From: Steven G. Kargl <kargl@gcc.gnu.org>
Date: Wed, 25 Apr 2018 00:12:58 +0000 (+0000)
Subject: re PR fortran/85520 (Out of memory when declaring a character with len << 0)
X-Git-Tag: releases/gcc-6.5.0~357
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=be1f04f75c6a926659b932ef02169844a74bec76;p=thirdparty%2Fgcc.git

re PR fortran/85520 (Out of memory when declaring a character with len << 0)

2018-04-24  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/85520
	* decl.c (gfc_match_char_spec): Check for negative length and set to 0.

2018-04-24  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/85520
	* gfortran.dg/pr85520.f90: New test.

From-SVN: r259625
---

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index d0554695aea0..e7c919c9f2fc 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,8 @@
+2018-04-24  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	PR fortran/85520
+	* decl.c (gfc_match_char_spec): Check for negative length and set to 0.
+
 2018-03-28  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	PR fortran/85084
diff --git a/gcc/fortran/decl.c b/gcc/fortran/decl.c
index 4000a0c76b6d..917b89f0a482 100644
--- a/gcc/fortran/decl.c
+++ b/gcc/fortran/decl.c
@@ -3023,7 +3023,11 @@ done:
 	  e = gfc_copy_expr (len);
 	  gfc_reduce_init_expr (e);
 	  if (e->expr_type == EXPR_CONSTANT)
-	    gfc_replace_expr (len, e);
+	    {
+	      gfc_replace_expr (len, e);
+	      if (mpz_cmp_si (len->value.integer, 0) < 0)
+		mpz_set_ui (len->value.integer, 0);
+	    }
 	  else
 	    gfc_free_expr (e);
 	  cl->length = len;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 2f36f83abf93..84ea927b2318 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-04-24  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	PR fortran/85520
+	* gfortran.dg/pr85520.f90: New test.
+
 2018-04-23  Aaron Sawdey  <acsawdey@linux.ibm.com>
 
 	Backport from mainline
diff --git a/gcc/testsuite/gfortran.dg/pr85520.f90 b/gcc/testsuite/gfortran.dg/pr85520.f90
new file mode 100644
index 000000000000..3e66a9020f8d
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr85520.f90
@@ -0,0 +1,7 @@
+! { dg-do run }
+! PR fortran/85520
+! Original code from Gerhard Steinmetz <gscfq at t-online dot de>
+program p
+   character(-huge(1)) :: c = ' '
+    if (len(c) /= 0) stop 1
+end