grammar.y

含有BACKTARACKING的編譯軟體

/* $Id: grammar.y,v 1.1 2004/03/24 21:29:23 tom Exp $
 *
 * yacc grammar for C function prototype generator
 * This was derived from the grammar in Appendix A of
 * "The C Programming Language" by Kernighan and Ritchie.
 */

%token <text> '(' '*' '&'
	/* identifiers that are not reserved words */
	T_IDENTIFIER T_TYPEDEF_NAME T_DEFINE_NAME

	/* storage class */
	T_AUTO T_EXTERN T_REGISTER T_STATIC T_TYPEDEF
	/* This keyword included for compatibility with C++. */
	T_INLINE
	/* This keyword included for compatibility with GCC */
	T_EXTENSION

	/* type specifiers */
	T_CHAR T_DOUBLE T_FLOAT T_INT T_VOID
	T_LONG T_SHORT T_SIGNED T_UNSIGNED
	T_ENUM T_STRUCT T_UNION
	/* C9X new types */
	T_Bool T_Complex T_Imaginary

	/* type qualifiers */
	T_TYPE_QUALIFIER

	/* paired square brackets and everything between them: [ ... ] */
	T_BRACKETS

%token
	/* left brace */
	T_LBRACE
	/* all input to the matching right brace */
	T_MATCHRBRACE

	/* three periods */
	T_ELLIPSIS

	/* constant expression or paired braces following an equal sign */
	T_INITIALIZER

	/* string literal */
	T_STRING_LITERAL

	/* asm */
	T_ASM
	/* ( "string literal" ) following asm keyword */
	T_ASMARG

	/* va_dcl from <varargs.h> */
	T_VA_DCL

%type <decl_spec> decl_specifiers decl_specifier
%type <decl_spec> storage_class type_specifier type_qualifier
%type <decl_spec> struct_or_union_specifier enum_specifier
%type <decl_list> init_declarator_list
%type <declarator> init_declarator declarator direct_declarator
%type <declarator> abs_declarator direct_abs_declarator
%type <param_list> parameter_type_list parameter_list
%type <parameter> parameter_declaration
%type <param_list> opt_identifier_list identifier_list
%type <text> struct_or_union pointer opt_type_qualifiers type_qualifier_list
	any_id identifier_or_ref
%type <text> enumeration

%{
#include <stdio.h>
#include <ctype.h>
#include "cproto.h"
#include "symbol.h"
#include "semantic.h"

#define YYMAXDEPTH 150

extern	int	yylex (void);

/* declaration specifier attributes for the typedef statement currently being
 * scanned
 */
static int cur_decl_spec_flags;

/* pointer to parameter list for the current function definition */
static ParameterList *func_params;

/* A parser semantic action sets this pointer to the current declarator in
 * a function parameter declaration in order to catch any comments following
 * the parameter declaration on the same line.  If the lexer scans a comment
 * and <cur_declarator> is not NULL, then the comment is attached to the
 * declarator.  To ignore subsequent comments, the lexer sets this to NULL
 * after scanning a comment or end of line.
 */
static Declarator *cur_declarator;

/* temporary string buffer */
static char buf[MAX_TEXT_SIZE];

/* table of typedef names */
static SymbolTable *typedef_names;

/* table of define names */
static SymbolTable *define_names;

/* table of type qualifiers */
static SymbolTable *type_qualifiers;

/* information about the current input file */
typedef struct {
    char *base_name;		/* base input file name */
    char *file_name;		/* current file name */
    FILE *file; 		/* input file */
    unsigned line_num;		/* current line number in input file */
    FILE *tmp_file;		/* temporary file */
    long begin_comment; 	/* tmp file offset after last written ) or ; */
    long end_comment;		/* tmp file offset after last comment */
    boolean convert;		/* if TRUE, convert function definitions */
    boolean changed;		/* TRUE if conversion done in this file */
} IncludeStack;

static IncludeStack *cur_file;	/* current input file */

#include "yyerror.c"

static int haveAnsiParam (void);


/* Flags to enable us to find if a procedure returns a value.
 */
static int return_val,	/* nonzero on BRACES iff return-expression found */
	   returned_at;	/* marker for token-number to set 'return_val' */

#if OPT_LINTLIBRARY
static char *dft_decl_spec (void);

static char *
dft_decl_spec (void)
{
    return (lintLibrary() && !return_val) ? "void" : "int";
}

#else
#define dft_decl_spec() "int"
#endif

static int
haveAnsiParam (void)
{
    Parameter *p;
    if (func_params != 0) {
	for (p = func_params->first; p != 0; p = p->next) {
	    if (p->declarator->func_def == FUNC_ANSI) {
		return TRUE;
	    }
	}
    }
    return FALSE;
}
%}
%%

program
	: /* empty */
	| translation_unit
	;

translation_unit
	: external_declaration
	| translation_unit external_declaration
	;

external_declaration
	: declaration
	| function_definition
	| ';'
	| linkage_specification
	| T_ASM T_ASMARG ';'
	| error T_MATCHRBRACE
	{
	    yyerrok;
	}
	| error ';'
	{
	    yyerrok;
	}
	;

braces
	: T_LBRACE T_MATCHRBRACE
	;

linkage_specification
	: T_EXTERN T_STRING_LITERAL braces
	{
	    /* Provide an empty action here so bison will not complain about
	     * incompatible types in the default action it normally would
	     * have generated.
	     */
	}
	| T_EXTERN T_STRING_LITERAL declaration
	{
	    /* empty */
	}
	;

declaration
	: decl_specifiers ';'
	{
#if OPT_LINTLIBRARY
	    if (types_out && want_typedef()) {
		gen_declarations(&$1, (DeclaratorList *)0);
		flush_varargs();
	    }
#endif
	    free_decl_spec(&$1);
	    end_typedef();
	}
	| decl_specifiers init_declarator_list ';'
	{
	    if (func_params != NULL) {
		set_param_types(func_params, &$1, &$2);
	    } else {
		gen_declarations(&$1, &$2);
#if OPT_LINTLIBRARY
		flush_varargs();
#endif
		free_decl_list(&$2);
	    }
	    free_decl_spec(&$1);
	    end_typedef();
	}
	| any_typedef decl_specifiers
	{
	    cur_decl_spec_flags = $2.flags;
	    free_decl_spec(&$2);
	}
	  opt_declarator_list ';'
	{
	    end_typedef();
	}
	;

any_typedef
	: T_EXTENSION T_TYPEDEF
	{
	    begin_typedef();
	}
	| T_TYPEDEF
	{
	    begin_typedef();
	}
	;

opt_declarator_list
	: /* empty */
	| declarator_list
	;

declarator_list
	: declarator
	{
	    int flags = cur_decl_spec_flags;

	    /* If the typedef is a pointer type, then reset the short type
	     * flags so it does not get promoted.
	     */
	    if (strcmp($1->text, $1->name) != 0)
		flags &= ~(DS_CHAR | DS_SHORT | DS_FLOAT);
	    new_symbol(typedef_names, $1->name, NULL, flags);
	    free_declarator($1);
	}
	| declarator_list ',' declarator
	{
	    int flags = cur_decl_spec_flags;

	    if (strcmp($3->text, $3->name) != 0)
		flags &= ~(DS_CHAR | DS_SHORT | DS_FLOAT);
	    new_symbol(typedef_names, $3->name, NULL, flags);
	    free_declarator($3);
	}
	;

function_definition
	: decl_specifiers declarator
	{
	    check_untagged(&$1);
	    if ($2->func_def == FUNC_NONE) {
		yyerror("syntax error");
		YYERROR;
	    }
	    func_params = &($2->head->params);
	    func_params->begin_comment = cur_file->begin_comment;
	    func_params->end_comment = cur_file->end_comment;
	}
	  opt_declaration_list T_LBRACE
	{
	    /* If we're converting to K&R and we've got a nominally K&R
	     * function which has a parameter which is ANSI (i.e., a prototyped
	     * function pointer), then we must override the deciphered value of
	     * 'func_def' so that the parameter will be converted.
	     */
	    if (func_style == FUNC_TRADITIONAL
	     && haveAnsiParam()
	     && $2->head->func_def == func_style) {
		$2->head->func_def = FUNC_BOTH;
	    }

	    func_params = NULL;

	    if (cur_file->convert)
		gen_func_definition(&$1, $2);
	    gen_prototype(&$1, $2);
#if OPT_LINTLIBRARY
	    flush_varargs();
#endif
	    free_decl_spec(&$1);
	    free_declarator($2);
	}
	  T_MATCHRBRACE
	| declarator
	{
	    if ($1->func_def == FUNC_NONE) {
		yyerror("syntax error");
		YYERROR;
	    }
	    func_params = &($1->head->params);
	    func_params->begin_comment = cur_file->begin_comment;
	    func_params->end_comment = cur_file->end_comment;
	}
	  opt_declaration_list T_LBRACE T_MATCHRBRACE
	{
	    DeclSpec decl_spec;

	    func_params = NULL;

	    new_decl_spec(&decl_spec, dft_decl_spec(), $1->begin, DS_NONE);
	    if (cur_file->convert)
		gen_func_definition(&decl_spec, $1);
	    gen_prototype(&decl_spec, $1);
#if OPT_LINTLIBRARY
	    flush_varargs();
#endif
	    free_decl_spec(&decl_spec);
	    free_declarator($1);
	}
	;

opt_declaration_list
	: /* empty */
	| T_VA_DCL
	| declaration_list
	;

declaration_list
	: declaration
	| declaration_list declaration
	;

decl_specifiers
	: decl_specifier
	| decl_specifiers decl_specifier
	{
	    join_decl_specs(&$$, &$1, &$2);
	    free($1.text);
	    free($2.text);
	}
	;

decl_specifier
	: storage_class
	| type_specifier
	| type_qualifier
	;

storage_class
	: T_AUTO
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_NONE);
	}
	| T_EXTERN
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_EXTERN);
	}
	| T_REGISTER
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_NONE);
	}
	| T_STATIC
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_STATIC);
	}
	| T_INLINE
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_INLINE);
	}
	| T_EXTENSION
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_JUNK);
	}
	;

type_specifier
	: T_CHAR
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_CHAR);
	}
	| T_DOUBLE
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_NONE);
	}
	| T_FLOAT
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_FLOAT);
	}
	| T_INT
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_NONE);
	}
	| T_LONG
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_NONE);
	}
	| T_SHORT
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_SHORT);
	}
	| T_SIGNED
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_NONE);
	}
	| T_UNSIGNED
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_NONE);
	}
	| T_VOID
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_NONE);
	}
	| T_Bool
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_CHAR);
	}
	| T_Complex
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_NONE);
	}
	| T_Imaginary
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_NONE);
	}
	| T_TYPEDEF_NAME
	{
	    Symbol *s;
	    s = find_symbol(typedef_names, $1.text);
	    if (s != NULL)
		new_decl_spec(&$$, $1.text, $1.begin, s->flags);
	}
	| struct_or_union_specifier
	| enum_specifier
	;

type_qualifier
	: T_TYPE_QUALIFIER
	{
	    new_decl_spec(&$$, $1.text, $1.begin, DS_NONE);
	}
	| T_DEFINE_NAME
	{
	    /* This rule allows the <pointer> nonterminal to scan #define
	     * names as if they were type modifiers.
	     */
	    Symbol *s;
	    s = find_symbol(define_names, $1.text);
	    if (s != NULL)
		new_decl_spec(&$$, $1.text, $1.begin, s->flags);
	}
	;

struct_or_union_specifier
	: struct_or_union any_id braces
	{
	    char *s;
	    if ((s = implied_typedef()) == 0)
	        (void)sprintf(s = buf, "%s %s", $1.text, $2.text);
	    new_decl_spec(&$$, s, $1.begin, DS_NONE);
	}
	| struct_or_union braces