lintlibs.c

/* $Id: lintlibs.c,v 4.21 2011/01/02 19:24:03 tom Exp $
 *
 * C prototype/lint-library generator
 * These routines implement the semantic actions for lint libraries executed by
 * the yacc parser.
 */
#include <semantic.h>
#include <symbol.h>

#if OPT_LINTLIBRARY

unsigned in_include;

static SymbolTable *include_list;
static SymbolTable *declared_list;

static int in_typedef;
static int blank_lines;		/* used to filter blank lines from typedefs */

static int implied_cnt;		/* state-count associated with implied_buf */
static char *implied_buf;

static char quote_l = '"';
static char quote_r = '"';

/*
 * Output a string to standard output, keeping track of the trailing newlines
 * to make it simple to format with blank lines.
 */
void
put_string(FILE *outf, const char *s)
{
    if (*s != '\0') {
	fputs(s, outf);
	if (outf == stdout) {	/* ensure we aren't doing temp-file! */
	    while (*s != '\0') {
		if (*s++ == '\n')
		    blank_lines++;
		else
		    blank_lines = 0;
	    }
	}
    }
}

/*
 * Output a single character
 */
void
put_char(FILE *outf, int c)
{
    static char s[] = "?";
    s[0] = (char) c;
    put_string(outf, s);
}

/*
 * Write a newline, taking care not to make a blank line
 */
void
put_newline(FILE *outf)
{
    while (!blank_lines)
	put_string(outf, "\n");
}

/*
 * Make a blank line (limited to 2 successive newlines)
 */
void
put_blankline(FILE *outf)
{
    while (blank_lines < 2)
	put_string(outf, "\n");
}

/*
 * Put a token, padded by a tab if it is short enough
 */
void
put_padded(FILE *outf, const char *s)
{
    put_string(outf, s);
    put_char(outf, (lintLibrary() && strlen(s) < 8) ? '\t' : ' ');
}

/*
 * Format lint-library so that we put a blank line before each item that may
 * take up multiple lines:
 *	0) functions
 *	1) typedefs (explicit and implied)
 * as well as when transitioning to
 *	2) variable declarations
 *
 * If the "-T" option is set, we skip a blank line around typedefs.
 */
void
fmt_library(int code)
{
    if (lintLibrary() || types_out) {
	static int save;

	if (!lintLibrary() && code == 0)
	    code = 3;
	if (code <= 1 || code != save)
	    put_blankline(stdout);
	save = code;
    }
}

/*
 * conversion for names so test-diffs are less
 * (patch: should use relpath)
 */
static char *
strip_name(char *s)
{
#ifdef	vms
    static char stripped[BUFSIZ];
    auto int len = strlen(getwd(stripped));
    if (strlen(s) > len
	&& !strncmp(s, stripped, len))
	s += len;
    s = (vms2name(stripped, s));
#else
    static char GccLeaf[] = "/gcc-lib/";
    static char IncLeaf[] = "/include/";
    char *t;
    unsigned n;
    size_t len;
    int standard = FALSE;

    for (n = 1; n < num_inc_dir; n++) {
	len = strlen(inc_dir[n]);
	if (!strncmp(inc_dir[n], s, len)
	    && is_path_sep(s[len])) {
	    standard = TRUE;
	    s += len + 1;
	    quote_l = '<';
	    quote_r = '>';
	    break;
	}
    }
    if (!standard) {
	quote_l =
	    quote_r = '"';
	if (*s == '.' && is_path_sep(s[1]))
	    s += 2;
	else if ((t = strstr(s, GccLeaf)) != 0
		 && (t = strstr(t, IncLeaf)) != 0) {
	    s = t + sizeof(IncLeaf) - 1;
	    quote_l = '<';
	    quote_r = '>';
	}
    }
#endif
    return s;
}
#define	CUR_FILE	strip_name(cur_file_name())

static unsigned base_level;
static unsigned inc_depth = 0;
static char **inc_stack = 0;

static char *
get_inc_stack(unsigned n)
{
    return (((int) n) < 0 || n >= inc_depth) ? 0 : inc_stack[n];
}

#ifdef	DEBUG
static void
dump_stack(char *tag)
{
    unsigned j;
    printf("/* stack%s:%s", tag, cur_file_name());
    for (j = 0; j <= in_include; j++)
	printf("\n\t%d%s:%s", j,
	       j == base_level ? "*" : "",
	       get_inc_stack(j) ? get_inc_stack(j) : "?");
    printf(" */\n");
}
#endif /* DEBUG */

static void
free_inc_stack(unsigned n)
{
    if (get_inc_stack(n) != 0) {
	free(inc_stack[n]);
	inc_stack[n] = 0;
    }
}

static void
make_inc_stack(unsigned n, char *s)
{
    if (n != 0) {
	unsigned need = (n | 31) + 1;

	free_inc_stack(n);
	if (n > inc_depth) {
	    inc_stack = type_realloc(char *, inc_stack, need);
	    while (inc_depth < need)
		inc_stack[inc_depth++] = 0;
	    inc_depth = need;
	}
	inc_stack[n] = xstrdup(s);
    }
}

/*
 * Keep track of include-files so that we only include each once.
 */
static int
already_included(char *path)
{
    if (!include_list)
	include_list = new_symbol_table();
    if (find_symbol(include_list, path) != NULL)
	return TRUE;
    new_symbol(include_list, path, NULL, DS_NONE);
    return FALSE;
}

/*
 * Keep track of variables that may have been implicitly declared via
 * include-files so that we declare them only once in the lint library
 * output.
 */
int
already_declared(char *name)
{
    if (declared_list == 0)
	declared_list = new_symbol_table();
    if (find_symbol(declared_list, name) == 0) {
	(void) new_symbol(declared_list, name, 0, 0);
	return FALSE;
    }
    return TRUE;
}

/*
 * Initialize state for 'track_in()'
 */
static int InitTracking;

void
begin_tracking(void)
{
    InitTracking = FALSE;
}

static int
c_suffix(char *path)
{
    char *last = path + strlen(path);
#ifdef	vms
    char *vers = strrchr(path, ';');
    if (vers != 0)
	last = vers;
#endif
    return ((last - path) > 2 && !strcmp(last - 2, ".c"));
}

/*
 * Keep track of "include files" that we always want to filter out (ignore).
 */
static int
ignored(char *path)
{
    if (strcmp(path, "<built-in>") == 0
	|| strcmp(path, "<command line>") == 0)
	return TRUE;
    return FALSE;
}

static const char *
skip_dot(const char *a)
{
    if (!strncmp(a, "./", (size_t) 2))
	a += 2;
    return a;
}

static int
same_file(const char *a, const char *b)
{
    return !strcmp(skip_dot(a), skip_dot(b));
}

/*
 * For lint-library, we want to keep track of what file we are in so that we
 * can generate appropriate comments and include-statements.
 *
 * The main program 'cproto' is invoked with 'cpp' once for each C-file,
 * relying on it to spit out "#" comments which identify the name and line
 * number of each processed file.  After the first '#' comment, all others
 * refer to included files.
 */
void
track_in(void)
{
    static char old_file[MAX_TEXT_SIZE];	/* from last call */
    auto int show = lintLibrary();

    if (!show && !do_tracking && !debug_trace)
	return;

#ifdef	DEBUG
    printf("/* track_in: in_include=%d line_num=%d base_file=%s */\n",
	   in_include, cur_line_num(), base_file);
    dump_stack("-before");
#endif /* DEBUG */

    if (cur_line_num() == 0) {	/* begin new (nested?) file */
	if (!InitTracking) {
	    InitTracking = TRUE;
	    /* yacc may omit first cpp-line! */
	    in_include =
		base_level = (unsigned) !same_file(cur_file_name(), base_file);
	    make_inc_stack(0, base_file);
	} else if (same_file(cur_file_name(), base_file)) {
	    flush_varargs();
	    in_include = 0;	/* reset level */
	} else {
	    make_inc_stack(in_include, old_file);
	    if (in_include++ == 0) {
		char *s = CUR_FILE;
		if (show && !already_included(s) && !ignored(s)) {
		    fmt_library(4);
		    put_string(stdout, "#include ");
		    put_char(stdout, quote_l);
		    put_string(stdout, s);
		    put_char(stdout, quote_r);
		    put_newline(stdout);
		}
		if (debug_trace)
		    fprintf(stderr, "++ %s\n", cur_file_name());
	    }
	    make_inc_stack(in_include, cur_file_name());
	}
	(void) strcpy(old_file, cur_file_name());
    } else if (same_file(cur_file_name(), base_file)) {
	in_include = 0;		/* kludgy bison! */
	(void) strcpy(old_file, cur_file_name());
    } else if (!same_file(old_file, cur_file_name())) {		/* continue/unnest ? */
	unsigned n;
	int found;
	char *s = cur_file_name();
#ifdef DEBUG
	char temp[80];
#endif

	flush_varargs();
	for (n = in_include, found = FALSE; (int) n >= 0; n--) {
	    if (same_file(get_inc_stack(n), s)) {
		found = TRUE;
		in_include--;
		break;
	    }
	}
	if (!found) {
	    /*
	     * There's two kinds of broken programs that can cause
	     * us to lose sync at this point:  (1) programs such as
	     * yacc that don't reference the grammar file, instead
	     * referencing the generated file, and (2) broken
	     * preprocessors (such as on OSF/1) that neglect to
	     * report line #1 on headers that are rejected due to
	     * prior inclusion.
	     *
	     * If the source file's extension is ".h", we'll assume
	     * the latter case (i.e., just report it).  The former
	     * case requires that we reset the stack.
	     */
#ifdef DEBUG
	    sprintf(temp, "/* lost sync @%d: ", cur_line_num() + 1);
	    put_blankline(stdout);
	    put_string(stdout, temp);
	    put_string(stdout, s);
	    put_string(stdout, " */\n");
#endif
	    if (in_include == 1 && c_suffix(s)) {
		/* yacc did it again! */
		in_include = 0;
		make_inc_stack(in_include, strcpy(base_file, s));
#ifdef DEBUG
		put_string(stdout, "/* processed ");
		put_string(stdout, s);
		put_string(stdout, " */\n");
#endif
	    }
	}
	(void) strcpy(old_file, get_inc_stack(in_include));
    }
#ifdef	DEBUG
    dump_stack("-after");
#endif /* DEBUG */
}

/*
 * Copy/append to 'implied_buf[]'
 */
static void
add2implied_buf(const char *s, int append)
{
    static size_t implied_len;	/* current strlen(implied_buf) */
    static size_t implied_max;	/* maximum size of implied_buf */

    if (!append)
	implied_len = 0;
    implied_len += strlen(s);

    if (implied_buf == 0)
	*(implied_buf = (char *) malloc(implied_max = BUFSIZ)) = '\0';
    if (implied_max < implied_len + 2)
	implied_buf = (char *) realloc(implied_buf, implied_max +=
				       implied_len + 2);
    if (!append)
	*implied_buf = '\0';
    (void) strcat(implied_buf, s);
}

/*
 * If the "-t" option is set (or if we are generating a lint-library), we
 * intercept tokens which are part of a typedef, copying them to the output.
 *
 * The 'imply_typedef()' entrypoint is called from the grammar for the special
 * cases of struct/union/enum when we expect to be getting curly-braces which
 * define the structure.  If no curly-braces are found by the end of the
 * rule, we can discard the buffer.
 */
int
want_typedef(void)
{
    if (lintLibrary()) {
	if (in_include == 0)
	    return (TRUE);
    } else if (types_out) {
	return (TRUE);
    }
    return (FALSE);
}

void
begin_typedef(void)
{
    if (want_typedef()) {
	in_typedef = TRUE;
	fmt_library(1);
	copy_typedef("typedef");
    }
}

void
copy_typedef(const char *s)
{
    if (!strcmp(s, "/*")
	|| *s == '#') ;		/* ignore */
    else if (in_typedef) {
	if (*s == '\n')
	    put_newline(stdout);
	else
	    put_string(stdout, s);
    } else if (implied_cnt > 0) {	/* "KEY ID {" ? */
	add2implied_buf(s, TRUE);
	if (!isspace(UCH(*s)))
	    implied_cnt--;
	if ((implied_cnt == 2 || implied_cnt == 1)
	    && !strcmp(s, "{")) {
	    implied_cnt = 9999;
	}
    }
}

void
end_typedef(void)
{
    copy_typedef("\n");
    in_typedef = FALSE;
    (void) implied_typedef();
}

void
imply_typedef(const char *s)
{
    if (!in_typedef && want_typedef()) {
	add2implied_buf(s, FALSE);
	implied_cnt = 3;
    }
}

char *
implied_typedef(void)
{
    if (implied_cnt > 0) {
	implied_cnt = 0;
	return (implied_buf);
    }
    return (0);
}

/*
 * Indent lint-library stuff to make it readable
 */
void
indent(FILE *outf)
{
    put_string(outf, "\n\t\t");
}

/* Test for the special case of an ellipsis-parameter when trying to make a
 * lint-library
 */
int
lint_ellipsis(Parameter * p)
{
    return (knrLintLibrary()
	    && (!strcmp(p->declarator->name, ELLIPSIS)));
}

/*
 * Reset the data used for "VARARGS" comment.  Actually, reset almost any
 * special attribute that's attached to a function, so we don't accidentally
 * propagate it to the next function (or data) to be output.
 */
void
flush_varargs(void)
{
    exitlike_func = FALSE;

    varargs_num = 0;
    if (varargs_str != 0) {
	free(varargs_str);
	varargs_str = 0;
    }
}

/* If either we received a "VARARGS" comment in the lexical scanner, or if the
 * parameter list contains an ellipsis, generate a corresponding "VARARGS"
 * comment for lint-library output.
 */
void
ellipsis_varargs(Declarator * d)
{
    int count;
    Parameter *p;

    fmt_library(0);
    for (p = d->params.first, count = 0; p != 0; p = p->next, count++)
	if (lint_ellipsis(p)) {
	    varargs_num = count;
	    break;
	}
    if (varargs_num != 0) {
	put_string(stdout, "\t/* VARARGS");
	if (varargs_num > 0) {
	    printf("%d", varargs_num);
	    if (varargs_str != 0) {
		put_char(stdout, ' ');
		put_string(stdout, varargs_str);
	    }
	}
	flush_varargs();
	put_string(stdout, " */\n");
    }
}

/* (Attempt to) create a parameter name for lint-library applications in which
 * we are starting from a function prototype which has no explicit parameter
 * name.
 */
char *
supply_parm(int count)
{
    static char temp[80];
    (void) sprintf(temp, "p%d", count);
    while (is_typedef_name(temp) && (strlen(temp) < sizeof(temp) - 1))
	(void) strcat(temp, "_");
    return (temp);
}

/*
 * (Attempt to) distinguish between declarators for functions and for
 * function pointers.
 */
int
is_actual_func(Declarator * d)
{
    if (lintLibrary() && (d->func_def != FUNC_NONE)) {
	if (d->func_stack->text[0] == PAREN_L
	    && d->func_stack->text[1] == '*') {
	    if (strstr(d->func_stack->text, "()") != 0)
		return TRUE;
	} else {
	    return TRUE;
	}
    }
    return FALSE;
}

/*
 * Output the body (or terminating semicolon) of a procedure
 */
void
put_body(
	    FILE *outf,
	    DeclSpec * decl_spec,	/* declaration specifier */
	    Declarator * declarator)
{
    const char *spec_text;

    if (is_actual_func(declarator)) {
	strcut(decl_spec->text, "static");
	strcut(decl_spec->text, "extern");
	indent(outf);
	put_char(outf, CURL_L);
	if (!*(spec_text = decl_spec->text))
	    spec_text = "void";
	if (exitlike_func) {
	    put_string(outf, " for(;;); /* no return */ ");
	} else if (!strcmp(spec_text, "void")
		   && declarator->text[0] != '*'
		   && declarator->func_stack->func_def == FUNC_NONE) {
	    put_string(outf, " /* void */ ");
	} else {
	    put_string(outf, " return(*(");
	    if (declarator->func_stack->func_def == FUNC_NONE) {
		put_string(outf, spec_text);
		put_char(outf, ' ');
		if (declarator->pointer) {
		    char *s = declarator->text;
		    while (*s++ == '*')
			put_char(outf, '*');
		}
		put_char(outf, '*');
	    } else {
		put_string(outf, spec_text);
		put_string(outf, "(*)()");
	    }
	    put_string(outf, ")0); ");
	}
	put_char(outf, CURL_R);
    } else {
	if (proto_style == PROTO_LINTLIBRARY
	    || proto_style == PROTO_ANSI_LLIB) {
	    /* SVR4 lint complains if we declare const data without an
	     * initializer.
	     */
	    if (strkey(decl_spec->text, "const") != NULL
		|| strkey(declarator->text, "const") != NULL) {
		put_string(outf, " = {0}");
	    }
	}
	put_string(outf, ";");
    }
    put_newline(outf);
    exitlike_func = FALSE;
}

#ifdef NO_LEAKS
void
free_lintlibs(void)
{
    unsigned n;

    if (implied_buf != 0)
	free(implied_buf);
    if (inc_stack != 0) {
	for (n = 0; n < inc_depth; n++)
	    free_inc_stack(n);
	free(inc_stack);
    }
    if (include_list != 0)
	free_symbol_table(include_list);
    if (declared_list != 0)
	free_symbol_table(declared_list);
}
#endif

#endif /* OPT_LINTLIBRARY */