[PING] Re: [PATCH v3] Dwarf: Don't add nameless modules to partial symbol table.

[Paweł Wódkowski <pwodkowski at sii dot pl>]

Hi,

Can someone take a look at this patch?

Thanks
Pawel

On 05.01.2019 12:43, Pawel Wodkowski wrote:
> From: Bernhard Heckel <bernhard.heckel@intel.com>
> 
> A name for BLOCK DATA in Fortran is optional.  If no
> name has been assigned, GDB will crash 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 emited.  For Intel ifort the nameless
> DW_TAG_module is present and have following form:
> 
> ...
>   <1><dd>: 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
> ...
> 
> Missing name lead to crash in add_partial_symbol function
> during length calculation.
> 
> 2016-06-15  Bernhard Heckel  <bernhard.heckel@intel.com>
> 
> gdb/Changelog:
> 	* dwarf2read.c (add_partial_symbol): Skip nameless modules.
> 
> gdb/testsuite/Changelog:
> 	* gdb.fortran/block-data.f: New.
> 	* gdb.fortran/block-data.exp: New.
> 
> Changes from V1 to V2:
> 	* No changes - just sent with other patches in series.
> 
> Changes from V2 to V3:
> 	* Decouple from other patches and send stand alone.
> 	* Provide example DW_TAG_module in commit message.
> 	* Fix mistakes in comments.
> ---
>   gdb/dwarf2read.c                         | 13 +++++---
>   gdb/testsuite/gdb.fortran/block-data.exp | 49 ++++++++++++++++++++++++++++
>   gdb/testsuite/gdb.fortran/block-data.f   | 56 ++++++++++++++++++++++++++++++++
>   3 files changed, 113 insertions(+), 5 deletions(-)
>   create mode 100644 gdb/testsuite/gdb.fortran/block-data.exp
>   create mode 100644 gdb/testsuite/gdb.fortran/block-data.f
> 
> diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
> index d2a8cd44f9a5..389b21d27f3f 100644
> --- a/gdb/dwarf2read.c
> +++ b/gdb/dwarf2read.c
> @@ -8995,11 +8995,14 @@ 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, -1,
> -			   &objfile->global_psymbols,
> -			   0, cu->language, objfile);
> +      /* In Fortran 77 there might be a "BLOCK DATA" module available wihout
> +         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 != nullptr,
> +			     MODULE_DOMAIN, LOC_TYPEDEF, -1,
> +			     &objfile->global_psymbols,
> +			     0, cu->language, objfile);
>         break;
>       case DW_TAG_class_type:
>       case DW_TAG_interface_type:
> diff --git a/gdb/testsuite/gdb.fortran/block-data.exp b/gdb/testsuite/gdb.fortran/block-data.exp
> new file mode 100644
> index 000000000000..bb40be23d26b
> --- /dev/null
> +++ b/gdb/testsuite/gdb.fortran/block-data.exp
> @@ -0,0 +1,49 @@
> +# Copyright 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/>.
> +
> +# This test is supposed to test anonymous block-data statement.
> +
> +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
> +}
> +
> +gdb_test "print doub1" "= 1.11\\d+" "print doub1, default values"
> +gdb_test "print doub2" "= 2.22\\d+" "print doub2, default values"
> +gdb_test "print char1" "= 'abcdef'" "print char1, default values"
> +gdb_test "print char2" "= 'ghijkl'" "print char2, default values"
> +
> +gdb_breakpoint [gdb_get_line_number "! BP_BEFORE_SUB"]
> +gdb_continue_to_breakpoint "! BP_BEFORE_SUB" ".*! BP_BEFORE_SUB.*"
> +gdb_test "print doub1" "= 11.11\\d+" "print doub1, before sub"
> +gdb_test "print doub2" "= 22.22\\d+" "print doub2, before sub"
> +gdb_test "print char1" "= 'ABCDEF'" "print char1, before sub"
> +gdb_test "print char2" "= 'GHIJKL'" "print char2, before sub"
> +
> +gdb_breakpoint [gdb_get_line_number "! BP_SUB"]
> +gdb_continue_to_breakpoint "! BP_SUB" ".*! BP_SUB.*"
> +gdb_test "print doub1" "= 11.11\\d+" "print char1, in sub"
> +gdb_test "print doub2" "= 22.22\\d+" "print doub2, in sub"
> +gdb_test "print char1" "= 'ABCDEF'" "print char1, in sub"
> +gdb_test "print char2" "= 'GHIJKL'" "print char2, in sub"
> diff --git a/gdb/testsuite/gdb.fortran/block-data.f b/gdb/testsuite/gdb.fortran/block-data.f
> new file mode 100644
> index 000000000000..5f50e644d303
> --- /dev/null
> +++ b/gdb/testsuite/gdb.fortran/block-data.f
> @@ -0,0 +1,56 @@
> +! Copyright 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 if GDB can handle block data without 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
>