index a7f1da98fc3d411877f383ce4b99d6d109a0d554..3607fa7bbd63da7fb9b7c3ba053cf5c69df4a0cc 100644 (file)
@@ -114,6 +114,10 @@ static int composite_read (m4_input_block *, m4 *, bool, bool,
static void composite_unget (m4_input_block *, int);
static bool composite_clean (m4_input_block *, m4 *, bool);
static void composite_print (m4_input_block *, m4 *, m4_obstack *);
+static int eof_peek (m4_input_block *, m4 *, bool);
+static int eof_read (m4_input_block *, m4 *, bool, bool,
+ bool);
+static void eof_unget (m4_input_block *, int);
static void init_builtin_token (m4 *, m4_symbol_value *);
static void append_quote_token (m4 *, m4_obstack *,
/* Read input, return an unsigned char, CHAR_BUILTIN if it is a
builtin, or CHAR_RETRY if none available. If ALLOW_QUOTE, then
CHAR_QUOTE may be returned. If ALLOW_ARGV, then CHAR_ARGV may be
- returned. If SAFE, then do not alter the current file or
- line. */
+ returned. If ALLOW_UNGET, then ensure that the next unget_func
+ will work with the returned character. */
int (*read_func) (m4_input_block *, m4 *, bool allow_quote,
- bool allow_argv, bool safe);
+ bool allow_argv, bool allow_unget);
/* Unread a single unsigned character or CHAR_BUILTIN, must be the
same character previously read by read_func. */
/* Bottom of token_stack, for obstack_free. */
static void *token_bottom;
-/* Pointer to top of current_input. */
+/* Pointer to top of current_input, never NULL. */
static m4_input_block *isp;
-/* Pointer to top of wrapup_stack. */
+/* Pointer to top of wrapup_stack, never NULL. */
static m4_input_block *wsp;
-/* Aux. for handling split m4_push_string (). */
+/* Auxiliary for handling split m4_push_string (), NULL when not
+ pushing text for rescanning. */
static m4_input_block *next;
/* Flag for next_char () to increment current_line. */
@@ -249,6 +254,14 @@ static struct input_funcs composite_funcs = {
composite_print
};
+/* Vtable for recognizing end of input. */
+static struct input_funcs eof_funcs = {
+ eof_peek, eof_read, eof_unget, NULL, NULL
+};
+
+/* Marker at end of an input stack. */
+static m4_input_block input_eof = { NULL, &eof_funcs, "", 0 };
+
\f
/* Input files, from command line or [s]include. */
static int
@@ -270,7 +283,7 @@ file_peek (m4_input_block *me, m4 *context M4_GNUC_UNUSED,
static int
file_read (m4_input_block *me, m4 *context, bool allow_quote M4_GNUC_UNUSED,
- bool allow_argv M4_GNUC_UNUSED, bool safe M4_GNUC_UNUSED)
+ bool allow_argv M4_GNUC_UNUSED, bool allow_unget M4_GNUC_UNUSED)
{
int ch;
@@ -313,7 +326,7 @@ file_clean (m4_input_block *me, m4 *context, bool cleanup)
{
if (!cleanup)
return false;
- if (me->prev)
+ if (me->prev != &input_eof)
m4_debug_message (context, M4_DEBUG_TRACE_INPUT,
_("input reverted to %s, line %d"),
me->prev->file, me->prev->line);
@@ -397,7 +410,7 @@ builtin_peek (m4_input_block *me, m4 *context M4_GNUC_UNUSED,
static int
builtin_read (m4_input_block *me, m4 *context M4_GNUC_UNUSED,
bool allow_quote M4_GNUC_UNUSED, bool allow_argv M4_GNUC_UNUSED,
- bool safe M4_GNUC_UNUSED)
+ bool allow_unget M4_GNUC_UNUSED)
{
/* Not consumed here - wait until init_builtin_token. */
return me->u.builtin ? CHAR_BUILTIN : CHAR_RETRY;
@@ -457,7 +470,7 @@ string_peek (m4_input_block *me, m4 *context M4_GNUC_UNUSED,
static int
string_read (m4_input_block *me, m4 *context M4_GNUC_UNUSED,
bool allow_quote M4_GNUC_UNUSED, bool allow_argv M4_GNUC_UNUSED,
- bool safe M4_GNUC_UNUSED)
+ bool allow_unget M4_GNUC_UNUSED)
{
if (!me->u.u_s.len)
return CHAR_RETRY;
{
/* Free any memory occupied by completely parsed input. */
assert (!next);
- while (isp && pop_input (context, false));
+ while (pop_input (context, false));
/* Reserve the next location on the obstack. */
next = (m4_input_block *) obstack_alloc (current_input, sizeof *next);
@@ -764,7 +777,7 @@ composite_peek (m4_input_block *me, m4 *context, bool allow_argv)
static int
composite_read (m4_input_block *me, m4 *context, bool allow_quote,
- bool allow_argv, bool safe)
+ bool allow_argv, bool allow_unget)
{
m4__symbol_chain *chain = me->u.u_c.chain;
size_t argc;
@@ -818,13 +831,13 @@ composite_read (m4_input_block *me, m4 *context, bool allow_quote,
chain->u.u_a.index++;
chain->u.u_a.comma = true;
m4_push_string_finish ();
- return next_char (context, allow_quote, allow_argv, !safe);
+ return next_char (context, allow_quote, allow_argv, allow_unget);
case M4__CHAIN_LOC:
me->file = chain->u.u_l.file;
me->line = chain->u.u_l.line;
input_change = true;
me->u.u_c.chain = chain->next;
- return next_char (context, allow_quote, allow_argv, !safe);
+ return next_char (context, allow_quote, allow_argv, allow_unget);
default:
assert (!"composite_read");
abort ();
@@ -975,6 +988,33 @@ m4__make_text_link (m4_obstack *obs, m4__symbol_chain **start,
}
+\f
+/* End of input optimization. By providing these dummy callback
+ functions, we guarantee that the input stack is never NULL, and
+ thus make fewer execution branches. */
+static int
+eof_peek (m4_input_block *me, m4 *context M4_GNUC_UNUSED,
+ bool allow_argv M4_GNUC_UNUSED)
+{
+ assert (me == &input_eof);
+ return CHAR_EOF;
+}
+
+static int
+eof_read (m4_input_block *me, m4 *context M4_GNUC_UNUSED,
+ bool allow_quote M4_GNUC_UNUSED, bool allow_argv M4_GNUC_UNUSED,
+ bool allow_unget M4_GNUC_UNUSED)
+{
+ assert (me == &input_eof);
+ return CHAR_EOF;
+}
+
+static void
+eof_unget (m4_input_block *me M4_GNUC_UNUSED, int ch)
+{
+ assert (ch == CHAR_EOF);
+}
+
\f
/* When tracing, print a summary of the contents of the input block
created by push_string_init/push_string_finish to OBS. */
m4__symbol_chain *chain;
assert (obstack_object_size (wrapup_stack) == 0);
- if (wsp)
+ if (wsp != &input_eof)
{
i = wsp;
assert (i->funcs == &composite_funcs && i->u.u_c.end
: (isp->funcs->peek_func (isp, context, true) != CHAR_RETRY))
return false;
- if (tmp != NULL)
- {
- obstack_free (current_input, isp);
- m4__quote_uncache (M4SYNTAX);
- next = NULL; /* might be set in m4_push_string_init () */
- }
+ obstack_free (current_input, isp);
+ m4__quote_uncache (M4SYNTAX);
+ next = NULL; /* might be set in m4_push_string_init () */
isp = tmp;
input_change = true;
obstack_free (current_input, NULL);
free (current_input);
- if (wsp == NULL)
+ if (wsp == &input_eof)
{
obstack_free (wrapup_stack, NULL);
m4_set_current_file (context, NULL);
obstack_init (wrapup_stack);
isp = wsp;
- wsp = NULL;
+ wsp = &input_eof;
input_change = true;
return true;
@@ -1251,21 +1288,15 @@ init_argv_symbol (m4 *context, m4_obstack *obs, m4_symbol_value *value)
for append_quote_token; otherwise, if ALLOW_ARGV, and the current
input matches an argv reference with the correct quoting, return
CHAR_ARGV and leave consumption of data for init_argv_symbol. If
- RETRY, then avoid returning CHAR_RETRY by popping input. */
+ ALLOW_UNGET, then pop input to avoid returning CHAR_RETRY, and
+ ensure that unget_input can safely be called next. */
static int
-next_char (m4 *context, bool allow_quote, bool allow_argv, bool retry)
+next_char (m4 *context, bool allow_quote, bool allow_argv, bool allow_unget)
{
int ch;
while (1)
{
- if (isp == NULL)
- {
- m4_set_current_file (context, NULL);
- m4_set_current_line (context, 0);
- return CHAR_EOF;
- }
-
if (input_change)
{
m4_set_current_file (context, isp->file);
@@ -1274,9 +1305,9 @@ next_char (m4 *context, bool allow_quote, bool allow_argv, bool retry)
assert (isp->funcs->read_func);
while (((ch = isp->funcs->read_func (isp, context, allow_quote,
- allow_argv, !retry))
+ allow_argv, allow_unget))
!= CHAR_RETRY)
- || !retry)
+ || allow_unget)
{
/* if (!IS_IGNORE (ch)) */
return ch;
while (1)
{
- if (block == NULL)
- return CHAR_EOF;
-
assert (block->funcs->peek_func);
ch = block->funcs->peek_func (block, context, allow_argv);
if (ch != CHAR_RETRY)
{
/* if (IS_IGNORE (ch)) */
-/* return next_char (context, false, true, true); */
+/* return next_char (context, false, true, false); */
return ch;
}
/* The function unget_input () puts back a character on the input
stack, using an existing input_block if possible. This is not safe
- to call except immediately after next_char(context, aq, aa, false). */
+ to call except immediately after next_char(context, aq, aa, true). */
static void
unget_input (int ch)
{
- assert (isp != NULL && isp->funcs->unget_func != NULL);
+ assert (isp->funcs->unget_func != NULL);
isp->funcs->unget_func (isp, ch);
}
const char *file = m4_get_current_file (context);
int line = m4_get_current_line (context);
- while ((ch = next_char (context, false, false, true)) != CHAR_EOF
+ while ((ch = next_char (context, false, false, false)) != CHAR_EOF
&& ch != '\n')
;
if (ch == CHAR_EOF)
if (s[1] == '0円')
{
if (consume)
- next_char (context, false, false, true);
+ next_char (context, false, false, false);
return true; /* short match */
}
- next_char (context, false, false, true);
+ next_char (context, false, false, false);
for (n = 1, t = s++; (ch = peek_char (context, false)) == to_uchar (*s++); )
{
- next_char (context, false, false, true);
+ next_char (context, false, false, false);
n++;
if (*s == '0円') /* long match */
{
@@ -1435,7 +1463,7 @@ consume_syntax (m4 *context, m4_obstack *obs, unsigned int syntax)
by CHAR_RETRY. We exploit the fact that CHAR_EOF,
CHAR_BUILTIN, CHAR_QUOTE, and CHAR_ARGV do not satisfy any
syntax categories. */
- while ((ch = next_char (context, allow, allow, false)) != CHAR_RETRY
+ while ((ch = next_char (context, allow, allow, true)) != CHAR_RETRY
&& m4_has_syntax (M4SYNTAX, ch, syntax))
{
assert (ch < CHAR_EOF);
@@ -1448,7 +1476,7 @@ consume_syntax (m4 *context, m4_obstack *obs, unsigned int syntax)
{
assert (ch < CHAR_EOF);
obstack_1grow (obs, ch);
- next_char (context, false, false, true);
+ next_char (context, false, false, false);
continue;
}
return ch == CHAR_EOF;
obstack_init (&token_stack);
token_bottom = obstack_finish (&token_stack);
- isp = NULL;
- wsp = NULL;
+ isp = &input_eof;
+ wsp = &input_eof;
next = NULL;
start_of_input_line = false;
void
m4_input_exit (void)
{
- assert (current_input == NULL);
- assert (wrapup_stack == NULL);
+ assert (!current_input && isp == &input_eof);
+ assert (!wrapup_stack && wsp == &input_eof);
obstack_free (&file_names, NULL);
obstack_free (&token_stack, NULL);
}
@@ -1536,7 +1564,7 @@ m4__next_token (m4 *context, m4_symbol_value *token, int *line,
/* Must consume an input character. */
ch = next_char (context, false, allow_argv && m4__quote_age (M4SYNTAX),
- true);
+ false);
if (ch == CHAR_EOF) /* EOF */
{
#ifdef DEBUG_INPUT
@@ -1568,7 +1596,7 @@ m4__next_token (m4 *context, m4_symbol_value *token, int *line,
if (m4_has_syntax (M4SYNTAX, ch, M4_SYNTAX_ESCAPE))
{ /* ESCAPED WORD */
obstack_1grow (&token_stack, ch);
- if ((ch = next_char (context, false, false, true)) < CHAR_EOF)
+ if ((ch = next_char (context, false, false, false)) < CHAR_EOF)
{
obstack_1grow (&token_stack, ch);
if (m4_has_syntax (M4SYNTAX, ch, M4_SYNTAX_ALPHA))
@@ -1597,7 +1625,7 @@ m4__next_token (m4 *context, m4_symbol_value *token, int *line,
while (1)
{
ch = next_char (context, obs && m4__quote_age (M4SYNTAX), false,
- true);
+ false);
if (ch == CHAR_EOF)
m4_error_at_line (context, EXIT_FAILURE, 0, file, *line, caller,
_("end of file in string"));
@@ -1614,7 +1642,7 @@ m4__next_token (m4 *context, m4_symbol_value *token, int *line,
ch = peek_char (context, false);
if (m4_has_syntax (M4SYNTAX, ch, M4_SYNTAX_RQUOTE))
{
- ch = next_char (context, false, false, true);
+ ch = next_char (context, false, false, false);
#ifdef DEBUG_INPUT
m4_print_token (context, "next_token", M4_TOKEN_MACDEF,
token);
@@ -1656,7 +1684,7 @@ m4__next_token (m4 *context, m4_symbol_value *token, int *line,
assert (!m4__quote_age (M4SYNTAX));
while (1)
{
- ch = next_char (context, false, false, true);
+ ch = next_char (context, false, false, false);
if (ch == CHAR_EOF)
m4_error_at_line (context, EXIT_FAILURE, 0, file, *line, caller,
_("end of file in string"));
@@ -1674,7 +1702,7 @@ m4__next_token (m4 *context, m4_symbol_value *token, int *line,
if (MATCH (context, ch, context->syntax->quote.str2,
false))
{
- ch = next_char (context, false, false, true);
+ ch = next_char (context, false, false, false);
MATCH (context, ch, context->syntax->quote.str2, true);
#ifdef DEBUG_INPUT
m4_print_token (context, "next_token", M4_TOKEN_MACDEF,
@@ -1714,7 +1742,7 @@ m4__next_token (m4 *context, m4_symbol_value *token, int *line,
obstack_1grow (obs_safe, ch);
while (1)
{
- ch = next_char (context, false, false, true);
+ ch = next_char (context, false, false, false);
if (ch == CHAR_EOF)
m4_error_at_line (context, EXIT_FAILURE, 0, file, *line, caller,
_("end of file in comment"));
@@ -1746,7 +1774,7 @@ m4__next_token (m4 *context, m4_symbol_value *token, int *line,
context->syntax->comm.len1);
while (1)
{
- ch = next_char (context, false, false, true);
+ ch = next_char (context, false, false, false);
if (ch == CHAR_EOF)
m4_error_at_line (context, EXIT_FAILURE, 0, file, *line, caller,
_("end of file in comment"));