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Diffstat (limited to 'gdb/parse.c')
| -rw-r--r-- | gdb/parse.c | 1351 |
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diff --git a/gdb/parse.c b/gdb/parse.c new file mode 100644 index 00000000000..af68fbfbcd2 --- /dev/null +++ b/gdb/parse.c @@ -0,0 +1,1351 @@ +/* Parse expressions for GDB. + Copyright (C) 1986, 89, 90, 91, 94, 1998 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 2 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, write to the Free Software +Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +/* 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 "defs.h" +#include "gdb_string.h" +#include <ctype.h> +#include "symtab.h" +#include "gdbtypes.h" +#include "frame.h" +#include "expression.h" +#include "value.h" +#include "command.h" +#include "language.h" +#include "parser-defs.h" +#include "gdbcmd.h" +#include "symfile.h" /* for overlay functions */ + +/* Global variables declared in parser-defs.h (and commented there). */ +struct expression *expout; +int expout_size; +int expout_ptr; +struct block *expression_context_block; +struct block *innermost_block; +int arglist_len; +union type_stack_elt *type_stack; +int type_stack_depth, type_stack_size; +char *lexptr; +char *namecopy; +int paren_depth; +int comma_terminates; + +#ifdef MAINTENANCE_CMDS +static int expressiondebug = 0; +#endif + +extern int hp_som_som_object_present; + +static void +free_funcalls PARAMS ((void)); + +static void +prefixify_expression PARAMS ((struct expression *)); + +static void +prefixify_subexp PARAMS ((struct expression *, struct expression *, int, int)); + +/* 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; + +/* Assign machine-independent names to certain registers + (unless overridden by the REGISTER_NAMES table) */ + +#ifdef NO_STD_REGS +unsigned num_std_regs = 0; +struct std_regs std_regs[1]; +#else +struct std_regs std_regs[] = { + +#ifdef PC_REGNUM + { "pc", PC_REGNUM }, +#endif +#ifdef FP_REGNUM + { "fp", FP_REGNUM }, +#endif +#ifdef SP_REGNUM + { "sp", SP_REGNUM }, +#endif +#ifdef PS_REGNUM + { "ps", PS_REGNUM }, +#endif + +}; + +unsigned num_std_regs = (sizeof std_regs / sizeof std_regs[0]); + +#endif + +/* The generic method for targets to specify how their registers are + named. The mapping can be derived from three sources: + REGISTER_NAME; std_regs; or a target specific alias hook. */ + +int +target_map_name_to_register (str, len) + char *str; + int len; +{ + int i; + + /* First try target specific aliases. We try these first because on some + systems standard names can be context dependent (eg. $pc on a + multiprocessor can be could be any of several PCs). */ +#ifdef REGISTER_NAME_ALIAS_HOOK + i = REGISTER_NAME_ALIAS_HOOK (str, len); + if (i >= 0) + return i; +#endif + + /* Search architectural register name space. */ + for (i = 0; i < NUM_REGS; i++) + if (REGISTER_NAME (i) && len == strlen (REGISTER_NAME (i)) + && STREQN (str, REGISTER_NAME (i), len)) + { + return i; + } + + /* Try standard aliases */ + for (i = 0; i < num_std_regs; i++) + if (std_regs[i].name && len == strlen (std_regs[i].name) + && STREQN (str, std_regs[i].name, len)) + { + return std_regs[i].regnum; + } + + return -1; +} + +/* Begin counting arguments for a function call, + saving the data about any containing call. */ + +void +start_arglist () +{ + register 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 () +{ + register int val = arglist_len; + register struct funcall *call = funcall_chain; + funcall_chain = call->next; + arglist_len = call->arglist_len; + free ((PTR)call); + return val; +} + +/* Free everything in the funcall chain. + Used when there is an error inside parsing. */ + +static void +free_funcalls () +{ + register struct funcall *call, *next; + + for (call = funcall_chain; call; call = next) + { + next = call->next; + free ((PTR)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 (expelt) + 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 (expelt) + enum exp_opcode expelt; +{ + union exp_element tmp; + + tmp.opcode = expelt; + + write_exp_elt (tmp); +} + +void +write_exp_elt_sym (expelt) + struct symbol *expelt; +{ + union exp_element tmp; + + tmp.symbol = expelt; + + write_exp_elt (tmp); +} + +void +write_exp_elt_block (b) + struct block *b; +{ + union exp_element tmp; + tmp.block = b; + write_exp_elt (tmp); +} + +void +write_exp_elt_longcst (expelt) + LONGEST expelt; +{ + union exp_element tmp; + + tmp.longconst = expelt; + + write_exp_elt (tmp); +} + +void +write_exp_elt_dblcst (expelt) + DOUBLEST expelt; +{ + union exp_element tmp; + + tmp.doubleconst = expelt; + + write_exp_elt (tmp); +} + +void +write_exp_elt_type (expelt) + struct type *expelt; +{ + union exp_element tmp; + + tmp.type = expelt; + + write_exp_elt (tmp); +} + +void +write_exp_elt_intern (expelt) + struct internalvar *expelt; +{ + union exp_element tmp; + + 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 (str) + struct stoken str; +{ + register int len = str.length; + register int lenelt; + register 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 (str) + struct stoken str; +{ + register int bits = str.length; /* length in bits */ + register int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT; + register int lenelt; + register 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. */ + +static struct type *msym_text_symbol_type; +static struct type *msym_data_symbol_type; +static struct type *msym_unknown_symbol_type; + +void +write_exp_msymbol (msymbol, text_symbol_type, data_symbol_type) + struct minimal_symbol *msymbol; + struct type *text_symbol_type; + struct type *data_symbol_type; +{ + CORE_ADDR addr; + + write_exp_elt_opcode (OP_LONG); + write_exp_elt_type (lookup_pointer_type (builtin_type_void)); + + 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); + + write_exp_elt_opcode (UNOP_MEMVAL); + switch (msymbol -> type) + { + case mst_text: + case mst_file_text: + case mst_solib_trampoline: + write_exp_elt_type (msym_text_symbol_type); + break; + + case mst_data: + case mst_file_data: + case mst_bss: + case mst_file_bss: + write_exp_elt_type (msym_data_symbol_type); + break; + + default: + write_exp_elt_type (msym_unknown_symbol_type); + 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 (str) + struct stoken str; +{ + /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1) + and $$digits (equivalent to $<-digits> if you could type that). */ + + struct symbol * sym = NULL; + struct minimal_symbol * msym = NULL; + + int negate = 0; + int i = 1; + /* Double dollar means negate the number and add -1 as well. + Thus $$ 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 = target_map_name_to_register( str.ptr + 1, str.length - 1 ); + if( i >= 0 ) + goto handle_register; + + /* On HP-UX, certain system routines (millicode) have names beginning + with $ or $$, e.g. $$dyncall, which handles inter-space procedure + calls on PA-RISC. Check for those, first. */ + + sym = lookup_symbol (copy_name (str), (struct block *) NULL, + VAR_NAMESPACE, (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 starting in $ are debugger internal variables. */ + + write_exp_elt_opcode (OP_INTERNALVAR); + write_exp_elt_intern (lookup_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); + write_exp_elt_longcst (i); + write_exp_elt_opcode (OP_REGISTER); + return; +} + + +/* Parse a string that is possibly a namespace / nested class + specification, i.e., something of the form A::B::C::x. Input + (NAME) is the entire string; LEN is the current valid length; the + output is a string, TOKEN, which points to the largest recognized + prefix which is a series of namespaces or classes. CLASS_PREFIX is + another output, which records whether a nested class spec was + recognized (= 1) or a fully qualified variable name was found (= + 0). ARGPTR is side-effected (if non-NULL) to point to beyond the + string recognized and consumed by this routine. + + The return value is a pointer to the symbol for the base class or + variable if found, or NULL if not found. Callers must check this + first -- if NULL, the outputs may not be correct. + + This function is used c-exp.y. This is used specifically to get + around HP aCC (and possibly other compilers), which insists on + generating names with embedded colons for namespace or nested class + members. + + (Argument LEN is currently unused. 1997-08-27) + + Callers must free memory allocated for the output string TOKEN. */ + +static const char coloncolon[2] = {':',':'}; + +struct symbol * +parse_nested_classes_for_hpacc (name, len, token, class_prefix, argptr) + char * name; + int len; + char ** token; + int * class_prefix; + char ** argptr; +{ + /* Comment below comes from decode_line_1 which has very similar + code, which is called for "break" command parsing. */ + + /* We have what looks like a class or namespace + scope specification (A::B), possibly with many + levels of namespaces or classes (A::B::C::D). + + Some versions of the HP ANSI C++ compiler (as also possibly + other compilers) generate class/function/member names with + embedded double-colons if they are inside namespaces. To + handle this, we loop a few times, considering larger and + larger prefixes of the string as though they were single + symbols. So, if the initially supplied string is + A::B::C::D::foo, we have to look up "A", then "A::B", + then "A::B::C", then "A::B::C::D", and finally + "A::B::C::D::foo" as single, monolithic symbols, because + A, B, C or D may be namespaces. + + Note that namespaces can nest only inside other + namespaces, and not inside classes. So we need only + consider *prefixes* of the string; there is no need to look up + "B::C" separately as a symbol in the previous example. */ + + register char * p; + char * start, * end; + char * prefix = NULL; + char * tmp; + struct symbol * sym_class = NULL; + struct symbol * sym_var = NULL; + struct type * t; + register int i; + int colons_found = 0; + int prefix_len = 0; + int done = 0; + char * q; + + /* Check for HP-compiled executable -- in other cases + return NULL, and caller must default to standard GDB + behaviour. */ + + if (!hp_som_som_object_present) + return (struct symbol *) NULL; + + p = name; + + /* Skip over whitespace and possible global "::" */ + while (*p && (*p == ' ' || *p == '\t')) p++; + if (p[0] == ':' && p[1] == ':') + p += 2; + while (*p && (*p == ' ' || *p == '\t')) p++; + + while (1) + { + /* Get to the end of the next namespace or class spec. */ + /* If we're looking at some non-token, fail immediately */ + start = p; + if (!(isalpha (*p) || *p == '$' || *p == '_')) + return (struct symbol *) NULL; + p++; + while (*p && (isalnum (*p) || *p == '$' || *p == '_')) p++; + + if (*p == '<') + { + /* If we have the start of a template specification, + scan right ahead to its end */ + q = find_template_name_end (p); + if (q) + p = q; + } + + end = p; + + /* Skip over "::" and whitespace for next time around */ + while (*p && (*p == ' ' || *p == '\t')) p++; + if (p[0] == ':' && p[1] == ':') + p += 2; + while (*p && (*p == ' ' || *p == '\t')) p++; + + /* Done with tokens? */ + if (!*p || !(isalpha (*p) || *p == '$' || *p == '_')) + done = 1; + + tmp = (char *) alloca (prefix_len + end - start + 3); + if (prefix) + { + memcpy (tmp, prefix, prefix_len); + memcpy (tmp + prefix_len, coloncolon, 2); + memcpy (tmp + prefix_len + 2, start, end - start); + tmp[prefix_len + 2 + end - start] = '\000'; + } + else + { + memcpy (tmp, start, end - start); + tmp[end - start] = '\000'; + } + + prefix = tmp; + prefix_len = strlen (prefix); + +#if 0 /* DEBUGGING */ + printf ("Searching for nested class spec: Prefix is %s\n", prefix); +#endif + + /* See if the prefix we have now is something we know about */ + + if (!done) + { + /* More tokens to process, so this must be a class/namespace */ + sym_class = lookup_symbol (prefix, 0, STRUCT_NAMESPACE, + 0, (struct symtab **) NULL); + } + else + { + /* No more tokens, so try as a variable first */ + sym_var = lookup_symbol (prefix, 0, VAR_NAMESPACE, + 0, (struct symtab **) NULL); + /* If failed, try as class/namespace */ + if (!sym_var) + sym_class = lookup_symbol (prefix, 0, STRUCT_NAMESPACE, + 0, (struct symtab **) NULL); + } + + if (sym_var || + (sym_class && + (t = check_typedef (SYMBOL_TYPE (sym_class)), + (TYPE_CODE (t) == TYPE_CODE_STRUCT + || TYPE_CODE (t) == TYPE_CODE_UNION)))) + { + /* We found a valid token */ + *token = (char *) xmalloc (prefix_len + 1 ); + memcpy (*token, prefix, prefix_len); + (*token)[prefix_len] = '\000'; + break; + } + + /* No variable or class/namespace found, no more tokens */ + if (done) + return (struct symbol *) NULL; + } + + /* Out of loop, so we must have found a valid token */ + if (sym_var) + *class_prefix = 0; + else + *class_prefix = 1; + + if (argptr) + *argptr = done ? p : end; + +#if 0 /* DEBUGGING */ + printf ("Searching for nested class spec: Token is %s, class_prefix %d\n", *token, *class_prefix); +#endif + + return sym_var ? sym_var : sym_class; /* found */ +} + +char * +find_template_name_end (p) + 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 (token) + struct stoken token; +{ + 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 (expr) + register struct expression *expr; +{ + register int len = + sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts); + register struct expression *temp; + register 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 subexpression of EXPR + whose last exp_element is at index ENDPOS - 1 in EXPR. */ + +int +length_of_subexp (expr, endpos) + register struct expression *expr; + register int endpos; +{ + register int oplen = 1; + register int args = 0; + register int i; + + if (endpos < 1) + error ("?error in length_of_subexp"); + + 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_VAR_VALUE: + oplen = 4; + break; + + case OP_TYPE: + case OP_BOOL: + case OP_LAST: + case OP_REGISTER: + 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 UNOP_MAX: + case UNOP_MIN: + oplen = 3; + break; + + case BINOP_VAL: + case UNOP_CAST: + case UNOP_MEMVAL: + oplen = 3; + 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_M2_STRING: + case OP_STRING: + case OP_NAME: + case OP_EXPRSTRING: + 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: + oplen = 2; + break; + + default: + args = 1 + (i < (int) BINOP_END); + } + + while (args > 0) + { + oplen += length_of_subexp (expr, endpos - oplen); + args--; + } + + return oplen; +} + +/* 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 (inexpr, outexpr, inend, outbeg) + register struct expression *inexpr; + struct expression *outexpr; + register int inend; + int outbeg; +{ + register int oplen = 1; + register int args = 0; + register int i; + int *arglens; + enum exp_opcode opcode; + + /* Compute how long the last operation is (in OPLEN), + and also how many preceding subexpressions serve as + arguments for it (in ARGS). */ + + opcode = inexpr->elts[inend - 1].opcode; + switch (opcode) + { + /* C++ */ + case OP_SCOPE: + oplen = longest_to_int (inexpr->elts[inend - 2].longconst); + oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1); + break; + + case OP_LONG: + case OP_DOUBLE: + case OP_VAR_VALUE: + oplen = 4; + break; + + case OP_TYPE: + case OP_BOOL: + case OP_LAST: + case OP_REGISTER: + 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 (inexpr->elts[inend - 2].longconst); + break; + + case UNOP_MIN: + case UNOP_MAX: + oplen = 3; + break; + + case UNOP_CAST: + case UNOP_MEMVAL: + oplen = 3; + 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 STRUCTOP_STRUCT: + case STRUCTOP_PTR: + case OP_LABELED: + args = 1; + /* fall through */ + case OP_M2_STRING: + case OP_STRING: + case OP_NAME: + case OP_EXPRSTRING: + oplen = longest_to_int (inexpr->elts[inend - 2].longconst); + oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1); + break; + + case OP_BITSTRING: + oplen = longest_to_int (inexpr->elts[inend - 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 (inexpr->elts[inend - 2].longconst); + args -= longest_to_int (inexpr->elts[inend - 3].longconst); + args += 1; + break; + + case TERNOP_COND: + case TERNOP_SLICE: + case TERNOP_SLICE_COUNT: + args = 3; + break; + + case BINOP_ASSIGN_MODIFY: + oplen = 3; + args = 2; + break; + + /* Modula-2 */ + case MULTI_SUBSCRIPT: + oplen = 3; + args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst); + break; + + /* C++ */ + case OP_THIS: + oplen = 2; + break; + + default: + args = 1 + ((int) opcode < (int) BINOP_END); + } + + /* 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 (stringptr, block, comma) + char **stringptr; + struct block *block; + int comma; +{ + struct cleanup *old_chain; + + lexptr = *stringptr; + + 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 ((make_cleanup_func) free_funcalls, 0); + funcall_chain = 0; + + expression_context_block = block ? block : get_selected_block (); + + namecopy = (char *) alloca (strlen (lexptr) + 1); + 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 ((make_cleanup_func) 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. */ + +#ifdef MAINTENANCE_CMDS + if (expressiondebug) + dump_prefix_expression (expout, gdb_stdout, + "before conversion to prefix form"); +#endif /* MAINTENANCE_CMDS */ + + prefixify_expression (expout); + +#ifdef MAINTENANCE_CMDS + if (expressiondebug) + dump_postfix_expression (expout, gdb_stdout, + "after conversion to prefix form"); +#endif /* MAINTENANCE_CMDS */ + + *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 (string) + char *string; +{ + register struct expression *exp; + exp = parse_exp_1 (&string, 0, 0); + if (*string) + error ("Junk after end of expression."); + return exp; +} + +/* Stuff for maintaining a stack of types. Currently just used by C, but + probably useful for any language which declares its types "backwards". */ + +void +push_type (tp) + enum type_pieces tp; +{ + 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)); + } + type_stack[type_stack_depth++].piece = tp; +} + +void +push_type_int (n) + int n; +{ + 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)); + } + type_stack[type_stack_depth++].int_val = n; +} + +enum type_pieces +pop_type () +{ + if (type_stack_depth) + return type_stack[--type_stack_depth].piece; + return tp_end; +} + +int +pop_type_int () +{ + 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 (follow_type) + struct type *follow_type; +{ + int done = 0; + int array_size; + struct type *range_type; + + while (!done) + switch (pop_type ()) + { + case tp_end: + done = 1; + break; + case tp_pointer: + follow_type = lookup_pointer_type (follow_type); + break; + case tp_reference: + follow_type = lookup_reference_type (follow_type); + 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; +} + +void +_initialize_parse () +{ + type_stack_size = 80; + type_stack_depth = 0; + type_stack = (union type_stack_elt *) + xmalloc (type_stack_size * sizeof (*type_stack)); + + msym_text_symbol_type = + init_type (TYPE_CODE_FUNC, 1, 0, "<text variable, no debug info>", NULL); + TYPE_TARGET_TYPE (msym_text_symbol_type) = builtin_type_int; + msym_data_symbol_type = + init_type (TYPE_CODE_INT, TARGET_INT_BIT / HOST_CHAR_BIT, 0, + "<data variable, no debug info>", NULL); + msym_unknown_symbol_type = + init_type (TYPE_CODE_INT, 1, 0, + "<variable (not text or data), no debug info>", + NULL); + +#ifdef MAINTENANCE_CMDS + add_show_from_set ( + add_set_cmd ("expressiondebug", class_maintenance, var_zinteger, + (char *)&expressiondebug, + "Set expression debugging.\n\ +When non-zero, the internal representation of expressions will be printed.", + &setlist), + &showlist); +#endif +} |