| /* Parse expressions for GDB. |
| |
| Copyright (C) 1986, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, |
| 1998, 1999, 2000, 2001, 2004, 2005, 2007, 2008 |
| Free Software Foundation, Inc. |
| |
| Modified from expread.y by the Department of Computer Science at the |
| State University of New York at Buffalo, 1991. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| /* Parse an expression from text in a string, |
| and return the result as a struct expression pointer. |
| That structure contains arithmetic operations in reverse polish, |
| with constants represented by operations that are followed by special data. |
| See expression.h for the details of the format. |
| What is important here is that it can be built up sequentially |
| during the process of parsing; the lower levels of the tree always |
| come first in the result. */ |
| |
| #include <ctype.h> |
| |
| #include "defs.h" |
| #include "gdb_string.h" |
| #include "symtab.h" |
| #include "gdbtypes.h" |
| #include "frame.h" |
| #include "expression.h" |
| #include "value.h" |
| #include "command.h" |
| #include "language.h" |
| #include "f-lang.h" |
| #include "parser-defs.h" |
| #include "gdbcmd.h" |
| #include "symfile.h" /* for overlay functions */ |
| #include "inferior.h" |
| #include "doublest.h" |
| #include "gdb_assert.h" |
| #include "block.h" |
| #include "source.h" |
| #include "objfiles.h" |
| |
| /* Standard set of definitions for printing, dumping, prefixifying, |
| * and evaluating expressions. */ |
| |
| const struct exp_descriptor exp_descriptor_standard = |
| { |
| print_subexp_standard, |
| operator_length_standard, |
| op_name_standard, |
| dump_subexp_body_standard, |
| evaluate_subexp_standard |
| }; |
| |
| /* Global variables declared in parser-defs.h (and commented there). */ |
| struct expression *expout; |
| int expout_size; |
| int expout_ptr; |
| struct block *expression_context_block; |
| CORE_ADDR expression_context_pc; |
| struct block *innermost_block; |
| int arglist_len; |
| union type_stack_elt *type_stack; |
| int type_stack_depth, type_stack_size; |
| char *lexptr; |
| char *prev_lexptr; |
| int paren_depth; |
| int comma_terminates; |
| |
| /* A temporary buffer for identifiers, so we can null-terminate them. |
| |
| We allocate this with xrealloc. parse_exp_1 used to allocate with |
| alloca, using the size of the whole expression as a conservative |
| estimate of the space needed. However, macro expansion can |
| introduce names longer than the original expression; there's no |
| practical way to know beforehand how large that might be. */ |
| char *namecopy; |
| size_t namecopy_size; |
| |
| static int expressiondebug = 0; |
| static void |
| show_expressiondebug (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, _("Expression debugging is %s.\n"), value); |
| } |
| |
| static void free_funcalls (void *ignore); |
| |
| static void prefixify_expression (struct expression *); |
| |
| static void prefixify_subexp (struct expression *, struct expression *, int, |
| int); |
| |
| static struct expression *parse_exp_in_context (char **, struct block *, int, |
| int); |
| |
| void _initialize_parse (void); |
| |
| /* Data structure for saving values of arglist_len for function calls whose |
| arguments contain other function calls. */ |
| |
| struct funcall |
| { |
| struct funcall *next; |
| int arglist_len; |
| }; |
| |
| static struct funcall *funcall_chain; |
| |
| /* Begin counting arguments for a function call, |
| saving the data about any containing call. */ |
| |
| void |
| start_arglist (void) |
| { |
| struct funcall *new; |
| |
| new = (struct funcall *) xmalloc (sizeof (struct funcall)); |
| new->next = funcall_chain; |
| new->arglist_len = arglist_len; |
| arglist_len = 0; |
| funcall_chain = new; |
| } |
| |
| /* Return the number of arguments in a function call just terminated, |
| and restore the data for the containing function call. */ |
| |
| int |
| end_arglist (void) |
| { |
| int val = arglist_len; |
| struct funcall *call = funcall_chain; |
| funcall_chain = call->next; |
| arglist_len = call->arglist_len; |
| xfree (call); |
| return val; |
| } |
| |
| /* Free everything in the funcall chain. |
| Used when there is an error inside parsing. */ |
| |
| static void |
| free_funcalls (void *ignore) |
| { |
| struct funcall *call, *next; |
| |
| for (call = funcall_chain; call; call = next) |
| { |
| next = call->next; |
| xfree (call); |
| } |
| } |
| |
| /* This page contains the functions for adding data to the struct expression |
| being constructed. */ |
| |
| /* Add one element to the end of the expression. */ |
| |
| /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into |
| a register through here */ |
| |
| void |
| write_exp_elt (union exp_element expelt) |
| { |
| if (expout_ptr >= expout_size) |
| { |
| expout_size *= 2; |
| expout = (struct expression *) |
| xrealloc ((char *) expout, sizeof (struct expression) |
| + EXP_ELEM_TO_BYTES (expout_size)); |
| } |
| expout->elts[expout_ptr++] = expelt; |
| } |
| |
| void |
| write_exp_elt_opcode (enum exp_opcode expelt) |
| { |
| union exp_element tmp; |
| memset (&tmp, 0, sizeof (union exp_element)); |
| |
| tmp.opcode = expelt; |
| |
| write_exp_elt (tmp); |
| } |
| |
| void |
| write_exp_elt_sym (struct symbol *expelt) |
| { |
| union exp_element tmp; |
| memset (&tmp, 0, sizeof (union exp_element)); |
| |
| tmp.symbol = expelt; |
| |
| write_exp_elt (tmp); |
| } |
| |
| void |
| write_exp_elt_block (struct block *b) |
| { |
| union exp_element tmp; |
| memset (&tmp, 0, sizeof (union exp_element)); |
| tmp.block = b; |
| write_exp_elt (tmp); |
| } |
| |
| void |
| write_exp_elt_objfile (struct objfile *objfile) |
| { |
| union exp_element tmp; |
| memset (&tmp, 0, sizeof (union exp_element)); |
| tmp.objfile = objfile; |
| write_exp_elt (tmp); |
| } |
| |
| void |
| write_exp_elt_longcst (LONGEST expelt) |
| { |
| union exp_element tmp; |
| memset (&tmp, 0, sizeof (union exp_element)); |
| |
| tmp.longconst = expelt; |
| |
| write_exp_elt (tmp); |
| } |
| |
| void |
| write_exp_elt_dblcst (DOUBLEST expelt) |
| { |
| union exp_element tmp; |
| memset (&tmp, 0, sizeof (union exp_element)); |
| |
| tmp.doubleconst = expelt; |
| |
| write_exp_elt (tmp); |
| } |
| |
| void |
| write_exp_elt_decfloatcst (gdb_byte expelt[16]) |
| { |
| union exp_element tmp; |
| int index; |
| |
| for (index = 0; index < 16; index++) |
| tmp.decfloatconst[index] = expelt[index]; |
| |
| write_exp_elt (tmp); |
| } |
| |
| void |
| write_exp_elt_type (struct type *expelt) |
| { |
| union exp_element tmp; |
| memset (&tmp, 0, sizeof (union exp_element)); |
| |
| tmp.type = expelt; |
| |
| write_exp_elt (tmp); |
| } |
| |
| void |
| write_exp_elt_intern (struct internalvar *expelt) |
| { |
| union exp_element tmp; |
| memset (&tmp, 0, sizeof (union exp_element)); |
| |
| tmp.internalvar = expelt; |
| |
| write_exp_elt (tmp); |
| } |
| |
| /* Add a string constant to the end of the expression. |
| |
| String constants are stored by first writing an expression element |
| that contains the length of the string, then stuffing the string |
| constant itself into however many expression elements are needed |
| to hold it, and then writing another expression element that contains |
| the length of the string. I.E. an expression element at each end of |
| the string records the string length, so you can skip over the |
| expression elements containing the actual string bytes from either |
| end of the string. Note that this also allows gdb to handle |
| strings with embedded null bytes, as is required for some languages. |
| |
| Don't be fooled by the fact that the string is null byte terminated, |
| this is strictly for the convenience of debugging gdb itself. Gdb |
| Gdb does not depend up the string being null terminated, since the |
| actual length is recorded in expression elements at each end of the |
| string. The null byte is taken into consideration when computing how |
| many expression elements are required to hold the string constant, of |
| course. */ |
| |
| |
| void |
| write_exp_string (struct stoken str) |
| { |
| int len = str.length; |
| int lenelt; |
| char *strdata; |
| |
| /* Compute the number of expression elements required to hold the string |
| (including a null byte terminator), along with one expression element |
| at each end to record the actual string length (not including the |
| null byte terminator). */ |
| |
| lenelt = 2 + BYTES_TO_EXP_ELEM (len + 1); |
| |
| /* Ensure that we have enough available expression elements to store |
| everything. */ |
| |
| if ((expout_ptr + lenelt) >= expout_size) |
| { |
| expout_size = max (expout_size * 2, expout_ptr + lenelt + 10); |
| expout = (struct expression *) |
| xrealloc ((char *) expout, (sizeof (struct expression) |
| + EXP_ELEM_TO_BYTES (expout_size))); |
| } |
| |
| /* Write the leading length expression element (which advances the current |
| expression element index), then write the string constant followed by a |
| terminating null byte, and then write the trailing length expression |
| element. */ |
| |
| write_exp_elt_longcst ((LONGEST) len); |
| strdata = (char *) &expout->elts[expout_ptr]; |
| memcpy (strdata, str.ptr, len); |
| *(strdata + len) = '\0'; |
| expout_ptr += lenelt - 2; |
| write_exp_elt_longcst ((LONGEST) len); |
| } |
| |
| /* Add a bitstring constant to the end of the expression. |
| |
| Bitstring constants are stored by first writing an expression element |
| that contains the length of the bitstring (in bits), then stuffing the |
| bitstring constant itself into however many expression elements are |
| needed to hold it, and then writing another expression element that |
| contains the length of the bitstring. I.E. an expression element at |
| each end of the bitstring records the bitstring length, so you can skip |
| over the expression elements containing the actual bitstring bytes from |
| either end of the bitstring. */ |
| |
| void |
| write_exp_bitstring (struct stoken str) |
| { |
| int bits = str.length; /* length in bits */ |
| int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT; |
| int lenelt; |
| char *strdata; |
| |
| /* Compute the number of expression elements required to hold the bitstring, |
| along with one expression element at each end to record the actual |
| bitstring length in bits. */ |
| |
| lenelt = 2 + BYTES_TO_EXP_ELEM (len); |
| |
| /* Ensure that we have enough available expression elements to store |
| everything. */ |
| |
| if ((expout_ptr + lenelt) >= expout_size) |
| { |
| expout_size = max (expout_size * 2, expout_ptr + lenelt + 10); |
| expout = (struct expression *) |
| xrealloc ((char *) expout, (sizeof (struct expression) |
| + EXP_ELEM_TO_BYTES (expout_size))); |
| } |
| |
| /* Write the leading length expression element (which advances the current |
| expression element index), then write the bitstring constant, and then |
| write the trailing length expression element. */ |
| |
| write_exp_elt_longcst ((LONGEST) bits); |
| strdata = (char *) &expout->elts[expout_ptr]; |
| memcpy (strdata, str.ptr, len); |
| expout_ptr += lenelt - 2; |
| write_exp_elt_longcst ((LONGEST) bits); |
| } |
| |
| /* Add the appropriate elements for a minimal symbol to the end of |
| the expression. The rationale behind passing in text_symbol_type and |
| data_symbol_type was so that Modula-2 could pass in WORD for |
| data_symbol_type. Perhaps it still is useful to have those types vary |
| based on the language, but they no longer have names like "int", so |
| the initial rationale is gone. */ |
| |
| void |
| write_exp_msymbol (struct minimal_symbol *msymbol, |
| struct type *text_symbol_type, |
| struct type *data_symbol_type) |
| { |
| struct gdbarch *gdbarch = current_gdbarch; |
| CORE_ADDR addr; |
| |
| write_exp_elt_opcode (OP_LONG); |
| /* Let's make the type big enough to hold a 64-bit address. */ |
| write_exp_elt_type (builtin_type_CORE_ADDR); |
| |
| addr = SYMBOL_VALUE_ADDRESS (msymbol); |
| if (overlay_debugging) |
| addr = symbol_overlayed_address (addr, SYMBOL_BFD_SECTION (msymbol)); |
| write_exp_elt_longcst ((LONGEST) addr); |
| |
| write_exp_elt_opcode (OP_LONG); |
| |
| if (SYMBOL_BFD_SECTION (msymbol) |
| && SYMBOL_BFD_SECTION (msymbol)->flags & SEC_THREAD_LOCAL) |
| { |
| bfd *bfd = SYMBOL_BFD_SECTION (msymbol)->owner; |
| struct objfile *ofp; |
| |
| ALL_OBJFILES (ofp) |
| if (ofp->obfd == bfd) |
| break; |
| |
| write_exp_elt_opcode (UNOP_MEMVAL_TLS); |
| write_exp_elt_objfile (ofp); |
| write_exp_elt_type (builtin_type (gdbarch)->nodebug_tls_symbol); |
| write_exp_elt_opcode (UNOP_MEMVAL_TLS); |
| return; |
| } |
| |
| write_exp_elt_opcode (UNOP_MEMVAL); |
| switch (msymbol->type) |
| { |
| case mst_text: |
| case mst_file_text: |
| case mst_solib_trampoline: |
| write_exp_elt_type (builtin_type (gdbarch)->nodebug_text_symbol); |
| break; |
| |
| case mst_data: |
| case mst_file_data: |
| case mst_bss: |
| case mst_file_bss: |
| write_exp_elt_type (builtin_type (gdbarch)->nodebug_data_symbol); |
| break; |
| |
| default: |
| write_exp_elt_type (builtin_type (gdbarch)->nodebug_unknown_symbol); |
| break; |
| } |
| write_exp_elt_opcode (UNOP_MEMVAL); |
| } |
| |
| /* Recognize tokens that start with '$'. These include: |
| |
| $regname A native register name or a "standard |
| register name". |
| |
| $variable A convenience variable with a name chosen |
| by the user. |
| |
| $digits Value history with index <digits>, starting |
| from the first value which has index 1. |
| |
| $$digits Value history with index <digits> relative |
| to the last value. I.E. $$0 is the last |
| value, $$1 is the one previous to that, $$2 |
| is the one previous to $$1, etc. |
| |
| $ | $0 | $$0 The last value in the value history. |
| |
| $$ An abbreviation for the second to the last |
| value in the value history, I.E. $$1 |
| |
| */ |
| |
| void |
| write_dollar_variable (struct stoken str) |
| { |
| struct symbol *sym = NULL; |
| struct minimal_symbol *msym = NULL; |
| struct internalvar *isym = NULL; |
| |
| /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1) |
| and $$digits (equivalent to $<-digits> if you could type that). */ |
| |
| int negate = 0; |
| int i = 1; |
| /* Double dollar means negate the number and add -1 as well. |
| Thus $$ alone means -1. */ |
| if (str.length >= 2 && str.ptr[1] == '$') |
| { |
| negate = 1; |
| i = 2; |
| } |
| if (i == str.length) |
| { |
| /* Just dollars (one or two) */ |
| i = -negate; |
| goto handle_last; |
| } |
| /* Is the rest of the token digits? */ |
| for (; i < str.length; i++) |
| if (!(str.ptr[i] >= '0' && str.ptr[i] <= '9')) |
| break; |
| if (i == str.length) |
| { |
| i = atoi (str.ptr + 1 + negate); |
| if (negate) |
| i = -i; |
| goto handle_last; |
| } |
| |
| /* Handle tokens that refer to machine registers: |
| $ followed by a register name. */ |
| i = frame_map_name_to_regnum (deprecated_safe_get_selected_frame (), |
| str.ptr + 1, str.length - 1); |
| if (i >= 0) |
| goto handle_register; |
| |
| /* Any names starting with $ are probably debugger internal variables. */ |
| |
| isym = lookup_only_internalvar (copy_name (str) + 1); |
| if (isym) |
| { |
| write_exp_elt_opcode (OP_INTERNALVAR); |
| write_exp_elt_intern (isym); |
| write_exp_elt_opcode (OP_INTERNALVAR); |
| return; |
| } |
| |
| /* On some systems, such as HP-UX and hppa-linux, certain system routines |
| have names beginning with $ or $$. Check for those, first. */ |
| |
| sym = lookup_symbol (copy_name (str), (struct block *) NULL, |
| VAR_DOMAIN, (int *) NULL, (struct symtab **) NULL); |
| if (sym) |
| { |
| write_exp_elt_opcode (OP_VAR_VALUE); |
| write_exp_elt_block (block_found); /* set by lookup_symbol */ |
| write_exp_elt_sym (sym); |
| write_exp_elt_opcode (OP_VAR_VALUE); |
| return; |
| } |
| msym = lookup_minimal_symbol (copy_name (str), NULL, NULL); |
| if (msym) |
| { |
| write_exp_msymbol (msym, |
| lookup_function_type (builtin_type_int), |
| builtin_type_int); |
| return; |
| } |
| |
| /* Any other names are assumed to be debugger internal variables. */ |
| |
| write_exp_elt_opcode (OP_INTERNALVAR); |
| write_exp_elt_intern (create_internalvar (copy_name (str) + 1)); |
| write_exp_elt_opcode (OP_INTERNALVAR); |
| return; |
| handle_last: |
| write_exp_elt_opcode (OP_LAST); |
| write_exp_elt_longcst ((LONGEST) i); |
| write_exp_elt_opcode (OP_LAST); |
| return; |
| handle_register: |
| write_exp_elt_opcode (OP_REGISTER); |
| str.length--; |
| str.ptr++; |
| write_exp_string (str); |
| write_exp_elt_opcode (OP_REGISTER); |
| return; |
| } |
| |
| |
| char * |
| find_template_name_end (char *p) |
| { |
| int depth = 1; |
| int just_seen_right = 0; |
| int just_seen_colon = 0; |
| int just_seen_space = 0; |
| |
| if (!p || (*p != '<')) |
| return 0; |
| |
| while (*++p) |
| { |
| switch (*p) |
| { |
| case '\'': |
| case '\"': |
| case '{': |
| case '}': |
| /* In future, may want to allow these?? */ |
| return 0; |
| case '<': |
| depth++; /* start nested template */ |
| if (just_seen_colon || just_seen_right || just_seen_space) |
| return 0; /* but not after : or :: or > or space */ |
| break; |
| case '>': |
| if (just_seen_colon || just_seen_right) |
| return 0; /* end a (nested?) template */ |
| just_seen_right = 1; /* but not after : or :: */ |
| if (--depth == 0) /* also disallow >>, insist on > > */ |
| return ++p; /* if outermost ended, return */ |
| break; |
| case ':': |
| if (just_seen_space || (just_seen_colon > 1)) |
| return 0; /* nested class spec coming up */ |
| just_seen_colon++; /* we allow :: but not :::: */ |
| break; |
| case ' ': |
| break; |
| default: |
| if (!((*p >= 'a' && *p <= 'z') || /* allow token chars */ |
| (*p >= 'A' && *p <= 'Z') || |
| (*p >= '0' && *p <= '9') || |
| (*p == '_') || (*p == ',') || /* commas for template args */ |
| (*p == '&') || (*p == '*') || /* pointer and ref types */ |
| (*p == '(') || (*p == ')') || /* function types */ |
| (*p == '[') || (*p == ']'))) /* array types */ |
| return 0; |
| } |
| if (*p != ' ') |
| just_seen_space = 0; |
| if (*p != ':') |
| just_seen_colon = 0; |
| if (*p != '>') |
| just_seen_right = 0; |
| } |
| return 0; |
| } |
| |
| |
| |
| /* Return a null-terminated temporary copy of the name |
| of a string token. */ |
| |
| char * |
| copy_name (struct stoken token) |
| { |
| /* Make sure there's enough space for the token. */ |
| if (namecopy_size < token.length + 1) |
| { |
| namecopy_size = token.length + 1; |
| namecopy = xrealloc (namecopy, token.length + 1); |
| } |
| |
| memcpy (namecopy, token.ptr, token.length); |
| namecopy[token.length] = 0; |
| |
| return namecopy; |
| } |
| |
| /* Reverse an expression from suffix form (in which it is constructed) |
| to prefix form (in which we can conveniently print or execute it). */ |
| |
| static void |
| prefixify_expression (struct expression *expr) |
| { |
| int len = sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts); |
| struct expression *temp; |
| int inpos = expr->nelts, outpos = 0; |
| |
| temp = (struct expression *) alloca (len); |
| |
| /* Copy the original expression into temp. */ |
| memcpy (temp, expr, len); |
| |
| prefixify_subexp (temp, expr, inpos, outpos); |
| } |
| |
| /* Return the number of exp_elements in the postfix subexpression |
| of EXPR whose operator is at index ENDPOS - 1 in EXPR. */ |
| |
| int |
| length_of_subexp (struct expression *expr, int endpos) |
| { |
| int oplen, args, i; |
| |
| operator_length (expr, endpos, &oplen, &args); |
| |
| while (args > 0) |
| { |
| oplen += length_of_subexp (expr, endpos - oplen); |
| args--; |
| } |
| |
| return oplen; |
| } |
| |
| /* Sets *OPLENP to the length of the operator whose (last) index is |
| ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that |
| operator takes. */ |
| |
| void |
| operator_length (struct expression *expr, int endpos, int *oplenp, int *argsp) |
| { |
| expr->language_defn->la_exp_desc->operator_length (expr, endpos, |
| oplenp, argsp); |
| } |
| |
| /* Default value for operator_length in exp_descriptor vectors. */ |
| |
| void |
| operator_length_standard (struct expression *expr, int endpos, |
| int *oplenp, int *argsp) |
| { |
| int oplen = 1; |
| int args = 0; |
| enum f90_range_type range_type; |
| int i; |
| |
| if (endpos < 1) |
| error (_("?error in operator_length_standard")); |
| |
| i = (int) expr->elts[endpos - 1].opcode; |
| |
| switch (i) |
| { |
| /* C++ */ |
| case OP_SCOPE: |
| oplen = longest_to_int (expr->elts[endpos - 2].longconst); |
| oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1); |
| break; |
| |
| case OP_LONG: |
| case OP_DOUBLE: |
| case OP_DECFLOAT: |
| case OP_VAR_VALUE: |
| oplen = 4; |
| break; |
| |
| case OP_TYPE: |
| case OP_BOOL: |
| case OP_LAST: |
| case OP_INTERNALVAR: |
| oplen = 3; |
| break; |
| |
| case OP_COMPLEX: |
| oplen = 1; |
| args = 2; |
| break; |
| |
| case OP_FUNCALL: |
| case OP_F77_UNDETERMINED_ARGLIST: |
| oplen = 3; |
| args = 1 + longest_to_int (expr->elts[endpos - 2].longconst); |
| break; |
| |
| case OP_OBJC_MSGCALL: /* Objective C message (method) call */ |
| oplen = 4; |
| args = 1 + longest_to_int (expr->elts[endpos - 2].longconst); |
| break; |
| |
| case UNOP_MAX: |
| case UNOP_MIN: |
| oplen = 3; |
| break; |
| |
| case BINOP_VAL: |
| case UNOP_CAST: |
| case UNOP_MEMVAL: |
| oplen = 3; |
| args = 1; |
| break; |
| |
| case UNOP_MEMVAL_TLS: |
| oplen = 4; |
| args = 1; |
| break; |
| |
| case UNOP_ABS: |
| case UNOP_CAP: |
| case UNOP_CHR: |
| case UNOP_FLOAT: |
| case UNOP_HIGH: |
| case UNOP_ODD: |
| case UNOP_ORD: |
| case UNOP_TRUNC: |
| oplen = 1; |
| args = 1; |
| break; |
| |
| case OP_LABELED: |
| case STRUCTOP_STRUCT: |
| case STRUCTOP_PTR: |
| args = 1; |
| /* fall through */ |
| case OP_REGISTER: |
| case OP_M2_STRING: |
| case OP_STRING: |
| case OP_OBJC_NSSTRING: /* Objective C Foundation Class NSString constant */ |
| case OP_OBJC_SELECTOR: /* Objective C "@selector" pseudo-op */ |
| case OP_NAME: |
| oplen = longest_to_int (expr->elts[endpos - 2].longconst); |
| oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1); |
| break; |
| |
| case OP_BITSTRING: |
| oplen = longest_to_int (expr->elts[endpos - 2].longconst); |
| oplen = (oplen + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT; |
| oplen = 4 + BYTES_TO_EXP_ELEM (oplen); |
| break; |
| |
| case OP_ARRAY: |
| oplen = 4; |
| args = longest_to_int (expr->elts[endpos - 2].longconst); |
| args -= longest_to_int (expr->elts[endpos - 3].longconst); |
| args += 1; |
| break; |
| |
| case TERNOP_COND: |
| case TERNOP_SLICE: |
| case TERNOP_SLICE_COUNT: |
| args = 3; |
| break; |
| |
| /* Modula-2 */ |
| case MULTI_SUBSCRIPT: |
| oplen = 3; |
| args = 1 + longest_to_int (expr->elts[endpos - 2].longconst); |
| break; |
| |
| case BINOP_ASSIGN_MODIFY: |
| oplen = 3; |
| args = 2; |
| break; |
| |
| /* C++ */ |
| case OP_THIS: |
| case OP_OBJC_SELF: |
| oplen = 2; |
| break; |
| |
| case OP_F90_RANGE: |
| oplen = 3; |
| |
| range_type = longest_to_int (expr->elts[endpos - 2].longconst); |
| switch (range_type) |
| { |
| case LOW_BOUND_DEFAULT: |
| case HIGH_BOUND_DEFAULT: |
| args = 1; |
| break; |
| case BOTH_BOUND_DEFAULT: |
| args = 0; |
| break; |
| case NONE_BOUND_DEFAULT: |
| args = 2; |
| break; |
| } |
| |
| break; |
| |
| default: |
| args = 1 + (i < (int) BINOP_END); |
| } |
| |
| *oplenp = oplen; |
| *argsp = args; |
| } |
| |
| /* Copy the subexpression ending just before index INEND in INEXPR |
| into OUTEXPR, starting at index OUTBEG. |
| In the process, convert it from suffix to prefix form. */ |
| |
| static void |
| prefixify_subexp (struct expression *inexpr, |
| struct expression *outexpr, int inend, int outbeg) |
| { |
| int oplen; |
| int args; |
| int i; |
| int *arglens; |
| enum exp_opcode opcode; |
| |
| operator_length (inexpr, inend, &oplen, &args); |
| |
| /* Copy the final operator itself, from the end of the input |
| to the beginning of the output. */ |
| inend -= oplen; |
| memcpy (&outexpr->elts[outbeg], &inexpr->elts[inend], |
| EXP_ELEM_TO_BYTES (oplen)); |
| outbeg += oplen; |
| |
| /* Find the lengths of the arg subexpressions. */ |
| arglens = (int *) alloca (args * sizeof (int)); |
| for (i = args - 1; i >= 0; i--) |
| { |
| oplen = length_of_subexp (inexpr, inend); |
| arglens[i] = oplen; |
| inend -= oplen; |
| } |
| |
| /* Now copy each subexpression, preserving the order of |
| the subexpressions, but prefixifying each one. |
| In this loop, inend starts at the beginning of |
| the expression this level is working on |
| and marches forward over the arguments. |
| outbeg does similarly in the output. */ |
| for (i = 0; i < args; i++) |
| { |
| oplen = arglens[i]; |
| inend += oplen; |
| prefixify_subexp (inexpr, outexpr, inend, outbeg); |
| outbeg += oplen; |
| } |
| } |
| |
| /* This page contains the two entry points to this file. */ |
| |
| /* Read an expression from the string *STRINGPTR points to, |
| parse it, and return a pointer to a struct expression that we malloc. |
| Use block BLOCK as the lexical context for variable names; |
| if BLOCK is zero, use the block of the selected stack frame. |
| Meanwhile, advance *STRINGPTR to point after the expression, |
| at the first nonwhite character that is not part of the expression |
| (possibly a null character). |
| |
| If COMMA is nonzero, stop if a comma is reached. */ |
| |
| struct expression * |
| parse_exp_1 (char **stringptr, struct block *block, int comma) |
| { |
| return parse_exp_in_context (stringptr, block, comma, 0); |
| } |
| |
| /* As for parse_exp_1, except that if VOID_CONTEXT_P, then |
| no value is expected from the expression. */ |
| |
| static struct expression * |
| parse_exp_in_context (char **stringptr, struct block *block, int comma, |
| int void_context_p) |
| { |
| struct cleanup *old_chain; |
| |
| lexptr = *stringptr; |
| prev_lexptr = NULL; |
| |
| paren_depth = 0; |
| type_stack_depth = 0; |
| |
| comma_terminates = comma; |
| |
| if (lexptr == 0 || *lexptr == 0) |
| error_no_arg (_("expression to compute")); |
| |
| old_chain = make_cleanup (free_funcalls, 0 /*ignore*/); |
| funcall_chain = 0; |
| |
| /* If no context specified, try using the current frame, if any. */ |
| |
| if (!block) |
| block = get_selected_block (&expression_context_pc); |
| |
| /* Fall back to using the current source static context, if any. */ |
| |
| if (!block) |
| { |
| struct symtab_and_line cursal = get_current_source_symtab_and_line (); |
| if (cursal.symtab) |
| block = BLOCKVECTOR_BLOCK (BLOCKVECTOR (cursal.symtab), STATIC_BLOCK); |
| } |
| |
| /* Save the context, if specified by caller, or found above. */ |
| |
| if (block) |
| { |
| expression_context_block = block; |
| expression_context_pc = BLOCK_START (block); |
| } |
| |
| expout_size = 10; |
| expout_ptr = 0; |
| expout = (struct expression *) |
| xmalloc (sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_size)); |
| expout->language_defn = current_language; |
| make_cleanup (free_current_contents, &expout); |
| |
| if (current_language->la_parser ()) |
| current_language->la_error (NULL); |
| |
| discard_cleanups (old_chain); |
| |
| /* Record the actual number of expression elements, and then |
| reallocate the expression memory so that we free up any |
| excess elements. */ |
| |
| expout->nelts = expout_ptr; |
| expout = (struct expression *) |
| xrealloc ((char *) expout, |
| sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_ptr));; |
| |
| /* Convert expression from postfix form as generated by yacc |
| parser, to a prefix form. */ |
| |
| if (expressiondebug) |
| dump_raw_expression (expout, gdb_stdlog, |
| "before conversion to prefix form"); |
| |
| prefixify_expression (expout); |
| |
| current_language->la_post_parser (&expout, void_context_p); |
| |
| if (expressiondebug) |
| dump_prefix_expression (expout, gdb_stdlog); |
| |
| *stringptr = lexptr; |
| return expout; |
| } |
| |
| /* Parse STRING as an expression, and complain if this fails |
| to use up all of the contents of STRING. */ |
| |
| struct expression * |
| parse_expression (char *string) |
| { |
| struct expression *exp; |
| exp = parse_exp_1 (&string, 0, 0); |
| if (*string) |
| error (_("Junk after end of expression.")); |
| return exp; |
| } |
| |
| /* A post-parser that does nothing */ |
| |
| void |
| null_post_parser (struct expression **exp, int void_context_p) |
| { |
| } |
| |
| /* Stuff for maintaining a stack of types. Currently just used by C, but |
| probably useful for any language which declares its types "backwards". */ |
| |
| static void |
| check_type_stack_depth (void) |
| { |
| if (type_stack_depth == type_stack_size) |
| { |
| type_stack_size *= 2; |
| type_stack = (union type_stack_elt *) |
| xrealloc ((char *) type_stack, type_stack_size * sizeof (*type_stack)); |
| } |
| } |
| |
| void |
| push_type (enum type_pieces tp) |
| { |
| check_type_stack_depth (); |
| type_stack[type_stack_depth++].piece = tp; |
| } |
| |
| void |
| push_type_int (int n) |
| { |
| check_type_stack_depth (); |
| type_stack[type_stack_depth++].int_val = n; |
| } |
| |
| void |
| push_type_address_space (char *string) |
| { |
| push_type_int (address_space_name_to_int (string)); |
| } |
| |
| enum type_pieces |
| pop_type (void) |
| { |
| if (type_stack_depth) |
| return type_stack[--type_stack_depth].piece; |
| return tp_end; |
| } |
| |
| int |
| pop_type_int (void) |
| { |
| if (type_stack_depth) |
| return type_stack[--type_stack_depth].int_val; |
| /* "Can't happen". */ |
| return 0; |
| } |
| |
| /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE |
| as modified by all the stuff on the stack. */ |
| struct type * |
| follow_types (struct type *follow_type) |
| { |
| int done = 0; |
| int make_const = 0; |
| int make_volatile = 0; |
| int make_addr_space = 0; |
| int array_size; |
| struct type *range_type; |
| |
| while (!done) |
| switch (pop_type ()) |
| { |
| case tp_end: |
| done = 1; |
| if (make_const) |
| follow_type = make_cv_type (make_const, |
| TYPE_VOLATILE (follow_type), |
| follow_type, 0); |
| if (make_volatile) |
| follow_type = make_cv_type (TYPE_CONST (follow_type), |
| make_volatile, |
| follow_type, 0); |
| if (make_addr_space) |
| follow_type = make_type_with_address_space (follow_type, |
| make_addr_space); |
| make_const = make_volatile = 0; |
| make_addr_space = 0; |
| break; |
| case tp_const: |
| make_const = 1; |
| break; |
| case tp_volatile: |
| make_volatile = 1; |
| break; |
| case tp_space_identifier: |
| make_addr_space = pop_type_int (); |
| break; |
| case tp_pointer: |
| follow_type = lookup_pointer_type (follow_type); |
| if (make_const) |
| follow_type = make_cv_type (make_const, |
| TYPE_VOLATILE (follow_type), |
| follow_type, 0); |
| if (make_volatile) |
| follow_type = make_cv_type (TYPE_CONST (follow_type), |
| make_volatile, |
| follow_type, 0); |
| if (make_addr_space) |
| follow_type = make_type_with_address_space (follow_type, |
| make_addr_space); |
| make_const = make_volatile = 0; |
| make_addr_space = 0; |
| break; |
| case tp_reference: |
| follow_type = lookup_reference_type (follow_type); |
| if (make_const) |
| follow_type = make_cv_type (make_const, |
| TYPE_VOLATILE (follow_type), |
| follow_type, 0); |
| if (make_volatile) |
| follow_type = make_cv_type (TYPE_CONST (follow_type), |
| make_volatile, |
| follow_type, 0); |
| if (make_addr_space) |
| follow_type = make_type_with_address_space (follow_type, |
| make_addr_space); |
| make_const = make_volatile = 0; |
| make_addr_space = 0; |
| break; |
| case tp_array: |
| array_size = pop_type_int (); |
| /* FIXME-type-allocation: need a way to free this type when we are |
| done with it. */ |
| range_type = |
| create_range_type ((struct type *) NULL, |
| builtin_type_int, 0, |
| array_size >= 0 ? array_size - 1 : 0); |
| follow_type = |
| create_array_type ((struct type *) NULL, |
| follow_type, range_type); |
| if (array_size < 0) |
| TYPE_ARRAY_UPPER_BOUND_TYPE (follow_type) |
| = BOUND_CANNOT_BE_DETERMINED; |
| break; |
| case tp_function: |
| /* FIXME-type-allocation: need a way to free this type when we are |
| done with it. */ |
| follow_type = lookup_function_type (follow_type); |
| break; |
| } |
| return follow_type; |
| } |
| |
| /* This function avoids direct calls to fprintf |
| in the parser generated debug code. */ |
| void |
| parser_fprintf (FILE *x, const char *y, ...) |
| { |
| va_list args; |
| va_start (args, y); |
| if (x == stderr) |
| vfprintf_unfiltered (gdb_stderr, y, args); |
| else |
| { |
| fprintf_unfiltered (gdb_stderr, " Unknown FILE used.\n"); |
| vfprintf_unfiltered (gdb_stderr, y, args); |
| } |
| va_end (args); |
| } |
| |
| void |
| _initialize_parse (void) |
| { |
| type_stack_size = 80; |
| type_stack_depth = 0; |
| type_stack = (union type_stack_elt *) |
| xmalloc (type_stack_size * sizeof (*type_stack)); |
| |
| add_setshow_zinteger_cmd ("expression", class_maintenance, |
| &expressiondebug, _("\ |
| Set expression debugging."), _("\ |
| Show expression debugging."), _("\ |
| When non-zero, the internal representation of expressions will be printed."), |
| NULL, |
| show_expressiondebug, |
| &setdebuglist, &showdebuglist); |
| } |