Dear Fortranners,
while we detect invalid uses of type(*), we may run into other issues
later when the declared variable is used, leading to an ICE due to a
NULL pointer dereference. This is demonstrated by Gerhard's testcase.
Steve and I came to rather similar fixes, see PR. Mine is attached.
Regtested on x86_64-pc-linux-gnu. OK for mainline?
Thanks,
Harald
From 01d629506edca711f02912e2cc124f8894cfa389 Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anl...@gmx.de>
Date: Wed, 16 Feb 2022 22:13:02 +0100
Subject: [PATCH] Fortran: error recovery after invalid assumed type
declaration
gcc/fortran/ChangeLog:
PR fortran/104573
* resolve.cc (resolve_structure_cons): Avoid NULL pointer
dereference when there is no valid component.
gcc/testsuite/ChangeLog:
PR fortran/104573
* gfortran.dg/assumed_type_14.f90: New test.
---
gcc/fortran/resolve.cc | 8 +++++---
gcc/testsuite/gfortran.dg/assumed_type_14.f90 | 12 ++++++++++++
2 files changed, 17 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gfortran.dg/assumed_type_14.f90
diff --git a/gcc/fortran/resolve.cc b/gcc/fortran/resolve.cc
index 266e41e25b1..2fa1acdbd6d 100644
--- a/gcc/fortran/resolve.cc
+++ b/gcc/fortran/resolve.cc
@@ -1288,15 +1288,17 @@ resolve_structure_cons (gfc_expr *expr, int init)
}
}
- cons = gfc_constructor_first (expr->value.constructor);
-
/* A constructor may have references if it is the result of substituting a
parameter variable. In this case we just pull out the component we
want. */
if (expr->ref)
comp = expr->ref->u.c.sym->components;
- else
+ else if (expr->ts.u.derived)
comp = expr->ts.u.derived->components;
+ else
+ return false;
+
+ cons = gfc_constructor_first (expr->value.constructor);
for (; comp && cons; comp = comp->next, cons = gfc_constructor_next (cons))
{
diff --git a/gcc/testsuite/gfortran.dg/assumed_type_14.f90 b/gcc/testsuite/gfortran.dg/assumed_type_14.f90
new file mode 100644
index 00000000000..6cfe2e4fb73
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/assumed_type_14.f90
@@ -0,0 +1,12 @@
+! { dg-do compile }
+! PR fortran/104573 - ICE in resolve_structure_cons
+! Contributed by G.Steinmetz
+
+program p
+ type t
+ end type
+ type(*), parameter :: x = t() ! { dg-error "Assumed type of variable" }
+ print *, x
+end
+
+! { dg-prune-output "Cannot convert" }
--
2.34.1
