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/* Expression parser.
Copyright (C) 2000-2021 Free Software Foundation, Inc.
Contributed by Andy Vaught
This file is part of GCC.
GCC 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.
GCC 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 GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "gfortran.h"
#include "arith.h"
#include "match.h"
static const char expression_syntax[] = N_("Syntax error in expression at %C");
/* Match a user-defined operator name. This is a normal name with a
few restrictions. The error_flag controls whether an error is
raised if 'true' or 'false' are used or not. */
match
gfc_match_defined_op_name (char *result, int error_flag)
{
static const char * const badops[] = {
"and", "or", "not", "eqv", "neqv", "eq", "ne", "ge", "le", "lt", "gt",
NULL
};
char name[GFC_MAX_SYMBOL_LEN + 1];
locus old_loc;
match m;
int i;
old_loc = gfc_current_locus;
m = gfc_match (" . %n .", name);
if (m != MATCH_YES)
return m;
/* .true. and .false. have interpretations as constants. Trying to
use these as operators will fail at a later time. */
if (strcmp (name, "true") == 0 || strcmp (name, "false") == 0)
{
if (error_flag)
goto error;
gfc_current_locus = old_loc;
return MATCH_NO;
}
for (i = 0; badops[i]; i++)
if (strcmp (badops[i], name) == 0)
goto error;
for (i = 0; name[i]; i++)
if (!ISALPHA (name[i]))
{
gfc_error ("Bad character %qc in OPERATOR name at %C", name[i]);
return MATCH_ERROR;
}
strcpy (result, name);
return MATCH_YES;
error:
gfc_error ("The name %qs cannot be used as a defined operator at %C",
name);
gfc_current_locus = old_loc;
return MATCH_ERROR;
}
/* Match a user defined operator. The symbol found must be an
operator already. */
static match
match_defined_operator (gfc_user_op **result)
{
char name[GFC_MAX_SYMBOL_LEN + 1];
match m;
m = gfc_match_defined_op_name (name, 0);
if (m != MATCH_YES)
return m;
*result = gfc_get_uop (name);
return MATCH_YES;
}
/* Check to see if the given operator is next on the input. If this
is not the case, the parse pointer remains where it was. */
static int
next_operator (gfc_intrinsic_op t)
{
gfc_intrinsic_op u;
locus old_loc;
old_loc = gfc_current_locus;
if (gfc_match_intrinsic_op (&u) == MATCH_YES && t == u)
return 1;
gfc_current_locus = old_loc;
return 0;
}
/* Call the INTRINSIC_PARENTHESES function. This is both
used explicitly, as below, or by resolve.c to generate
temporaries. */
gfc_expr *
gfc_get_parentheses (gfc_expr *e)
{
gfc_expr *e2;
e2 = gfc_get_operator_expr (&e->where, INTRINSIC_PARENTHESES, e, NULL);
e2->ts = e->ts;
e2->rank = e->rank;
return e2;
}
/* Match a primary expression. */
static match
match_primary (gfc_expr **result)
{
match m;
gfc_expr *e;
m = gfc_match_literal_constant (result, 0);
if (m != MATCH_NO)
return m;
m = gfc_match_array_constructor (result);
if (m != MATCH_NO)
return m;
m = gfc_match_rvalue (result);
if (m != MATCH_NO)
return m;
/* Match an expression in parentheses. */
if (gfc_match_char ('(') != MATCH_YES)
return MATCH_NO;
m = gfc_match_expr (&e);
if (m == MATCH_NO)
goto syntax;
if (m == MATCH_ERROR)
return m;
m = gfc_match_char (')');
if (m == MATCH_NO)
gfc_error ("Expected a right parenthesis in expression at %C");
/* Now we have the expression inside the parentheses, build the
expression pointing to it. By 7.1.7.2, any expression in
parentheses shall be treated as a data entity. */
*result = gfc_get_parentheses (e);
if (m != MATCH_YES)
{
gfc_free_expr (*result);
return MATCH_ERROR;
}
return MATCH_YES;
syntax:
gfc_error (expression_syntax);
return MATCH_ERROR;
}
/* Match a level 1 expression. */
static match
match_level_1 (gfc_expr **result)
{
gfc_user_op *uop;
gfc_expr *e, *f;
locus where;
match m;
gfc_gobble_whitespace ();
where = gfc_current_locus;
uop = NULL;
m = match_defined_operator (&uop);
if (m == MATCH_ERROR)
return m;
m = match_primary (&e);
if (m != MATCH_YES)
return m;
if (uop == NULL)
*result = e;
else
{
f = gfc_get_operator_expr (&where, INTRINSIC_USER, e, NULL);
f->value.op.uop = uop;
*result = f;
}
return MATCH_YES;
}
/* As a GNU extension we support an expanded level-2 expression syntax.
Via this extension we support (arbitrary) nesting of unary plus and
minus operations following unary and binary operators, such as **.
The grammar of section 7.1.1.3 is effectively rewritten as:
R704 mult-operand is level-1-expr [ power-op ext-mult-operand ]
R704' ext-mult-operand is add-op ext-mult-operand
or mult-operand
R705 add-operand is add-operand mult-op ext-mult-operand
or mult-operand
R705' ext-add-operand is add-op ext-add-operand
or add-operand
R706 level-2-expr is [ level-2-expr ] add-op ext-add-operand
or add-operand
*/
static match match_ext_mult_operand (gfc_expr **result);
static match match_ext_add_operand (gfc_expr **result);
static int
match_add_op (void)
{
if (next_operator (INTRINSIC_MINUS))
return -1;
if (next_operator (INTRINSIC_PLUS))
return 1;
return 0;
}
static match
match_mult_operand (gfc_expr **result)
{
/* Workaround -Wmaybe-uninitialized false positive during
profiledbootstrap by initializing them. */
gfc_expr *e = NULL, *exp, *r;
locus where;
match m;
m = match_level_1 (&e);
if (m != MATCH_YES)
return m;
if (!next_operator (INTRINSIC_POWER))
{
*result = e;
return MATCH_YES;
}
where = gfc_current_locus;
m = match_ext_mult_operand (&exp);
if (m == MATCH_NO)
gfc_error ("Expected exponent in expression at %C");
if (m != MATCH_YES)
{
gfc_free_expr (e);
return MATCH_ERROR;
}
r = gfc_power (e, exp);
if (r == NULL)
{
gfc_free_expr (e);
gfc_free_expr (exp);
return MATCH_ERROR;
}
r->where = where;
*result = r;
return MATCH_YES;
}
static match
match_ext_mult_operand (gfc_expr **result)
{
gfc_expr *all, *e;
locus where;
match m;
int i;
where = gfc_current_locus;
i = match_add_op ();
if (i == 0)
return match_mult_operand (result);
if (gfc_notification_std (GFC_STD_GNU) == ERROR)
{
gfc_error ("Extension: Unary operator following "
"arithmetic operator (use parentheses) at %C");
return MATCH_ERROR;
}
else
gfc_warning (0, "Extension: Unary operator following "
"arithmetic operator (use parentheses) at %C");
m = match_ext_mult_operand (&e);
if (m != MATCH_YES)
return m;
if (i == -1)
all = gfc_uminus (e);
else
all = gfc_uplus (e);
if (all == NULL)
{
gfc_free_expr (e);
return MATCH_ERROR;
}
all->where = where;
*result = all;
return MATCH_YES;
}
static match
match_add_operand (gfc_expr **result)
{
gfc_expr *all, *e, *total;
locus where, old_loc;
match m;
gfc_intrinsic_op i;
m = match_mult_operand (&all);
if (m != MATCH_YES)
return m;
for (;;)
{
/* Build up a string of products or quotients. */
old_loc = gfc_current_locus;
if (next_operator (INTRINSIC_TIMES))
i = INTRINSIC_TIMES;
else
{
if (next_operator (INTRINSIC_DIVIDE))
i = INTRINSIC_DIVIDE;
else
break;
}
where = gfc_current_locus;
m = match_ext_mult_operand (&e);
if (m == MATCH_NO)
{
gfc_current_locus = old_loc;
break;
}
if (m == MATCH_ERROR)
{
gfc_free_expr (all);
return MATCH_ERROR;
}
if (i == INTRINSIC_TIMES)
total = gfc_multiply (all, e);
else
total = gfc_divide (all, e);
if (total == NULL)
{
gfc_free_expr (all);
gfc_free_expr (e);
return MATCH_ERROR;
}
all = total;
all->where = where;
}
*result = all;
return MATCH_YES;
}
static match
match_ext_add_operand (gfc_expr **result)
{
gfc_expr *all, *e;
locus where;
match m;
int i;
where = gfc_current_locus;
i = match_add_op ();
if (i == 0)
return match_add_operand (result);
if (gfc_notification_std (GFC_STD_GNU) == ERROR)
{
gfc_error ("Extension: Unary operator following "
"arithmetic operator (use parentheses) at %C");
return MATCH_ERROR;
}
else
gfc_warning (0, "Extension: Unary operator following "
"arithmetic operator (use parentheses) at %C");
m = match_ext_add_operand (&e);
if (m != MATCH_YES)
return m;
if (i == -1)
all = gfc_uminus (e);
else
all = gfc_uplus (e);
if (all == NULL)
{
gfc_free_expr (e);
return MATCH_ERROR;
}
all->where = where;
*result = all;
return MATCH_YES;
}
/* Match a level 2 expression. */
static match
match_level_2 (gfc_expr **result)
{
gfc_expr *all, *e, *total;
locus where;
match m;
int i;
where = gfc_current_locus;
i = match_add_op ();
if (i != 0)
{
m = match_ext_add_operand (&e);
if (m == MATCH_NO)
{
gfc_error (expression_syntax);
m = MATCH_ERROR;
}
}
else
m = match_add_operand (&e);
if (m != MATCH_YES)
return m;
if (i == 0)
all = e;
else
{
if (i == -1)
all = gfc_uminus (e);
else
all = gfc_uplus (e);
if (all == NULL)
{
gfc_free_expr (e);
return MATCH_ERROR;
}
}
all->where = where;
/* Append add-operands to the sum. */
for (;;)
{
where = gfc_current_locus;
i = match_add_op ();
if (i == 0)
break;
m = match_ext_add_operand (&e);
if (m == MATCH_NO)
gfc_error (expression_syntax);
if (m != MATCH_YES)
{
gfc_free_expr (all);
return MATCH_ERROR;
}
if (i == -1)
total = gfc_subtract (all, e);
else
total = gfc_add (all, e);
if (total == NULL)
{
gfc_free_expr (all);
gfc_free_expr (e);
return MATCH_ERROR;
}
all = total;
all->where = where;
}
*result = all;
return MATCH_YES;
}
/* Match a level three expression. */
static match
match_level_3 (gfc_expr **result)
{
gfc_expr *all, *e, *total = NULL;
locus where;
match m;
m = match_level_2 (&all);
if (m != MATCH_YES)
return m;
for (;;)
{
if (!next_operator (INTRINSIC_CONCAT))
break;
where = gfc_current_locus;
m = match_level_2 (&e);
if (m == MATCH_NO)
gfc_error (expression_syntax);
if (m != MATCH_YES)
{
gfc_free_expr (all);
return MATCH_ERROR;
}
total = gfc_concat (all, e);
if (total == NULL)
{
gfc_free_expr (all);
gfc_free_expr (e);
return MATCH_ERROR;
}
all = total;
all->where = where;
}
*result = all;
return MATCH_YES;
}
/* Match a level 4 expression. */
static match
match_level_4 (gfc_expr **result)
{
gfc_expr *left, *right, *r;
gfc_intrinsic_op i;
locus old_loc;
locus where;
match m;
m = match_level_3 (&left);
if (m != MATCH_YES)
return m;
old_loc = gfc_current_locus;
if (gfc_match_intrinsic_op (&i) != MATCH_YES)
{
*result = left;
return MATCH_YES;
}
if (i != INTRINSIC_EQ && i != INTRINSIC_NE && i != INTRINSIC_GE
&& i != INTRINSIC_LE && i != INTRINSIC_LT && i != INTRINSIC_GT
&& i != INTRINSIC_EQ_OS && i != INTRINSIC_NE_OS && i != INTRINSIC_GE_OS
&& i != INTRINSIC_LE_OS && i != INTRINSIC_LT_OS && i != INTRINSIC_GT_OS)
{
gfc_current_locus = old_loc;
*result = left;
return MATCH_YES;
}
where = gfc_current_locus;
m = match_level_3 (&right);
if (m == MATCH_NO)
gfc_error (expression_syntax);
if (m != MATCH_YES)
{
gfc_free_expr (left);
return MATCH_ERROR;
}
switch (i)
{
case INTRINSIC_EQ:
case INTRINSIC_EQ_OS:
r = gfc_eq (left, right, i);
break;
case INTRINSIC_NE:
case INTRINSIC_NE_OS:
r = gfc_ne (left, right, i);
break;
case INTRINSIC_LT:
case INTRINSIC_LT_OS:
r = gfc_lt (left, right, i);
break;
case INTRINSIC_LE:
case INTRINSIC_LE_OS:
r = gfc_le (left, right, i);
break;
case INTRINSIC_GT:
case INTRINSIC_GT_OS:
r = gfc_gt (left, right, i);
break;
case INTRINSIC_GE:
case INTRINSIC_GE_OS:
r = gfc_ge (left, right, i);
break;
default:
gfc_internal_error ("match_level_4(): Bad operator");
}
if (r == NULL)
{
gfc_free_expr (left);
gfc_free_expr (right);
return MATCH_ERROR;
}
r->where = where;
*result = r;
return MATCH_YES;
}
static match
match_and_operand (gfc_expr **result)
{
gfc_expr *e, *r;
locus where;
match m;
int i;
i = next_operator (INTRINSIC_NOT);
where = gfc_current_locus;
m = match_level_4 (&e);
if (m != MATCH_YES)
return m;
r = e;
if (i)
{
r = gfc_not (e);
if (r == NULL)
{
gfc_free_expr (e);
return MATCH_ERROR;
}
}
r->where = where;
*result = r;
return MATCH_YES;
}
static match
match_or_operand (gfc_expr **result)
{
gfc_expr *all, *e, *total;
locus where;
match m;
m = match_and_operand (&all);
if (m != MATCH_YES)
return m;
for (;;)
{
if (!next_operator (INTRINSIC_AND))
break;
where = gfc_current_locus;
m = match_and_operand (&e);
if (m == MATCH_NO)
gfc_error (expression_syntax);
if (m != MATCH_YES)
{
gfc_free_expr (all);
return MATCH_ERROR;
}
total = gfc_and (all, e);
if (total == NULL)
{
gfc_free_expr (all);
gfc_free_expr (e);
return MATCH_ERROR;
}
all = total;
all->where = where;
}
*result = all;
return MATCH_YES;
}
static match
match_equiv_operand (gfc_expr **result)
{
gfc_expr *all, *e, *total;
locus where;
match m;
m = match_or_operand (&all);
if (m != MATCH_YES)
return m;
for (;;)
{
if (!next_operator (INTRINSIC_OR))
break;
where = gfc_current_locus;
m = match_or_operand (&e);
if (m == MATCH_NO)
gfc_error (expression_syntax);
if (m != MATCH_YES)
{
gfc_free_expr (all);
return MATCH_ERROR;
}
total = gfc_or (all, e);
if (total == NULL)
{
gfc_free_expr (all);
gfc_free_expr (e);
return MATCH_ERROR;
}
all = total;
all->where = where;
}
*result = all;
return MATCH_YES;
}
/* Match a level 5 expression. */
static match
match_level_5 (gfc_expr **result)
{
gfc_expr *all, *e, *total;
locus where;
match m;
gfc_intrinsic_op i;
m = match_equiv_operand (&all);
if (m != MATCH_YES)
return m;
for (;;)
{
if (next_operator (INTRINSIC_EQV))
i = INTRINSIC_EQV;
else
{
if (next_operator (INTRINSIC_NEQV))
i = INTRINSIC_NEQV;
else
break;
}
where = gfc_current_locus;
m = match_equiv_operand (&e);
if (m == MATCH_NO)
gfc_error (expression_syntax);
if (m != MATCH_YES)
{
gfc_free_expr (all);
return MATCH_ERROR;
}
if (i == INTRINSIC_EQV)
total = gfc_eqv (all, e);
else
total = gfc_neqv (all, e);
if (total == NULL)
{
gfc_free_expr (all);
gfc_free_expr (e);
return MATCH_ERROR;
}
all = total;
all->where = where;
}
*result = all;
return MATCH_YES;
}
/* Match an expression. At this level, we are stringing together
level 5 expressions separated by binary operators. */
match
gfc_match_expr (gfc_expr **result)
{
gfc_expr *all, *e;
gfc_user_op *uop;
locus where;
match m;
m = match_level_5 (&all);
if (m != MATCH_YES)
return m;
for (;;)
{
uop = NULL;
m = match_defined_operator (&uop);
if (m == MATCH_NO)
break;
if (m == MATCH_ERROR)
{
gfc_free_expr (all);
return MATCH_ERROR;
}
where = gfc_current_locus;
m = match_level_5 (&e);
if (m == MATCH_NO)
gfc_error (expression_syntax);
if (m != MATCH_YES)
{
gfc_free_expr (all);
return MATCH_ERROR;
}
all = gfc_get_operator_expr (&where, INTRINSIC_USER, all, e);
all->value.op.uop = uop;
}
*result = all;
return MATCH_YES;
}