/* Append the macro buffer SRC to the end of DEST, and ensure that
doing so doesn't splice the token at the end of SRC with the token
at the beginning of DEST. SRC and DEST must have their last_token
fields set. Upon return, DEST's last_token field is set correctly.
For example:
If DEST is "(" and SRC is "y", then we can return with
DEST set to "(y" --- we've simply appended the two buffers.
However, if DEST is "x" and SRC is "y", then we must not return
with DEST set to "xy" --- that would splice the two tokens "x" and
"y" together to make a single token "xy". However, it would be
fine to return with DEST set to "x y". Similarly, "<" and "<" must
yield "< <", not "<<", etc. */
static void
append_tokens_without_splicing (struct macro_buffer *dest,
struct macro_buffer *src)
{
int original_dest_len = dest->len;
struct macro_buffer dest_tail, new_token;
gdb_assert (src->last_token != -1);
gdb_assert (dest->last_token != -1);
/* First, just try appending the two, and call get_token to see if
we got a splice. */
appendmem (dest, src->text, src->len);
/* If DEST originally had no token abutting its end, then we can't
have spliced anything, so we're done. */
if (dest->last_token == original_dest_len)
{
dest->last_token = original_dest_len + src->last_token;
return;
}
/* Set DEST_TAIL to point to the last token in DEST, followed by
all the stuff we just appended. */
init_shared_buffer (&dest_tail,
dest->text + dest->last_token,
dest->len - dest->last_token);
/* Re-parse DEST's last token. We know that DEST used to contain
at least one token, so if it doesn't contain any after the
append, then we must have spliced "/" and "*" or "/" and "/" to
make a comment start. (Just for the record, I got this right
the first time. This is not a bug fix.) */
if (get_token (&new_token, &dest_tail)
&& (new_token.text + new_token.len
== dest->text + original_dest_len))
{
/* No splice, so we're done. */
dest->last_token = original_dest_len + src->last_token;
return;
}
/* Okay, a simple append caused a splice. Let's chop dest back to
its original length and try again, but separate the texts with a
space. */
dest->len = original_dest_len;
appendc (dest, ' ');
appendmem (dest, src->text, src->len);
init_shared_buffer (&dest_tail,
dest->text + dest->last_token,
dest->len - dest->last_token);
/* Try to re-parse DEST's last token, as above. */
if (get_token (&new_token, &dest_tail)
&& (new_token.text + new_token.len
== dest->text + original_dest_len))
{
/* No splice, so we're done. */
dest->last_token = original_dest_len + 1 + src->last_token;
return;
}
/* As far as I know, there's no case where inserting a space isn't
enough to prevent a splice. */
internal_error (__FILE__, __LINE__,
_("unable to avoid splicing tokens during macro expansion"));
}
static void
substitute_args (struct macro_buffer *dest,
struct macro_definition *def,
int is_varargs, const struct macro_buffer *va_arg_name,
int argc, struct macro_buffer *argv,
struct macro_name_list *no_loop,
macro_lookup_ftype *lookup_func,
void *lookup_baton)
{
/* A macro buffer for the macro's replacement list. */
struct macro_buffer replacement_list;
/* The token we are currently considering. */
struct macro_buffer tok;
/* The replacement list's pointer from just before TOK was lexed. */
char *original_rl_start;
/* We have a single lookahead token to handle token splicing. */
struct macro_buffer lookahead;
/* The lookahead token might not be valid. */
int lookahead_valid;
/* The replacement list's pointer from just before LOOKAHEAD was
lexed. */
char *lookahead_rl_start;
init_shared_buffer (&replacement_list, (char *) def->replacement,
strlen (def->replacement));
gdb_assert (dest->len == 0);
dest->last_token = 0;
original_rl_start = replacement_list.text;
if (! get_token (&tok, &replacement_list))
return;
lookahead_rl_start = replacement_list.text;
lookahead_valid = get_token (&lookahead, &replacement_list);
for (;;)
{
/* Just for aesthetics. If we skipped some whitespace, copy
that to DEST. */
if (tok.text > original_rl_start)
{
appendmem (dest, original_rl_start, tok.text - original_rl_start);
dest->last_token = dest->len;
}
/* Is this token the stringification operator? */
if (tok.len == 1
&& tok.text[0] == '#')
{
int arg;
if (!lookahead_valid)
error (_("Stringification operator requires an argument."));
arg = find_parameter (&lookahead, is_varargs, va_arg_name,
def->argc, def->argv);
if (arg == -1)
error (_("Argument to stringification operator must name "
"a macro parameter."));
stringify (dest, argv[arg].text, argv[arg].len);
/* Read one token and let the loop iteration code handle the
rest. */
lookahead_rl_start = replacement_list.text;
lookahead_valid = get_token (&lookahead, &replacement_list);
}
/* Is this token the splicing operator? */
else if (tok.len == 2
&& tok.text[0] == '#'
&& tok.text[1] == '#')
error (_("Stray splicing operator"));
/* Is the next token the splicing operator? */
else if (lookahead_valid
&& lookahead.len == 2
&& lookahead.text[0] == '#'
&& lookahead.text[1] == '#')
{
int finished = 0;
int prev_was_comma = 0;
/* Note that GCC warns if the result of splicing is not a
token. In the debugger there doesn't seem to be much
benefit from doing this. */
/* Insert the first token. */
if (tok.len == 1 && tok.text[0] == ',')
prev_was_comma = 1;
else
{
int arg = find_parameter (&tok, is_varargs, va_arg_name,
def->argc, def->argv);
if (arg != -1)
appendmem (dest, argv[arg].text, argv[arg].len);
else
appendmem (dest, tok.text, tok.len);
}
/* Apply a possible sequence of ## operators. */
for (;;)
{
if (! get_token (&tok, &replacement_list))
error (_("Splicing operator at end of macro"));
/* Handle a comma before a ##. If we are handling
varargs, and the token on the right hand side is the
varargs marker, and the final argument is empty or
missing, then drop the comma. This is a GNU
extension. There is one ambiguous case here,
involving pedantic behavior with an empty argument,
but we settle that in favor of GNU-style (GCC uses an
option). If we aren't dealing with varargs, we
simply insert the comma. */
if (prev_was_comma)
{
if (! (is_varargs
&& tok.len == va_arg_name->len
&& !memcmp (tok.text, va_arg_name->text, tok.len)
&& argv[argc - 1].len == 0))
appendmem (dest, ",", 1);
prev_was_comma = 0;
}
/* Insert the token. If it is a parameter, insert the
argument. If it is a comma, treat it specially. */
if (tok.len == 1 && tok.text[0] == ',')
prev_was_comma = 1;
else
{
int arg = find_parameter (&tok, is_varargs, va_arg_name,
def->argc, def->argv);
if (arg != -1)
appendmem (dest, argv[arg].text, argv[arg].len);
else
appendmem (dest, tok.text, tok.len);
}
/* Now read another token. If it is another splice, we
loop. */
original_rl_start = replacement_list.text;
if (! get_token (&tok, &replacement_list))
{
finished = 1;
break;
}
if (! (tok.len == 2
&& tok.text[0] == '#'
&& tok.text[1] == '#'))
break;
}
if (prev_was_comma)
{
/* We saw a comma. Insert it now. */
appendmem (dest, ",", 1);
}
dest->last_token = dest->len;
if (finished)
lookahead_valid = 0;
else
{
/* Set up for the loop iterator. */
lookahead = tok;
lookahead_rl_start = original_rl_start;
lookahead_valid = 1;
}
}
else
{
/* Is this token an identifier? */
int substituted = 0;
int arg = find_parameter (&tok, is_varargs, va_arg_name,
def->argc, def->argv);
if (arg != -1)
{
struct macro_buffer arg_src;
/* Expand any macro invocations in the argument text,
and append the result to dest. Remember that scan
mutates its source, so we need to scan a new buffer
referring to the argument's text, not the argument
itself. */
init_shared_buffer (&arg_src, argv[arg].text, argv[arg].len);
scan (dest, &arg_src, no_loop, lookup_func, lookup_baton);
substituted = 1;
}
/* If it wasn't a parameter, then just copy it across. */
if (! substituted)
append_tokens_without_splicing (dest, &tok);
}
if (! lookahead_valid)
break;
tok = lookahead;
original_rl_start = lookahead_rl_start;
lookahead_rl_start = replacement_list.text;
lookahead_valid = get_token (&lookahead, &replacement_list);
}
}
/* Given the macro definition DEF, being invoked with the actual
arguments given by ARGC and ARGV, substitute the arguments into the
replacement list, and store the result in DEST.
If it is necessary to expand macro invocations in one of the
arguments, use LOOKUP_FUNC and LOOKUP_BATON to find the macro
definitions, and don't expand invocations of the macros listed in
NO_LOOP. */
static void
substitute_args (struct macro_buffer *dest,
struct macro_definition *def,
int argc, struct macro_buffer *argv,
struct macro_name_list *no_loop,
macro_lookup_ftype *lookup_func,
void *lookup_baton)
{
/* A macro buffer for the macro's replacement list. */
struct macro_buffer replacement_list;
init_shared_buffer (&replacement_list, (char *) def->replacement,
strlen (def->replacement));
gdb_assert (dest->len == 0);
dest->last_token = 0;
for (;;)
{
struct macro_buffer tok;
char *original_rl_start = replacement_list.text;
int substituted = 0;
/* Find the next token in the replacement list. */
if (! get_token (&tok, &replacement_list))
break;
/* Just for aesthetics. If we skipped some whitespace, copy
that to DEST. */
if (tok.text > original_rl_start)
{
appendmem (dest, original_rl_start, tok.text - original_rl_start);
dest->last_token = dest->len;
}
/* Is this token the stringification operator? */
if (tok.len == 1
&& tok.text[0] == '#')
error (_("Stringification is not implemented yet."));
/* Is this token the splicing operator? */
if (tok.len == 2
&& tok.text[0] == '#'
&& tok.text[1] == '#')
error (_("Token splicing is not implemented yet."));
/* Is this token an identifier? */
if (tok.is_identifier)
{
int i;
/* Is it the magic varargs parameter? */
if (tok.len == 11
&& ! memcmp (tok.text, "__VA_ARGS__", 11))
error (_("Variable-arity macros not implemented yet."));
/* Is it one of the parameters? */
for (i = 0; i < def->argc; i++)
if (tok.len == strlen (def->argv[i])
&& ! memcmp (tok.text, def->argv[i], tok.len))
{
struct macro_buffer arg_src;
/* Expand any macro invocations in the argument text,
and append the result to dest. Remember that scan
mutates its source, so we need to scan a new buffer
referring to the argument's text, not the argument
itself. */
init_shared_buffer (&arg_src, argv[i].text, argv[i].len);
scan (dest, &arg_src, no_loop, lookup_func, lookup_baton);
substituted = 1;
break;
}
}
/* If it wasn't a parameter, then just copy it across. */
if (! substituted)
append_tokens_without_splicing (dest, &tok);
}
}
