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[Patch, Fortran] PR fortran/37779: Diagnose missing RECURSIVE, part 2
- From: Daniel Kraft <d at domob dot eu>
- To: fortran List <fortran at gcc dot gnu dot org>, gcc-patches <gcc-patches at gcc dot gnu dot org>
- Date: Sat, 29 Nov 2008 21:41:38 +0100
- Subject: [Patch, Fortran] PR fortran/37779: Diagnose missing RECURSIVE, part 2
Hi all,
this is a follow-up patch for PR 37779, to detect cases like this:
SUBROUTINE foo ()
CALL bar ()
CONTAINS
SUBROUTINE bar ()
CALL foo () ! { dg-error "recursive call to non-recursive foo" }
END SUBROUTINE bar
END SUBROUTINE foo
Because bar is contained in foo, it can only ever be called from within
foo; thus, if bar calls foo, too, this is necessarily an illegal
recursive call.
I did refactor and clean-up recursive-ness detection in resolve.c a bit,
and hope I did get it all right (the ENTRY handling, too). No
regressions on GNU/Linux-x86-32.
Ok for trunk (4.4)? Or should we wait even with this patch for 4.5? I
believe this is enough of a bug-fix to go in for 4.4, though.
Cheers,
Daniel
--
Done: Arc-Bar-Cav-Rog-Sam-Val-Wiz
To go: Hea-Kni-Mon-Pri-Ran-Tou
2008-11-29 Daniel Kraft <d@domob.eu>
PR fortran/37779
* gfortran.h (struct gfc_entry_list): Fixed typo in comment.
* resolve.c (is_illegal_recursion): New method.
(resolve_procedure_expression): Use new is_illegal_recursion instead of
direct check and handle function symbols correctly.
(resolve_actual_arglist): Removed useless recursion check.
(resolve_function): Use is_illegal_recursion instead of direct check.
(resolve_call): Ditto.
2008-11-29 Daniel Kraft <d@domob.eu>
PR fortran/37779
* gfortran.dg/recursive_check_1.f: Changed expected error message to
the more general new one.
* gfortran.dg/recursive_check_2.f90: Ditto.
* gfortran.dg/entry_18.f90: Ditto.
* gfortran.dg/recursive_check_4.f03: Do "the same" check also for
FUNCTIONS, as this is different in details from SUBROUTINES.
* gfortran.dg/recursive_check_6.f03: New test.
Index: gcc/fortran/gfortran.h
===================================================================
--- gcc/fortran/gfortran.h (revision 142157)
+++ gcc/fortran/gfortran.h (working copy)
@@ -1157,7 +1157,7 @@ typedef struct gfc_entry_list
int id;
/* The LABEL_EXPR marking this entry point. */
tree label;
- /* The nest item in the list. */
+ /* The next item in the list. */
struct gfc_entry_list *next;
}
gfc_entry_list;
Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c (revision 142158)
+++ gcc/fortran/resolve.c (working copy)
@@ -1073,6 +1073,58 @@ count_specific_procs (gfc_expr *e)
}
+/* See if a call to sym could possibly be a not allowed RECURSION because of
+ a missing RECURIVE declaration. This means that either sym is the current
+ context itself, or sym is the parent of a contained procedure calling its
+ non-RECURSIVE containing procedure.
+ This also works if sym is an ENTRY. */
+
+static bool
+is_illegal_recursion (gfc_symbol* sym, gfc_namespace* context)
+{
+ gfc_symbol* proc_sym;
+ gfc_symbol* context_proc;
+
+ gcc_assert (sym->attr.flavor == FL_PROCEDURE);
+
+ /* If we've got an ENTRY, find real procedure. */
+ if (sym->attr.entry && sym->ns->entries)
+ proc_sym = sym->ns->entries->sym;
+ else
+ proc_sym = sym;
+
+ /* If sym is RECURSIVE, all is well of course. */
+ if (proc_sym->attr.recursive || gfc_option.flag_recursive)
+ return false;
+
+ /* Find the context procdure's "real" symbol if it has entries. */
+ context_proc = (context->entries ? context->entries->sym
+ : context->proc_name);
+ if (!context_proc)
+ return true;
+
+ /* A call from sym's body to itself is recursion, of course. */
+ if (context_proc == proc_sym)
+ return true;
+
+ /* The same is true if context is a contained procedure and sym the
+ containing one. */
+ if (context_proc->attr.contained)
+ {
+ gfc_symbol* parent_proc;
+
+ gcc_assert (context->parent);
+ parent_proc = (context->parent->entries ? context->parent->entries->sym
+ : context->parent->proc_name);
+
+ if (parent_proc == proc_sym)
+ return true;
+ }
+
+ return false;
+}
+
+
/* Resolve a procedure expression, like passing it to a called procedure or as
RHS for a procedure pointer assignment. */
@@ -1081,16 +1133,18 @@ resolve_procedure_expression (gfc_expr*
{
gfc_symbol* sym;
- if (expr->ts.type != BT_PROCEDURE || expr->expr_type != EXPR_VARIABLE)
+ if (expr->expr_type != EXPR_VARIABLE)
return SUCCESS;
gcc_assert (expr->symtree);
+
sym = expr->symtree->n.sym;
- gcc_assert (sym->attr.flavor == FL_PROCEDURE);
+ if (sym->attr.flavor != FL_PROCEDURE
+ || (sym->attr.function && sym->result == sym))
+ return SUCCESS;
/* A non-RECURSIVE procedure that is used as procedure expression within its
own body is in danger of being called recursively. */
- if (!sym->attr.recursive && sym == gfc_current_ns->proc_name
- && !gfc_option.flag_recursive)
+ if (is_illegal_recursion (sym, gfc_current_ns))
gfc_warning ("Non-RECURSIVE procedure '%s' at %L is possibly calling"
" itself recursively. Declare it RECURSIVE or use"
" -frecursive", sym->name, &expr->where);
@@ -1203,15 +1257,6 @@ resolve_actual_arglist (gfc_actual_argli
/* Just in case a specific was found for the expression. */
sym = e->symtree->n.sym;
- if (sym->attr.entry && sym->ns->entries
- && sym->ns == gfc_current_ns
- && !sym->ns->entries->sym->attr.recursive)
- {
- gfc_error ("Reference to ENTRY '%s' at %L is recursive, but"
- " procedure '%s' is not declared as RECURSIVE",
- sym->name, &e->where, sym->ns->entries->sym->name);
- }
-
/* If the symbol is the function that names the current (or
parent) scope, then we really have a variable reference. */
@@ -2455,22 +2500,19 @@ resolve_function (gfc_expr *expr)
* call themselves. */
if (expr->value.function.esym && !expr->value.function.esym->attr.recursive)
{
- gfc_symbol *esym, *proc;
+ gfc_symbol *esym;
esym = expr->value.function.esym;
- proc = gfc_current_ns->proc_name;
- if (esym == proc)
- {
- gfc_error ("Function '%s' at %L cannot call itself, as it is not "
- "RECURSIVE", name, &expr->where);
- t = FAILURE;
- }
- if (esym->attr.entry && esym->ns->entries && proc->ns->entries
- && esym->ns->entries->sym == proc->ns->entries->sym)
+ if (is_illegal_recursion (esym, gfc_current_ns))
{
- gfc_error ("Call to ENTRY '%s' at %L is recursive, but function "
- "'%s' is not declared as RECURSIVE",
- esym->name, &expr->where, esym->ns->entries->sym->name);
+ if (esym->attr.entry && esym->ns->entries)
+ gfc_error ("ENTRY '%s' at %L cannot be called recursively, as"
+ " function '%s' is not RECURSIVE",
+ esym->name, &expr->where, esym->ns->entries->sym->name);
+ else
+ gfc_error ("Function '%s' at %L cannot be called recursively, as it"
+ " is not RECURSIVE", esym->name, &expr->where);
+
t = FAILURE;
}
}
@@ -2919,25 +2961,17 @@ resolve_call (gfc_code *c)
/* Subroutines without the RECURSIVE attribution are not allowed to
* call themselves. */
- if (csym && !csym->attr.recursive)
+ if (csym && is_illegal_recursion (csym, gfc_current_ns))
{
- gfc_symbol *proc;
- proc = gfc_current_ns->proc_name;
- if (csym == proc)
- {
- gfc_error ("SUBROUTINE '%s' at %L cannot call itself, as it is not "
- "RECURSIVE", csym->name, &c->loc);
- t = FAILURE;
- }
-
- if (csym->attr.entry && csym->ns->entries && proc->ns->entries
- && csym->ns->entries->sym == proc->ns->entries->sym)
- {
- gfc_error ("Call to ENTRY '%s' at %L is recursive, but subroutine "
- "'%s' is not declared as RECURSIVE",
+ if (csym->attr.entry && csym->ns->entries)
+ gfc_error ("ENTRY '%s' at %L cannot be called recursively, as"
+ " subroutine '%s' is not RECURSIVE",
csym->name, &c->loc, csym->ns->entries->sym->name);
- t = FAILURE;
- }
+ else
+ gfc_error ("SUBROUTINE '%s' at %L cannot be called recursively, as it"
+ " is not RECURSIVE", csym->name, &c->loc);
+
+ t = FAILURE;
}
/* Switch off assumed size checking and do this again for certain kinds
Index: gcc/testsuite/gfortran.dg/recursive_check_1.f
===================================================================
--- gcc/testsuite/gfortran.dg/recursive_check_1.f (revision 142157)
+++ gcc/testsuite/gfortran.dg/recursive_check_1.f (working copy)
@@ -1,17 +1,17 @@
! { dg-do compile }
! PR fortran/26551
SUBROUTINE SUB()
- CALL SUB() ! { dg-error "cannot call itself, as it is not RECURSIVE" }
+ CALL SUB() ! { dg-error "is not RECURSIVE" }
END SUBROUTINE
FUNCTION FUNC() RESULT (FOO)
INTEGER FOO
- FOO = FUNC() ! { dg-error "cannot call itself, as it is not RECURSIVE" }
+ FOO = FUNC() ! { dg-error "is not RECURSIVE" }
END FUNCTION
SUBROUTINE SUB2()
ENTRY ENT2()
- CALL ENT2() ! { dg-error "is not declared as RECURSIVE" }
+ CALL ENT2() ! { dg-error "is not RECURSIVE" }
END SUBROUTINE
function func2()
@@ -19,7 +19,7 @@
func2 = 42
return
entry c() result (foo)
- foo = b() ! { dg-error "is not declared as RECURSIVE" }
+ foo = b() ! { dg-error "is not RECURSIVE" }
return
entry b() result (bar)
bar = 12
Index: gcc/testsuite/gfortran.dg/recursive_check_4.f03
===================================================================
--- gcc/testsuite/gfortran.dg/recursive_check_4.f03 (revision 142158)
+++ gcc/testsuite/gfortran.dg/recursive_check_4.f03 (working copy)
@@ -16,6 +16,16 @@ CONTAINS
procptr => test ! { dg-warning "Non-RECURSIVE" }
END SUBROUTINE test
+ INTEGER FUNCTION test2 () RESULT (x)
+ IMPLICIT NONE
+ PROCEDURE(test2), POINTER :: procptr
+
+ CALL bar (test2) ! { dg-warning "Non-RECURSIVE" }
+ procptr => test2 ! { dg-warning "Non-RECURSIVE" }
+
+ x = 1812
+ END FUNCTION test2
+
INTEGER FUNCTION func ()
! Using a result variable is ok of course!
func = 42 ! { dg-bogus "Non-RECURSIVE" }
Index: gcc/testsuite/gfortran.dg/recursive_check_2.f90
===================================================================
--- gcc/testsuite/gfortran.dg/recursive_check_2.f90 (revision 142157)
+++ gcc/testsuite/gfortran.dg/recursive_check_2.f90 (working copy)
@@ -12,6 +12,6 @@
return
contains
function barbar ()
- barbar = b () ! { dg-error "is not declared as RECURSIVE" }
+ barbar = b () ! { dg-error "is not RECURSIVE" }
end function barbar
end function
Index: gcc/testsuite/gfortran.dg/recursive_check_6.f03
===================================================================
--- gcc/testsuite/gfortran.dg/recursive_check_6.f03 (revision 0)
+++ gcc/testsuite/gfortran.dg/recursive_check_6.f03 (revision 0)
@@ -0,0 +1,66 @@
+! { dg-do compile }
+
+! PR fortran/37779
+! Check that a call to a procedure's containing procedure counts as recursive
+! and is rejected if the containing procedure is not RECURSIVE.
+
+MODULE m
+ IMPLICIT NONE
+
+CONTAINS
+
+ SUBROUTINE test_sub ()
+ CALL bar ()
+ CONTAINS
+ SUBROUTINE bar ()
+ IMPLICIT NONE
+ PROCEDURE(test_sub), POINTER :: procptr
+
+ CALL test_sub () ! { dg-error "not RECURSIVE" }
+ procptr => test_sub ! { dg-warning "Non-RECURSIVE" }
+ CALL foobar (test_sub) ! { dg-warning "Non-RECURSIVE" }
+ END SUBROUTINE bar
+ END SUBROUTINE test_sub
+
+ INTEGER FUNCTION test_func () RESULT (x)
+ x = bar ()
+ CONTAINS
+ INTEGER FUNCTION bar ()
+ IMPLICIT NONE
+ PROCEDURE(test_func), POINTER :: procptr
+
+ bar = test_func () ! { dg-error "not RECURSIVE" }
+ procptr => test_func ! { dg-warning "Non-RECURSIVE" }
+ CALL foobar (test_func) ! { dg-warning "Non-RECURSIVE" }
+ END FUNCTION bar
+ END FUNCTION test_func
+
+ SUBROUTINE sub_entries ()
+ ENTRY sub_entry_1 ()
+ ENTRY sub_entry_2 ()
+ CALL bar ()
+ CONTAINS
+ SUBROUTINE bar ()
+ CALL sub_entry_1 () ! { dg-error "is not RECURSIVE" }
+ END SUBROUTINE bar
+ END SUBROUTINE sub_entries
+
+ INTEGER FUNCTION func_entries () RESULT (x)
+ ENTRY func_entry_1 () RESULT (x)
+ ENTRY func_entry_2 () RESULT (x)
+ x = bar ()
+ CONTAINS
+ INTEGER FUNCTION bar ()
+ bar = func_entry_1 () ! { dg-error "is not RECURSIVE" }
+ END FUNCTION bar
+ END FUNCTION func_entries
+
+ SUBROUTINE main ()
+ CALL test_sub ()
+ CALL sub_entries ()
+ PRINT *, test_func (), func_entries ()
+ END SUBROUTINE main
+
+END MODULE m
+
+! { dg-final { cleanup-modules "m" } }
Index: gcc/testsuite/gfortran.dg/entry_18.f90
===================================================================
--- gcc/testsuite/gfortran.dg/entry_18.f90 (revision 142157)
+++ gcc/testsuite/gfortran.dg/entry_18.f90 (working copy)
@@ -27,7 +27,7 @@ subroutine subb( g )
end function
end interface
real :: x, y
- call mysub( glocalb ) ! { dg-error "is recursive" }
+ call mysub( glocalb ) ! { dg-warning "Non-RECURSIVE" }
return
entry glocalb( x, y )
y = x