From FEDORA_PATCHES Mon Sep 17 00:00:00 2001

From: Keith Seitz <keiths@redhat.com>

Date: Wed, 5 May 2021 13:57:13 -0700

Subject: gdb-rhbz1934673-fortran-nameless-modules.patch

;; Fix segfault with nameless fortran modules.

;; Bernhard Heckel, RH BZ 1943673

    Dwarf: Don't add nameless modules to partial symbol table

    A name for BLOCK DATA in Fortran is optional.  If no name has been

    assigned, GDB crashes during read-in of DWARF when BLOCK DATA is

    represented via DW_TAG_module.  BLOCK DATA is used for one-time

    initialization of non-pointer variables in named common blocks.

    As of now there is no issue when gfortran is used as DW_TAG_module is

    not emitted.  However, with Intel ifort the nameless DW_TAG_module is

    present and has the following form:

     ...

      <1>
: Abbrev Number: 7 (DW_TAG_module)

         <de>   DW_AT_decl_line   : 46

         <df>   DW_AT_decl_file   : 1

         <e0>   DW_AT_description : (indirect string, offset: 0x110): block

     data

         <e4>   DW_AT_high_pc     : 0x402bb7

         <ec>   DW_AT_low_pc      : 0x402bb7

     ...

    The missing name leads to a crash in add_partial_symbol, during length

    calculation.

    gdb/ChangeLog:

    2019-06-11  Bernhard Heckel  <bernhard.heckel@intel.com>

            * dwarf2read.c (add_partial_symbol): Skip nameless modules.

    gdb/testsuite/Changelog:

    2019-06-11  Bernhard Heckel  <bernhard.heckel@intel.com>

            * gdb.fortran/block-data.f: New.

            * gdb.fortran/block-data.exp: New.

diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c

--- a/gdb/dwarf2read.c

+++ b/gdb/dwarf2read.c

@@ -8936,11 +8936,15 @@ add_partial_symbol (struct partial_die_info *pdi, struct dwarf2_cu *cu)

 			   0, cu->language, objfile);

       break;

     case DW_TAG_module:

-      add_psymbol_to_list (actual_name, strlen (actual_name),

-			   built_actual_name != NULL,

-			   MODULE_DOMAIN, LOC_TYPEDEF,

-			   &objfile->global_psymbols,

-			   0, cu->language, objfile);

+      /* With Fortran 77 there might be a "BLOCK DATA" module

+         available without any name.  If so, we skip the module as it

+         doesn't bring any value.  */

+      if (actual_name != nullptr)

+	add_psymbol_to_list (actual_name, strlen (actual_name),

+			     built_actual_name != NULL,

+			     MODULE_DOMAIN, LOC_TYPEDEF,

+			     &objfile->global_psymbols,

+			     0, cu->language, objfile);

       break;

     case DW_TAG_class_type:

     case DW_TAG_interface_type:

@@ -16777,9 +16781,6 @@ read_module_type (struct die_info *die, struct dwarf2_cu *cu)

   struct type *type;

   module_name = dwarf2_name (die, cu);

-  if (!module_name)

-    complaint (_("DW_TAG_module has no name, offset %s"),

-               sect_offset_str (die->sect_off));

   type = init_type (objfile, TYPE_CODE_MODULE, 0, module_name);

   return set_die_type (die, type, cu);

diff --git a/gdb/testsuite/gdb.fortran/block-data.exp b/gdb/testsuite/gdb.fortran/block-data.exp

new file mode 100644

--- /dev/null

+++ b/gdb/testsuite/gdb.fortran/block-data.exp

@@ -0,0 +1,63 @@

+# Copyright 2016-2019 Free Software Foundation, Inc.

+#

+# This program is free software; you can redistribute it and/or modify

+# it under the terms of the GNU General Public License as published by

+# the Free Software Foundation; either version 3 of the License, or

+# (at your option) any later version.

+#

+# This program is distributed in the hope that it will be useful,

+# but WITHOUT ANY WARRANTY; without even the implied warranty of

+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+# GNU General Public License for more details.

+#

+# You should have received a copy of the GNU General Public License

+# along with this program.  If not, see <http://www.gnu.org/licenses/>.

+

+# Test anonymous block-data statements.

+

+# A name for BLOCK DATA in Fortran is optional.  BLOCK DATA is used

+# for one-time initialization of non-pointer variables in named common

+# blocks.  GDB used to crash with 'Intel ifort'-generated code, which

+# outputs nameless DW_TAG_module, unlike with gfortran which just

+# doesn't emit DW_TAG_module in this case.

+

+if { [skip_fortran_tests] } { return -1 }

+

+standard_testfile .f

+load_lib "fortran.exp"

+

+if {[prepare_for_testing $testfile.exp $testfile $srcfile {debug f90}]} {

+    return -1

+}

+

+if ![runto MAIN__] then {

+    untested "couldn't run to breakpoint MAIN__"

+    return -1

+}

+

+with_test_prefix "default values" {

+    gdb_test "print doub1" "= 1\.11\\d+"

+    gdb_test "print doub2" "= 2\.22\\d+"

+    gdb_test "print char1" "= 'abcdef'"

+    gdb_test "print char2" "= 'ghijkl'"

+}

+

+gdb_breakpoint [gdb_get_line_number "! BP_BEFORE_SUB"]

+gdb_continue_to_breakpoint "! BP_BEFORE_SUB" ".*! BP_BEFORE_SUB.*"

+

+with_test_prefix "before sub" {

+    gdb_test "print doub1" "= 11\.11\\d+"

+    gdb_test "print doub2" "= 22\.22\\d+"

+    gdb_test "print char1" "= 'ABCDEF'"

+    gdb_test "print char2" "= 'GHIJKL'"

+}

+

+gdb_breakpoint [gdb_get_line_number "! BP_SUB"]

+gdb_continue_to_breakpoint "! BP_SUB" ".*! BP_SUB.*"

+

+with_test_prefix "in sub" {

+    gdb_test "print doub1" "= 11\.11\\d+"

+    gdb_test "print doub2" "= 22\.22\\d+"

+    gdb_test "print char1" "= 'ABCDEF'"

+    gdb_test "print char2" "= 'GHIJKL'"

+}

diff --git a/gdb/testsuite/gdb.fortran/block-data.f b/gdb/testsuite/gdb.fortran/block-data.f

new file mode 100644

--- /dev/null

+++ b/gdb/testsuite/gdb.fortran/block-data.f

@@ -0,0 +1,56 @@

+! Copyright 2016-2019 Free Software Foundation, Inc.

+!

+! This program is free software; you can redistribute it and/or modify

+! it under the terms of the GNU General Public License as published by

+! the Free Software Foundation; either version 3 of the License, or

+! (at your option) any later version.

+!

+! This program is distributed in the hope that it will be useful,

+! but WITHOUT ANY WARRANTY; without even the implied warranty of

+! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+! GNU General Public License for more details.

+!

+! You should have received a copy of the GNU General Public License

+! along with this program.  If not, see <http://www.gnu.org/licenses/>.

+!

+! Check that GDB can handle block data with no global name.

+!

+! MAIN

+        PROGRAM bdata

+        DOUBLE PRECISION doub1, doub2

+        CHARACTER*6 char1, char2

+

+        COMMON /BLK1/ doub1, char1

+        COMMON /BLK2/ doub2, char2

+

+        doub1 = 11.111

+        doub2 = 22.222

+        char1 = 'ABCDEF'

+        char2 = 'GHIJKL'

+        CALL sub_block_data      ! BP_BEFORE_SUB

+        STOP

+        END

+

+! BLOCK DATA

+        BLOCK DATA

+

+        DOUBLE PRECISION doub1, doub2

+        CHARACTER*6 char1, char2

+

+        COMMON /BLK1/ doub1, char1

+        COMMON /BLK2/ doub2, char2

+        DATA doub1, doub2 /1.111, 2.222/

+        DATA char1, char2 /'abcdef', 'ghijkl'/

+        END

+

+! SUBROUTINE

+        SUBROUTINE sub_block_data

+

+        DOUBLE PRECISION doub1, doub2

+        CHARACTER*6 char1, char2

+

+        COMMON /BLK1/ doub1, char1

+        COMMON /BLK2/ doub2, char2

+

+        char1 = char2;    ! BP_SUB

+        END