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Re: [patch] PR python/11407
- From: Phil Muldoon <pmuldoon at redhat dot com>
- To: tromey at redhat dot com
- Cc: gdb-patches at sourceware dot org, vladimir at codesourcery dot com
- Date: Wed, 07 Jul 2010 18:02:17 +0100
- Subject: Re: [patch] PR python/11407
- References: <4C23426F.4020502@redhat.com> <m3aaqk8foj.fsf@fleche.redhat.com> <4C23D5CB.5040702@redhat.com> <m3y6e33r7d.fsf@fleche.redhat.com> <4C251D93.6020909@redhat.com>
On 25/06/10 22:20, Phil Muldoon wrote:
> On 06/25/2010 07:25 PM, Tom Tromey wrote:
>>>>>>> "Phil" == Phil Muldoon <pmuldoon@redhat.com> writes:
>>
>> Phil> I'm not sure what to do in this case. There seems to be no direct
>> Phil> equivalent of converting an exception to error output on a stream in MI
>> Phil> (or any cases of TRY ... exception handlers). There are many cases of
>> Phil> MI raising an error() though, so I thought it appropriate in our case
>> Phil> to raise a warning() instead. Because of the peculiarities of the MI
>> Phil> cases I just report a warning generically and move on. This is not
>> Phil> totally ideal, but it does allow the error/warning preamble followed
>> Phil> by the actual locals information.
>>
>> I'm not convinced a warning is the best thing.
>>
>> Why not catch the exception and print the text of it as the variable's
>> value? Something like <error reading variable: %s>
>> I think this will work ok with existing front ends.
>
> Here is a patch that does that.
>
> What do you think?
>
> Cheers,
>
> Phil
>
Tom >> I am curious to hear what Volodya wants.
Adding Vladimir Prus to the CC list.
Cheers,
Phil
> --
>
> diff --git a/gdb/mi/mi-cmd-stack.c b/gdb/mi/mi-cmd-stack.c
> index 6797055..7ee075c 100644
> --- a/gdb/mi/mi-cmd-stack.c
> +++ b/gdb/mi/mi-cmd-stack.c
> @@ -31,7 +31,7 @@
> #include "gdb_string.h"
> #include "language.h"
> #include "valprint.h"
> -
> +#include "exceptions.h"
>
> enum what_to_list { locals, arguments, all };
>
> @@ -334,27 +334,47 @@ list_args_or_locals (enum what_to_list what, int values, struct frame_info *fi)
> && TYPE_CODE (type) != TYPE_CODE_STRUCT
> && TYPE_CODE (type) != TYPE_CODE_UNION)
> {
> - struct value_print_options opts;
> -
> - val = read_var_value (sym2, fi);
> - get_raw_print_options (&opts);
> - opts.deref_ref = 1;
> - common_val_print
> - (val, stb->stream, 0, &opts,
> - language_def (SYMBOL_LANGUAGE (sym2)));
> + volatile struct gdb_exception except;
> +
> + TRY_CATCH (except, RETURN_MASK_ERROR)
> + {
> + struct value_print_options opts;
> +
> + val = read_var_value (sym2, fi);
> + get_raw_print_options (&opts);
> + opts.deref_ref = 1;
> + common_val_print
> + (val, stb->stream, 0, &opts,
> + language_def (SYMBOL_LANGUAGE (sym2)));
> + }
> + if (except.reason < 0)
> + fprintf_filtered (stb->stream,
> + _("<error reading variable: %s>"),
> + except.message);
> +
> ui_out_field_stream (uiout, "value", stb);
> }
> break;
> case PRINT_ALL_VALUES:
> {
> - struct value_print_options opts;
> -
> - val = read_var_value (sym2, fi);
> - get_raw_print_options (&opts);
> - opts.deref_ref = 1;
> - common_val_print
> - (val, stb->stream, 0, &opts,
> - language_def (SYMBOL_LANGUAGE (sym2)));
> + volatile struct gdb_exception except;
> +
> + TRY_CATCH (except, RETURN_MASK_ERROR)
> + {
> + struct value_print_options opts;
> +
> + val = read_var_value (sym2, fi);
> + get_raw_print_options (&opts);
> + opts.deref_ref = 1;
> + common_val_print
> + (val, stb->stream, 0, &opts,
> + language_def (SYMBOL_LANGUAGE (sym2)));
> + }
> + if (except.reason < 0)
> + fprintf_filtered (stb->stream,
> + _("<error reading variable: %s>"),
> + except.message);
> +
> ui_out_field_stream (uiout, "value", stb);
> }
> break;
> diff --git a/gdb/testsuite/gdb.mi/dw2-ref-missing-frame-func.c b/gdb/testsuite/gdb.mi/dw2-ref-missing-frame-func.c
> new file mode 100644
> index 0000000..10ddd81
> --- /dev/null
> +++ b/gdb/testsuite/gdb.mi/dw2-ref-missing-frame-func.c
> @@ -0,0 +1,54 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> + Copyright 2010 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/>. */
> +
> +asm (".globl cu_text_start");
> +asm ("cu_text_start:");
> +
> +asm (".globl func_nofb_start");
> +asm ("func_nofb_start:");
> +
> +void
> +func_nofb (void)
> +{
> + /* int func_nofb_var; */
> + /* int func_nofb_var2; */
> +
> + extern void func_nofb_marker (void);
> + func_nofb_marker ();
> +}
> +
> +asm (".globl func_nofb_end");
> +asm ("func_nofb_end:");
> +
> +asm (".globl func_loopfb_start");
> +asm ("func_loopfb_start:");
> +
> +void
> +func_loopfb (void)
> +{
> + /* int func_loopfb_var; */
> + /* int func_loopfb_var2; */
> +
> + extern void func_loopfb_marker (void);
> + func_loopfb_marker ();
> +}
> +
> +asm (".globl func_loopfb_end");
> +asm ("func_loopfb_end:");
> +
> +asm (".globl cu_text_end");
> +asm ("cu_text_end:");
> diff --git a/gdb/testsuite/gdb.mi/dw2-ref-missing-frame-main.c b/gdb/testsuite/gdb.mi/dw2-ref-missing-frame-main.c
> new file mode 100644
> index 0000000..b3ec33a
> --- /dev/null
> +++ b/gdb/testsuite/gdb.mi/dw2-ref-missing-frame-main.c
> @@ -0,0 +1,40 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> + Copyright 2009, 2010 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/>. */
> +
> +extern void func_nofb (void);
> +extern void func_loopfb (void);
> +
> +void
> +func_nofb_marker (void)
> +{
> +}
> +
> +void
> +func_loopfb_marker (void)
> +{
> +}
> +
> +int
> +main (void)
> +{
> + int main_var = 1;
> +
> + func_nofb ();
> + func_loopfb ();
> +
> + return 0;
> +}
> diff --git a/gdb/testsuite/gdb.mi/dw2-ref-missing-frame.S b/gdb/testsuite/gdb.mi/dw2-ref-missing-frame.S
> new file mode 100644
> index 0000000..a93b3a6
> --- /dev/null
> +++ b/gdb/testsuite/gdb.mi/dw2-ref-missing-frame.S
> @@ -0,0 +1,165 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> + Copyright 2007, 2008, 2009, 2010 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/>. */
> +
> +/* Debug information */
> +
> + .section .debug_info
> +.Lcu1_begin:
> + /* CU header */
> + .4byte .Lcu1_end - .Lcu1_start /* Length of Compilation Unit */
> +.Lcu1_start:
> + .2byte 2 /* DWARF Version */
> + .4byte .Labbrev1_begin /* Offset into abbrev section */
> + .byte 4 /* Pointer size */
> +
> + /* CU die */
> + .uleb128 1 /* Abbrev: DW_TAG_compile_unit */
> + .4byte cu_text_end /* DW_AT_high_pc */
> + .4byte cu_text_start /* DW_AT_low_pc */
> + .ascii "file1.txt\0" /* DW_AT_name */
> + .ascii "GNU C 3.3.3\0" /* DW_AT_producer */
> + .byte 1 /* DW_AT_language (C) */
> +
> +.Ltype_int:
> + .uleb128 3 /* Abbrev: DW_TAG_base_type */
> + .ascii "int\0" /* DW_AT_name */
> + .byte 4 /* DW_AT_byte_size */
> + .byte 5 /* DW_AT_encoding */
> +
> + /* func_nofb */
> + .uleb128 5 /* Abbrev: DW_TAG_subprogram (no fb) */
> + .ascii "func_nofb\0" /* DW_AT_name */
> + .4byte func_nofb_start /* DW_AT_low_pc */
> + .4byte func_nofb_end /* DW_AT_high_pc */
> +
> + .uleb128 7 /* Abbrev: DW_TAG_variable (location) */
> + .ascii "func_nofb_var\0" /* DW_AT_name */
> + .byte 2f - 1f /* DW_AT_location */
> +1: .byte 0x91 /* DW_OP_fbreg */
> + .sleb128 0 /* 0 */
> +2: .4byte .Ltype_int-.Lcu1_begin /* DW_AT_type */
> +
> + .uleb128 7 /* Abbrev: DW_TAG_variable (location) */
> + .ascii "func_nofb_var2\0" /* DW_AT_name */
> + .byte 2f - 1f /* DW_AT_location */
> +1: .byte 0x91 /* DW_OP_fbreg */
> + .sleb128 0 /* 0 */
> +2: .4byte .Ltype_int-.Lcu1_begin /* DW_AT_type */
> +
> + .byte 0 /* End of children of func */
> +
> + /* func_loopfb */
> + .uleb128 6 /* Abbrev: DW_TAG_subprogram (loop fb) */
> + .ascii "func_loopfb\0" /* DW_AT_name */
> + .4byte func_loopfb_start /* DW_AT_low_pc */
> + .4byte func_loopfb_end /* DW_AT_high_pc */
> + .byte 2f - 1f /* DW_AT_frame_base */
> +1: .byte 0x91 /* DW_OP_fbreg */
> + .sleb128 0 /* 0 */
> +2:
> +
> + .uleb128 7 /* Abbrev: DW_TAG_variable (location) */
> + .ascii "func_loopfb_var\0" /* DW_AT_name */
> + .byte 2f - 1f /* DW_AT_location */
> +1: .byte 0x91 /* DW_OP_fbreg */
> + .sleb128 0 /* 0 */
> +2: .4byte .Ltype_int-.Lcu1_begin /* DW_AT_type */
> +
> + .uleb128 7 /* Abbrev: DW_TAG_variable (location) */
> + .ascii "func_loopfb_var2\0" /* DW_AT_name */
> + .byte 2f - 1f /* DW_AT_location */
> +1: .byte 0x91 /* DW_OP_fbreg */
> + .sleb128 0 /* 0 */
> +2: .4byte .Ltype_int-.Lcu1_begin /* DW_AT_type */
> +
> + .byte 0 /* End of children of func */
> +
> + .byte 0 /* End of children of CU */
> +
> +.Lcu1_end:
> +
> +/* Abbrev table */
> + .section .debug_abbrev
> +.Labbrev1_begin:
> + .uleb128 1 /* Abbrev code */
> + .uleb128 0x11 /* DW_TAG_compile_unit */
> + .byte 1 /* has_children */
> + .uleb128 0x12 /* DW_AT_high_pc */
> + .uleb128 0x1 /* DW_FORM_addr */
> + .uleb128 0x11 /* DW_AT_low_pc */
> + .uleb128 0x1 /* DW_FORM_addr */
> + .uleb128 0x3 /* DW_AT_name */
> + .uleb128 0x8 /* DW_FORM_string */
> + .uleb128 0x25 /* DW_AT_producer */
> + .uleb128 0x8 /* DW_FORM_string */
> + .uleb128 0x13 /* DW_AT_language */
> + .uleb128 0xb /* DW_FORM_data1 */
> + .byte 0x0 /* Terminator */
> + .byte 0x0 /* Terminator */
> +
> + .uleb128 3 /* Abbrev code */
> + .uleb128 0x24 /* DW_TAG_base_type */
> + .byte 0 /* has_children */
> + .uleb128 0x3 /* DW_AT_name */
> + .uleb128 0x8 /* DW_FORM_string */
> + .uleb128 0xb /* DW_AT_byte_size */
> + .uleb128 0xb /* DW_FORM_data1 */
> + .uleb128 0x3e /* DW_AT_encoding */
> + .uleb128 0xb /* DW_FORM_data1 */
> + .byte 0x0 /* Terminator */
> + .byte 0x0 /* Terminator */
> +
> + .uleb128 5 /* Abbrev code */
> + .uleb128 0x2e /* DW_TAG_subprogram (no fb) */
> + .byte 1 /* has_children */
> + .uleb128 0x3 /* DW_AT_name */
> + .uleb128 0x8 /* DW_FORM_string */
> + .uleb128 0x11 /* DW_AT_low_pc */
> + .uleb128 0x1 /* DW_FORM_addr */
> + .uleb128 0x12 /* DW_AT_high_pc */
> + .uleb128 0x1 /* DW_FORM_addr */
> + .byte 0x0 /* Terminator */
> + .byte 0x0 /* Terminator */
> +
> + .uleb128 6 /* Abbrev code */
> + .uleb128 0x2e /* DW_TAG_subprogram (loop fb) */
> + .byte 1 /* has_children */
> + .uleb128 0x3 /* DW_AT_name */
> + .uleb128 0x8 /* DW_FORM_string */
> + .uleb128 0x11 /* DW_AT_low_pc */
> + .uleb128 0x1 /* DW_FORM_addr */
> + .uleb128 0x12 /* DW_AT_high_pc */
> + .uleb128 0x1 /* DW_FORM_addr */
> + .uleb128 0x40 /* DW_AT_frame_base */
> + .uleb128 0xa /* DW_FORM_block1 */
> + .byte 0x0 /* Terminator */
> + .byte 0x0 /* Terminator */
> +
> + .uleb128 7 /* Abbrev code (location) */
> + .uleb128 0x34 /* DW_TAG_variable */
> + .byte 0 /* has_children */
> + .uleb128 0x3 /* DW_AT_name */
> + .uleb128 0x8 /* DW_FORM_string */
> + .uleb128 0x2 /* DW_AT_location */
> + .uleb128 0xa /* DW_FORM_block1 */
> + .uleb128 0x49 /* DW_AT_type */
> + .uleb128 0x13 /* DW_FORM_ref4 */
> + .byte 0x0 /* Terminator */
> + .byte 0x0 /* Terminator */
> +
> + .byte 0x0 /* Terminator */
> + .byte 0x0 /* Terminator */
> diff --git a/gdb/testsuite/gdb.mi/dw2-ref-missing-frame.exp b/gdb/testsuite/gdb.mi/dw2-ref-missing-frame.exp
> new file mode 100644
> index 0000000..cd29de5
> --- /dev/null
> +++ b/gdb/testsuite/gdb.mi/dw2-ref-missing-frame.exp
> @@ -0,0 +1,77 @@
> +# Copyright 2008, 2009, 2010 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 can only be run on targets which support DWARF-2 and use gas.
> +# For now pick a sampling of likely targets.
> +load_lib mi-support.exp
> +set MIFLAGS "-i=mi"
> +
> +if {![istarget *-*-linux*]
> + && ![istarget *-*-gnu*]
> + && ![istarget *-*-elf*]
> + && ![istarget *-*-openbsd*]
> + && ![istarget arm-*-eabi*]
> + && ![istarget powerpc-*-eabi*]} {
> + return 0
> +}
> +
> +set testfile "dw2-ref-missing-frame"
> +set srcsfile ${testfile}.S
> +set objsfile ${objdir}/${subdir}/${testfile}.o
> +set srcfuncfile ${testfile}-func.c
> +set objfuncfile ${objdir}/${subdir}/${testfile}-func.o
> +set srcmainfile ${testfile}-main.c
> +set objmainfile ${objdir}/${subdir}/${testfile}-main.o
> +set executable ${testfile}
> +set binfile ${objdir}/${subdir}/${executable}
> +
> +if { [gdb_compile "${srcdir}/${subdir}/${srcsfile}" $objsfile object {}] != ""
> + || [gdb_compile "${srcdir}/${subdir}/${srcfuncfile}" $objfuncfile object {}] != ""
> + || [gdb_compile "${srcdir}/${subdir}/${srcmainfile}" $objmainfile object {debug}] != ""
> + || [gdb_compile "$objsfile $objfuncfile $objmainfile" $binfile executable {}] != "" } {
> + return -1
> +}
> +
> +if [mi_gdb_start] {
> + continue
> +}
> +
> +mi_delete_breakpoints
> +mi_gdb_reinitialize_dir $srcdir/$subdir
> +mi_gdb_load ${binfile}
> +
> +if [mi_runto func_nofb_marker] {
> + # First try referencing DW_AT_frame_base which is not defined.
> + mi_gdb_test "300-stack-list-locals --thread 1 --frame 1 --all-values" \
> + "300\\^done,locals=\\\[\{name=\"func_nofb_var\",value=\"\\\<error reading variable: Could not find the frame base for \\\\\"func_nofb\\\\\"\\\.\\\>\"\},\{name=\"func_nofb_var2\",value=\"\\\<error reading variable: Could not find the frame base for \\\\\"func_nofb\\\\\"\\\.\\\>\"\}\\\].*" \
> + "test func_nofb_marker"
> +}
> +
> +# GDB could have crashed.
> +mi_gdb_exit
> +if [mi_gdb_start] {
> + continue
> +}
> +mi_delete_breakpoints
> +mi_gdb_reinitialize_dir $srcdir/$subdir
> +mi_gdb_load ${binfile}
> +
> +# And now try referencing DW_AT_frame_base defined using a self-reference
> +# (DW_OP_fbreg).
> +if [mi_runto func_loopfb_marker] {
> + mi_gdb_test "301-stack-list-locals --thread 1 --frame 1 --all-values" \
> + "301\\^done,locals=\\\[\{name=\"func_loopfb_var\",value=\"\\\<error reading variable: DWARF-2 expression error: Loop detected.*\"\},\{name=\"func_loopfb_var2\",value=\"\\\<error reading variable: DWARF-2 expression error: Loop detected.*\"\}\\\]" \
> + "test func_loopfb_var"
> +}