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- /* YACC parser for Go expressions, for GDB.
- Copyright (C) 2012-2022 Free Software Foundation, Inc.
- 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/>. */
- /* This file is derived from c-exp.y, p-exp.y. */
- /* Parse a Go 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.
- Note that malloc's and realloc's in this file are transformed to
- xmalloc and xrealloc respectively by the same sed command in the
- makefile that remaps any other malloc/realloc inserted by the parser
- generator. Doing this with #defines and trying to control the interaction
- with include files (<malloc.h> and <stdlib.h> for example) just became
- too messy, particularly when such includes can be inserted at random
- times by the parser generator. */
- /* Known bugs or limitations:
- - Unicode
- - &^
- - '_' (blank identifier)
- - automatic deref of pointers
- - method expressions
- - interfaces, channels, etc.
- And lots of other things.
- I'm sure there's some cleanup to do.
- */
- %{
- #include "defs.h"
- #include <ctype.h>
- #include "expression.h"
- #include "value.h"
- #include "parser-defs.h"
- #include "language.h"
- #include "c-lang.h"
- #include "go-lang.h"
- #include "bfd.h" /* Required by objfiles.h. */
- #include "symfile.h" /* Required by objfiles.h. */
- #include "objfiles.h" /* For have_full_symbols and have_partial_symbols */
- #include "charset.h"
- #include "block.h"
- #include "expop.h"
- #define parse_type(ps) builtin_type (ps->gdbarch ())
- /* Remap normal yacc parser interface names (yyparse, yylex, yyerror,
- etc). */
- #define GDB_YY_REMAP_PREFIX go_
- #include "yy-remap.h"
- /* The state of the parser, used internally when we are parsing the
- expression. */
- static struct parser_state *pstate = NULL;
- int yyparse (void);
- static int yylex (void);
- static void yyerror (const char *);
- %}
- /* Although the yacc "value" of an expression is not used,
- since the result is stored in the structure being created,
- other node types do have values. */
- %union
- {
- LONGEST lval;
- struct {
- LONGEST val;
- struct type *type;
- } typed_val_int;
- struct {
- gdb_byte val[16];
- struct type *type;
- } typed_val_float;
- struct stoken sval;
- struct symtoken ssym;
- struct type *tval;
- struct typed_stoken tsval;
- struct ttype tsym;
- int voidval;
- enum exp_opcode opcode;
- struct internalvar *ivar;
- struct stoken_vector svec;
- }
- %{
- /* YYSTYPE gets defined by %union. */
- static int parse_number (struct parser_state *,
- const char *, int, int, YYSTYPE *);
- using namespace expr;
- %}
- %type <voidval> exp exp1 type_exp start variable lcurly
- %type <lval> rcurly
- %type <tval> type
- %token <typed_val_int> INT
- %token <typed_val_float> FLOAT
- /* Both NAME and TYPENAME tokens represent symbols in the input,
- and both convey their data as strings.
- But a TYPENAME is a string that happens to be defined as a type
- or builtin type name (such as int or char)
- and a NAME is any other symbol.
- Contexts where this distinction is not important can use the
- nonterminal "name", which matches either NAME or TYPENAME. */
- %token <tsval> RAW_STRING
- %token <tsval> STRING
- %token <tsval> CHAR
- %token <ssym> NAME
- %token <tsym> TYPENAME /* Not TYPE_NAME cus already taken. */
- %token <voidval> COMPLETE
- /*%type <sval> name*/
- %type <svec> string_exp
- %type <ssym> name_not_typename
- /* A NAME_OR_INT is a symbol which is not known in the symbol table,
- but which would parse as a valid number in the current input radix.
- E.g. "c" when input_radix==16. Depending on the parse, it will be
- turned into a name or into a number. */
- %token <ssym> NAME_OR_INT
- %token <lval> TRUE_KEYWORD FALSE_KEYWORD
- %token STRUCT_KEYWORD INTERFACE_KEYWORD TYPE_KEYWORD CHAN_KEYWORD
- %token SIZEOF_KEYWORD
- %token LEN_KEYWORD CAP_KEYWORD
- %token NEW_KEYWORD
- %token IOTA_KEYWORD NIL_KEYWORD
- %token CONST_KEYWORD
- %token DOTDOTDOT
- %token ENTRY
- %token ERROR
- /* Special type cases. */
- %token BYTE_KEYWORD /* An alias of uint8. */
- %token <sval> DOLLAR_VARIABLE
- %token <opcode> ASSIGN_MODIFY
- %left ','
- %left ABOVE_COMMA
- %right '=' ASSIGN_MODIFY
- %right '?'
- %left OROR
- %left ANDAND
- %left '|'
- %left '^'
- %left '&'
- %left ANDNOT
- %left EQUAL NOTEQUAL
- %left '<' '>' LEQ GEQ
- %left LSH RSH
- %left '@'
- %left '+' '-'
- %left '*' '/' '%'
- %right UNARY INCREMENT DECREMENT
- %right LEFT_ARROW '.' '[' '('
- %%
- start : exp1
- | type_exp
- ;
- type_exp: type
- { pstate->push_new<type_operation> ($1); }
- ;
- /* Expressions, including the comma operator. */
- exp1 : exp
- | exp1 ',' exp
- { pstate->wrap2<comma_operation> (); }
- ;
- /* Expressions, not including the comma operator. */
- exp : '*' exp %prec UNARY
- { pstate->wrap<unop_ind_operation> (); }
- ;
- exp : '&' exp %prec UNARY
- { pstate->wrap<unop_addr_operation> (); }
- ;
- exp : '-' exp %prec UNARY
- { pstate->wrap<unary_neg_operation> (); }
- ;
- exp : '+' exp %prec UNARY
- { pstate->wrap<unary_plus_operation> (); }
- ;
- exp : '!' exp %prec UNARY
- { pstate->wrap<unary_logical_not_operation> (); }
- ;
- exp : '^' exp %prec UNARY
- { pstate->wrap<unary_complement_operation> (); }
- ;
- exp : exp INCREMENT %prec UNARY
- { pstate->wrap<postinc_operation> (); }
- ;
- exp : exp DECREMENT %prec UNARY
- { pstate->wrap<postdec_operation> (); }
- ;
- /* foo->bar is not in Go. May want as a gdb extension. Later. */
- exp : exp '.' name_not_typename
- {
- pstate->push_new<structop_operation>
- (pstate->pop (), copy_name ($3.stoken));
- }
- ;
- exp : exp '.' name_not_typename COMPLETE
- {
- structop_base_operation *op
- = new structop_operation (pstate->pop (),
- copy_name ($3.stoken));
- pstate->mark_struct_expression (op);
- pstate->push (operation_up (op));
- }
- ;
- exp : exp '.' COMPLETE
- {
- structop_base_operation *op
- = new structop_operation (pstate->pop (), "");
- pstate->mark_struct_expression (op);
- pstate->push (operation_up (op));
- }
- ;
- exp : exp '[' exp1 ']'
- { pstate->wrap2<subscript_operation> (); }
- ;
- exp : exp '('
- /* This is to save the value of arglist_len
- being accumulated by an outer function call. */
- { pstate->start_arglist (); }
- arglist ')' %prec LEFT_ARROW
- {
- std::vector<operation_up> args
- = pstate->pop_vector (pstate->end_arglist ());
- pstate->push_new<funcall_operation>
- (pstate->pop (), std::move (args));
- }
- ;
- lcurly : '{'
- { pstate->start_arglist (); }
- ;
- arglist :
- ;
- arglist : exp
- { pstate->arglist_len = 1; }
- ;
- arglist : arglist ',' exp %prec ABOVE_COMMA
- { pstate->arglist_len++; }
- ;
- rcurly : '}'
- { $$ = pstate->end_arglist () - 1; }
- ;
- exp : lcurly type rcurly exp %prec UNARY
- {
- pstate->push_new<unop_memval_operation>
- (pstate->pop (), $2);
- }
- ;
- exp : type '(' exp ')' %prec UNARY
- {
- pstate->push_new<unop_cast_operation>
- (pstate->pop (), $1);
- }
- ;
- exp : '(' exp1 ')'
- { }
- ;
- /* Binary operators in order of decreasing precedence. */
- exp : exp '@' exp
- { pstate->wrap2<repeat_operation> (); }
- ;
- exp : exp '*' exp
- { pstate->wrap2<mul_operation> (); }
- ;
- exp : exp '/' exp
- { pstate->wrap2<div_operation> (); }
- ;
- exp : exp '%' exp
- { pstate->wrap2<rem_operation> (); }
- ;
- exp : exp '+' exp
- { pstate->wrap2<add_operation> (); }
- ;
- exp : exp '-' exp
- { pstate->wrap2<sub_operation> (); }
- ;
- exp : exp LSH exp
- { pstate->wrap2<lsh_operation> (); }
- ;
- exp : exp RSH exp
- { pstate->wrap2<rsh_operation> (); }
- ;
- exp : exp EQUAL exp
- { pstate->wrap2<equal_operation> (); }
- ;
- exp : exp NOTEQUAL exp
- { pstate->wrap2<notequal_operation> (); }
- ;
- exp : exp LEQ exp
- { pstate->wrap2<leq_operation> (); }
- ;
- exp : exp GEQ exp
- { pstate->wrap2<geq_operation> (); }
- ;
- exp : exp '<' exp
- { pstate->wrap2<less_operation> (); }
- ;
- exp : exp '>' exp
- { pstate->wrap2<gtr_operation> (); }
- ;
- exp : exp '&' exp
- { pstate->wrap2<bitwise_and_operation> (); }
- ;
- exp : exp '^' exp
- { pstate->wrap2<bitwise_xor_operation> (); }
- ;
- exp : exp '|' exp
- { pstate->wrap2<bitwise_ior_operation> (); }
- ;
- exp : exp ANDAND exp
- { pstate->wrap2<logical_and_operation> (); }
- ;
- exp : exp OROR exp
- { pstate->wrap2<logical_or_operation> (); }
- ;
- exp : exp '?' exp ':' exp %prec '?'
- {
- operation_up last = pstate->pop ();
- operation_up mid = pstate->pop ();
- operation_up first = pstate->pop ();
- pstate->push_new<ternop_cond_operation>
- (std::move (first), std::move (mid),
- std::move (last));
- }
- ;
- exp : exp '=' exp
- { pstate->wrap2<assign_operation> (); }
- ;
- exp : exp ASSIGN_MODIFY exp
- {
- operation_up rhs = pstate->pop ();
- operation_up lhs = pstate->pop ();
- pstate->push_new<assign_modify_operation>
- ($2, std::move (lhs), std::move (rhs));
- }
- ;
- exp : INT
- {
- pstate->push_new<long_const_operation>
- ($1.type, $1.val);
- }
- ;
- exp : CHAR
- {
- struct stoken_vector vec;
- vec.len = 1;
- vec.tokens = &$1;
- pstate->push_c_string ($1.type, &vec);
- }
- ;
- exp : NAME_OR_INT
- { YYSTYPE val;
- parse_number (pstate, $1.stoken.ptr,
- $1.stoken.length, 0, &val);
- pstate->push_new<long_const_operation>
- (val.typed_val_int.type,
- val.typed_val_int.val);
- }
- ;
- exp : FLOAT
- {
- float_data data;
- std::copy (std::begin ($1.val), std::end ($1.val),
- std::begin (data));
- pstate->push_new<float_const_operation> ($1.type, data);
- }
- ;
- exp : variable
- ;
- exp : DOLLAR_VARIABLE
- {
- pstate->push_dollar ($1);
- }
- ;
- exp : SIZEOF_KEYWORD '(' type ')' %prec UNARY
- {
- /* TODO(dje): Go objects in structs. */
- /* TODO(dje): What's the right type here? */
- struct type *size_type
- = parse_type (pstate)->builtin_unsigned_int;
- $3 = check_typedef ($3);
- pstate->push_new<long_const_operation>
- (size_type, (LONGEST) TYPE_LENGTH ($3));
- }
- ;
- exp : SIZEOF_KEYWORD '(' exp ')' %prec UNARY
- {
- /* TODO(dje): Go objects in structs. */
- pstate->wrap<unop_sizeof_operation> ();
- }
- string_exp:
- STRING
- {
- /* We copy the string here, and not in the
- lexer, to guarantee that we do not leak a
- string. */
- /* Note that we NUL-terminate here, but just
- for convenience. */
- struct typed_stoken *vec = XNEW (struct typed_stoken);
- $$.len = 1;
- $$.tokens = vec;
- vec->type = $1.type;
- vec->length = $1.length;
- vec->ptr = (char *) malloc ($1.length + 1);
- memcpy (vec->ptr, $1.ptr, $1.length + 1);
- }
- | string_exp '+' STRING
- {
- /* Note that we NUL-terminate here, but just
- for convenience. */
- char *p;
- ++$$.len;
- $$.tokens = XRESIZEVEC (struct typed_stoken,
- $$.tokens, $$.len);
- p = (char *) malloc ($3.length + 1);
- memcpy (p, $3.ptr, $3.length + 1);
- $$.tokens[$$.len - 1].type = $3.type;
- $$.tokens[$$.len - 1].length = $3.length;
- $$.tokens[$$.len - 1].ptr = p;
- }
- ;
- exp : string_exp %prec ABOVE_COMMA
- {
- int i;
- /* Always utf8. */
- pstate->push_c_string (0, &$1);
- for (i = 0; i < $1.len; ++i)
- free ($1.tokens[i].ptr);
- free ($1.tokens);
- }
- ;
- exp : TRUE_KEYWORD
- { pstate->push_new<bool_operation> ($1); }
- ;
- exp : FALSE_KEYWORD
- { pstate->push_new<bool_operation> ($1); }
- ;
- variable: name_not_typename ENTRY
- { struct symbol *sym = $1.sym.symbol;
- if (sym == NULL
- || !sym->is_argument ()
- || !symbol_read_needs_frame (sym))
- error (_("@entry can be used only for function "
- "parameters, not for \"%s\""),
- copy_name ($1.stoken).c_str ());
- pstate->push_new<var_entry_value_operation> (sym);
- }
- ;
- variable: name_not_typename
- { struct block_symbol sym = $1.sym;
- if (sym.symbol)
- {
- if (symbol_read_needs_frame (sym.symbol))
- pstate->block_tracker->update (sym);
- pstate->push_new<var_value_operation> (sym);
- }
- else if ($1.is_a_field_of_this)
- {
- /* TODO(dje): Can we get here?
- E.g., via a mix of c++ and go? */
- gdb_assert_not_reached ("go with `this' field");
- }
- else
- {
- struct bound_minimal_symbol msymbol;
- std::string arg = copy_name ($1.stoken);
- msymbol =
- lookup_bound_minimal_symbol (arg.c_str ());
- if (msymbol.minsym != NULL)
- pstate->push_new<var_msym_value_operation>
- (msymbol);
- else if (!have_full_symbols ()
- && !have_partial_symbols ())
- error (_("No symbol table is loaded. "
- "Use the \"file\" command."));
- else
- error (_("No symbol \"%s\" in current context."),
- arg.c_str ());
- }
- }
- ;
- /* TODO
- method_exp: PACKAGENAME '.' name '.' name
- {
- }
- ;
- */
- type /* Implements (approximately): [*] type-specifier */
- : '*' type
- { $$ = lookup_pointer_type ($2); }
- | TYPENAME
- { $$ = $1.type; }
- /*
- | STRUCT_KEYWORD name
- { $$ = lookup_struct (copy_name ($2),
- expression_context_block); }
- */
- | BYTE_KEYWORD
- { $$ = builtin_go_type (pstate->gdbarch ())
- ->builtin_uint8; }
- ;
- /* TODO
- name : NAME { $$ = $1.stoken; }
- | TYPENAME { $$ = $1.stoken; }
- | NAME_OR_INT { $$ = $1.stoken; }
- ;
- */
- name_not_typename
- : NAME
- /* These would be useful if name_not_typename was useful, but it is just
- a fake for "variable", so these cause reduce/reduce conflicts because
- the parser can't tell whether NAME_OR_INT is a name_not_typename (=variable,
- =exp) or just an exp. If name_not_typename was ever used in an lvalue
- context where only a name could occur, this might be useful.
- | NAME_OR_INT
- */
- ;
- %%
- /* Take care of parsing a number (anything that starts with a digit).
- Set yylval and return the token type; update lexptr.
- LEN is the number of characters in it. */
- /* FIXME: Needs some error checking for the float case. */
- /* FIXME(dje): IWBN to use c-exp.y's parse_number if we could.
- That will require moving the guts into a function that we both call
- as our YYSTYPE is different than c-exp.y's */
- static int
- parse_number (struct parser_state *par_state,
- const char *p, int len, int parsed_float, YYSTYPE *putithere)
- {
- ULONGEST n = 0;
- ULONGEST prevn = 0;
- ULONGEST un;
- int i = 0;
- int c;
- int base = input_radix;
- int unsigned_p = 0;
- /* Number of "L" suffixes encountered. */
- int long_p = 0;
- /* We have found a "L" or "U" suffix. */
- int found_suffix = 0;
- ULONGEST high_bit;
- struct type *signed_type;
- struct type *unsigned_type;
- if (parsed_float)
- {
- const struct builtin_go_type *builtin_go_types
- = builtin_go_type (par_state->gdbarch ());
- /* Handle suffixes: 'f' for float32, 'l' for long double.
- FIXME: This appears to be an extension -- do we want this? */
- if (len >= 1 && tolower (p[len - 1]) == 'f')
- {
- putithere->typed_val_float.type
- = builtin_go_types->builtin_float32;
- len--;
- }
- else if (len >= 1 && tolower (p[len - 1]) == 'l')
- {
- putithere->typed_val_float.type
- = parse_type (par_state)->builtin_long_double;
- len--;
- }
- /* Default type for floating-point literals is float64. */
- else
- {
- putithere->typed_val_float.type
- = builtin_go_types->builtin_float64;
- }
- if (!parse_float (p, len,
- putithere->typed_val_float.type,
- putithere->typed_val_float.val))
- return ERROR;
- return FLOAT;
- }
- /* Handle base-switching prefixes 0x, 0t, 0d, 0. */
- if (p[0] == '0' && len > 1)
- switch (p[1])
- {
- case 'x':
- case 'X':
- if (len >= 3)
- {
- p += 2;
- base = 16;
- len -= 2;
- }
- break;
- case 'b':
- case 'B':
- if (len >= 3)
- {
- p += 2;
- base = 2;
- len -= 2;
- }
- break;
- case 't':
- case 'T':
- case 'd':
- case 'D':
- if (len >= 3)
- {
- p += 2;
- base = 10;
- len -= 2;
- }
- break;
- default:
- base = 8;
- break;
- }
- while (len-- > 0)
- {
- c = *p++;
- if (c >= 'A' && c <= 'Z')
- c += 'a' - 'A';
- if (c != 'l' && c != 'u')
- n *= base;
- if (c >= '0' && c <= '9')
- {
- if (found_suffix)
- return ERROR;
- n += i = c - '0';
- }
- else
- {
- if (base > 10 && c >= 'a' && c <= 'f')
- {
- if (found_suffix)
- return ERROR;
- n += i = c - 'a' + 10;
- }
- else if (c == 'l')
- {
- ++long_p;
- found_suffix = 1;
- }
- else if (c == 'u')
- {
- unsigned_p = 1;
- found_suffix = 1;
- }
- else
- return ERROR; /* Char not a digit */
- }
- if (i >= base)
- return ERROR; /* Invalid digit in this base. */
- /* Portably test for overflow (only works for nonzero values, so make
- a second check for zero). FIXME: Can't we just make n and prevn
- unsigned and avoid this? */
- if (c != 'l' && c != 'u' && (prevn >= n) && n != 0)
- unsigned_p = 1; /* Try something unsigned. */
- /* Portably test for unsigned overflow.
- FIXME: This check is wrong; for example it doesn't find overflow
- on 0x123456789 when LONGEST is 32 bits. */
- if (c != 'l' && c != 'u' && n != 0)
- {
- if ((unsigned_p && prevn >= n))
- error (_("Numeric constant too large."));
- }
- prevn = n;
- }
- /* An integer constant is an int, a long, or a long long. An L
- suffix forces it to be long; an LL suffix forces it to be long
- long. If not forced to a larger size, it gets the first type of
- the above that it fits in. To figure out whether it fits, we
- shift it right and see whether anything remains. Note that we
- can't shift sizeof (LONGEST) * HOST_CHAR_BIT bits or more in one
- operation, because many compilers will warn about such a shift
- (which always produces a zero result). Sometimes gdbarch_int_bit
- or gdbarch_long_bit will be that big, sometimes not. To deal with
- the case where it is we just always shift the value more than
- once, with fewer bits each time. */
- un = n >> 2;
- if (long_p == 0
- && (un >> (gdbarch_int_bit (par_state->gdbarch ()) - 2)) == 0)
- {
- high_bit
- = ((ULONGEST)1) << (gdbarch_int_bit (par_state->gdbarch ()) - 1);
- /* A large decimal (not hex or octal) constant (between INT_MAX
- and UINT_MAX) is a long or unsigned long, according to ANSI,
- never an unsigned int, but this code treats it as unsigned
- int. This probably should be fixed. GCC gives a warning on
- such constants. */
- unsigned_type = parse_type (par_state)->builtin_unsigned_int;
- signed_type = parse_type (par_state)->builtin_int;
- }
- else if (long_p <= 1
- && (un >> (gdbarch_long_bit (par_state->gdbarch ()) - 2)) == 0)
- {
- high_bit
- = ((ULONGEST)1) << (gdbarch_long_bit (par_state->gdbarch ()) - 1);
- unsigned_type = parse_type (par_state)->builtin_unsigned_long;
- signed_type = parse_type (par_state)->builtin_long;
- }
- else
- {
- int shift;
- if (sizeof (ULONGEST) * HOST_CHAR_BIT
- < gdbarch_long_long_bit (par_state->gdbarch ()))
- /* A long long does not fit in a LONGEST. */
- shift = (sizeof (ULONGEST) * HOST_CHAR_BIT - 1);
- else
- shift = (gdbarch_long_long_bit (par_state->gdbarch ()) - 1);
- high_bit = (ULONGEST) 1 << shift;
- unsigned_type = parse_type (par_state)->builtin_unsigned_long_long;
- signed_type = parse_type (par_state)->builtin_long_long;
- }
- putithere->typed_val_int.val = n;
- /* If the high bit of the worked out type is set then this number
- has to be unsigned. */
- if (unsigned_p || (n & high_bit))
- {
- putithere->typed_val_int.type = unsigned_type;
- }
- else
- {
- putithere->typed_val_int.type = signed_type;
- }
- return INT;
- }
- /* Temporary obstack used for holding strings. */
- static struct obstack tempbuf;
- static int tempbuf_init;
- /* Parse a string or character literal from TOKPTR. The string or
- character may be wide or unicode. *OUTPTR is set to just after the
- end of the literal in the input string. The resulting token is
- stored in VALUE. This returns a token value, either STRING or
- CHAR, depending on what was parsed. *HOST_CHARS is set to the
- number of host characters in the literal. */
- static int
- parse_string_or_char (const char *tokptr, const char **outptr,
- struct typed_stoken *value, int *host_chars)
- {
- int quote;
- /* Build the gdb internal form of the input string in tempbuf. Note
- that the buffer is null byte terminated *only* for the
- convenience of debugging gdb itself and printing the buffer
- contents when the buffer contains no embedded nulls. Gdb does
- not depend upon the buffer being null byte terminated, it uses
- the length string instead. This allows gdb to handle C strings
- (as well as strings in other languages) with embedded null
- bytes */
- if (!tempbuf_init)
- tempbuf_init = 1;
- else
- obstack_free (&tempbuf, NULL);
- obstack_init (&tempbuf);
- /* Skip the quote. */
- quote = *tokptr;
- ++tokptr;
- *host_chars = 0;
- while (*tokptr)
- {
- char c = *tokptr;
- if (c == '\\')
- {
- ++tokptr;
- *host_chars += c_parse_escape (&tokptr, &tempbuf);
- }
- else if (c == quote)
- break;
- else
- {
- obstack_1grow (&tempbuf, c);
- ++tokptr;
- /* FIXME: this does the wrong thing with multi-byte host
- characters. We could use mbrlen here, but that would
- make "set host-charset" a bit less useful. */
- ++*host_chars;
- }
- }
- if (*tokptr != quote)
- {
- if (quote == '"')
- error (_("Unterminated string in expression."));
- else
- error (_("Unmatched single quote."));
- }
- ++tokptr;
- value->type = (int) C_STRING | (quote == '\'' ? C_CHAR : 0); /*FIXME*/
- value->ptr = (char *) obstack_base (&tempbuf);
- value->length = obstack_object_size (&tempbuf);
- *outptr = tokptr;
- return quote == '\'' ? CHAR : STRING;
- }
- struct token
- {
- const char *oper;
- int token;
- enum exp_opcode opcode;
- };
- static const struct token tokentab3[] =
- {
- {">>=", ASSIGN_MODIFY, BINOP_RSH},
- {"<<=", ASSIGN_MODIFY, BINOP_LSH},
- /*{"&^=", ASSIGN_MODIFY, BINOP_BITWISE_ANDNOT}, TODO */
- {"...", DOTDOTDOT, OP_NULL},
- };
- static const struct token tokentab2[] =
- {
- {"+=", ASSIGN_MODIFY, BINOP_ADD},
- {"-=", ASSIGN_MODIFY, BINOP_SUB},
- {"*=", ASSIGN_MODIFY, BINOP_MUL},
- {"/=", ASSIGN_MODIFY, BINOP_DIV},
- {"%=", ASSIGN_MODIFY, BINOP_REM},
- {"|=", ASSIGN_MODIFY, BINOP_BITWISE_IOR},
- {"&=", ASSIGN_MODIFY, BINOP_BITWISE_AND},
- {"^=", ASSIGN_MODIFY, BINOP_BITWISE_XOR},
- {"++", INCREMENT, OP_NULL},
- {"--", DECREMENT, OP_NULL},
- /*{"->", RIGHT_ARROW, OP_NULL}, Doesn't exist in Go. */
- {"<-", LEFT_ARROW, OP_NULL},
- {"&&", ANDAND, OP_NULL},
- {"||", OROR, OP_NULL},
- {"<<", LSH, OP_NULL},
- {">>", RSH, OP_NULL},
- {"==", EQUAL, OP_NULL},
- {"!=", NOTEQUAL, OP_NULL},
- {"<=", LEQ, OP_NULL},
- {">=", GEQ, OP_NULL},
- /*{"&^", ANDNOT, OP_NULL}, TODO */
- };
- /* Identifier-like tokens. */
- static const struct token ident_tokens[] =
- {
- {"true", TRUE_KEYWORD, OP_NULL},
- {"false", FALSE_KEYWORD, OP_NULL},
- {"nil", NIL_KEYWORD, OP_NULL},
- {"const", CONST_KEYWORD, OP_NULL},
- {"struct", STRUCT_KEYWORD, OP_NULL},
- {"type", TYPE_KEYWORD, OP_NULL},
- {"interface", INTERFACE_KEYWORD, OP_NULL},
- {"chan", CHAN_KEYWORD, OP_NULL},
- {"byte", BYTE_KEYWORD, OP_NULL}, /* An alias of uint8. */
- {"len", LEN_KEYWORD, OP_NULL},
- {"cap", CAP_KEYWORD, OP_NULL},
- {"new", NEW_KEYWORD, OP_NULL},
- {"iota", IOTA_KEYWORD, OP_NULL},
- };
- /* This is set if a NAME token appeared at the very end of the input
- string, with no whitespace separating the name from the EOF. This
- is used only when parsing to do field name completion. */
- static int saw_name_at_eof;
- /* This is set if the previously-returned token was a structure
- operator -- either '.' or ARROW. This is used only when parsing to
- do field name completion. */
- static int last_was_structop;
- /* Depth of parentheses. */
- static int paren_depth;
- /* Read one token, getting characters through lexptr. */
- static int
- lex_one_token (struct parser_state *par_state)
- {
- int c;
- int namelen;
- const char *tokstart;
- int saw_structop = last_was_structop;
- last_was_structop = 0;
- retry:
- par_state->prev_lexptr = par_state->lexptr;
- tokstart = par_state->lexptr;
- /* See if it is a special token of length 3. */
- for (const auto &token : tokentab3)
- if (strncmp (tokstart, token.oper, 3) == 0)
- {
- par_state->lexptr += 3;
- yylval.opcode = token.opcode;
- return token.token;
- }
- /* See if it is a special token of length 2. */
- for (const auto &token : tokentab2)
- if (strncmp (tokstart, token.oper, 2) == 0)
- {
- par_state->lexptr += 2;
- yylval.opcode = token.opcode;
- /* NOTE: -> doesn't exist in Go, so we don't need to watch for
- setting last_was_structop here. */
- return token.token;
- }
- switch (c = *tokstart)
- {
- case 0:
- if (saw_name_at_eof)
- {
- saw_name_at_eof = 0;
- return COMPLETE;
- }
- else if (saw_structop)
- return COMPLETE;
- else
- return 0;
- case ' ':
- case '\t':
- case '\n':
- par_state->lexptr++;
- goto retry;
- case '[':
- case '(':
- paren_depth++;
- par_state->lexptr++;
- return c;
- case ']':
- case ')':
- if (paren_depth == 0)
- return 0;
- paren_depth--;
- par_state->lexptr++;
- return c;
- case ',':
- if (pstate->comma_terminates
- && paren_depth == 0)
- return 0;
- par_state->lexptr++;
- return c;
- case '.':
- /* Might be a floating point number. */
- if (par_state->lexptr[1] < '0' || par_state->lexptr[1] > '9')
- {
- if (pstate->parse_completion)
- last_was_structop = 1;
- goto symbol; /* Nope, must be a symbol. */
- }
- /* FALL THRU. */
- case '0':
- case '1':
- case '2':
- case '3':
- case '4':
- case '5':
- case '6':
- case '7':
- case '8':
- case '9':
- {
- /* It's a number. */
- int got_dot = 0, got_e = 0, toktype;
- const char *p = tokstart;
- int hex = input_radix > 10;
- if (c == '0' && (p[1] == 'x' || p[1] == 'X'))
- {
- p += 2;
- hex = 1;
- }
- for (;; ++p)
- {
- /* This test includes !hex because 'e' is a valid hex digit
- and thus does not indicate a floating point number when
- the radix is hex. */
- if (!hex && !got_e && (*p == 'e' || *p == 'E'))
- got_dot = got_e = 1;
- /* This test does not include !hex, because a '.' always indicates
- a decimal floating point number regardless of the radix. */
- else if (!got_dot && *p == '.')
- got_dot = 1;
- else if (got_e && (p[-1] == 'e' || p[-1] == 'E')
- && (*p == '-' || *p == '+'))
- /* This is the sign of the exponent, not the end of the
- number. */
- continue;
- /* We will take any letters or digits. parse_number will
- complain if past the radix, or if L or U are not final. */
- else if ((*p < '0' || *p > '9')
- && ((*p < 'a' || *p > 'z')
- && (*p < 'A' || *p > 'Z')))
- break;
- }
- toktype = parse_number (par_state, tokstart, p - tokstart,
- got_dot|got_e, &yylval);
- if (toktype == ERROR)
- {
- char *err_copy = (char *) alloca (p - tokstart + 1);
- memcpy (err_copy, tokstart, p - tokstart);
- err_copy[p - tokstart] = 0;
- error (_("Invalid number \"%s\"."), err_copy);
- }
- par_state->lexptr = p;
- return toktype;
- }
- case '@':
- {
- const char *p = &tokstart[1];
- size_t len = strlen ("entry");
- while (isspace (*p))
- p++;
- if (strncmp (p, "entry", len) == 0 && !isalnum (p[len])
- && p[len] != '_')
- {
- par_state->lexptr = &p[len];
- return ENTRY;
- }
- }
- /* FALLTHRU */
- case '+':
- case '-':
- case '*':
- case '/':
- case '%':
- case '|':
- case '&':
- case '^':
- case '~':
- case '!':
- case '<':
- case '>':
- case '?':
- case ':':
- case '=':
- case '{':
- case '}':
- symbol:
- par_state->lexptr++;
- return c;
- case '\'':
- case '"':
- case '`':
- {
- int host_len;
- int result = parse_string_or_char (tokstart, &par_state->lexptr,
- &yylval.tsval, &host_len);
- if (result == CHAR)
- {
- if (host_len == 0)
- error (_("Empty character constant."));
- else if (host_len > 2 && c == '\'')
- {
- ++tokstart;
- namelen = par_state->lexptr - tokstart - 1;
- goto tryname;
- }
- else if (host_len > 1)
- error (_("Invalid character constant."));
- }
- return result;
- }
- }
- if (!(c == '_' || c == '$'
- || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')))
- /* We must have come across a bad character (e.g. ';'). */
- error (_("Invalid character '%c' in expression."), c);
- /* It's a name. See how long it is. */
- namelen = 0;
- for (c = tokstart[namelen];
- (c == '_' || c == '$' || (c >= '0' && c <= '9')
- || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'));)
- {
- c = tokstart[++namelen];
- }
- /* The token "if" terminates the expression and is NOT removed from
- the input stream. It doesn't count if it appears in the
- expansion of a macro. */
- if (namelen == 2
- && tokstart[0] == 'i'
- && tokstart[1] == 'f')
- {
- return 0;
- }
- /* For the same reason (breakpoint conditions), "thread N"
- terminates the expression. "thread" could be an identifier, but
- an identifier is never followed by a number without intervening
- punctuation.
- Handle abbreviations of these, similarly to
- breakpoint.c:find_condition_and_thread.
- TODO: Watch for "goroutine" here? */
- if (namelen >= 1
- && strncmp (tokstart, "thread", namelen) == 0
- && (tokstart[namelen] == ' ' || tokstart[namelen] == '\t'))
- {
- const char *p = tokstart + namelen + 1;
- while (*p == ' ' || *p == '\t')
- p++;
- if (*p >= '0' && *p <= '9')
- return 0;
- }
- par_state->lexptr += namelen;
- tryname:
- yylval.sval.ptr = tokstart;
- yylval.sval.length = namelen;
- /* Catch specific keywords. */
- std::string copy = copy_name (yylval.sval);
- for (const auto &token : ident_tokens)
- if (copy == token.oper)
- {
- /* It is ok to always set this, even though we don't always
- strictly need to. */
- yylval.opcode = token.opcode;
- return token.token;
- }
- if (*tokstart == '$')
- return DOLLAR_VARIABLE;
- if (pstate->parse_completion && *par_state->lexptr == '\0')
- saw_name_at_eof = 1;
- return NAME;
- }
- /* An object of this type is pushed on a FIFO by the "outer" lexer. */
- struct token_and_value
- {
- int token;
- YYSTYPE value;
- };
- /* A FIFO of tokens that have been read but not yet returned to the
- parser. */
- static std::vector<token_and_value> token_fifo;
- /* Non-zero if the lexer should return tokens from the FIFO. */
- static int popping;
- /* Temporary storage for yylex; this holds symbol names as they are
- built up. */
- static auto_obstack name_obstack;
- /* Build "package.name" in name_obstack.
- For convenience of the caller, the name is NUL-terminated,
- but the NUL is not included in the recorded length. */
- static struct stoken
- build_packaged_name (const char *package, int package_len,
- const char *name, int name_len)
- {
- struct stoken result;
- name_obstack.clear ();
- obstack_grow (&name_obstack, package, package_len);
- obstack_grow_str (&name_obstack, ".");
- obstack_grow (&name_obstack, name, name_len);
- obstack_grow (&name_obstack, "", 1);
- result.ptr = (char *) obstack_base (&name_obstack);
- result.length = obstack_object_size (&name_obstack) - 1;
- return result;
- }
- /* Return non-zero if NAME is a package name.
- BLOCK is the scope in which to interpret NAME; this can be NULL
- to mean the global scope. */
- static int
- package_name_p (const char *name, const struct block *block)
- {
- struct symbol *sym;
- struct field_of_this_result is_a_field_of_this;
- sym = lookup_symbol (name, block, STRUCT_DOMAIN, &is_a_field_of_this).symbol;
- if (sym
- && sym->aclass () == LOC_TYPEDEF
- && sym->type ()->code () == TYPE_CODE_MODULE)
- return 1;
- return 0;
- }
- /* Classify a (potential) function in the "unsafe" package.
- We fold these into "keywords" to keep things simple, at least until
- something more complex is warranted. */
- static int
- classify_unsafe_function (struct stoken function_name)
- {
- std::string copy = copy_name (function_name);
- if (copy == "Sizeof")
- {
- yylval.sval = function_name;
- return SIZEOF_KEYWORD;
- }
- error (_("Unknown function in `unsafe' package: %s"), copy.c_str ());
- }
- /* Classify token(s) "name1.name2" where name1 is known to be a package.
- The contents of the token are in `yylval'.
- Updates yylval and returns the new token type.
- The result is one of NAME, NAME_OR_INT, or TYPENAME. */
- static int
- classify_packaged_name (const struct block *block)
- {
- struct block_symbol sym;
- struct field_of_this_result is_a_field_of_this;
- std::string copy = copy_name (yylval.sval);
- sym = lookup_symbol (copy.c_str (), block, VAR_DOMAIN, &is_a_field_of_this);
- if (sym.symbol)
- {
- yylval.ssym.sym = sym;
- yylval.ssym.is_a_field_of_this = is_a_field_of_this.type != NULL;
- }
- return NAME;
- }
- /* Classify a NAME token.
- The contents of the token are in `yylval'.
- Updates yylval and returns the new token type.
- BLOCK is the block in which lookups start; this can be NULL
- to mean the global scope.
- The result is one of NAME, NAME_OR_INT, or TYPENAME. */
- static int
- classify_name (struct parser_state *par_state, const struct block *block)
- {
- struct type *type;
- struct block_symbol sym;
- struct field_of_this_result is_a_field_of_this;
- std::string copy = copy_name (yylval.sval);
- /* Try primitive types first so they win over bad/weird debug info. */
- type = language_lookup_primitive_type (par_state->language (),
- par_state->gdbarch (),
- copy.c_str ());
- if (type != NULL)
- {
- /* NOTE: We take advantage of the fact that yylval coming in was a
- NAME, and that struct ttype is a compatible extension of struct
- stoken, so yylval.tsym.stoken is already filled in. */
- yylval.tsym.type = type;
- return TYPENAME;
- }
- /* TODO: What about other types? */
- sym = lookup_symbol (copy.c_str (), block, VAR_DOMAIN, &is_a_field_of_this);
- if (sym.symbol)
- {
- yylval.ssym.sym = sym;
- yylval.ssym.is_a_field_of_this = is_a_field_of_this.type != NULL;
- return NAME;
- }
- /* If we didn't find a symbol, look again in the current package.
- This is to, e.g., make "p global_var" work without having to specify
- the package name. We intentionally only looks for objects in the
- current package. */
- {
- char *current_package_name = go_block_package_name (block);
- if (current_package_name != NULL)
- {
- struct stoken sval =
- build_packaged_name (current_package_name,
- strlen (current_package_name),
- copy.c_str (), copy.size ());
- xfree (current_package_name);
- sym = lookup_symbol (sval.ptr, block, VAR_DOMAIN,
- &is_a_field_of_this);
- if (sym.symbol)
- {
- yylval.ssym.stoken = sval;
- yylval.ssym.sym = sym;
- yylval.ssym.is_a_field_of_this = is_a_field_of_this.type != NULL;
- return NAME;
- }
- }
- }
- /* Input names that aren't symbols but ARE valid hex numbers, when
- the input radix permits them, can be names or numbers depending
- on the parse. Note we support radixes > 16 here. */
- if ((copy[0] >= 'a' && copy[0] < 'a' + input_radix - 10)
- || (copy[0] >= 'A' && copy[0] < 'A' + input_radix - 10))
- {
- YYSTYPE newlval; /* Its value is ignored. */
- int hextype = parse_number (par_state, copy.c_str (),
- yylval.sval.length, 0, &newlval);
- if (hextype == INT)
- {
- yylval.ssym.sym.symbol = NULL;
- yylval.ssym.sym.block = NULL;
- yylval.ssym.is_a_field_of_this = 0;
- return NAME_OR_INT;
- }
- }
- yylval.ssym.sym.symbol = NULL;
- yylval.ssym.sym.block = NULL;
- yylval.ssym.is_a_field_of_this = 0;
- return NAME;
- }
- /* This is taken from c-exp.y mostly to get something working.
- The basic structure has been kept because we may yet need some of it. */
- static int
- yylex (void)
- {
- token_and_value current, next;
- if (popping && !token_fifo.empty ())
- {
- token_and_value tv = token_fifo[0];
- token_fifo.erase (token_fifo.begin ());
- yylval = tv.value;
- /* There's no need to fall through to handle package.name
- as that can never happen here. In theory. */
- return tv.token;
- }
- popping = 0;
- current.token = lex_one_token (pstate);
- /* TODO: Need a way to force specifying name1 as a package.
- .name1.name2 ? */
- if (current.token != NAME)
- return current.token;
- /* See if we have "name1 . name2". */
- current.value = yylval;
- next.token = lex_one_token (pstate);
- next.value = yylval;
- if (next.token == '.')
- {
- token_and_value name2;
- name2.token = lex_one_token (pstate);
- name2.value = yylval;
- if (name2.token == NAME)
- {
- /* Ok, we have "name1 . name2". */
- std::string copy = copy_name (current.value.sval);
- if (copy == "unsafe")
- {
- popping = 1;
- return classify_unsafe_function (name2.value.sval);
- }
- if (package_name_p (copy.c_str (), pstate->expression_context_block))
- {
- popping = 1;
- yylval.sval = build_packaged_name (current.value.sval.ptr,
- current.value.sval.length,
- name2.value.sval.ptr,
- name2.value.sval.length);
- return classify_packaged_name (pstate->expression_context_block);
- }
- }
- token_fifo.push_back (next);
- token_fifo.push_back (name2);
- }
- else
- token_fifo.push_back (next);
- /* If we arrive here we don't have a package-qualified name. */
- popping = 1;
- yylval = current.value;
- return classify_name (pstate, pstate->expression_context_block);
- }
- /* See language.h. */
- int
- go_language::parser (struct parser_state *par_state) const
- {
- /* Setting up the parser state. */
- scoped_restore pstate_restore = make_scoped_restore (&pstate);
- gdb_assert (par_state != NULL);
- pstate = par_state;
- scoped_restore restore_yydebug = make_scoped_restore (&yydebug,
- parser_debug);
- /* Initialize some state used by the lexer. */
- last_was_structop = 0;
- saw_name_at_eof = 0;
- paren_depth = 0;
- token_fifo.clear ();
- popping = 0;
- name_obstack.clear ();
- int result = yyparse ();
- if (!result)
- pstate->set_operation (pstate->pop ());
- return result;
- }
- static void
- yyerror (const char *msg)
- {
- if (pstate->prev_lexptr)
- pstate->lexptr = pstate->prev_lexptr;
- error (_("A %s in expression, near `%s'."), msg, pstate->lexptr);
- }
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