[PATCH] PR fortran/104211 - ICE in find_array_section, at fortran/expr.cc:1720

[PATCH] PR fortran/104211 - ICE in find_array_section, at fortran/expr.cc:1720

[Harald Anlauf]

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Dear Fortranners,

when referencing a bad array section after an erroneous previous
declaration we might hit an assert.  The assert can be replaced
by a more gracious error recovery.  Reported by Gerhard.

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

Thanks,
Harald


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From d0250b563eb51f5f5fba5a73a40451cedeb5900d Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anlauf@gmx.de>
Date: Thu, 10 Feb 2022 21:22:48 +0100
Subject: [PATCH] Fortran: improve error recovery on bad array section

gcc/fortran/ChangeLog:

	PR fortran/104211
	* expr.cc (find_array_section): Replace assertion by error
	recovery when encountering bad array constructor.

gcc/testsuite/ChangeLog:

	PR fortran/104211
	* gfortran.dg/pr104211.f90: New test.
---
 gcc/fortran/expr.cc                    |  8 +++++++-
 gcc/testsuite/gfortran.dg/pr104211.f90 | 11 +++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gfortran.dg/pr104211.f90

diff --git a/gcc/fortran/expr.cc b/gcc/fortran/expr.cc
index ed82a94022f..c9c0ba4cc2e 100644
--- a/gcc/fortran/expr.cc
+++ b/gcc/fortran/expr.cc
@@ -1718,7 +1718,13 @@ find_array_section (gfc_expr *expr, gfc_ref *ref)
 	}

       cons = gfc_constructor_lookup (base, limit);
-      gcc_assert (cons);
+      if (cons == NULL)
+	{
+	  gfc_error ("Error in array constructor referenced at %L",
+		     &ref->u.ar.where);
+	  t = false;
+	  goto cleanup;
+	}
       gfc_constructor_append_expr (&expr->value.constructor,
 				   gfc_copy_expr (cons->expr), NULL);
     }
diff --git a/gcc/testsuite/gfortran.dg/pr104211.f90 b/gcc/testsuite/gfortran.dg/pr104211.f90
new file mode 100644
index 00000000000..21b0a26a17f
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr104211.f90
@@ -0,0 +1,11 @@
+! { dg-do compile }
+! PR fortran/104211 - ICE in find_array_section
+! Contributed by G.Steinmetz
+
+program p
+  type t
+     real :: n
+  end type
+  type(t), parameter :: a(3) = [t(2)] ! { dg-error "Different shape" }
+  type(t), parameter :: b(2) = a(2:3) ! { dg-error "Error in array constructor" }
+end
--
2.34.1

Re: [PATCH] PR fortran/104211 - ICE in find_array_section, at fortran/expr.cc:1720

[Thomas Koenig]

Hi Harald,

> when referencing a bad array section after an erroneous previous
> declaration we might hit an assert.  The assert can be replaced
> by a more gracious error recovery.  Reported by Gerhard.
> 
> Regtested on x86_64-pc-linux-gnu.  OK for mainline?

OK.

Thanks for the patch!

Best regards

	Thomas