From 77d455ee81ec3a23f8b20259a31ab963716f8e82 Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anlauf@gmx.de>
Date: Thu, 25 Jun 2020 20:34:48 +0200
Subject: [PATCH] PR fortran/95828 - Buffer overflows with SELECT RANK

With SELECT RANK, name mangling results in long internal symbols that
overflows internal buffers.  Fix that.

gcc/fortran/
	PR fortran/95828
	* match.c (select_rank_set_tmp): Enlarge internal buffer used in
	generating a mangled name.
	* resolve.c (resolve_select_rank): Likewise.
---
 gcc/fortran/match.c                   |  2 +-
 gcc/fortran/resolve.c                 |  2 +-
 gcc/testsuite/gfortran.dg/pr95828.f90 | 21 +++++++++++++++++++++
 3 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gfortran.dg/pr95828.f90

diff --git a/gcc/fortran/match.c b/gcc/fortran/match.c
index 8063fcad295..b011634792e 100644
--- a/gcc/fortran/match.c
+++ b/gcc/fortran/match.c
@@ -6496,7 +6496,7 @@ static void
 select_rank_set_tmp (gfc_typespec *ts, int *case_value)
 {
   char name[2 * GFC_MAX_SYMBOL_LEN];
-  char tname[GFC_MAX_SYMBOL_LEN];
+  char tname[GFC_MAX_SYMBOL_LEN + 7];
   gfc_symtree *tmp;
   gfc_symbol *selector = select_type_stack->selector;
   gfc_symbol *sym;
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 8c602daf1cb..6fa34caec54 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -9635,7 +9635,7 @@ resolve_select_rank (gfc_code *code, gfc_namespace *old_ns)
   gfc_namespace *ns;
   gfc_code *body, *new_st, *tail;
   gfc_case *c;
-  char tname[GFC_MAX_SYMBOL_LEN];
+  char tname[GFC_MAX_SYMBOL_LEN + 7];
   char name[2 * GFC_MAX_SYMBOL_LEN];
   gfc_symtree *st;
   gfc_expr *selector_expr = NULL;
diff --git a/gcc/testsuite/gfortran.dg/pr95828.f90 b/gcc/testsuite/gfortran.dg/pr95828.f90
new file mode 100644
index 00000000000..e85b2f11869
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr95828.f90
@@ -0,0 +1,21 @@
+! { dg-do compile }
+! { dg-options "-fsecond-underscore" }
+! PR fortran/95828 - ICE in resolve_select_rank, at fortran/resolve.c:9774
+
+module m2345678901234567890123456789012345678901234567890123456789_123
+  type t2345678901234567890123456789012345678901234567890123456789_123
+  end type
+contains
+  subroutine s2345678901234567890123456789012345678901234567890123456789_123 &
+            (x2345678901234567890123456789012345678901234567890123456789_123)
+    type    (t2345678901234567890123456789012345678901234567890123456789_123) :: &
+             x2345678901234567890123456789012345678901234567890123456789_123(..)
+
+    select rank (y2345678901234567890123456789012345678901234567890123456789_123 &
+              => x2345678901234567890123456789012345678901234567890123456789_123)
+    rank (2)
+    rank (3)
+    rank default
+    end select
+  end
+end
-- 
2.43.5