/* cond.c - conditional assembly pseudo-ops, and .include
Copyright (C) 1990-2020 Free Software Foundation, Inc.
This file is part of GAS, the GNU Assembler.
GAS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GAS; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
02110-1301, USA. */
#include "as.h"
#include "sb.h"
#include "macro.h"
#include "obstack.h"
/* This is allocated to grow and shrink as .ifdef/.endif pairs are
scanned. */
struct obstack cond_obstack;
struct file_line
{
const char *file;
unsigned int line;
};
/* We push one of these structures for each .if, and pop it at the
.endif. */
struct conditional_frame
{
/* The source file & line number of the "if". */
struct file_line if_file_line;
/* The source file & line of the "else". */
struct file_line else_file_line;
/* The previous conditional. */
struct conditional_frame *previous_cframe;
/* Have we seen an else yet? */
int else_seen;
/* Whether we are currently ignoring input. */
int ignoring;
/* Whether a conditional at a higher level is ignoring input.
Set also when a branch of an "if .. elseif .." tree has matched
to prevent further matches. */
int dead_tree;
/* Macro nesting level at which this conditional was created. */
int macro_nest;
};
static void initialize_cframe (struct conditional_frame *cframe);
static char *get_mri_string (int, int *);
static struct conditional_frame *current_cframe = NULL;
/* Performs the .ifdef (test_defined == 1) and
the .ifndef (test_defined == 0) pseudo op. */
void
s_ifdef (int test_defined)
{
/* Points to name of symbol. */
char *name;
/* Points to symbol. */
symbolS *symbolP;
struct conditional_frame cframe;
char c;
/* Leading whitespace is part of operand. */
SKIP_WHITESPACE ();
name = input_line_pointer;
if (!is_name_beginner (*name) && *name != '"')
{
as_bad (_("invalid identifier for \".ifdef\""));
obstack_1grow (&cond_obstack, 0);
ignore_rest_of_line ();
return;
}
c = get_symbol_name (& name);
symbolP = symbol_find (name);
(void) restore_line_pointer (c);
initialize_cframe (&cframe);
if (cframe.dead_tree)
cframe.ignoring = 1;
else
{
int is_defined;
/* Use the same definition of 'defined' as .equiv so that a symbol
which has been referenced but not yet given a value/address is
considered to be undefined. */
is_defined =
symbolP != NULL
&& (S_IS_DEFINED (symbolP) || symbol_equated_p (symbolP))
&& S_GET_SEGMENT (symbolP) != reg_section;
cframe.ignoring = ! (test_defined ^ is_defined);
}
current_cframe =
(struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
memcpy (current_cframe, &cframe, sizeof cframe);
if (LISTING_SKIP_COND ()
&& cframe.ignoring
&& (cframe.previous_cframe == NULL
|| ! cframe.previous_cframe->ignoring))
listing_list (2);
demand_empty_rest_of_line ();
}
void
s_if (int arg)
{
expressionS operand;
struct conditional_frame cframe;
int t;
char *stop = NULL;
char stopc = 0;
if (flag_mri)
stop = mri_comment_field (&stopc);
/* Leading whitespace is part of operand. */
SKIP_WHITESPACE ();
if (current_cframe != NULL && current_cframe->ignoring)
{
operand.X_add_number = 0;
while (! is_end_of_line[(unsigned char) *input_line_pointer])
++input_line_pointer;
}
else
{
expression_and_evaluate (&operand);
if (operand.X_op != O_constant)
as_bad (_("non-constant expression in \".if\" statement"));
}
switch ((operatorT) arg)
{
case O_eq: t = operand.X_add_number == 0; break;
case O_ne: t = operand.X_add_number != 0; break;
case O_lt: t = operand.X_add_number < 0; break;
case O_le: t = operand.X_add_number <= 0; break;
case O_ge: t = operand.X_add_number >= 0; break;
case O_gt: t = operand.X_add_number > 0; break;
default:
abort ();
return;
}
/* If the above error is signaled, this will dispatch
using an undefined result. No big deal. */
initialize_cframe (&cframe);
cframe.ignoring = cframe.dead_tree || ! t;
current_cframe =
(struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
memcpy (current_cframe, & cframe, sizeof cframe);
if (LISTING_SKIP_COND ()
&& cframe.ignoring
&& (cframe.previous_cframe == NULL
|| ! cframe.previous_cframe->ignoring))
listing_list (2);
if (flag_mri)
mri_comment_end (stop, stopc);
demand_empty_rest_of_line ();
}
/* Performs the .ifb (test_blank == 1) and
the .ifnb (test_blank == 0) pseudo op. */
void
s_ifb (int test_blank)
{
struct conditional_frame cframe;
initialize_cframe (&cframe);
if (cframe.dead_tree)
cframe.ignoring = 1;
else
{
int is_eol;
SKIP_WHITESPACE ();
is_eol = is_end_of_line[(unsigned char) *input_line_pointer];
cframe.ignoring = (test_blank == !is_eol);
}
current_cframe =
(struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
memcpy (current_cframe, &cframe, sizeof cframe);
if (LISTING_SKIP_COND ()
&& cframe.ignoring
&& (cframe.previous_cframe == NULL
|| ! cframe.previous_cframe->ignoring))
listing_list (2);
ignore_rest_of_line ();
}
/* Get a string for the MRI IFC or IFNC pseudo-ops. */
static char *
get_mri_string (int terminator, int *len)
{
char *ret;
char *s;
SKIP_WHITESPACE ();
s = ret = input_line_pointer;
if (*input_line_pointer == '\'')
{
++s;
++input_line_pointer;
while (! is_end_of_line[(unsigned char) *input_line_pointer])
{
*s++ = *input_line_pointer++;
if (s[-1] == '\'')
{
if (*input_line_pointer != '\'')
break;
++input_line_pointer;
}
}
SKIP_WHITESPACE ();
}
else
{
while (*input_line_pointer != terminator
&& ! is_end_of_line[(unsigned char) *input_line_pointer])
++input_line_pointer;
s = input_line_pointer;
while (s > ret && (s[-1] == ' ' || s[-1] == '\t'))
--s;
}
*len = s - ret;
return ret;
}
/* The MRI IFC and IFNC pseudo-ops. */
void
s_ifc (int arg)
{
char *stop = NULL;
char stopc = 0;
char *s1, *s2;
int len1, len2;
int res;
struct conditional_frame cframe;
if (flag_mri)
stop = mri_comment_field (&stopc);
s1 = get_mri_string (',', &len1);
if (*input_line_pointer != ',')
as_bad (_("bad format for ifc or ifnc"));
else
++input_line_pointer;
s2 = get_mri_string (';', &len2);
res = len1 == len2 && strncmp (s1, s2, len1) == 0;
initialize_cframe (&cframe);
cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
current_cframe =
(struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
memcpy (current_cframe, &cframe, sizeof cframe);
if (LISTING_SKIP_COND ()
&& cframe.ignoring
&& (cframe.previous_cframe == NULL
|| ! cframe.previous_cframe->ignoring))
listing_list (2);
if (flag_mri)
mri_comment_end (stop, stopc);
demand_empty_rest_of_line ();
}
void
s_elseif (int arg)
{
if (current_cframe == NULL)
{
as_bad (_("\".elseif\" without matching \".if\""));
}
else if (current_cframe->else_seen)
{
as_bad (_("\".elseif\" after \".else\""));
as_bad_where (current_cframe->else_file_line.file,
current_cframe->else_file_line.line,
_("here is the previous \".else\""));
as_bad_where (current_cframe->if_file_line.file,
current_cframe->if_file_line.line,
_("here is the previous \".if\""));
}
else
{
current_cframe->else_file_line.file
= as_where (¤t_cframe->else_file_line.line);
current_cframe->dead_tree |= !current_cframe->ignoring;
current_cframe->ignoring = current_cframe->dead_tree;
}
if (current_cframe == NULL || current_cframe->ignoring)
{
while (! is_end_of_line[(unsigned char) *input_line_pointer])
++input_line_pointer;
if (current_cframe == NULL)
return;
}
else
{
expressionS operand;
int t;
/* Leading whitespace is part of operand. */
SKIP_WHITESPACE ();
expression_and_evaluate (&operand);
if (operand.X_op != O_constant)
as_bad (_("non-constant expression in \".elseif\" statement"));
switch ((operatorT) arg)
{
case O_eq: t = operand.X_add_number == 0; break;
case O_ne: t = operand.X_add_number != 0; break;
case O_lt: t = operand.X_add_number < 0; break;
case O_le: t = operand.X_add_number <= 0; break;
case O_ge: t = operand.X_add_number >= 0; break;
case O_gt: t = operand.X_add_number > 0; break;
default:
abort ();
return;
}
current_cframe->ignoring = current_cframe->dead_tree || ! t;
}
if (LISTING_SKIP_COND ()
&& (current_cframe->previous_cframe == NULL
|| ! current_cframe->previous_cframe->ignoring))
{
if (! current_cframe->ignoring)
listing_list (1);
else
listing_list (2);
}
demand_empty_rest_of_line ();
}
void
s_endif (int arg ATTRIBUTE_UNUSED)
{
struct conditional_frame *hold;
if (current_cframe == NULL)
{
as_bad (_("\".endif\" without \".if\""));
}
else
{
if (LISTING_SKIP_COND ()
&& current_cframe->ignoring
&& (current_cframe->previous_cframe == NULL
|| ! current_cframe->previous_cframe->ignoring))
listing_list (1);
hold = current_cframe;
current_cframe = current_cframe->previous_cframe;
obstack_free (&cond_obstack, hold);
} /* if one pop too many */
if (flag_mri)
{
while (! is_end_of_line[(unsigned char) *input_line_pointer])
++input_line_pointer;
}
demand_empty_rest_of_line ();
}
void
s_else (int arg ATTRIBUTE_UNUSED)
{
if (current_cframe == NULL)
{
as_bad (_("\".else\" without matching \".if\""));
}
else if (current_cframe->else_seen)
{
as_bad (_("duplicate \".else\""));
as_bad_where (current_cframe->else_file_line.file,
current_cframe->else_file_line.line,
_("here is the previous \".else\""));
as_bad_where (current_cframe->if_file_line.file,
current_cframe->if_file_line.line,
_("here is the previous \".if\""));
}
else
{
current_cframe->else_file_line.file
= as_where (¤t_cframe->else_file_line.line);
current_cframe->ignoring =
current_cframe->dead_tree | !current_cframe->ignoring;
if (LISTING_SKIP_COND ()
&& (current_cframe->previous_cframe == NULL
|| ! current_cframe->previous_cframe->ignoring))
{
if (! current_cframe->ignoring)
listing_list (1);
else
listing_list (2);
}
current_cframe->else_seen = 1;
}
if (flag_mri)
{
while (! is_end_of_line[(unsigned char) *input_line_pointer])
++input_line_pointer;
}
demand_empty_rest_of_line ();
}
void
s_ifeqs (int arg)
{
char *s1, *s2;
int len1, len2;
int res;
struct conditional_frame cframe;
s1 = demand_copy_C_string (&len1);
SKIP_WHITESPACE ();
if (*input_line_pointer != ',')
{
as_bad (_(".ifeqs syntax error"));
ignore_rest_of_line ();
return;
}
++input_line_pointer;
s2 = demand_copy_C_string (&len2);
res = len1 == len2 && strncmp (s1, s2, len1) == 0;
initialize_cframe (&cframe);
cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
current_cframe =
(struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
memcpy (current_cframe, &cframe, sizeof cframe);
if (LISTING_SKIP_COND ()
&& cframe.ignoring
&& (cframe.previous_cframe == NULL
|| ! cframe.previous_cframe->ignoring))
listing_list (2);
demand_empty_rest_of_line ();
}
int
ignore_input (void)
{
char *s;
s = input_line_pointer;
if (NO_PSEUDO_DOT || flag_m68k_mri)
{
if (s[-1] != '.')
--s;
}
else
{
if (s[-1] != '.')
return (current_cframe != NULL) && (current_cframe->ignoring);
}
/* We cannot ignore certain pseudo ops. */
if (((s[0] == 'i'
|| s[0] == 'I')
&& (!strncasecmp (s, "if", 2)
|| !strncasecmp (s, "ifdef", 5)
|| !strncasecmp (s, "ifndef", 6)))
|| ((s[0] == 'e'
|| s[0] == 'E')
&& (!strncasecmp (s, "else", 4)
|| !strncasecmp (s, "endif", 5)
|| !strncasecmp (s, "endc", 4))))
return 0;
return (current_cframe != NULL) && (current_cframe->ignoring);
}
static void
initialize_cframe (struct conditional_frame *cframe)
{
memset (cframe, 0, sizeof (*cframe));
cframe->if_file_line.file
= as_where (&cframe->if_file_line.line);
cframe->previous_cframe = current_cframe;
cframe->dead_tree = current_cframe != NULL && current_cframe->ignoring;
cframe->macro_nest = macro_nest;
}
/* Give an error if a conditional is unterminated inside a macro or
the assembly as a whole. If NEST is non negative, we are being
called because of the end of a macro expansion. If NEST is
negative, we are being called at the of the input files. */
void
cond_finish_check (int nest)
{
if (current_cframe != NULL && current_cframe->macro_nest >= nest)
{
if (nest >= 0)
as_bad (_("end of macro inside conditional"));
else
as_bad (_("end of file inside conditional"));
as_bad_where (current_cframe->if_file_line.file,
current_cframe->if_file_line.line,
_("here is the start of the unterminated conditional"));
if (current_cframe->else_seen)
as_bad_where (current_cframe->else_file_line.file,
current_cframe->else_file_line.line,
_("here is the \"else\" of the unterminated conditional"));
}
}
/* This function is called when we exit out of a macro. We assume
that any conditionals which began within the macro are correctly
nested, and just pop them off the stack. */
void
cond_exit_macro (int nest)
{
while (current_cframe != NULL && current_cframe->macro_nest >= nest)
{
struct conditional_frame *hold;
hold = current_cframe;
current_cframe = current_cframe->previous_cframe;
obstack_free (&cond_obstack, hold);
}
}