aicasm_scan.l

linux内核源码

				BEGIN MACROARGLIST;
				yylval.sym = symtable_get(yytext);
				unput('(');
				return T_SYMBOL;
			}
<MACROARGLIST>{WORD}	{
				yylval.str = yytext;
				return T_ARG;
			}
<MACROARGLIST>{SPACE}   ;
<MACROARGLIST>[(,]	{
				return yytext[0];
			}
<MACROARGLIST>[)]	{
				string_buf_ptr = string_buf;
				BEGIN MACROBODY;
				return ')';
			}
<MACROARGLIST>.		{
				snprintf(buf, sizeof(buf), "Invalid character "
					 "'%c' in macro argument list",
					 yytext[0]);
				stop(buf, EX_DATAERR);
			}
<MACROCALLARGS>{SPACE}  ;
<MACROCALLARGS>\(	{
				parren_count++;
				if (parren_count == 1)
					return ('(');
				*string_buf_ptr++ = '(';
			}
<MACROCALLARGS>\)	{
				parren_count--;
				if (parren_count == 0) {
					BEGIN INITIAL;
					return (')');
				}
				*string_buf_ptr++ = ')';
			}
<MACROCALLARGS>{MCARG}	{
				char *yptr;

				yptr = yytext;
				while (*yptr)
					*string_buf_ptr++ = *yptr++;
			}
<MACROCALLARGS>\,	{
				if (string_buf_ptr != string_buf) {
					/*
					 * Return an argument and
					 * rescan this comma so we
					 * can return it as well.
					 */
					*string_buf_ptr = '\0';
					yylval.str = string_buf;
					string_buf_ptr = string_buf;
					unput(',');
					return T_ARG;
				}
				return ',';
			}
<MACROBODY>\\\n		{
				/* Eat escaped newlines. */
				++yylineno;
			}
<MACROBODY>\r		;
<MACROBODY>\n		{
				/* Macros end on the first unescaped newline. */
				BEGIN INITIAL;
				*string_buf_ptr = '\0';
				yylval.str = string_buf;
				++yylineno;
				return T_MACROBODY;
			}
<MACROBODY>{MBODY}	{
				char *yptr;
				char c;

				yptr = yytext;
				while (c = *yptr++) {
					/*
					 * Strip carriage returns.
					 */
					if (c == '\r')
						continue;
					*string_buf_ptr++ = c;
				}
			}
{WORD}\(		{
				char *yptr;
				char *ycopy;

				/* May be a symbol or a macro invocation. */
				yylval.sym = symtable_get(yytext);
				if (yylval.sym->type == MACRO) {
					YY_BUFFER_STATE old_state;
					YY_BUFFER_STATE temp_state;

					ycopy = strdup(yytext);
					yptr = ycopy + yyleng;
					while (yptr > ycopy)
						unput(*--yptr);
					old_state = YY_CURRENT_BUFFER;
					temp_state =
					    yy_create_buffer(stdin,
							     YY_BUF_SIZE);
					yy_switch_to_buffer(temp_state);
					mm_switch_to_buffer(old_state);
					mmparse();
					mm_switch_to_buffer(temp_state);
					yy_switch_to_buffer(old_state);
					mm_delete_buffer(temp_state);
					expand_macro(yylval.sym);
				} else {
					if (yylval.sym->type == UNINITIALIZED) {
						/* Try without the '(' */
						symbol_delete(yylval.sym);
						yytext[yyleng-1] = '\0';
						yylval.sym =
						    symtable_get(yytext);
					}
					unput('(');
					return T_SYMBOL;
				}
			}
{WORD}			{
				yylval.sym = symtable_get(yytext);
				if (yylval.sym->type == MACRO) {
					expand_macro(yylval.sym);
				} else {
					return T_SYMBOL;
				}
			}
.			{ 
				snprintf(buf, sizeof(buf), "Invalid character "
					 "'%c'", yytext[0]);
				stop(buf, EX_DATAERR);
			}
%%

typedef struct include {
        YY_BUFFER_STATE  buffer;
        int              lineno;
        char            *filename;
	SLIST_ENTRY(include) links;
}include_t;

SLIST_HEAD(, include) include_stack;

void
include_file(char *file_name, include_type type)
{
	FILE *newfile;
	include_t *include;

	newfile = NULL;
	/* Try the current directory first */
	if (includes_search_curdir != 0 || type == SOURCE_FILE)
		newfile = fopen(file_name, "r");

	if (newfile == NULL && type != SOURCE_FILE) {
                path_entry_t include_dir;
                for (include_dir = search_path.slh_first;
                     include_dir != NULL;                
                     include_dir = include_dir->links.sle_next) {
			char fullname[PATH_MAX];

			if ((include_dir->quoted_includes_only == TRUE)
			 && (type != QUOTED_INCLUDE))
				continue;

			snprintf(fullname, sizeof(fullname),
				 "%s/%s", include_dir->directory, file_name);

			if ((newfile = fopen(fullname, "r")) != NULL)
				break;
                }
        }

	if (newfile == NULL) {
		perror(file_name);
		stop("Unable to open input file", EX_SOFTWARE);
		/* NOTREACHED */
	}

	if (type != SOURCE_FILE) {
		include = (include_t *)malloc(sizeof(include_t));
		if (include == NULL) {
			stop("Unable to allocate include stack entry",
			     EX_SOFTWARE);
			/* NOTREACHED */
		}
		include->buffer = YY_CURRENT_BUFFER;
		include->lineno = yylineno;
		include->filename = yyfilename;
		SLIST_INSERT_HEAD(&include_stack, include, links);
	}
	yy_switch_to_buffer(yy_create_buffer(newfile, YY_BUF_SIZE));
	yylineno = 1;
	yyfilename = strdup(file_name);
}

static void next_substitution(struct symbol *mac_symbol, const char *body_pos,
			      const char **next_match,
			      struct macro_arg **match_marg, regmatch_t *match);

void
expand_macro(struct symbol *macro_symbol)
{
	struct macro_arg *marg;
	struct macro_arg *match_marg;
	const char *body_head;
	const char *body_pos;
	const char *next_match;

	/*
	 * Due to the nature of unput, we must work
	 * backwards through the macro body performing
	 * any expansions.
	 */
	body_head = macro_symbol->info.macroinfo->body;
	body_pos = body_head + strlen(body_head);
	while (body_pos > body_head) {
		regmatch_t match;

		next_match = body_head;
		match_marg = NULL;
		next_substitution(macro_symbol, body_pos, &next_match,
				  &match_marg, &match);

		/* Put back everything up until the replacement. */
		while (body_pos > next_match)
			unput(*--body_pos);

		/* Perform the replacement. */
		if (match_marg != NULL) {
			const char *strp;

			next_match = match_marg->replacement_text;
			strp = next_match + strlen(next_match);
			while (strp > next_match)
				unput(*--strp);

			/* Skip past the unexpanded macro arg. */
			body_pos -= match.rm_eo - match.rm_so;
		}
	}

	/* Cleanup replacement text. */
	STAILQ_FOREACH(marg, &macro_symbol->info.macroinfo->args, links) {
		free(marg->replacement_text);
	}
}

/*
 * Find the next substitution in the macro working backwards from
 * body_pos until the beginning of the macro buffer.  next_match
 * should be initialized to the beginning of the macro buffer prior
 * to calling this routine.
 */
static void
next_substitution(struct symbol *mac_symbol, const char *body_pos,
		  const char **next_match, struct macro_arg **match_marg,
		  regmatch_t *match)
{
	regmatch_t	  matches[2];
	struct macro_arg *marg;
	const char	 *search_pos;
	int		  retval;

	do {
		search_pos = *next_match;

		STAILQ_FOREACH(marg, &mac_symbol->info.macroinfo->args, links) {

			retval = regexec(&marg->arg_regex, search_pos, 2,
					 matches, 0);
			if (retval == 0
			 && (matches[1].rm_eo + search_pos) <= body_pos
			 && (matches[1].rm_eo + search_pos) > *next_match) {
				*match = matches[1];
				*next_match = match->rm_eo + search_pos;
				*match_marg = marg;
			}
		}
	} while (search_pos != *next_match);
}

int
yywrap()
{
	include_t *include;

	yy_delete_buffer(YY_CURRENT_BUFFER);
	(void)fclose(yyin);
	if (yyfilename != NULL)
		free(yyfilename);
	yyfilename = NULL;
	include = include_stack.slh_first;
	if (include != NULL) {
		yy_switch_to_buffer(include->buffer);
		yylineno = include->lineno;
		yyfilename = include->filename;
		SLIST_REMOVE_HEAD(&include_stack, links);
		free(include);
		return (0);
	}
	return (1);
}