1 /* Parse expressions for GDB.
2 Copyright 1986, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
4 Modified from expread.y by the Department of Computer Science at the
5 State University of New York at Buffalo, 1991.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
24 /* Parse an expression from text in a string,
25 and return the result as a struct expression pointer.
26 That structure contains arithmetic operations in reverse polish,
27 with constants represented by operations that are followed by special data.
28 See expression.h for the details of the format.
29 What is important here is that it can be built up sequentially
30 during the process of parsing; the lower levels of the tree always
31 come first in the result. */
36 #include "gdb_string.h"
40 #include "expression.h"
44 #include "parser-defs.h"
46 #include "symfile.h" /* for overlay functions */
47 #include "inferior.h" /* for NUM_PSEUDO_REGS. NOTE: replace
48 with "gdbarch.h" when appropriate. */
50 #include "gdb_assert.h"
53 /* Symbols which architectures can redefine. */
55 /* Some systems have routines whose names start with `$'. Giving this
56 macro a non-zero value tells GDB's expression parser to check for
57 such routines when parsing tokens that begin with `$'.
59 On HP-UX, certain system routines (millicode) have names beginning
60 with `$' or `$$'. For example, `$$dyncall' is a millicode routine
61 that handles inter-space procedure calls on PA-RISC. */
62 #ifndef SYMBOLS_CAN_START_WITH_DOLLAR
63 #define SYMBOLS_CAN_START_WITH_DOLLAR (0)
68 /* Global variables declared in parser-defs.h (and commented there). */
69 struct expression *expout;
72 struct block *expression_context_block;
73 CORE_ADDR expression_context_pc;
74 struct block *innermost_block;
76 union type_stack_elt *type_stack;
77 int type_stack_depth, type_stack_size;
84 static int expressiondebug = 0;
86 extern int hp_som_som_object_present;
88 static void free_funcalls (void *ignore);
90 static void prefixify_expression (struct expression *);
92 static void prefixify_subexp (struct expression *, struct expression *, int,
95 void _initialize_parse (void);
97 /* Data structure for saving values of arglist_len for function calls whose
98 arguments contain other function calls. */
102 struct funcall *next;
106 static struct funcall *funcall_chain;
108 /* Begin counting arguments for a function call,
109 saving the data about any containing call. */
114 register struct funcall *new;
116 new = (struct funcall *) xmalloc (sizeof (struct funcall));
117 new->next = funcall_chain;
118 new->arglist_len = arglist_len;
123 /* Return the number of arguments in a function call just terminated,
124 and restore the data for the containing function call. */
129 register int val = arglist_len;
130 register struct funcall *call = funcall_chain;
131 funcall_chain = call->next;
132 arglist_len = call->arglist_len;
137 /* Free everything in the funcall chain.
138 Used when there is an error inside parsing. */
141 free_funcalls (void *ignore)
143 register struct funcall *call, *next;
145 for (call = funcall_chain; call; call = next)
152 /* This page contains the functions for adding data to the struct expression
153 being constructed. */
155 /* Add one element to the end of the expression. */
157 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
158 a register through here */
161 write_exp_elt (union exp_element expelt)
163 if (expout_ptr >= expout_size)
166 expout = (struct expression *)
167 xrealloc ((char *) expout, sizeof (struct expression)
168 + EXP_ELEM_TO_BYTES (expout_size));
170 expout->elts[expout_ptr++] = expelt;
174 write_exp_elt_opcode (enum exp_opcode expelt)
176 union exp_element tmp;
184 write_exp_elt_sym (struct symbol *expelt)
186 union exp_element tmp;
194 write_exp_elt_block (struct block *b)
196 union exp_element tmp;
202 write_exp_elt_longcst (LONGEST expelt)
204 union exp_element tmp;
206 tmp.longconst = expelt;
212 write_exp_elt_dblcst (DOUBLEST expelt)
214 union exp_element tmp;
216 tmp.doubleconst = expelt;
222 write_exp_elt_type (struct type *expelt)
224 union exp_element tmp;
232 write_exp_elt_intern (struct internalvar *expelt)
234 union exp_element tmp;
236 tmp.internalvar = expelt;
241 /* Add a string constant to the end of the expression.
243 String constants are stored by first writing an expression element
244 that contains the length of the string, then stuffing the string
245 constant itself into however many expression elements are needed
246 to hold it, and then writing another expression element that contains
247 the length of the string. I.E. an expression element at each end of
248 the string records the string length, so you can skip over the
249 expression elements containing the actual string bytes from either
250 end of the string. Note that this also allows gdb to handle
251 strings with embedded null bytes, as is required for some languages.
253 Don't be fooled by the fact that the string is null byte terminated,
254 this is strictly for the convenience of debugging gdb itself. Gdb
255 Gdb does not depend up the string being null terminated, since the
256 actual length is recorded in expression elements at each end of the
257 string. The null byte is taken into consideration when computing how
258 many expression elements are required to hold the string constant, of
263 write_exp_string (struct stoken str)
265 register int len = str.length;
267 register char *strdata;
269 /* Compute the number of expression elements required to hold the string
270 (including a null byte terminator), along with one expression element
271 at each end to record the actual string length (not including the
272 null byte terminator). */
274 lenelt = 2 + BYTES_TO_EXP_ELEM (len + 1);
276 /* Ensure that we have enough available expression elements to store
279 if ((expout_ptr + lenelt) >= expout_size)
281 expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);
282 expout = (struct expression *)
283 xrealloc ((char *) expout, (sizeof (struct expression)
284 + EXP_ELEM_TO_BYTES (expout_size)));
287 /* Write the leading length expression element (which advances the current
288 expression element index), then write the string constant followed by a
289 terminating null byte, and then write the trailing length expression
292 write_exp_elt_longcst ((LONGEST) len);
293 strdata = (char *) &expout->elts[expout_ptr];
294 memcpy (strdata, str.ptr, len);
295 *(strdata + len) = '\0';
296 expout_ptr += lenelt - 2;
297 write_exp_elt_longcst ((LONGEST) len);
300 /* Add a bitstring constant to the end of the expression.
302 Bitstring constants are stored by first writing an expression element
303 that contains the length of the bitstring (in bits), then stuffing the
304 bitstring constant itself into however many expression elements are
305 needed to hold it, and then writing another expression element that
306 contains the length of the bitstring. I.E. an expression element at
307 each end of the bitstring records the bitstring length, so you can skip
308 over the expression elements containing the actual bitstring bytes from
309 either end of the bitstring. */
312 write_exp_bitstring (struct stoken str)
314 register int bits = str.length; /* length in bits */
315 register int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
317 register char *strdata;
319 /* Compute the number of expression elements required to hold the bitstring,
320 along with one expression element at each end to record the actual
321 bitstring length in bits. */
323 lenelt = 2 + BYTES_TO_EXP_ELEM (len);
325 /* Ensure that we have enough available expression elements to store
328 if ((expout_ptr + lenelt) >= expout_size)
330 expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);
331 expout = (struct expression *)
332 xrealloc ((char *) expout, (sizeof (struct expression)
333 + EXP_ELEM_TO_BYTES (expout_size)));
336 /* Write the leading length expression element (which advances the current
337 expression element index), then write the bitstring constant, and then
338 write the trailing length expression element. */
340 write_exp_elt_longcst ((LONGEST) bits);
341 strdata = (char *) &expout->elts[expout_ptr];
342 memcpy (strdata, str.ptr, len);
343 expout_ptr += lenelt - 2;
344 write_exp_elt_longcst ((LONGEST) bits);
347 /* Add the appropriate elements for a minimal symbol to the end of
348 the expression. The rationale behind passing in text_symbol_type and
349 data_symbol_type was so that Modula-2 could pass in WORD for
350 data_symbol_type. Perhaps it still is useful to have those types vary
351 based on the language, but they no longer have names like "int", so
352 the initial rationale is gone. */
354 static struct type *msym_text_symbol_type;
355 static struct type *msym_data_symbol_type;
356 static struct type *msym_unknown_symbol_type;
359 write_exp_msymbol (struct minimal_symbol *msymbol,
360 struct type *text_symbol_type,
361 struct type *data_symbol_type)
365 write_exp_elt_opcode (OP_LONG);
366 /* Let's make the type big enough to hold a 64-bit address. */
367 write_exp_elt_type (builtin_type_CORE_ADDR);
369 addr = SYMBOL_VALUE_ADDRESS (msymbol);
370 if (overlay_debugging)
371 addr = symbol_overlayed_address (addr, SYMBOL_BFD_SECTION (msymbol));
372 write_exp_elt_longcst ((LONGEST) addr);
374 write_exp_elt_opcode (OP_LONG);
376 write_exp_elt_opcode (UNOP_MEMVAL);
377 switch (msymbol->type)
381 case mst_solib_trampoline:
382 write_exp_elt_type (msym_text_symbol_type);
389 write_exp_elt_type (msym_data_symbol_type);
393 write_exp_elt_type (msym_unknown_symbol_type);
396 write_exp_elt_opcode (UNOP_MEMVAL);
399 /* Recognize tokens that start with '$'. These include:
401 $regname A native register name or a "standard
404 $variable A convenience variable with a name chosen
407 $digits Value history with index <digits>, starting
408 from the first value which has index 1.
410 $$digits Value history with index <digits> relative
411 to the last value. I.E. $$0 is the last
412 value, $$1 is the one previous to that, $$2
413 is the one previous to $$1, etc.
415 $ | $0 | $$0 The last value in the value history.
417 $$ An abbreviation for the second to the last
418 value in the value history, I.E. $$1
423 write_dollar_variable (struct stoken str)
425 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
426 and $$digits (equivalent to $<-digits> if you could type that). */
430 /* Double dollar means negate the number and add -1 as well.
431 Thus $$ alone means -1. */
432 if (str.length >= 2 && str.ptr[1] == '$')
439 /* Just dollars (one or two) */
443 /* Is the rest of the token digits? */
444 for (; i < str.length; i++)
445 if (!(str.ptr[i] >= '0' && str.ptr[i] <= '9'))
449 i = atoi (str.ptr + 1 + negate);
455 /* Handle tokens that refer to machine registers:
456 $ followed by a register name. */
457 i = frame_map_name_to_regnum (str.ptr + 1, str.length - 1);
459 goto handle_register;
461 if (SYMBOLS_CAN_START_WITH_DOLLAR)
463 struct symbol *sym = NULL;
464 struct minimal_symbol *msym = NULL;
466 /* On HP-UX, certain system routines (millicode) have names beginning
467 with $ or $$, e.g. $$dyncall, which handles inter-space procedure
468 calls on PA-RISC. Check for those, first. */
470 /* This code is not enabled on non HP-UX systems, since worst case
471 symbol table lookup performance is awful, to put it mildly. */
473 sym = lookup_symbol (copy_name (str), (struct block *) NULL,
474 VAR_NAMESPACE, (int *) NULL, (struct symtab **) NULL);
477 write_exp_elt_opcode (OP_VAR_VALUE);
478 write_exp_elt_block (block_found); /* set by lookup_symbol */
479 write_exp_elt_sym (sym);
480 write_exp_elt_opcode (OP_VAR_VALUE);
483 msym = lookup_minimal_symbol (copy_name (str), NULL, NULL);
486 write_exp_msymbol (msym,
487 lookup_function_type (builtin_type_int),
493 /* Any other names starting in $ are debugger internal variables. */
495 write_exp_elt_opcode (OP_INTERNALVAR);
496 write_exp_elt_intern (lookup_internalvar (copy_name (str) + 1));
497 write_exp_elt_opcode (OP_INTERNALVAR);
500 write_exp_elt_opcode (OP_LAST);
501 write_exp_elt_longcst ((LONGEST) i);
502 write_exp_elt_opcode (OP_LAST);
505 write_exp_elt_opcode (OP_REGISTER);
506 write_exp_elt_longcst (i);
507 write_exp_elt_opcode (OP_REGISTER);
512 /* Parse a string that is possibly a namespace / nested class
513 specification, i.e., something of the form A::B::C::x. Input
514 (NAME) is the entire string; LEN is the current valid length; the
515 output is a string, TOKEN, which points to the largest recognized
516 prefix which is a series of namespaces or classes. CLASS_PREFIX is
517 another output, which records whether a nested class spec was
518 recognized (= 1) or a fully qualified variable name was found (=
519 0). ARGPTR is side-effected (if non-NULL) to point to beyond the
520 string recognized and consumed by this routine.
522 The return value is a pointer to the symbol for the base class or
523 variable if found, or NULL if not found. Callers must check this
524 first -- if NULL, the outputs may not be correct.
526 This function is used c-exp.y. This is used specifically to get
527 around HP aCC (and possibly other compilers), which insists on
528 generating names with embedded colons for namespace or nested class
531 (Argument LEN is currently unused. 1997-08-27)
533 Callers must free memory allocated for the output string TOKEN. */
535 static const char coloncolon[2] =
539 parse_nested_classes_for_hpacc (char *name, int len, char **token,
540 int *class_prefix, char **argptr)
542 /* Comment below comes from decode_line_1 which has very similar
543 code, which is called for "break" command parsing. */
545 /* We have what looks like a class or namespace
546 scope specification (A::B), possibly with many
547 levels of namespaces or classes (A::B::C::D).
549 Some versions of the HP ANSI C++ compiler (as also possibly
550 other compilers) generate class/function/member names with
551 embedded double-colons if they are inside namespaces. To
552 handle this, we loop a few times, considering larger and
553 larger prefixes of the string as though they were single
554 symbols. So, if the initially supplied string is
555 A::B::C::D::foo, we have to look up "A", then "A::B",
556 then "A::B::C", then "A::B::C::D", and finally
557 "A::B::C::D::foo" as single, monolithic symbols, because
558 A, B, C or D may be namespaces.
560 Note that namespaces can nest only inside other
561 namespaces, and not inside classes. So we need only
562 consider *prefixes* of the string; there is no need to look up
563 "B::C" separately as a symbol in the previous example. */
569 struct symbol *sym_class = NULL;
570 struct symbol *sym_var = NULL;
576 /* Check for HP-compiled executable -- in other cases
577 return NULL, and caller must default to standard GDB
580 if (!hp_som_som_object_present)
581 return (struct symbol *) NULL;
585 /* Skip over whitespace and possible global "::" */
586 while (*p && (*p == ' ' || *p == '\t'))
588 if (p[0] == ':' && p[1] == ':')
590 while (*p && (*p == ' ' || *p == '\t'))
595 /* Get to the end of the next namespace or class spec. */
596 /* If we're looking at some non-token, fail immediately */
598 if (!(isalpha (*p) || *p == '$' || *p == '_'))
599 return (struct symbol *) NULL;
601 while (*p && (isalnum (*p) || *p == '$' || *p == '_'))
606 /* If we have the start of a template specification,
607 scan right ahead to its end */
608 q = find_template_name_end (p);
615 /* Skip over "::" and whitespace for next time around */
616 while (*p && (*p == ' ' || *p == '\t'))
618 if (p[0] == ':' && p[1] == ':')
620 while (*p && (*p == ' ' || *p == '\t'))
623 /* Done with tokens? */
624 if (!*p || !(isalpha (*p) || *p == '$' || *p == '_'))
627 tmp = (char *) alloca (prefix_len + end - start + 3);
630 memcpy (tmp, prefix, prefix_len);
631 memcpy (tmp + prefix_len, coloncolon, 2);
632 memcpy (tmp + prefix_len + 2, start, end - start);
633 tmp[prefix_len + 2 + end - start] = '\000';
637 memcpy (tmp, start, end - start);
638 tmp[end - start] = '\000';
642 prefix_len = strlen (prefix);
644 /* See if the prefix we have now is something we know about */
648 /* More tokens to process, so this must be a class/namespace */
649 sym_class = lookup_symbol (prefix, 0, STRUCT_NAMESPACE,
650 0, (struct symtab **) NULL);
654 /* No more tokens, so try as a variable first */
655 sym_var = lookup_symbol (prefix, 0, VAR_NAMESPACE,
656 0, (struct symtab **) NULL);
657 /* If failed, try as class/namespace */
659 sym_class = lookup_symbol (prefix, 0, STRUCT_NAMESPACE,
660 0, (struct symtab **) NULL);
665 (t = check_typedef (SYMBOL_TYPE (sym_class)),
666 (TYPE_CODE (t) == TYPE_CODE_STRUCT
667 || TYPE_CODE (t) == TYPE_CODE_UNION))))
669 /* We found a valid token */
670 *token = (char *) xmalloc (prefix_len + 1);
671 memcpy (*token, prefix, prefix_len);
672 (*token)[prefix_len] = '\000';
676 /* No variable or class/namespace found, no more tokens */
678 return (struct symbol *) NULL;
681 /* Out of loop, so we must have found a valid token */
688 *argptr = done ? p : end;
690 return sym_var ? sym_var : sym_class; /* found */
694 find_template_name_end (char *p)
697 int just_seen_right = 0;
698 int just_seen_colon = 0;
699 int just_seen_space = 0;
701 if (!p || (*p != '<'))
712 /* In future, may want to allow these?? */
715 depth++; /* start nested template */
716 if (just_seen_colon || just_seen_right || just_seen_space)
717 return 0; /* but not after : or :: or > or space */
720 if (just_seen_colon || just_seen_right)
721 return 0; /* end a (nested?) template */
722 just_seen_right = 1; /* but not after : or :: */
723 if (--depth == 0) /* also disallow >>, insist on > > */
724 return ++p; /* if outermost ended, return */
727 if (just_seen_space || (just_seen_colon > 1))
728 return 0; /* nested class spec coming up */
729 just_seen_colon++; /* we allow :: but not :::: */
734 if (!((*p >= 'a' && *p <= 'z') || /* allow token chars */
735 (*p >= 'A' && *p <= 'Z') ||
736 (*p >= '0' && *p <= '9') ||
737 (*p == '_') || (*p == ',') || /* commas for template args */
738 (*p == '&') || (*p == '*') || /* pointer and ref types */
739 (*p == '(') || (*p == ')') || /* function types */
740 (*p == '[') || (*p == ']'))) /* array types */
755 /* Return a null-terminated temporary copy of the name
756 of a string token. */
759 copy_name (struct stoken token)
761 memcpy (namecopy, token.ptr, token.length);
762 namecopy[token.length] = 0;
766 /* Reverse an expression from suffix form (in which it is constructed)
767 to prefix form (in which we can conveniently print or execute it). */
770 prefixify_expression (register struct expression *expr)
773 sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts);
774 register struct expression *temp;
775 register int inpos = expr->nelts, outpos = 0;
777 temp = (struct expression *) alloca (len);
779 /* Copy the original expression into temp. */
780 memcpy (temp, expr, len);
782 prefixify_subexp (temp, expr, inpos, outpos);
785 /* Return the number of exp_elements in the subexpression of EXPR
786 whose last exp_element is at index ENDPOS - 1 in EXPR. */
789 length_of_subexp (register struct expression *expr, register int endpos)
791 register int oplen = 1;
792 register int args = 0;
796 error ("?error in length_of_subexp");
798 i = (int) expr->elts[endpos - 1].opcode;
804 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
805 oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1);
828 case OP_F77_UNDETERMINED_ARGLIST:
830 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
833 case OP_OBJC_MSGCALL: /* Objective C message (method) call */
835 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
863 case STRUCTOP_STRUCT:
869 case OP_OBJC_NSSTRING: /* Objective C Foundation Class NSString constant */
870 case OP_OBJC_SELECTOR: /* Objective C "@selector" pseudo-op */
873 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
874 oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
878 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
879 oplen = (oplen + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
880 oplen = 4 + BYTES_TO_EXP_ELEM (oplen);
885 args = longest_to_int (expr->elts[endpos - 2].longconst);
886 args -= longest_to_int (expr->elts[endpos - 3].longconst);
892 case TERNOP_SLICE_COUNT:
897 case MULTI_SUBSCRIPT:
899 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
902 case BINOP_ASSIGN_MODIFY:
914 args = 1 + (i < (int) BINOP_END);
919 oplen += length_of_subexp (expr, endpos - oplen);
926 /* Copy the subexpression ending just before index INEND in INEXPR
927 into OUTEXPR, starting at index OUTBEG.
928 In the process, convert it from suffix to prefix form. */
931 prefixify_subexp (register struct expression *inexpr,
932 struct expression *outexpr, register int inend, int outbeg)
934 register int oplen = 1;
935 register int args = 0;
938 enum exp_opcode opcode;
940 /* Compute how long the last operation is (in OPLEN),
941 and also how many preceding subexpressions serve as
942 arguments for it (in ARGS). */
944 opcode = inexpr->elts[inend - 1].opcode;
949 oplen = longest_to_int (inexpr->elts[inend - 2].longconst);
950 oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1);
973 case OP_F77_UNDETERMINED_ARGLIST:
975 args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst);
978 case OP_OBJC_MSGCALL: /* Objective C message (method) call */
980 args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst);
1006 case STRUCTOP_STRUCT:
1013 case OP_OBJC_NSSTRING: /* Objective C Foundation Class NSString constant */
1014 case OP_OBJC_SELECTOR: /* Objective C "@selector" pseudo-op */
1017 oplen = longest_to_int (inexpr->elts[inend - 2].longconst);
1018 oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
1022 oplen = longest_to_int (inexpr->elts[inend - 2].longconst);
1023 oplen = (oplen + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
1024 oplen = 4 + BYTES_TO_EXP_ELEM (oplen);
1029 args = longest_to_int (inexpr->elts[inend - 2].longconst);
1030 args -= longest_to_int (inexpr->elts[inend - 3].longconst);
1036 case TERNOP_SLICE_COUNT:
1040 case BINOP_ASSIGN_MODIFY:
1046 case MULTI_SUBSCRIPT:
1048 args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst);
1058 args = 1 + ((int) opcode < (int) BINOP_END);
1061 /* Copy the final operator itself, from the end of the input
1062 to the beginning of the output. */
1064 memcpy (&outexpr->elts[outbeg], &inexpr->elts[inend],
1065 EXP_ELEM_TO_BYTES (oplen));
1068 /* Find the lengths of the arg subexpressions. */
1069 arglens = (int *) alloca (args * sizeof (int));
1070 for (i = args - 1; i >= 0; i--)
1072 oplen = length_of_subexp (inexpr, inend);
1077 /* Now copy each subexpression, preserving the order of
1078 the subexpressions, but prefixifying each one.
1079 In this loop, inend starts at the beginning of
1080 the expression this level is working on
1081 and marches forward over the arguments.
1082 outbeg does similarly in the output. */
1083 for (i = 0; i < args; i++)
1087 prefixify_subexp (inexpr, outexpr, inend, outbeg);
1092 /* This page contains the two entry points to this file. */
1094 /* Read an expression from the string *STRINGPTR points to,
1095 parse it, and return a pointer to a struct expression that we malloc.
1096 Use block BLOCK as the lexical context for variable names;
1097 if BLOCK is zero, use the block of the selected stack frame.
1098 Meanwhile, advance *STRINGPTR to point after the expression,
1099 at the first nonwhite character that is not part of the expression
1100 (possibly a null character).
1102 If COMMA is nonzero, stop if a comma is reached. */
1105 parse_exp_1 (char **stringptr, struct block *block, int comma)
1107 struct cleanup *old_chain;
1109 lexptr = *stringptr;
1113 type_stack_depth = 0;
1115 comma_terminates = comma;
1117 if (lexptr == 0 || *lexptr == 0)
1118 error_no_arg ("expression to compute");
1120 old_chain = make_cleanup (free_funcalls, 0 /*ignore*/);
1125 expression_context_block = block;
1126 expression_context_pc = BLOCK_START (block);
1129 expression_context_block = get_selected_block (&expression_context_pc);
1131 namecopy = (char *) alloca (strlen (lexptr) + 1);
1134 expout = (struct expression *)
1135 xmalloc (sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_size));
1136 expout->language_defn = current_language;
1137 make_cleanup (free_current_contents, &expout);
1139 if (current_language->la_parser ())
1140 current_language->la_error (NULL);
1142 discard_cleanups (old_chain);
1144 /* Record the actual number of expression elements, and then
1145 reallocate the expression memory so that we free up any
1148 expout->nelts = expout_ptr;
1149 expout = (struct expression *)
1150 xrealloc ((char *) expout,
1151 sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_ptr));;
1153 /* Convert expression from postfix form as generated by yacc
1154 parser, to a prefix form. */
1156 if (expressiondebug)
1157 dump_prefix_expression (expout, gdb_stdlog,
1158 "before conversion to prefix form");
1160 prefixify_expression (expout);
1162 if (expressiondebug)
1163 dump_postfix_expression (expout, gdb_stdlog,
1164 "after conversion to prefix form");
1166 *stringptr = lexptr;
1170 /* Parse STRING as an expression, and complain if this fails
1171 to use up all of the contents of STRING. */
1174 parse_expression (char *string)
1176 register struct expression *exp;
1177 exp = parse_exp_1 (&string, 0, 0);
1179 error ("Junk after end of expression.");
1183 /* Stuff for maintaining a stack of types. Currently just used by C, but
1184 probably useful for any language which declares its types "backwards". */
1187 check_type_stack_depth (void)
1189 if (type_stack_depth == type_stack_size)
1191 type_stack_size *= 2;
1192 type_stack = (union type_stack_elt *)
1193 xrealloc ((char *) type_stack, type_stack_size * sizeof (*type_stack));
1198 push_type (enum type_pieces tp)
1200 check_type_stack_depth ();
1201 type_stack[type_stack_depth++].piece = tp;
1205 push_type_int (int n)
1207 check_type_stack_depth ();
1208 type_stack[type_stack_depth++].int_val = n;
1212 push_type_address_space (char *string)
1214 push_type_int (address_space_name_to_int (string));
1220 if (type_stack_depth)
1221 return type_stack[--type_stack_depth].piece;
1228 if (type_stack_depth)
1229 return type_stack[--type_stack_depth].int_val;
1230 /* "Can't happen". */
1234 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1235 as modified by all the stuff on the stack. */
1237 follow_types (struct type *follow_type)
1241 int make_volatile = 0;
1242 int make_addr_space = 0;
1244 struct type *range_type;
1247 switch (pop_type ())
1252 follow_type = make_cv_type (make_const,
1253 TYPE_VOLATILE (follow_type),
1256 follow_type = make_cv_type (TYPE_CONST (follow_type),
1259 if (make_addr_space)
1260 follow_type = make_type_with_address_space (follow_type,
1262 make_const = make_volatile = 0;
1263 make_addr_space = 0;
1271 case tp_space_identifier:
1272 make_addr_space = pop_type_int ();
1275 follow_type = lookup_pointer_type (follow_type);
1277 follow_type = make_cv_type (make_const,
1278 TYPE_VOLATILE (follow_type),
1281 follow_type = make_cv_type (TYPE_CONST (follow_type),
1284 if (make_addr_space)
1285 follow_type = make_type_with_address_space (follow_type,
1287 make_const = make_volatile = 0;
1288 make_addr_space = 0;
1291 follow_type = lookup_reference_type (follow_type);
1293 follow_type = make_cv_type (make_const,
1294 TYPE_VOLATILE (follow_type),
1297 follow_type = make_cv_type (TYPE_CONST (follow_type),
1300 if (make_addr_space)
1301 follow_type = make_type_with_address_space (follow_type,
1303 make_const = make_volatile = 0;
1304 make_addr_space = 0;
1307 array_size = pop_type_int ();
1308 /* FIXME-type-allocation: need a way to free this type when we are
1311 create_range_type ((struct type *) NULL,
1312 builtin_type_int, 0,
1313 array_size >= 0 ? array_size - 1 : 0);
1315 create_array_type ((struct type *) NULL,
1316 follow_type, range_type);
1318 TYPE_ARRAY_UPPER_BOUND_TYPE (follow_type)
1319 = BOUND_CANNOT_BE_DETERMINED;
1322 /* FIXME-type-allocation: need a way to free this type when we are
1324 follow_type = lookup_function_type (follow_type);
1330 static void build_parse (void);
1336 msym_text_symbol_type =
1337 init_type (TYPE_CODE_FUNC, 1, 0, "<text variable, no debug info>", NULL);
1338 TYPE_TARGET_TYPE (msym_text_symbol_type) = builtin_type_int;
1339 msym_data_symbol_type =
1340 init_type (TYPE_CODE_INT, TARGET_INT_BIT / HOST_CHAR_BIT, 0,
1341 "<data variable, no debug info>", NULL);
1342 msym_unknown_symbol_type =
1343 init_type (TYPE_CODE_INT, 1, 0,
1344 "<variable (not text or data), no debug info>",
1348 /* This function avoids direct calls to fprintf
1349 in the parser generated debug code. */
1351 parser_fprintf (FILE *x, const char *y, ...)
1356 vfprintf_unfiltered (gdb_stderr, y, args);
1359 fprintf_unfiltered (gdb_stderr, " Unknown FILE used.\n");
1360 vfprintf_unfiltered (gdb_stderr, y, args);
1366 _initialize_parse (void)
1368 type_stack_size = 80;
1369 type_stack_depth = 0;
1370 type_stack = (union type_stack_elt *)
1371 xmalloc (type_stack_size * sizeof (*type_stack));
1375 /* FIXME - For the moment, handle types by swapping them in and out.
1376 Should be using the per-architecture data-pointer and a large
1378 register_gdbarch_swap (&msym_text_symbol_type, sizeof (msym_text_symbol_type), NULL);
1379 register_gdbarch_swap (&msym_data_symbol_type, sizeof (msym_data_symbol_type), NULL);
1380 register_gdbarch_swap (&msym_unknown_symbol_type, sizeof (msym_unknown_symbol_type), NULL);
1382 register_gdbarch_swap (NULL, 0, build_parse);
1385 add_set_cmd ("expression", class_maintenance, var_zinteger,
1386 (char *) &expressiondebug,
1387 "Set expression debugging.\n\
1388 When non-zero, the internal representation of expressions will be printed.",