@@ -3794,6 +3794,7 @@ match_attr_spec (void)
DECL_ALLOCATABLE = GFC_DECL_BEGIN, DECL_DIMENSION, DECL_EXTERNAL,
DECL_IN, DECL_OUT, DECL_INOUT, DECL_INTRINSIC, DECL_OPTIONAL,
DECL_PARAMETER, DECL_POINTER, DECL_PROTECTED, DECL_PRIVATE,
+ DECL_STATIC, DECL_AUTOMATIC,
DECL_PUBLIC, DECL_SAVE, DECL_TARGET, DECL_VALUE, DECL_VOLATILE,
DECL_IS_BIND_C, DECL_CODIMENSION, DECL_ASYNCHRONOUS, DECL_CONTIGUOUS,
DECL_NONE, GFC_DECL_END /* Sentinel */
@@ -3857,6 +3858,14 @@ match_attr_spec (void)
d = DECL_ASYNCHRONOUS;
}
break;
+
+ case 'u':
+ if (match_string_p ("tomatic"))
+ {
+ /* Matched "automatic". */
+ d = DECL_AUTOMATIC;
+ }
+ break;
}
break;
@@ -3986,8 +3995,25 @@ match_attr_spec (void)
break;
case 's':
- if (match_string_p ("save"))
- d = DECL_SAVE;
+ gfc_next_ascii_char ();
+ switch (gfc_next_ascii_char ())
+ {
+ case 'a':
+ if (match_string_p ("ve"))
+ {
+ /* Matched "save". */
+ d = DECL_SAVE;
+ }
+ break;
+
+ case 't':
+ if (match_string_p ("atic"))
+ {
+ /* Matched "static". */
+ d = DECL_STATIC;
+ }
+ break;
+ }
break;
case 't':
@@ -4124,6 +4150,12 @@ match_attr_spec (void)
case DECL_SAVE:
attr = "SAVE";
break;
+ case DECL_STATIC:
+ attr = "STATIC";
+ break;
+ case DECL_AUTOMATIC:
+ attr = "AUTOMATIC";
+ break;
case DECL_TARGET:
attr = "TARGET";
break;
@@ -4152,6 +4184,18 @@ match_attr_spec (void)
if (seen[d] == 0)
continue;
+ if ((d == DECL_STATIC || d == DECL_AUTOMATIC)
+ && !flag_dec_static)
+ {
+ gfc_error ("%s at %L is a DEC extension, enable with -fdec-static",
+ d == DECL_STATIC ? "STATIC" : "AUTOMATIC", &seen_at[d]);
+ m = MATCH_ERROR;
+ goto cleanup;
+ }
+ /* Allow SAVE with STATIC, but don't complain. */
+ if (d == DECL_STATIC && seen[DECL_SAVE])
+ continue;
+
if (gfc_current_state () == COMP_DERIVED
&& d != DECL_DIMENSION && d != DECL_CODIMENSION
&& d != DECL_POINTER && d != DECL_PRIVATE
@@ -4290,10 +4334,15 @@ match_attr_spec (void)
&seen_at[d]);
break;
+ case DECL_STATIC:
case DECL_SAVE:
t = gfc_add_save (¤t_attr, SAVE_EXPLICIT, NULL, &seen_at[d]);
break;
+ case DECL_AUTOMATIC:
+ t = gfc_add_automatic (¤t_attr, NULL, &seen_at[d]);
+ break;
+
case DECL_TARGET:
t = gfc_add_target (¤t_attr, &seen_at[d]);
break;
@@ -7767,6 +7816,110 @@ gfc_match_parameter (void)
}
+match
+gfc_match_automatic (void)
+{
+ gfc_symbol *sym;
+ match m;
+ bool seen_symbol = false;
+
+ if (!flag_dec_static)
+ {
+ gfc_error ("AUTOMATIC at %C is a DEC extension, enable with "
+ "-fdec-static");
+ return MATCH_ERROR;
+ }
+
+ gfc_match (" ::");
+
+ for (;;)
+ {
+ m = gfc_match_symbol (&sym, 0);
+ switch (m)
+ {
+ case MATCH_NO:
+ case MATCH_ERROR:
+ return MATCH_ERROR;
+
+ case MATCH_YES:
+ if (!gfc_add_automatic (&sym->attr, sym->name, &gfc_current_locus))
+ return MATCH_ERROR;
+ seen_symbol = true;
+ break;
+ }
+
+ if (gfc_match_eos () == MATCH_YES)
+ break;
+ if (gfc_match_char (',') != MATCH_YES)
+ goto syntax;
+ }
+
+ if (!seen_symbol)
+ {
+ gfc_error ("Expected var-list in AUTOMATIC statement at %C");
+ return MATCH_ERROR;
+ }
+
+ return MATCH_YES;
+
+syntax:
+ gfc_error ("Syntax error in AUTOMATIC statement at %C");
+ return MATCH_ERROR;
+}
+
+
+match
+gfc_match_static (void)
+{
+ gfc_symbol *sym;
+ match m;
+ bool seen_symbol = false;
+
+ if (!flag_dec_static)
+ {
+ gfc_error ("STATIC at %C is a DEC extension, enable with -fdec-static");
+ return MATCH_ERROR;
+ }
+
+ gfc_match (" ::");
+
+ for (;;)
+ {
+ m = gfc_match_symbol (&sym, 0);
+ switch (m)
+ {
+ case MATCH_NO:
+ case MATCH_ERROR:
+ return MATCH_ERROR;
+
+ case MATCH_YES:
+ if (!gfc_add_save (&sym->attr, SAVE_EXPLICIT, sym->name,
+ &gfc_current_locus))
+ return MATCH_ERROR;
+ seen_symbol = true;
+ break;
+ }
+
+ if (gfc_match_eos () == MATCH_YES)
+ break;
+ if (gfc_match_char (',') != MATCH_YES)
+ goto syntax;
+ }
+
+ if (!seen_symbol)
+ {
+ gfc_error ("Expected var-list in STATIC statement at %C");
+ return MATCH_ERROR;
+ }
+
+ return MATCH_YES;
+
+syntax:
+ gfc_error ("Syntax error in STATIC statement at %C");
+ return MATCH_ERROR;
+}
+
+
/* Save statements have a special syntax. */
match
@@ -726,7 +726,7 @@ typedef struct
optional:1, pointer:1, target:1, value:1, volatile_:1, temporary:1,
dummy:1, result:1, assign:1, threadprivate:1, not_always_present:1,
implied_index:1, subref_array_pointer:1, proc_pointer:1, asynchronous:1,
- contiguous:1, fe_temp: 1;
+ contiguous:1, fe_temp: 1, automatic: 1;
/* For CLASS containers, the pointer attribute is sometimes set internally
even though it was not directly specified. In this case, keep the
@@ -2803,6 +2803,7 @@ bool gfc_add_cray_pointee (symbol_attribute *, locus *);
match gfc_mod_pointee_as (gfc_array_spec *);
bool gfc_add_protected (symbol_attribute *, const char *, locus *);
bool gfc_add_result (symbol_attribute *, const char *, locus *);
+bool gfc_add_automatic (symbol_attribute *, const char *, locus *);
bool gfc_add_save (symbol_attribute *, save_state, const char *, locus *);
bool gfc_add_threadprivate (symbol_attribute *, const char *, locus *);
bool gfc_add_omp_declare_target (symbol_attribute *, const char *, locus *);
@@ -1462,6 +1462,7 @@ without warning.
* STRUCTURE and RECORD::
* UNION and MAP::
* Type variants for integer intrinsics::
+* AUTOMATIC and STATIC attributes::
@end menu
@node Old-style kind specifications
@@ -2120,7 +2121,6 @@ consider @code{BACKSPACE} or @code{REWIND} to properly position
the file before the EOF marker. As an extension, the run-time error may
be disabled using -std=legacy.
-
@node STRUCTURE and RECORD
@subsection @code{STRUCTURE} and @code{RECORD}
@cindex @code{STRUCTURE}
@@ -2420,6 +2420,53 @@ here:
@tab @code{--} @tab @code{FLOATI} @tab @code{FLOATJ} @tab @code{FLOATK}
@end multitable
+@node AUTOMATIC and STATIC attributes
+@subsection @code{AUTOMATIC} and @code{STATIC} attributes
+@cindex variable attributes
+@cindex @code{AUTOMATIC}
+@cindex @code{STATIC}
+
+With @option{-fdec-static} GNU Fortran supports the explicit specification of
+two addition variable attributes: @code{STATIC} and @code{AUTOMATIC}. These
+follow the syntax of the @code{SAVE} attribute.
+
+@code{STATIC} is exactly equivalent to @code{SAVE}.
+
+@code{AUTOMATIC} is the default for local variables smaller than
+@option{-fmax-stack-var-size}, unless @option{-fno-automatic} is given.
+Variables marked @code{AUTOMATIC} will be stack automatic variables whenever
+possible. This attribute overrides @option{-fno-automatic},
+@option{-fmax-stack-var-size}, and blanket @code{SAVE} statements.
+
+Examples:
+
+
+@example
+subroutine f
+ integer, automatic :: i ! automatic variable
+ integer x, y ! static variables
+ save
+ ...
+endsubroutine
+@end example
+@example
+subroutine f
+ integer a, b, c, x, y, z
+ static :: x
+ save y
+ automatic z, c
+ ! a, b, c, and z are automatic
+ ! x and y are static
+endsubroutine
+@end example
+@example
+! Compiled with -fno-automatic
+subroutine f
+ integer a, b, c, d
+ automatic :: a
+ ! a is automatic; b, c, and d are static
+endsubroutine
+@end example
@node Extensions not implemented in GNU Fortran
@section Extensions not implemented in GNU Fortran
@@ -2443,7 +2490,6 @@ code that uses them running with the GNU Fortran compiler.
* ENCODE and DECODE statements::
* Variable FORMAT expressions::
@c * Q edit descriptor::
-@c * AUTOMATIC statement::
@c * TYPE and ACCEPT I/O Statements::
@c * .XOR. operator::
@c * CARRIAGECONTROL, DEFAULTFILE, DISPOSE and RECORDTYPE I/O specifiers::
@@ -116,7 +116,7 @@ by type. Explanations are in the following sections.
@xref{Fortran Dialect Options,,Options controlling Fortran dialect}.
@gccoptlist{-fall-intrinsics -fbackslash -fcray-pointer -fd-lines-as-code @gol
-fd-lines-as-comments @gol
--fdec -fdec-structure -fdec-intrinsic-ints @gol
+-fdec -fdec-structure -fdec-intrinsic-ints -fdec-static @gol
-fdefault-double-8 -fdefault-integer-8 @gol
-fdefault-real-8 -fdollar-ok -ffixed-line-length-@var{n} @gol
-ffixed-line-length-none -ffree-form -ffree-line-length-@var{n} @gol
@@ -241,7 +241,7 @@ full documentation.
Other flags enabled by this switch are:
@option{-fdollar-ok} @option{-fcray-pointer} @option{-fdec-structure}
-@option{-fdec-intrinsic-ints}
+@option{-fdec-intrinsic-ints} @option{-fdec-static}
@item -fdec-structure
@opindex @code{fdec-structure}
@@ -255,6 +255,11 @@ instead where possible.
Enable B/I/J/K kind variants of existing integer functions (e.g. BIAND, IIAND,
JIAND, etc...). For a complete list of intrinsics see the full documentation.
+@item -fdec-static
+@opindex @code{fdec-static}
+Enable STATIC and AUTOMATIC as attributes specifying storage location.
+STATIC is equivalent to SAVE, and locals are typically AUTOMATIC by default.
+
@item -fdollar-ok
@opindex @code{fdollar-ok}
@cindex @code{$}
@@ -432,6 +432,10 @@ fdec-structure
Fortran
Enable support for DEC STRUCTURE/RECORD.
+fdec-static
+Fortran Var(flag_dec_static)
+Enable STATIC and AUTOMATIC attributes.
+
fdefault-double-8
Fortran Var(flag_default_double)
Set the default double precision kind to an 8 byte wide type.
@@ -223,6 +223,7 @@ void gfc_set_constant_character_len (int, gfc_expr *, int);
/* Matchers for attribute declarations. */
match gfc_match_allocatable (void);
match gfc_match_asynchronous (void);
+match gfc_match_automatic (void);
match gfc_match_codimension (void);
match gfc_match_contiguous (void);
match gfc_match_dimension (void);
@@ -238,6 +239,7 @@ match gfc_match_protected (void);
match gfc_match_private (gfc_statement *);
match gfc_match_public (gfc_statement *);
match gfc_match_save (void);
+match gfc_match_static (void);
match gfc_match_modproc (void);
match gfc_match_target (void);
match gfc_match_value (void);
@@ -54,6 +54,7 @@ set_dec_flags (int value)
{
gfc_option.flag_dec_structure = value;
flag_dec_intrinsic_ints = value;
+ flag_dec_static = value;
}
@@ -191,6 +191,7 @@ decode_specification_statement (void)
ST_INTERFACE);
match ("allocatable", gfc_match_allocatable, ST_ATTR_DECL);
match ("asynchronous", gfc_match_asynchronous, ST_ATTR_DECL);
+ match ("automatic", gfc_match_automatic, ST_ATTR_DECL);
break;
case 'b':
@@ -256,6 +257,7 @@ decode_specification_statement (void)
case 's':
match ("save", gfc_match_save, ST_ATTR_DECL);
+ match ("static", gfc_match_static, ST_ATTR_DECL);
match ("structure", gfc_match_structure_decl, ST_STRUCTURE_DECL);
break;
@@ -436,6 +438,7 @@ decode_statement (void)
match ("allocatable", gfc_match_allocatable, ST_ATTR_DECL);
match ("assign", gfc_match_assign, ST_LABEL_ASSIGNMENT);
match ("asynchronous", gfc_match_asynchronous, ST_ATTR_DECL);
+ match ("automatic", gfc_match_automatic, ST_ATTR_DECL);
break;
case 'b':
@@ -548,6 +551,7 @@ decode_statement (void)
match ("sequence", gfc_match_eos, ST_SEQUENCE);
match ("stop", gfc_match_stop, ST_STOP);
match ("save", gfc_match_save, ST_ATTR_DECL);
+ match ("static", gfc_match_static, ST_ATTR_DECL);
match ("submodule", gfc_match_submodule, ST_SUBMODULE);
match ("sync all", gfc_match_sync_all, ST_SYNC_ALL);
match ("sync images", gfc_match_sync_images, ST_SYNC_IMAGES);
@@ -11237,10 +11237,11 @@ apply_default_init_local (gfc_symbol *sym)
entry, so we just add a static initializer. Note that automatic variables
are stack allocated even with -fno-automatic; we have also to exclude
result variable, which are also nonstatic. */
- if (sym->attr.save || sym->ns->save_all
- || (flag_max_stack_var_size == 0 && !sym->attr.result
- && (sym->ns->proc_name && !sym->ns->proc_name->attr.recursive)
- && (!sym->attr.dimension || !is_non_constant_shape_array (sym))))
+ if (!sym->attr.automatic
+ && (sym->attr.save || sym->ns->save_all
+ || (flag_max_stack_var_size == 0 && !sym->attr.result
+ && (sym->ns->proc_name && !sym->ns->proc_name->attr.recursive)
+ && (!sym->attr.dimension || !is_non_constant_shape_array (sym)))))
{
/* Don't clobber an existing initializer! */
gcc_assert (sym->value == NULL);
@@ -11385,7 +11386,7 @@ resolve_fl_variable_derived (gfc_symbol *sym, int no_init_flag)
a hidden default for allocatable components. */
if (!(sym->value || no_init_flag) && sym->ns->proc_name
&& sym->ns->proc_name->attr.flavor == FL_MODULE
- && !sym->ns->save_all && !sym->attr.save
+ && !(sym->ns->save_all && !sym->attr.automatic) && !sym->attr.save
&& !sym->attr.pointer && !sym->attr.allocatable
&& gfc_has_default_initializer (sym->ts.u.derived)
&& !gfc_notify_std (GFC_STD_F2008, "Implied SAVE for module variable "
@@ -14159,7 +14160,7 @@ resolve_symbol (gfc_symbol *sym)
if (class_attr.codimension
&& !(class_attr.allocatable || sym->attr.dummy || sym->attr.save
|| sym->attr.select_type_temporary
- || sym->ns->save_all
+ || (sym->ns->save_all && !sym->attr.automatic)
|| sym->ns->proc_name->attr.flavor == FL_MODULE
|| sym->ns->proc_name->attr.is_main_program
|| sym->attr.function || sym->attr.result || sym->attr.use_assoc))
@@ -14311,7 +14312,8 @@ resolve_symbol (gfc_symbol *sym)
}
/* Check threadprivate restrictions. */
- if (sym->attr.threadprivate && !sym->attr.save && !sym->ns->save_all
+ if (sym->attr.threadprivate && !sym->attr.save
+ && !(sym->ns->save_all && !sym->attr.automatic)
&& (!sym->attr.in_common
&& sym->module == NULL
&& (sym->ns->proc_name == NULL
@@ -14322,7 +14324,7 @@ resolve_symbol (gfc_symbol *sym)
if (sym->attr.omp_declare_target
&& sym->attr.flavor == FL_VARIABLE
&& !sym->attr.save
- && !sym->ns->save_all
+ && !(sym->ns->save_all && !sym->attr.automatic)
&& (!sym->attr.in_common
&& sym->module == NULL
&& (sym->ns->proc_name == NULL
@@ -373,7 +373,7 @@ check_conflict (symbol_attribute *attr, const char *name, locus *where)
*is_bind_c = "BIND(C)", *procedure = "PROCEDURE",
*proc_pointer = "PROCEDURE POINTER", *abstract = "ABSTRACT",
*asynchronous = "ASYNCHRONOUS", *codimension = "CODIMENSION",
- *contiguous = "CONTIGUOUS", *generic = "GENERIC";
+ *contiguous = "CONTIGUOUS", *generic = "GENERIC", *automatic = "AUTOMATIC";
static const char *threadprivate = "THREADPRIVATE";
static const char *omp_declare_target = "OMP DECLARE TARGET";
static const char *oacc_declare_copyin = "OACC DECLARE COPYIN";
@@ -438,6 +438,7 @@ check_conflict (symbol_attribute *attr, const char *name, locus *where)
conf (dummy, save);
conf (in_common, save);
conf (result, save);
+ conf (automatic, save);
switch (attr->flavor)
{
@@ -479,6 +480,12 @@ check_conflict (symbol_attribute *attr, const char *name, locus *where)
conf (pointer, codimension);
conf (allocatable, elemental);
+ conf (in_common, automatic);
+ conf (in_equivalence, automatic);
+ conf (result, automatic);
+ conf (use_assoc, automatic);
+ conf (dummy, automatic);
+
conf (target, external);
conf (target, intrinsic);
@@ -933,6 +940,21 @@ gfc_add_allocatable (symbol_attribute *attr, locus *where)
bool
+gfc_add_automatic (symbol_attribute *attr, const char *name, locus *where)
+{
+ if (check_used (attr, name, where))
+ return false;
+
+ if (attr->automatic && !gfc_notify_std (GFC_STD_LEGACY,
+ "Duplicate AUTOMATIC attribute specified at %L", where))
+ return false;
+
+ attr->automatic = 1;
+ return check_conflict (attr, name, where);
+}
+
+
+bool
gfc_add_codimension (symbol_attribute *attr, const char *name, locus *where)
{
@@ -1880,6 +1902,8 @@ gfc_copy_attr (symbol_attribute *dest, symbol_attribute *src, locus *where)
if (src->allocatable && !gfc_add_allocatable (dest, where))
goto fail;
+ if (src->automatic && !gfc_add_automatic (dest, NULL, where))
+ goto fail;
if (src->dimension && !gfc_add_dimension (dest, NULL, where))
goto fail;
if (src->codimension && !gfc_add_codimension (dest, NULL, where))
@@ -3991,6 +4015,10 @@ gfc_is_var_automatic (gfc_symbol *sym)
&& sym->ts.u.cl
&& !gfc_is_constant_expr (sym->ts.u.cl->length))
return true;
+ /* Variables with explicit AUTOMATIC attribute. */
+ if (sym->attr.automatic)
+ return true;
+
return false;
}
@@ -647,7 +647,7 @@ gfc_finish_var_decl (tree decl, gfc_symbol * sym)
}
/* Keep variables larger than max-stack-var-size off stack. */
- if (!sym->ns->proc_name->attr.recursive
+ if (!sym->ns->proc_name->attr.recursive && !sym->attr.automatic
&& INTEGER_CST_P (DECL_SIZE_UNIT (decl))
&& !gfc_can_put_var_on_stack (DECL_SIZE_UNIT (decl))
/* Put variable length auto array pointers always into stack. */
new file mode 100644
@@ -0,0 +1,42 @@
+ ! { dg-do run }
+ ! { dg-options "-fdec-static -finit-local-zero" }
+ !
+ ! Test AUTOMATIC and STATIC attributes.
+ !
+ subroutine assert(s, i1, i2)
+ implicit none
+ integer, intent(in) :: i1, i2
+ character(*), intent(in) :: s
+ if (i1 .ne. i2) then
+ print *, s, ": expected ", i2, " but was ", i1
+ call abort
+ endif
+ endsubroutine assert
+
+ function f (x, y)
+ implicit none
+ integer f
+ integer, intent(in) :: x, y
+ integer :: a ! only a can actually be saved
+ integer, automatic :: c ! should actually be automatic
+ save
+
+ ! a should be incremented by x every time and saved
+ a = a + x
+ f = a
+
+ ! c should be zeroed every time, therefore equal y
+ c = c + y
+ call assert ("f%c", c, y)
+ return
+ endfunction
+
+ implicit none
+ integer :: f
+
+ ! Should return static value of a; accumulates x
+ call assert ("f()", f(1,3), 1)
+ call assert ("f()", f(1,4), 2)
+ call assert ("f()", f(1,2), 3)
+
+ end
new file mode 100644
@@ -0,0 +1,60 @@
+ ! { dg-do run }
+ ! { dg-options "-fdec-static -fno-automatic -finit-local-zero" }
+ !
+ ! Make sure a warning is produced when variables marked AUTOMATIC
+ ! cannot be automatic due to compilation with -fno-automatic, and
+ ! that they are in fact still saved.
+ !
+ subroutine assert(s, i1, i2)
+ implicit none
+ integer, intent(in) :: i1, i2
+ character(*), intent(in) :: s
+ if (i1 .ne. i2) then
+ print *, s, ": expected ", i2, " but was ", i1
+ call abort
+ endif
+ endsubroutine
+
+ function f (x)
+ implicit none
+ integer f
+ integer, intent(in) :: x
+ integer, static :: a ! should be SAVEd
+ a = a + x ! should increment by x every time
+ f = a
+ return
+ endfunction
+
+ recursive subroutine g (x)
+ implicit none
+ integer, intent(in) :: x
+ integer, automatic :: a ! should be automatic (in recursive)
+ a = a + x ! should be set to x every time
+ call assert ("g%a", a, x)
+ endsubroutine
+
+ subroutine h (x)
+ implicit none
+ integer, intent(in) :: x
+ integer, automatic :: a ! should be automatic (outside recursive)
+ a = a + x ! should be set to x every time
+ call assert ("h%a", a, x)
+ endsubroutine
+
+ implicit none
+ integer :: f
+
+ ! Should return static value of c; accumulates x
+ call assert ("f()", f(3), 3)
+ call assert ("f()", f(4), 7)
+ call assert ("f()", f(2), 9)
+
+ call g(3)
+ call g(4)
+ call g(2)
+
+ call h(3)
+ call h(4)
+ call h(2)
+
+ end
Greetings, This patch extends the GNU Fortran front-end to add support for DEC-style AUTOMATIC and STATIC symbol attributes with a new flag -fdec-static, allowing explicit control of variable storage. AUTOMATIC local variables are placed on the stack, whereas STATIC variables are placed in static storage. Currently, GNU Fortran provides some control over variable storage through the use of its options -f[no-]automatic, -f[no-]recursive, and -fmax-stack-var-size=, as well as the Fortran standard SAVE attribute. However there is no way to mark a particular variable to be allocated in automatic storage without potentially affecting other variables in a given program. There are programs written in legacy (non-standard) Fortran which do use the AUTOMATIC attribute for this reason. STATIC is just an alias for SAVE, but provides further compatibility for such legacy programs. AUTOMATIC is implemented as a new symbol_attribute 'automatic', which is checked in a couple places in resolve.c (apply_default_init_local, resolve_fl_variable_derived, resolve_symbol), symbol.c (gfc_is_var_automatic), and trans-decl.c (gfc_finish_var_decl). Note that AUTOMATIC does NOT override -fno-automatic; with the flag, a warning is produced for variables marked AUTOMATIC. STATIC is implemented by setting the 'save' attribute and no distinction is made from SAVE. Parser support for these attributes is enabled only with the new compile flag -fdec-static. Bootstraps and regtests on x86_64-redhat-linux. Questions, comments, and critique welcome. Ok for trunk? P.S. Historical note: a user of some legacy code pointed out to me that some other compilers allow the AUTOMATIC attribute to be specified for variables in an EQUIVALENCE, and that some legacy code contains usages of such. As one of my primary goals is (unfortunately) to provide support for legacy code I debated whether to allow this. In the end I restricted this combination for several reasons. Firstly, F95ยง5.5.1 states "... an equivalence object shall not be... an automatic object...". This is a less convincing reason, since the AUTOMATIC/STATIC attributes are already non-standard, and implement non-standard behavior, but GNU Fortran in implementing the standard will follow this behavior. Thus implementing an "automatic equivalence" variable would potentially be non-trivial and have strange consequences in the first place. Furthermore, I have found empirically that other compilers which accept the combination syntactically still specify in documentation that the combination is illegal, and the implementation is unpredictable. So AUTOMATIC + EQUIVALENCE seems like something to be fixed in user code. --- Fritz Reese 08-17-2016 Fritz Reese <fritzoreese@gmail.com> gcc/fortran/ * lang.opt, invoke.texi, gfortran.texi: New flag -fdec-static. * options.c (set_dec_flags): Set -fdec-static with -fdec. * gfortran.h (symbol_attribute): New attribute AUTOMATIC. * gfortran.h (gfc_add_automatic): New prototype. * match.h (gfc_match_automatic, gfc_match_static): New functions. * decl.c (gfc_match_automatic, gfc_match_static): Ditto. * symbol.c (gfc_add_automatic): Ditto. * decl.c (match_attr_spec): Match AUTOMATIC and STATIC decls. * parse.c (decode_specification_statement, decode_statement): Ditto. * resolve.c (apply_default_init_local, resolve_fl_variable_derived, resolve_symbol): Support for automatic attribute. * symbol.c (check_conflict, gfc_copy_attr, gfc_is_var_automatic): Ditto. * trans-decl.c (gfc_finish_var_decl): Ditto. gcc/testsuite/gfortran.dg/ * dec_static_1.f90, dec_static_2.f90: New testcases.