[PATCH] Fortran: error recovery with references of bad array constructors [PR105633]

[Harald Anlauf <anlauf@gmx.de>]

[-- Attachment #1: Type: text/plain, Size: 298 bytes --]

Dear Fortranners,

here's another patch that improves error receovery with references
of bad array constructors leading to an ICE after a NULL pointer
dereference.

Original patch by Steve, which I amended with a logic cleanup.

Regtested on x86_64-pc-linux-gnu.  OK for mainline?

Thanks,
Harald


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: pr105633.diff --]
[-- Type: text/x-patch, Size: 2146 bytes --]

From 0da12c71a6ccbefa1456be5759974a4b450c78e6 Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anlauf@gmx.de>
Date: Wed, 19 Oct 2022 22:37:56 +0200
Subject: [PATCH] Fortran: error recovery with references of bad array
 constructors [PR105633]

gcc/fortran/ChangeLog:

	PR fortran/105633
	* expr.cc (find_array_section): Move check for NULL pointers so
	that both subscript triplets and vector subscripts are covered.

gcc/testsuite/ChangeLog:

	PR fortran/105633
	* gfortran.dg/pr105633.f90: New test.

Co-authored-by: Steven G. Kargl <kargl@gcc.gnu.org>
---
 gcc/fortran/expr.cc                    | 10 +++++++---
 gcc/testsuite/gfortran.dg/pr105633.f90 |  8 ++++++++
 2 files changed, 15 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/gfortran.dg/pr105633.f90

diff --git a/gcc/fortran/expr.cc b/gcc/fortran/expr.cc
index 290ddf360c8..69d0b57c688 100644
--- a/gcc/fortran/expr.cc
+++ b/gcc/fortran/expr.cc
@@ -1552,6 +1552,12 @@ find_array_section (gfc_expr *expr, gfc_ref *ref)
       lower = ref->u.ar.as->lower[d];
       upper = ref->u.ar.as->upper[d];

+      if (!lower || !upper)
+	{
+	  t = false;
+	  goto cleanup;
+	}
+
       if (ref->u.ar.dimen_type[d] == DIMEN_VECTOR)  /* Vector subscript.  */
 	{
 	  gfc_constructor *ci;
@@ -1594,9 +1600,7 @@ find_array_section (gfc_expr *expr, gfc_ref *ref)
 	{
 	  if ((begin && begin->expr_type != EXPR_CONSTANT)
 	      || (finish && finish->expr_type != EXPR_CONSTANT)
-	      || (step && step->expr_type != EXPR_CONSTANT)
-	      || !lower
-	      || !upper)
+	      || (step && step->expr_type != EXPR_CONSTANT))
 	    {
 	      t = false;
 	      goto cleanup;
diff --git a/gcc/testsuite/gfortran.dg/pr105633.f90 b/gcc/testsuite/gfortran.dg/pr105633.f90
new file mode 100644
index 00000000000..f2dbc5e742a
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr105633.f90
@@ -0,0 +1,8 @@
+! { dg-do compile }
+! PR fortran/105633 - ICE in find_array_section
+! Contributed by G.Steinmetz
+
+program p
+  integer, parameter :: a(:) = [1,2] ! { dg-error "deferred shape" }
+  print *, [a([1,2])]
+end
--
2.35.3