Le 26/04/2022 à 19:12, Mikael Morin a écrit :
Le 26/04/2022 à 15:32, Jakub Jelinek a écrit :
or one can repeat it like:
if (DECL_P (expr)
&& DECL_LANG_SPECIFIC (expr)
&& GFC_DECL_SAVED_DESCRIPTOR (expr)
&& GFC_DECL_SAVED_DESCRIPTOR (expr) != expr)
return non_negative_strides_array_p (GFC_DECL_SAVED_DESCRIPTOR
(expr));
I think I’ll use that.
Here it comes.
Regression tested again. OK?
From 9da696478832bb3fe5ac25542ad9226ce3235368 Mon Sep 17 00:00:00 2001
From: Mikael Morin <mik...@gcc.gnu.org>
Date: Tue, 26 Apr 2022 13:05:32 +0200
Subject: [PATCH v2] fortran: Avoid infinite self-recursion [PR105381]
Dummy array decls are local decls different from the argument decl
accessible through GFC_DECL_SAVED_DESCRIPTOR. If the argument decl has
a DECL_LANG_SPECIFIC set, it is copied over to the local decl at the
time the latter is created, so that the DECL_LANG_SPECIFIC object is
shared between local dummy decl and argument decl, and thus the
GFC_DECL_SAVED_DESCRIPTOR of the argument decl is the argument decl
itself.
The r12-8230-g7964ab6c364c410c34efe7ca2eba797d36525349 change introduced
the non_negative_strides_array_p predicate which recurses through
GFC_DECL_SAVED_DESCRIPTOR to avoid seeing dummy decls as purely local
decls. As the GFC_DECL_SAVED_DESCRIPTOR of the argument decl is itself,
this can cause infinite recursion.
This change adds a check to avoid infinite recursion.
PR fortran/102043
PR fortran/105381
gcc/fortran/ChangeLog:
* trans-array.cc (non_negative_strides_array_p): Inline variable
orig_decl and merge nested if conditions. Add condition to not
recurse if the next argument is the same as the current.
gcc/testsuite/ChangeLog:
* gfortran.dg/character_array_dummy_1.f90: New test.
---
gcc/fortran/trans-array.cc | 7 ++++---
.../gfortran.dg/character_array_dummy_1.f90 | 21 +++++++++++++++++++
2 files changed, 25 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gfortran.dg/character_array_dummy_1.f90
diff --git a/gcc/fortran/trans-array.cc b/gcc/fortran/trans-array.cc
index e4b6270ccf8..05134952db4 100644
--- a/gcc/fortran/trans-array.cc
+++ b/gcc/fortran/trans-array.cc
@@ -3696,9 +3696,10 @@ non_negative_strides_array_p (tree expr)
/* If the array was originally a dummy with a descriptor, strides can be
negative. */
if (DECL_P (expr)
- && DECL_LANG_SPECIFIC (expr))
- if (tree orig_decl = GFC_DECL_SAVED_DESCRIPTOR (expr))
- return non_negative_strides_array_p (orig_decl);
+ && DECL_LANG_SPECIFIC (expr)
+ && GFC_DECL_SAVED_DESCRIPTOR (expr)
+ && GFC_DECL_SAVED_DESCRIPTOR (expr) != expr)
+ return non_negative_strides_array_p (GFC_DECL_SAVED_DESCRIPTOR (expr));
return true;
}
diff --git a/gcc/testsuite/gfortran.dg/character_array_dummy_1.f90 b/gcc/testsuite/gfortran.dg/character_array_dummy_1.f90
new file mode 100644
index 00000000000..da5ed636f4f
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/character_array_dummy_1.f90
@@ -0,0 +1,21 @@
+! { dg-do compile }
+!
+! PR fortran/105381
+! Infinite recursion with array references of character dummy arguments.
+!
+! Contributed by Harald Anlauf <anl...@gmx.de>
+
+MODULE m
+ implicit none
+ integer, parameter :: ncrit = 8
+ integer, parameter :: nterm = 7
+contains
+
+ subroutine new_thin_rule (rule1)
+ character(*),intent(in) ,optional :: rule1(ncrit)
+ character(len=8) :: rules (ncrit,nterm)
+ rules = ''
+ if (present (rule1)) rules(:,1) = rule1 ! <-- compile time hog
+ end subroutine new_thin_rule
+
+end module m
--
2.35.1
