 $$digits Value history with index <digits> relative
466 to the last value. I.E. $$0 is the last
467 value, $$1 is the one previous to that, $$2
468 is the one previous to $$1, etc.
470 $ | $0 | $$0 The last value in the value history.
472 $$ An abbreviation for the second to the last
473 value in the value history, I.E. $$1
478 write_dollar_variable (str)
481 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
482 and $$digits (equivalent to $<-digits> if you could type that). */
486 /* Double dollar means negate the number and add -1 as well.
487 Thus $$ alone means -1. */
488 if (str.length >= 2 && str.ptr[1] == '$')
495 /* Just dollars (one or two) */
499 /* Is the rest of the token digits? */
500 for (; i < str.length; i++)
501 if (!(str.ptr[i] >= '0' && str.ptr[i] <= '9'))
505 i = atoi (str.ptr + 1 + negate);
511 /* Handle tokens that refer to machine registers:
512 $ followed by a register name. */
513 i = target_map_name_to_register (str.ptr + 1, str.length - 1);
515 goto handle_register;
517 if (SYMBOLS_CAN_START_WITH_DOLLAR)
519 struct symbol *sym = NULL;
520 struct minimal_symbol *msym = NULL;
522 /* On HP-UX, certain system routines (millicode) have names beginning
523 with $ or $$, e.g. $$dyncall, which handles inter-space procedure
524 calls on PA-RISC. Check for those, first. */
526 /* This code is not enabled on non HP-UX systems, since worst case
527 symbol table lookup performance is awful, to put it mildly. */
529 sym = lookup_symbol (copy_name (str), (struct block *) NULL,
530 VAR_NAMESPACE, (int *) NULL, (struct symtab **) NULL);
533 write_exp_elt_opcode (OP_VAR_VALUE);
534 write_exp_elt_block (block_found); /* set by lookup_symbol */
535 write_exp_elt_sym (sym);
536 write_exp_elt_opcode (OP_VAR_VALUE);
539 msym = lookup_minimal_symbol (copy_name (str), NULL, NULL);
542 write_exp_msymbol (msym,
543 lookup_function_type (builtin_type_int),
549 /* Any other names starting in $ are debugger internal variables. */
551 write_exp_elt_opcode (OP_INTERNALVAR);
552 write_exp_elt_intern (lookup_internalvar (copy_name (str) + 1));
553 write_exp_elt_opcode (OP_INTERNALVAR);
556 write_exp_elt_opcode (OP_LAST);
557 write_exp_elt_longcst ((LONGEST) i);
558 write_exp_elt_opcode (OP_LAST);
561 write_exp_elt_opcode (OP_REGISTER);
562 write_exp_elt_longcst (i);
563 write_exp_elt_opcode (OP_REGISTER);
568 /* Parse a string that is possibly a namespace / nested class
569 specification, i.e., something of the form A::B::C::x. Input
570 (NAME) is the entire string; LEN is the current valid length; the
571 output is a string, TOKEN, which points to the largest recognized
572 prefix which is a series of namespaces or classes. CLASS_PREFIX is
573 another output, which records whether a nested class spec was
574 recognized (= 1) or a fully qualified variable name was found (=
575 0). ARGPTR is side-effected (if non-NULL) to point to beyond the
576 string recognized and consumed by this routine.
578 The return value is a pointer to the symbol for the base class or
579 variable if found, or NULL if not found. Callers must check this
580 first -- if NULL, the outputs may not be correct.
582 This function is used c-exp.y. This is used specifically to get
583 around HP aCC (and possibly other compilers), which insists on
584 generating names with embedded colons for namespace or nested class
587 (Argument LEN is currently unused. 1997-08-27)
589 Callers must free memory allocated for the output string TOKEN. */
591 static const char coloncolon[2] =
595 parse_nested_classes_for_hpacc (name, len, token, class_prefix, argptr)
602 /* Comment below comes from decode_line_1 which has very similar
603 code, which is called for "break" command parsing. */
605 /* We have what looks like a class or namespace
606 scope specification (A::B), possibly with many
607 levels of namespaces or classes (A::B::C::D).
609 Some versions of the HP ANSI C++ compiler (as also possibly
610 other compilers) generate class/function/member names with
611 embedded double-colons if they are inside namespaces. To
612 handle this, we loop a few times, considering larger and
613 larger prefixes of the string as though they were single
614 symbols. So, if the initially supplied string is
615 A::B::C::D::foo, we have to look up "A", then "A::B",
616 then "A::B::C", then "A::B::C::D", and finally
617 "A::B::C::D::foo" as single, monolithic symbols, because
618 A, B, C or D may be namespaces.
620 Note that namespaces can nest only inside other
621 namespaces, and not inside classes. So we need only
622 consider *prefixes* of the string; there is no need to look up
623 "B::C" separately as a symbol in the previous example. */
629 struct symbol *sym_class = NULL;
630 struct symbol *sym_var = NULL;
636 /* Check for HP-compiled executable -- in other cases
637 return NULL, and caller must default to standard GDB
640 if (!hp_som_som_object_present)
641 return (struct symbol *) NULL;
645 /* Skip over whitespace and possible global "::" */
646 while (*p && (*p == ' ' || *p == '\t'))
648 if (p[0] == ':' && p[1] == ':')
650 while (*p && (*p == ' ' || *p == '\t'))
655 /* Get to the end of the next namespace or class spec. */
656 /* If we're looking at some non-token, fail immediately */
658 if (!(isalpha (*p) || *p == '$' || *p == '_'))
659 return (struct symbol *) NULL;
661 while (*p && (isalnum (*p) || *p == '$' || *p == '_'))
666 /* If we have the start of a template specification,
667 scan right ahead to its end */
668 q = find_template_name_end (p);
675 /* Skip over "::" and whitespace for next time around */
676 while (*p && (*p == ' ' || *p == '\t'))
678 if (p[0] == ':' && p[1] == ':')
680 while (*p && (*p == ' ' || *p == '\t'))
683 /* Done with tokens? */
684 if (!*p || !(isalpha (*p) || *p == '$' || *p == '_'))
687 tmp = (char *) alloca (prefix_len + end - start + 3);
690 memcpy (tmp, prefix, prefix_len);
691 memcpy (tmp + prefix_len, coloncolon, 2);
692 memcpy (tmp + prefix_len + 2, start, end - start);
693 tmp[prefix_len + 2 + end - start] = '\000';
697 memcpy (tmp, start, end - start);
698 tmp[end - start] = '\000';
702 prefix_len = strlen (prefix);
704 /* See if the prefix we have now is something we know about */
708 /* More tokens to process, so this must be a class/namespace */
709 sym_class = lookup_symbol (prefix, 0, STRUCT_NAMESPACE,
710 0, (struct symtab **) NULL);
714 /* No more tokens, so try as a variable first */
715 sym_var = lookup_symbol (prefix, 0, VAR_NAMESPACE,
716 0, (struct symtab **) NULL);
717 /* If failed, try as class/namespace */
719 sym_class = lookup_symbol (prefix, 0, STRUCT_NAMESPACE,
720 0, (struct symtab **) NULL);
725 (t = check_typedef (SYMBOL_TYPE (sym_class)),
726 (TYPE_CODE (t) == TYPE_CODE_STRUCT
727 || TYPE_CODE (t) == TYPE_CODE_UNION))))
729 /* We found a valid token */
730 *token = (char *) xmalloc (prefix_len + 1);
731 memcpy (*token, prefix, prefix_len);
732 (*token)[prefix_len] = '\000';
736 /* No variable or class/namespace found, no more tokens */
738 return (struct symbol *) NULL;
741 /* Out of loop, so we must have found a valid token */
748 *argptr = done ? p : end;
750 return sym_var ? sym_var : sym_class; /* found */
754 find_template_name_end (p)
758 int just_seen_right = 0;
759 int just_seen_colon = 0;
760 int just_seen_space = 0;
762 if (!p || (*p != '<'))
773 /* In future, may want to allow these?? */
776 depth++; /* start nested template */
777 if (just_seen_colon || just_seen_right || just_seen_space)
778 return 0; /* but not after : or :: or > or space */
781 if (just_seen_colon || just_seen_right)
782 return 0; /* end a (nested?) template */
783 just_seen_right = 1; /* but not after : or :: */
784 if (--depth == 0) /* also disallow >>, insist on > > */
785 return ++p; /* if outermost ended, return */
788 if (just_seen_space || (just_seen_colon > 1))
789 return 0; /* nested class spec coming up */
790 just_seen_colon++; /* we allow :: but not :::: */
795 if (!((*p >= 'a' && *p <= 'z') || /* allow token chars */
796 (*p >= 'A' && *p <= 'Z') ||
797 (*p >= '0' && *p <= '9') ||
798 (*p == '_') || (*p == ',') || /* commas for template args */
799 (*p == '&') || (*p == '*') || /* pointer and ref types */
800 (*p == '(') || (*p == ')') || /* function types */
801 (*p == '[') || (*p == ']'))) /* array types */
816 /* Return a null-terminated temporary copy of the name
817 of a string token. */
823 memcpy (namecopy, token.ptr, token.length);
824 namecopy[token.length] = 0;
828 /* Reverse an expression from suffix form (in which it is constructed)
829 to prefix form (in which we can conveniently print or execute it). */
832 prefixify_expression (expr)
833 register struct expression *expr;
836 sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts);
837 register struct expression *temp;
838 register int inpos = expr->nelts, outpos = 0;
840 temp = (struct expression *) alloca (len);
842 /* Copy the original expression into temp. */
843 memcpy (temp, expr, len);
845 prefixify_subexp (temp, expr, inpos, outpos);
848 /* Return the number of exp_elements in the subexpression of EXPR
849 whose last exp_element is at index ENDPOS - 1 in EXPR. */
852 length_of_subexp (expr, endpos)
853 register struct expression *expr;
856 register int oplen = 1;
857 register int args = 0;
861 error ("?error in length_of_subexp");
863 i = (int) expr->elts[endpos - 1].opcode;
869 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
870 oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1);
893 case OP_F77_UNDETERMINED_ARGLIST:
895 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
923 case STRUCTOP_STRUCT:
931 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
932 oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
936 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
937 oplen = (oplen + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
938 oplen = 4 + BYTES_TO_EXP_ELEM (oplen);
943 args = longest_to_int (expr->elts[endpos - 2].longconst);
944 args -= longest_to_int (expr->elts[endpos - 3].longconst);
950 case TERNOP_SLICE_COUNT:
955 case MULTI_SUBSCRIPT:
957 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
960 case BINOP_ASSIGN_MODIFY:
971 args = 1 + (i < (int) BINOP_END);
976 oplen += length_of_subexp (expr, endpos - oplen);
983 /* Copy the subexpression ending just before index INEND in INEXPR
984 into OUTEXPR, starting at index OUTBEG.
985 In the process, convert it from suffix to prefix form. */
988 prefixify_subexp (inexpr, outexpr, inend, outbeg)
989 register struct expression *inexpr;
990 struct expression *outexpr;
994 register int oplen = 1;
995 register int args = 0;
998 enum exp_opcode opcode;
1000 /* Compute how long the last operation is (in OPLEN),
1001 and also how many preceding subexpressions serve as
1002 arguments for it (in ARGS). */
1004 opcode = inexpr->elts[inend - 1].opcode;
1009 oplen = longest_to_int (inexpr->elts[inend - 2].longconst);
1010 oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1);
1023 case OP_INTERNALVAR:
1033 case OP_F77_UNDETERMINED_ARGLIST:
1035 args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst);
1061 case STRUCTOP_STRUCT:
1070 oplen = longest_to_int (inexpr->elts[inend - 2].longconst);
1071 oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
1075 oplen = longest_to_int (inexpr->elts[inend - 2].longconst);
1076 oplen = (oplen + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
1077 oplen = 4 + BYTES_TO_EXP_ELEM (oplen);
1082 args = longest_to_int (inexpr->elts[inend - 2].longconst);
1083 args -= longest_to_int (inexpr->elts[inend - 3].longconst);
1089 case TERNOP_SLICE_COUNT:
1093 case BINOP_ASSIGN_MODIFY:
1099 case MULTI_SUBSCRIPT:
1101 args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst);
1110 args = 1 + ((int) opcode < (int) BINOP_END);
1113 /* Copy the final operator itself, from the end of the input
1114 to the beginning of the output. */
1116 memcpy (&outexpr->elts[outbeg], &inexpr->elts[inend],
1117 EXP_ELEM_TO_BYTES (oplen));
1120 /* Find the lengths of the arg subexpressions. */
1121 arglens = (int *) alloca (args * sizeof (int));
1122 for (i = args - 1; i >= 0; i--)
1124 oplen = length_of_subexp (inexpr, inend);
1129 /* Now copy each subexpression, preserving the order of
1130 the subexpressions, but prefixifying each one.
1131 In this loop, inend starts at the beginning of
1132 the expression this level is working on
1133 and marches forward over the arguments.
1134 outbeg does similarly in the output. */
1135 for (i = 0; i < args; i++)
1139 prefixify_subexp (inexpr, outexpr, inend, outbeg);
1144 /* This page contains the two entry points to this file. */
1146 /* Read an expression from the string *STRINGPTR points to,
1147 parse it, and return a pointer to a struct expression that we malloc.
1148 Use block BLOCK as the lexical context for variable names;
1149 if BLOCK is zero, use the block of the selected stack frame.
1150 Meanwhile, advance *STRINGPTR to point after the expression,
1151 at the first nonwhite character that is not part of the expression
1152 (possibly a null character).
1154 If COMMA is nonzero, stop if a comma is reached. */
1157 parse_exp_1 (stringptr, block, comma)
1159 struct block *block;
1162 struct cleanup *old_chain;
1164 lexptr = *stringptr;
1167 type_stack_depth = 0;
1169 comma_terminates = comma;
1171 if (lexptr == 0 || *lexptr == 0)
1172 error_no_arg ("expression to compute");
1174 old_chain = make_cleanup (free_funcalls, 0 /*ignore*/);
1177 expression_context_block = block ? block : get_selected_block ();
1179 namecopy = (char *) alloca (strlen (lexptr) + 1);
1182 expout = (struct expression *)
1183 xmalloc (sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_size));
1184 expout->language_defn = current_language;
1185 make_cleanup (free_current_contents, &expout);
1187 if (current_language->la_parser ())
1188 current_language->la_error (NULL);
1190 discard_cleanups (old_chain);
1192 /* Record the actual number of expression elements, and then
1193 reallocate the expression memory so that we free up any
1196 expout->nelts = expout_ptr;
1197 expout = (struct expression *)
1198 xrealloc ((char *) expout,
1199 sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_ptr));;
1201 /* Convert expression from postfix form as generated by yacc
1202 parser, to a prefix form. */
1204 if (expressiondebug)
1205 dump_prefix_expression (expout, gdb_stdlog,
1206 "before conversion to prefix form");
1208 prefixify_expression (expout);
1210 if (expressiondebug)
1211 dump_postfix_expression (expout, gdb_stdlog,
1212 "after conversion to prefix form");
1214 *stringptr = lexptr;
1218 /* Parse STRING as an expression, and complain if this fails
1219 to use up all of the contents of STRING. */
1222 parse_expression (string)
1225 register struct expression *exp;
1226 exp = parse_exp_1 (&string, 0, 0);
1228 error ("Junk after end of expression.");
1232 /* Stuff for maintaining a stack of types. Currently just used by C, but
1233 probably useful for any language which declares its types "backwards". */
1237 enum type_pieces tp;
1239 if (type_stack_depth == type_stack_size)
1241 type_stack_size *= 2;
1242 type_stack = (union type_stack_elt *)
1243 xrealloc ((char *) type_stack, type_stack_size * sizeof (*type_stack));
1245 type_stack[type_stack_depth++].piece = tp;
1252 if (type_stack_depth == type_stack_size)
1254 type_stack_size *= 2;
1255 type_stack = (union type_stack_elt *)
1256 xrealloc ((char *) type_stack, type_stack_size * sizeof (*type_stack));
1258 type_stack[type_stack_depth++].int_val = n;
1264 if (type_stack_depth)
1265 return type_stack[--type_stack_depth].piece;
1272 if (type_stack_depth)
1273 return type_stack[--type_stack_depth].int_val;
1274 /* "Can't happen". */
1278 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1279 as modified by all the stuff on the stack. */
1281 follow_types (follow_type)
1282 struct type *follow_type;
1286 struct type *range_type;
1289 switch (pop_type ())
1295 follow_type = lookup_pointer_type (follow_type);
1298 follow_type = lookup_reference_type (follow_type);
1301 array_size = pop_type_int ();
1302 /* FIXME-type-allocation: need a way to free this type when we are
1305 create_range_type ((struct type *) NULL,
1306 builtin_type_int, 0,
1307 array_size >= 0 ? array_size - 1 : 0);
1309 create_array_type ((struct type *) NULL,
1310 follow_type, range_type);
1312 TYPE_ARRAY_UPPER_BOUND_TYPE (follow_type)
1313 = BOUND_CANNOT_BE_DETERMINED;
1316 /* FIXME-type-allocation: need a way to free this type when we are
1318 follow_type = lookup_function_type (follow_type);
1324 static void build_parse (void);
1330 msym_text_symbol_type =
1331 init_type (TYPE_CODE_FUNC, 1, 0, "<text variable, no debug info>", NULL);
1332 TYPE_TARGET_TYPE (msym_text_symbol_type) = builtin_type_int;
1333 msym_data_symbol_type =
1334 init_type (TYPE_CODE_INT, TARGET_INT_BIT / HOST_CHAR_BIT, 0,
1335 "<data variable, no debug info>", NULL);
1336 msym_unknown_symbol_type =
1337 init_type (TYPE_CODE_INT, 1, 0,
1338 "<variable (not text or data), no debug info>",
1341 /* create the std_regs table */
1360 /* create an empty table */
1361 std_regs = xmalloc ((num_std_regs + 1) * sizeof *std_regs);
1365 std_regs[i].name = "pc";
1366 std_regs[i].regnum = PC_REGNUM;
1370 std_regs[i].name = "fp";
1371 std_regs[i].regnum = FP_REGNUM;
1375 std_regs[i].name = "sp";
1376 std_regs[i].regnum = SP_REGNUM;
1380 std_regs[i].name = "ps";
1381 std_regs[i].regnum = PS_REGNUM;
1384 memset (&std_regs[i], 0, sizeof (std_regs[i]));
1388 _initialize_parse ()
1390 type_stack_size = 80;
1391 type_stack_depth = 0;
1392 type_stack = (union type_stack_elt *)
1393 xmalloc (type_stack_size * sizeof (*type_stack));
1397 /* FIXME - For the moment, handle types by swapping them in and out.
1398 Should be using the per-architecture data-pointer and a large
1400 register_gdbarch_swap (&msym_text_symbol_type, sizeof (msym_text_symbol_type), NULL);
1401 register_gdbarch_swap (&msym_data_symbol_type, sizeof (msym_data_symbol_type), NULL);
1402 register_gdbarch_swap (&msym_unknown_symbol_type, sizeof (msym_unknown_symbol_type), NULL);
1404 register_gdbarch_swap (&num_std_regs, sizeof (std_regs), NULL);
1405 register_gdbarch_swap (&std_regs, sizeof (std_regs), NULL);
1406 register_gdbarch_swap (NULL, 0, build_parse);
1409 add_set_cmd ("expression", class_maintenance, var_zinteger,
1410 (char *) &expressiondebug,
1411 "Set expression debugging.\n\
1412 When non-zero, the internal representation of expressions will be printed.",