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Diffstat (limited to 'gcc/gengtype-parse.c')
| -rw-r--r-- | gcc/gengtype-parse.c | 988 |
1 files changed, 988 insertions, 0 deletions
diff --git a/gcc/gengtype-parse.c b/gcc/gengtype-parse.c new file mode 100644 index 000000000..a578da51d --- /dev/null +++ b/gcc/gengtype-parse.c @@ -0,0 +1,988 @@ +/* Process source files and output type information. + Copyright (C) 2006, 2007, 2010 Free Software Foundation, Inc. + + This file is part of GCC. + + GCC 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, or (at your option) any later + version. + + GCC 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 GCC; see the file COPYING3. If not see + <http://www.gnu.org/licenses/>. */ + +#include "bconfig.h" +#include "system.h" +#include "gengtype.h" + +/* This is a simple recursive-descent parser which understands a subset of + the C type grammar. + + Rule functions are suffixed _seq if they scan a sequence of items; + _opt if they may consume zero tokens; _seqopt if both are true. The + "consume_" prefix indicates that a sequence of tokens is parsed for + syntactic correctness and then thrown away. */ + +/* Simple one-token lookahead mechanism. */ + +struct token +{ + const char *value; + int code; + bool valid; +}; +static struct token T; + +/* Retrieve the code of the current token; if there is no current token, + get the next one from the lexer. */ +static inline int +token (void) +{ + if (!T.valid) + { + T.code = yylex (&T.value); + T.valid = true; + } + return T.code; +} + +/* Retrieve the value of the current token (if any) and mark it consumed. + The next call to token() will get another token from the lexer. */ +static inline const char * +advance (void) +{ + T.valid = false; + return T.value; +} + +/* Diagnostics. */ + +/* This array is indexed by the token code minus CHAR_TOKEN_OFFSET. */ +static const char *const token_names[] = { + "GTY", + "typedef", + "extern", + "static", + "union", + "struct", + "enum", + "VEC", + "DEF_VEC_[OP]", + "DEF_VEC_I", + "DEF_VEC_ALLOC_[IOP]", + "...", + "ptr_alias", + "nested_ptr", + "a param<N>_is option", + "a number", + "a scalar type", + "an identifier", + "a string constant", + "a character constant", + "an array declarator", +}; + +/* This array is indexed by token code minus FIRST_TOKEN_WITH_VALUE. */ +static const char *const token_value_format[] = { + "%s", + "'%s'", + "'%s'", + "'%s'", + "'\"%s\"'", + "\"'%s'\"", + "'[%s]'", +}; + +/* Produce a printable representation for a token defined by CODE and + VALUE. This sometimes returns pointers into malloc memory and + sometimes not, therefore it is unsafe to free the pointer it + returns, so that memory is leaked. This does not matter, as this + function is only used for diagnostics, and in a successful run of + the program there will be none. */ +static const char * +print_token (int code, const char *value) +{ + if (code < CHAR_TOKEN_OFFSET) + return xasprintf ("'%c'", code); + else if (code < FIRST_TOKEN_WITH_VALUE) + return xasprintf ("'%s'", token_names[code - CHAR_TOKEN_OFFSET]); + else if (!value) + return token_names[code - CHAR_TOKEN_OFFSET]; /* don't quote these */ + else + return xasprintf (token_value_format[code - FIRST_TOKEN_WITH_VALUE], + value); +} + +/* Convenience wrapper around print_token which produces the printable + representation of the current token. */ +static inline const char * +print_cur_token (void) +{ + return print_token (T.code, T.value); +} + +/* Report a parse error on the current line, with diagnostic MSG. + Behaves as standard printf with respect to additional arguments and + format escapes. */ +static void ATTRIBUTE_PRINTF_1 +parse_error (const char *msg, ...) +{ + va_list ap; + + fprintf (stderr, "%s:%d: parse error: ", + get_input_file_name (lexer_line.file), lexer_line.line); + + va_start (ap, msg); + vfprintf (stderr, msg, ap); + va_end (ap); + + fputc ('\n', stderr); + + hit_error = true; +} + +/* If the next token does not have code T, report a parse error; otherwise + return the token's value. */ +static const char * +require (int t) +{ + int u = token (); + const char *v = advance (); + if (u != t) + { + parse_error ("expected %s, have %s", + print_token (t, 0), print_token (u, v)); + return 0; + } + return v; +} + +/* If the next token does not have one of the codes T1 or T2, report a + parse error; otherwise return the token's value. */ +static const char * +require2 (int t1, int t2) +{ + int u = token (); + const char *v = advance (); + if (u != t1 && u != t2) + { + parse_error ("expected %s or %s, have %s", + print_token (t1, 0), print_token (t2, 0), + print_token (u, v)); + return 0; + } + return v; +} + +/* Near-terminals. */ + +/* C-style string constant concatenation: STRING+ + Bare STRING should appear nowhere else in this file. */ +static const char * +string_seq (void) +{ + const char *s1, *s2; + size_t l1, l2; + char *buf; + + s1 = require (STRING); + if (s1 == 0) + return ""; + while (token () == STRING) + { + s2 = advance (); + + l1 = strlen (s1); + l2 = strlen (s2); + buf = XRESIZEVEC (char, CONST_CAST (char *, s1), l1 + l2 + 1); + memcpy (buf + l1, s2, l2 + 1); + XDELETE (CONST_CAST (char *, s2)); + s1 = buf; + } + return s1; +} + +/* typedef_name: either an ID, or VEC(x,y) which is translated to VEC_x_y. + Use only where VEC(x,y) is legitimate, i.e. in positions where a + typedef name may appear. */ +static const char * +typedef_name (void) +{ + if (token () == VEC_TOKEN) + { + const char *c1, *c2, *r; + advance (); + require ('('); + c1 = require2 (ID, SCALAR); + require (','); + c2 = require (ID); + require (')'); + r = concat ("VEC_", c1, "_", c2, (char *) 0); + free (CONST_CAST (char *, c1)); + free (CONST_CAST (char *, c2)); + return r; + } + else + return require (ID); +} + +/* Absorb a sequence of tokens delimited by balanced ()[]{}. */ +static void +consume_balanced (int opener, int closer) +{ + require (opener); + for (;;) + switch (token ()) + { + default: + advance (); + break; + case '(': + consume_balanced ('(', ')'); + break; + case '[': + consume_balanced ('[', ']'); + break; + case '{': + consume_balanced ('{', '}'); + break; + + case '}': + case ']': + case ')': + if (token () != closer) + parse_error ("unbalanced delimiters - expected '%c', have '%c'", + closer, token ()); + advance (); + return; + + case EOF_TOKEN: + parse_error ("unexpected end of file within %c%c-delimited construct", + opener, closer); + return; + } +} + +/* Absorb a sequence of tokens, possibly including ()[]{}-delimited + expressions, until we encounter a semicolon outside any such + delimiters; absorb that too. If IMMEDIATE is true, it is an error + if the semicolon is not the first token encountered. */ +static void +consume_until_semi (bool immediate) +{ + if (immediate && token () != ';') + require (';'); + for (;;) + switch (token ()) + { + case ';': + advance (); + return; + default: + advance (); + break; + + case '(': + consume_balanced ('(', ')'); + break; + case '[': + consume_balanced ('[', ']'); + break; + case '{': + consume_balanced ('{', '}'); + break; + + case '}': + case ']': + case ')': + parse_error ("unmatched '%c' while scanning for ';'", token ()); + return; + + case EOF_TOKEN: + parse_error ("unexpected end of file while scanning for ';'"); + return; + } +} + +/* Absorb a sequence of tokens, possibly including ()[]{}-delimited + expressions, until we encounter a comma or semicolon outside any + such delimiters; absorb that too. If IMMEDIATE is true, it is an + error if the comma or semicolon is not the first token encountered. + Returns true if the loop ended with a comma. */ +static bool +consume_until_comma_or_semi (bool immediate) +{ + if (immediate && token () != ',' && token () != ';') + require2 (',', ';'); + for (;;) + switch (token ()) + { + case ',': + advance (); + return true; + case ';': + advance (); + return false; + default: + advance (); + break; + + case '(': + consume_balanced ('(', ')'); + break; + case '[': + consume_balanced ('[', ']'); + break; + case '{': + consume_balanced ('{', '}'); + break; + + case '}': + case ']': + case ')': + parse_error ("unmatched '%s' while scanning for ',' or ';'", + print_cur_token ()); + return false; + + case EOF_TOKEN: + parse_error ("unexpected end of file while scanning for ',' or ';'"); + return false; + } +} + + +/* GTY(()) option handling. */ +static type_p type (options_p *optsp, bool nested); + +/* Optional parenthesized string: ('(' string_seq ')')? */ +static options_p +str_optvalue_opt (options_p prev) +{ + const char *name = advance (); + const char *value = ""; + if (token () == '(') + { + advance (); + value = string_seq (); + require (')'); + } + return create_string_option (prev, name, value); +} + +/* absdecl: type '*'* + -- a vague approximation to what the C standard calls an abstract + declarator. The only kinds that are actually used are those that + are just a bare type and those that have trailing pointer-stars. + Further kinds should be implemented if and when they become + necessary. Used only within GTY(()) option values, therefore + further GTY(()) tags within the type are invalid. Note that the + return value has already been run through adjust_field_type. */ +static type_p +absdecl (void) +{ + type_p ty; + options_p opts; + + ty = type (&opts, true); + while (token () == '*') + { + ty = create_pointer (ty); + advance (); + } + + if (opts) + parse_error ("nested GTY(()) options are invalid"); + + return adjust_field_type (ty, 0); +} + +/* Type-option: '(' absdecl ')' */ +static options_p +type_optvalue (options_p prev, const char *name) +{ + type_p ty; + require ('('); + ty = absdecl (); + require (')'); + return create_type_option (prev, name, ty); +} + +/* Nested pointer data: '(' type '*'* ',' string_seq ',' string_seq ')' */ +static options_p +nestedptr_optvalue (options_p prev) +{ + type_p ty; + const char *from, *to; + + require ('('); + ty = absdecl (); + require (','); + to = string_seq (); + require (','); + from = string_seq (); + require (')'); + + return create_nested_ptr_option (prev, ty, to, from); +} + +/* One GTY(()) option: + ID str_optvalue_opt + | PTR_ALIAS type_optvalue + | PARAM_IS type_optvalue + | NESTED_PTR nestedptr_optvalue +*/ +static options_p +option (options_p prev) +{ + switch (token ()) + { + case ID: + return str_optvalue_opt (prev); + + case PTR_ALIAS: + advance (); + return type_optvalue (prev, "ptr_alias"); + + case PARAM_IS: + return type_optvalue (prev, advance ()); + + case NESTED_PTR: + advance (); + return nestedptr_optvalue (prev); + + default: + parse_error ("expected an option keyword, have %s", print_cur_token ()); + advance (); + return create_string_option (prev, "", ""); + } +} + +/* One comma-separated list of options. */ +static options_p +option_seq (void) +{ + options_p o; + + o = option (0); + while (token () == ',') + { + advance (); + o = option (o); + } + return o; +} + +/* GTY marker: 'GTY' '(' '(' option_seq? ')' ')' */ +static options_p +gtymarker (void) +{ + options_p result = 0; + require (GTY_TOKEN); + require ('('); + require ('('); + if (token () != ')') + result = option_seq (); + require (')'); + require (')'); + return result; +} + +/* Optional GTY marker. */ +static options_p +gtymarker_opt (void) +{ + if (token () != GTY_TOKEN) + return 0; + return gtymarker (); +} + +/* Declarators. The logic here is largely lifted from c-parser.c. + Note that we do not have to process abstract declarators, which can + appear only in parameter type lists or casts (but see absdecl, + above). Also, type qualifiers are thrown out in gengtype-lex.l so + we don't have to do it. */ + +/* array_and_function_declarators_opt: + \epsilon + array_and_function_declarators_opt ARRAY + array_and_function_declarators_opt '(' ... ')' + + where '...' indicates stuff we ignore except insofar as grouping + symbols ()[]{} must balance. + + Subroutine of direct_declarator - do not use elsewhere. */ + +static type_p +array_and_function_declarators_opt (type_p ty) +{ + if (token () == ARRAY) + { + const char *array = advance (); + return create_array (array_and_function_declarators_opt (ty), array); + } + else if (token () == '(') + { + /* We don't need exact types for functions. */ + consume_balanced ('(', ')'); + array_and_function_declarators_opt (ty); + return create_scalar_type ("function type"); + } + else + return ty; +} + +static type_p inner_declarator (type_p, const char **, options_p *); + +/* direct_declarator: + '(' inner_declarator ')' + gtymarker_opt ID array_and_function_declarators_opt + + Subroutine of declarator, mutually recursive with inner_declarator; + do not use elsewhere. */ +static type_p +direct_declarator (type_p ty, const char **namep, options_p *optsp) +{ + /* The first token in a direct-declarator must be an ID, a + GTY marker, or an open parenthesis. */ + switch (token ()) + { + case GTY_TOKEN: + *optsp = gtymarker (); + /* fall through */ + case ID: + *namep = require (ID); + break; + + case '(': + advance (); + ty = inner_declarator (ty, namep, optsp); + require (')'); + break; + + default: + parse_error ("expected '(', 'GTY', or an identifier, have %s", + print_cur_token ()); + /* Do _not_ advance if what we have is a close squiggle brace, as + we will get much better error recovery that way. */ + if (token () != '}') + advance (); + return 0; + } + return array_and_function_declarators_opt (ty); +} + +/* The difference between inner_declarator and declarator is in the + handling of stars. Consider this declaration: + + char * (*pfc) (void) + + It declares a pointer to a function that takes no arguments and + returns a char*. To construct the correct type for this + declaration, the star outside the parentheses must be processed + _before_ the function type, the star inside the parentheses must + be processed _after_ the function type. To accomplish this, + declarator() creates pointers before recursing (it is actually + coded as a while loop), whereas inner_declarator() recurses before + creating pointers. */ + +/* inner_declarator: + '*' inner_declarator + direct_declarator + + Mutually recursive subroutine of direct_declarator; do not use + elsewhere. */ + +static type_p +inner_declarator (type_p ty, const char **namep, options_p *optsp) +{ + if (token () == '*') + { + type_p inner; + advance (); + inner = inner_declarator (ty, namep, optsp); + if (inner == 0) + return 0; + else + return create_pointer (ty); + } + else + return direct_declarator (ty, namep, optsp); +} + +/* declarator: '*'+ direct_declarator + + This is the sole public interface to this part of the grammar. + Arguments are the type known so far, a pointer to where the name + may be stored, and a pointer to where GTY options may be stored. + Returns the final type. */ + +static type_p +declarator (type_p ty, const char **namep, options_p *optsp) +{ + *namep = 0; + *optsp = 0; + while (token () == '*') + { + advance (); + ty = create_pointer (ty); + } + return direct_declarator (ty, namep, optsp); +} + +/* Types and declarations. */ + +/* Structure field(s) declaration: + ( + type bitfield ';' + | type declarator bitfield? ( ',' declarator bitfield? )+ ';' + )+ + + Knows that such declarations must end with a close brace (or, + erroneously, at EOF). +*/ +static pair_p +struct_field_seq (void) +{ + pair_p f = 0; + type_p ty, dty; + options_p opts, dopts; + const char *name; + bool another; + + do + { + ty = type (&opts, true); + /* Another piece of the IFCVT_EXTRA_FIELDS special case, see type(). */ + if (!ty && token () == '}') + break; + + if (!ty || token () == ':') + { + consume_until_semi (false); + continue; + } + + do + { + dty = declarator (ty, &name, &dopts); + /* There could be any number of weird things after the declarator, + notably bitfield declarations and __attribute__s. If this + function returns true, the last thing was a comma, so we have + more than one declarator paired with the current type. */ + another = consume_until_comma_or_semi (false); + + if (!dty) + continue; + + if (opts && dopts) + parse_error ("two GTY(()) options for field %s", name); + if (opts && !dopts) + dopts = opts; + + f = create_field_at (f, dty, name, dopts, &lexer_line); + } + while (another); + } + while (token () != '}' && token () != EOF_TOKEN); + return nreverse_pairs (f); +} + +/* This is called type(), but what it parses (sort of) is what C calls + declaration-specifiers and specifier-qualifier-list: + + SCALAR + | ID // typedef + | (STRUCT|UNION) ID? gtymarker? ( '{' gtymarker? struct_field_seq '}' )? + | ENUM ID ( '{' ... '}' )? + + Returns a partial type; under some conditions (notably + "struct foo GTY((...)) thing;") it may write an options + structure to *OPTSP. +*/ +static type_p +type (options_p *optsp, bool nested) +{ + const char *s; + *optsp = 0; + switch (token ()) + { + case SCALAR: + s = advance (); + return create_scalar_type (s); + + case ID: + case VEC_TOKEN: + s = typedef_name (); + return resolve_typedef (s, &lexer_line); + + case STRUCT: + case UNION: + { + options_p opts = 0; + /* GTY annotations follow attribute syntax + GTY_BEFORE_ID is for union/struct declarations + GTY_AFTER_ID is for variable declarations. */ + enum + { + NO_GTY, + GTY_BEFORE_ID, + GTY_AFTER_ID + } is_gty = NO_GTY; + bool is_union = (token () == UNION); + advance (); + + /* Top-level structures that are not explicitly tagged GTY(()) + are treated as mere forward declarations. This is because + there are a lot of structures that we don't need to know + about, and some of those have weird macro stuff in them + that we can't handle. */ + if (nested || token () == GTY_TOKEN) + { + is_gty = GTY_BEFORE_ID; + opts = gtymarker_opt (); + } + + if (token () == ID) + s = advance (); + else + s = xasprintf ("anonymous:%s:%d", + get_input_file_name (lexer_line.file), + lexer_line.line); + + /* Unfortunately above GTY_TOKEN check does not capture the + typedef struct_type GTY case. */ + if (token () == GTY_TOKEN) + { + is_gty = GTY_AFTER_ID; + opts = gtymarker_opt (); + } + + if (is_gty) + { + if (token () == '{') + { + pair_p fields; + + if (is_gty == GTY_AFTER_ID) + parse_error ("GTY must be specified before identifier"); + + advance (); + fields = struct_field_seq (); + require ('}'); + return new_structure (s, is_union, &lexer_line, fields, opts); + } + } + else if (token () == '{') + consume_balanced ('{', '}'); + if (opts) + *optsp = opts; + return find_structure (s, is_union); + } + + case ENUM: + advance (); + if (token () == ID) + s = advance (); + else + s = xasprintf ("anonymous:%s:%d", + get_input_file_name (lexer_line.file), + lexer_line.line); + + if (token () == '{') + consume_balanced ('{', '}'); + return create_scalar_type (s); + + default: + parse_error ("expected a type specifier, have %s", print_cur_token ()); + advance (); + return create_scalar_type ("erroneous type"); + } +} + +/* Top level constructs. */ + +/* Dispatch declarations beginning with 'typedef'. */ + +static void +typedef_decl (void) +{ + type_p ty, dty; + const char *name; + options_p opts; + bool another; + + gcc_assert (token () == TYPEDEF); + advance (); + + ty = type (&opts, false); + if (!ty) + return; + if (opts) + parse_error ("GTY((...)) cannot be applied to a typedef"); + do + { + dty = declarator (ty, &name, &opts); + if (opts) + parse_error ("GTY((...)) cannot be applied to a typedef"); + + /* Yet another place where we could have junk (notably attributes) + after the declarator. */ + another = consume_until_comma_or_semi (false); + if (dty) + do_typedef (name, dty, &lexer_line); + } + while (another); +} + +/* Structure definition: type() does all the work. */ + +static void +struct_or_union (void) +{ + options_p dummy; + type (&dummy, false); + /* There may be junk after the type: notably, we cannot currently + distinguish 'struct foo *function(prototype);' from 'struct foo;' + ... we could call declarator(), but it's a waste of time at + present. Instead, just eat whatever token is currently lookahead + and go back to lexical skipping mode. */ + advance (); +} + +/* GC root declaration: + (extern|static) gtymarker? type ID array_declarators_opt (';'|'=') + If the gtymarker is not present, we ignore the rest of the declaration. */ +static void +extern_or_static (void) +{ + options_p opts, opts2, dopts; + type_p ty, dty; + const char *name; + require2 (EXTERN, STATIC); + + if (token () != GTY_TOKEN) + { + advance (); + return; + } + + opts = gtymarker (); + ty = type (&opts2, true); /* if we get here, it's got a GTY(()) */ + dty = declarator (ty, &name, &dopts); + + if ((opts && dopts) || (opts && opts2) || (opts2 && dopts)) + parse_error ("GTY((...)) specified more than once for %s", name); + else if (opts2) + opts = opts2; + else if (dopts) + opts = dopts; + + if (dty) + { + note_variable (name, adjust_field_type (dty, opts), opts, &lexer_line); + require2 (';', '='); + } +} + +/* Definition of a generic VEC structure: + + 'DEF_VEC_[IPO]' '(' id ')' ';' + + Scalar VECs require slightly different treatment than otherwise - + that's handled in note_def_vec, we just pass it along.*/ +static void +def_vec (void) +{ + bool is_scalar = (token () == DEFVEC_I); + const char *type; + + require2 (DEFVEC_OP, DEFVEC_I); + require ('('); + type = require2 (ID, SCALAR); + require (')'); + require (';'); + + if (!type) + return; + + note_def_vec (type, is_scalar, &lexer_line); + note_def_vec_alloc (type, "none", &lexer_line); +} + +/* Definition of an allocation strategy for a VEC structure: + + 'DEF_VEC_ALLOC_[IPO]' '(' id ',' id ')' ';' + + For purposes of gengtype, this just declares a wrapper structure. */ +static void +def_vec_alloc (void) +{ + const char *type, *astrat; + + require (DEFVEC_ALLOC); + require ('('); + type = require2 (ID, SCALAR); + require (','); + astrat = require (ID); + require (')'); + require (';'); + + if (!type || !astrat) + return; + + note_def_vec_alloc (type, astrat, &lexer_line); +} + +/* Parse the file FNAME for GC-relevant declarations and definitions. + This is the only entry point to this file. */ +void +parse_file (const char *fname) +{ + yybegin (fname); + for (;;) + { + switch (token ()) + { + case EXTERN: + case STATIC: + extern_or_static (); + break; + + case STRUCT: + case UNION: + struct_or_union (); + break; + + case TYPEDEF: + typedef_decl (); + break; + + case DEFVEC_OP: + case DEFVEC_I: + def_vec (); + break; + + case DEFVEC_ALLOC: + def_vec_alloc (); + break; + + case EOF_TOKEN: + goto eof; + + default: + parse_error ("unexpected top level token, %s", print_cur_token ()); + goto eof; + } + lexer_toplevel_done = 1; + } + + eof: + advance (); + yyend (); +} |