https://gcc.gnu.org/g:8fd2158acac181a308126ad7b798b478eb3b7087
commit r15-7212-g8fd2158acac181a308126ad7b798b478eb3b7087
Author: Harald Anlauf <anl...@gmx.de>
Date: Sat Jan 25 19:59:56 2025 +0100
Fortran: fix issues with variables in BLOCK DATA [PR58857]
PR fortran/58857
gcc/fortran/ChangeLog:
* class.cc (gfc_find_derived_vtab): Declare some frontend generated
variables and procedures (_vtab, _copy, _deallocate) as artificial.
(find_intrinsic_vtab): Likewise.
* trans-decl.cc (check_block_data_decls): New helper function.
(gfc_generate_block_data): Use it to emit warnings for variables
declared in a BLOCK DATA program unit but not in a COMMON block.
gcc/testsuite/ChangeLog:
* gfortran.dg/uncommon_block_data_2.f90: New test.
Diff:
---
gcc/fortran/class.cc | 4 ++++
gcc/fortran/trans-decl.cc | 23 ++++++++++++++++++++++
.../gfortran.dg/uncommon_block_data_2.f90 | 12 +++++++++++
3 files changed, 39 insertions(+)
diff --git a/gcc/fortran/class.cc b/gcc/fortran/class.cc
index 97ff54df5e1c..df18601e45bd 100644
--- a/gcc/fortran/class.cc
+++ b/gcc/fortran/class.cc
@@ -2498,6 +2498,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
vtab->attr.save = SAVE_IMPLICIT;
vtab->attr.vtab = 1;
vtab->attr.access = ACCESS_PUBLIC;
+ vtab->attr.artificial = 1;
gfc_set_sym_referenced (vtab);
free (name);
name = xasprintf ("__vtype_%s", tname);
@@ -2610,6 +2611,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
goto cleanup;
c->attr.proc_pointer = 1;
c->attr.access = ACCESS_PRIVATE;
+ c->attr.artificial = 1;
c->tb = XCNEW (gfc_typebound_proc);
c->tb->ppc = 1;
if (derived->attr.unlimited_polymorphic
@@ -2687,6 +2689,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
goto cleanup;
c->attr.proc_pointer = 1;
c->attr.access = ACCESS_PRIVATE;
+ c->attr.artificial = 1;
c->tb = XCNEW (gfc_typebound_proc);
c->tb->ppc = 1;
if (derived->attr.unlimited_polymorphic || derived->attr.abstract
@@ -2951,6 +2954,7 @@ find_intrinsic_vtab (gfc_typespec *ts)
goto cleanup;
c->attr.proc_pointer = 1;
c->attr.access = ACCESS_PRIVATE;
+ c->attr.artificial = 1;
c->tb = XCNEW (gfc_typebound_proc);
c->tb->ppc = 1;
diff --git a/gcc/fortran/trans-decl.cc b/gcc/fortran/trans-decl.cc
index 97bb0a418581..b8fc9a1d89c5 100644
--- a/gcc/fortran/trans-decl.cc
+++ b/gcc/fortran/trans-decl.cc
@@ -8295,6 +8295,26 @@ gfc_generate_constructors (void)
#endif
}
+
+/* Helper function for checking of variables declared in a BLOCK DATA program
+ unit. */
+
+static void
+check_block_data_decls (gfc_symbol * sym)
+{
+ if (warn_unused_variable
+ && sym->attr.flavor == FL_VARIABLE
+ && !sym->attr.in_common
+ && !sym->attr.artificial)
+ {
+ gfc_warning (OPT_Wunused_variable,
+ "Symbol %qs at %L is declared in a BLOCK DATA "
+ "program unit but is not in a COMMON block",
+ sym->name, &sym->declared_at);
+ }
+}
+
+
/* Translates a BLOCK DATA program unit. This means emitting the
commons contained therein plus their initializations. We also emit
a globally visible symbol to make sure that each BLOCK DATA program
@@ -8315,6 +8335,9 @@ gfc_generate_block_data (gfc_namespace * ns)
/* Process the DATA statements. */
gfc_trans_common (ns);
+ /* Check for variables declared in BLOCK DATA but not used in COMMON. */
+ gfc_traverse_ns (ns, check_block_data_decls);
+
/* Create a global symbol with the mane of the block data. This is to
generate linker errors if the same name is used twice. It is never
really used. */
diff --git a/gcc/testsuite/gfortran.dg/uncommon_block_data_2.f90
b/gcc/testsuite/gfortran.dg/uncommon_block_data_2.f90
new file mode 100644
index 000000000000..7b1a0b39a149
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/uncommon_block_data_2.f90
@@ -0,0 +1,12 @@
+! { dg-do compile }
+! { dg-additional-options "-Wunused-variable" }
+!
+! PR fortran/58857
+
+BLOCK DATA valid
+ integer :: i
+ integer :: n ! { dg-warning "not in a COMMON block" }
+ class(*) :: zz ! { dg-warning "not in a COMMON block" }
+ pointer :: zz
+ common /com/ i, r
+END BLOCK DATA valid
