Re: Displaying structure members named like C keywords.
2014-08-26 21:30 GMT+02:00 Sergio Durigan Junior sergi...@sergiodj.net: Aha, yeah, I was indeed suspecting that libstdc++'s debuginfo would be the cause. I managed to reproduce it here. [...] Hello Sergio, that's indeed good news, thank you very much for your efforts! Meanwhile, I strongly advise you to file a bug against GDB on https://sourceware.org/bugzilla. Also, please be aware that this list (bug-gdb@gnu.org) is not used by most of GDB developers anymore; there's just a few of us hanging around here. Instead, the official mailing list for users is g...@sourceware.org. Yes, I'm aware of this. Nevertheless the fact that I need to create yet another account kept me from using the bugzilla interface. It seems to me like an unnecessary barrier for an occasional bug reporter. All the best! Emílio ___ bug-gdb mailing list bug-gdb@gnu.org https://lists.gnu.org/mailman/listinfo/bug-gdb
Re: Displaying structure members named like C keywords.
On Wednesday, August 27 2014, Emilio Lopes wrote: Yes, I'm aware of this. Nevertheless the fact that I need to create yet another account kept me from using the bugzilla interface. It seems to me like an unnecessary barrier for an occasional bug reporter. Yeah, I understand and agree with you :-). If you wish, I can create the bug for you, and put you on the Cc list. How does that sound? -- Sergio GPG key ID: 0x65FC5E36 Please send encrypted e-mail if possible http://sergiodj.net/ ___ bug-gdb mailing list bug-gdb@gnu.org https://lists.gnu.org/mailman/listinfo/bug-gdb
Re: Displaying structure members named like C keywords.
2014-08-27 15:45 GMT+02:00 Sergio Durigan Junior sergi...@sergiodj.net: Yeah, I understand and agree with you :-). If you wish, I can create the bug for you, and put you on the Cc list. How does that sound? That's very nice from you, thank you very much! Emílio ___ bug-gdb mailing list bug-gdb@gnu.org https://lists.gnu.org/mailman/listinfo/bug-gdb
Re: Displaying structure members named like C keywords.
Hello Sergio,
I was able to reproduce this issue on the host (x86_64 GNU/Linux)!
Here we go:
$ cat gdb-reproducer.c
#include iostream
using std::cout;
typedef struct {
int rlevel;
int complex;
} param_t;
int main(int argc, char *argv[]) {
param_t foo;
foo.rlevel = 4;
foo.complex= foo.rlevel + 11;
cout foo.complex: foo.complex \n;
return(0);
}
$ g++ -Wall -ggdb3 gdb-reproducer.c ./a.out
foo.complex: 15
$ gdb a.out
GNU gdb (Debian 7.7.1+dfsg-3) 7.7.1
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
http://gnu.org/licenses/gpl.html
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type show copying
and show warranty for details.
This GDB was configured as x86_64-linux-gnu.
Type show configuration for configuration details.
For bug reporting instructions, please see:
http://www.gnu.org/software/gdb/bugs/.
Find the GDB manual and other documentation resources online at:
http://www.gnu.org/software/gdb/documentation/.
For help, type help.
Type apropos word to search for commands related to word...
Reading symbols from a.out...done.
(gdb) b main
Breakpoint 1 at 0x4007c6: file gdb-reproducer.c, line 13.
(gdb) r
Starting program: /home/lopes/projects/c/a.out
Breakpoint 1, main (argc=1, argv=0x7fffe958) at gdb-reproducer.c:13
13foo.rlevel = 4;
(gdb) n
14foo.complex= foo.rlevel + 11;
(gdb) n
16cout foo.complex: foo.complex \n;
(gdb) p foo
$1 = {rlevel = 4, complex = 15}
(gdb) ptype foo
type = struct param_t {
int rlevel;
int complex;
}
(gdb) p foo.complex
A syntax error in expression, near `'.
(gdb) info shared
FromTo Syms Read Shared Object Library
0x77ddcae0 0x77df5170 Yes
/lib64/ld-linux-x86-64.so.2
No linux-vdso.so.1
0x77b2c8e0 0x77b9480a Yes
/usr/lib/x86_64-linux-gnu/libstdc++.so.6
0x777d5580 0x77840de6 Yes
/lib/x86_64-linux-gnu/libm.so.6
0x775bcab0 0x775cc995 Yes
/lib/x86_64-linux-gnu/libgcc_s.so.1
0x772304a0 0x7735a613 Yes
/lib/x86_64-linux-gnu/libc.so.6
(gdb) noshared
(gdb) p foo.complex
$2 = 15
(gdb) p foo
$3 = {rlevel = 4, complex = 15}
(gdb) p foo.complex
$4 = 15
(gdb) shared libstdc.*
Reading symbols from
/usr/lib/x86_64-linux-gnu/libstdc++.so.6...Reading symbols from
/usr/lib/debug//usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.20...done.
done.
Loaded symbols for /usr/lib/x86_64-linux-gnu/libstdc++.so.6
(gdb) p foo.complex
A syntax error in expression, near `'.
(gdb) p foo
$5 = {rlevel = 4, complex = 15}
(gdb) ptype foo
type = struct param_t {
int rlevel;
int complex;
}
It seems that something in the debug info of libstdc++ is causing the problem.
Some info about the system I'm using:
$ uname -a
Linux lopes 3.14-1-amd64 #1 SMP Debian 3.14.12-1 (2014-07-11)
x86_64 GNU/Linux
$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.9/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian
4.9.1-4' --with-bugurl=file:///usr/share/doc/gcc-4.9/README.Bugs
--enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.9 --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.9
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--enable-gnu-unique-object --disable-vtable-verify --enable-plugin
--with-system-zlib --disable-browser-plugin --enable-java-awt=gtk
--enable-gtk-cairo
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64/jre
--enable-java-home
--with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.9-amd64
--with-arch-directory=amd64
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc
--enable-multiarch --with-arch-32=i586 --with-abi=m64
--with-multilib-list=m32,m64,mx32 --enable-multilib
--with-tune=generic --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.9.1 (Debian 4.9.1-4)
$ dpkg -l | grep -F 'libstdc++'
ii libstdc++-4.9-dev:amd64 4.9.1-4 amd64GNU
Standard C++ Library v3 (development files)
ii libstdc++6:amd644.9.1-4 amd64GNU
Standard C++ Library v3
Re: Displaying structure members named like C keywords.
On Tuesday, August 26 2014, Emilio Lopes wrote: Hello Sergio, I was able to reproduce this issue on the host (x86_64 GNU/Linux)! [...] It seems that something in the debug info of libstdc++ is causing the problem. Aha, yeah, I was indeed suspecting that libstdc++'s debuginfo would be the cause. I managed to reproduce it here. I still need to investigate this in order to identify what's going on, and I think I'll be able to do this only on the weekend. Meanwhile, I strongly advise you to file a bug against GDB on https://sourceware.org/bugzilla. Also, please be aware that this list (bug-gdb@gnu.org) is not used by most of GDB developers anymore; there's just a few of us hanging around here. Instead, the official mailing list for users is g...@sourceware.org. I will let you know if I make any progress about this issue. Cheers, -- Sergio GPG key ID: 0x65FC5E36 Please send encrypted e-mail if possible http://sergiodj.net/ ___ bug-gdb mailing list bug-gdb@gnu.org https://lists.gnu.org/mailman/listinfo/bug-gdb
Re: Displaying structure members named like C keywords.
On Friday, August 22 2014, Emilio Lopes wrote: Would it be possible for you to come up with a simpler reproducer and send it to this list? I am guessing there is something else in your code that might be triggering this. I was hoping for this to be something simple... Oh, well. Yeah, sometimes issues are not so simple... As you can imagine this is a somewhat larger codebase, with lots of automatically generated code from XML files, using those structures. Sure, that is also why I asked for a simpler reproducer :-). (gdb) p P_SLAVE_CMDS_OPTIONS_HAL_OPTMIN_ENABLED $1 = (struct param_t *) 0x10db9c _slave_cmds_options_hal_optmin (gdb) set sysroot ~/projects/hal/system/platform-tam3517/root-debug Reading symbols from /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/libpthread.so.0...done. Loaded symbols for /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/libpthread.so.0 Reading symbols from /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/librt.so.1...done. Loaded symbols for /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/librt.so.1 Reading symbols from /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/libstdc++.so.6...done. Loaded symbols for /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/libstdc++.so.6 Reading symbols from /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/libm.so.6...done. Loaded symbols for /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/libm.so.6 Reading symbols from /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/libgcc_s.so.1...done. Loaded symbols for /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/libgcc_s.so.1 Reading symbols from /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/libc.so.6...done. Loaded symbols for /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/libc.so.6 Reading symbols from /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/ld-linux.so.3...done. Loaded symbols for /home/lopes/projects/hal/system/platform-tam3517/root-debug/lib/ld-linux.so.3 (gdb) p P_SLAVE_CMDS_OPTIONS_HAL_OPTMIN_ENABLED A syntax error in expression, near `complex.paramv[29].info.complex.paramv[0].info.complex.paramv[1].info.complex.paramv[0])'. (gdb) set sysroot '' warning: Unable to find dynamic linker breakpoint function. GDB will be unable to debug shared library initializers and track explicitly loaded dynamic code. (gdb) p P_SLAVE_CMDS_OPTIONS_HAL_OPTMIN_ENABLED $2 = (struct param_t *) 0x10db9c _slave_cmds_options_hal_optmin (gdb) Problems come and go as I set/unset `sysroot'!!! (I'm debugging code running on an ARM evaluation board remotely.) Hm, OK, I'm thinking about some issue with symbols here (visibility maybe). I made lots of attempts here to reproduce it based on what you posted, but I still cannot see this behavior using GDB from git HEAD. If you cannot give more instructions on how to reproduce this, then I have to ask you to file a bug against GDB on https://sourceware.org/bugzilla, please. Can you give me a hint on what to look for from here? There are a few debug triggers that you can enable on GDB. Maybe 'set debug expression 1' could help. Also, you can use 'maintenance print symbols filename' to print all the symbols; this could help analyzing if 'complex' is being hidden by some other library. Feel free to post those things here. Cheers, -- Sergio GPG key ID: 0x65FC5E36 Please send encrypted e-mail if possible http://sergiodj.net/ ___ bug-gdb mailing list bug-gdb@gnu.org https://lists.gnu.org/mailman/listinfo/bug-gdb
Displaying structure members named like C keywords.
I'm having trouble trying to display structure members with names like
C keywords. GDB refuses to display the member called `complex' in
this case.
Here is the structure:
(gdb) p g_global_paramv[37].info
$27 = {
complex = {
paramc = 20,
paramv = 0xd14f4 _sys_opt
},
cmd = {
cmd_fct = 0x14,
wrap = 0xd14f4 _sys_opt
},
alias = {
type = 20,
link = 0xd14f4 _sys_opt
}
}
Printing other members is no problem:
(gdb) p g_global_paramv[37].info.cmd
$28 = {
cmd_fct = 0x14,
wrap = 0xd14f4 _sys_opt
}
(gdb) p g_global_paramv[37].info.alias
$29 = {
type = 20,
link = 0xd14f4 _sys_opt
}
But trying to print the member `complex' results in an error:
(gdb) p g_global_paramv[37].info.complex
A syntax error in expression, near `complex'.
Note that the error message for non-existing members is different
depending if their names are C keywords (`long' and `int' = syntax
error) or not (`foobar', `xyz' = no member named ...).
(gdb) p g_global_paramv[37].info.foobar
There is no member named foobar.
(gdb) p g_global_paramv[37].info.long
A syntax error in expression, near `long'.
(gdb) p g_global_paramv[37].info.int
A syntax error in expression, near `int'.
(gdb) p g_global_paramv[37].info.xyz
There is no member named xyz.
(gdb)
This happens using gdb-7.8 configured as following:
(gdb) show version
GNU gdb (GDB) 7.8
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
http://gnu.org/licenses/gpl.html
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type show copying
and show warranty for details.
This GDB was configured as --host=x86_64-unknown-linux-gnu
--target=arm-cortexa8-linux-gnueabi.
Type show configuration for configuration details.
For bug reporting instructions, please see:
http://www.gnu.org/software/gdb/bugs/.
Find the GDB manual and other documentation resources online at:
http://www.gnu.org/software/gdb/documentation/.
For help, type help.
Type apropos word to search for commands related to word.
(gdb) show configuration
This GDB was configured as follows:
configure --host=x86_64-unknown-linux-gnu
--target=arm-cortexa8-linux-gnueabi
--with-auto-load-dir=$debugdir:$datadir/auto-load
--with-auto-load-safe-path=$debugdir:$datadir/auto-load
--with-expat
--with-gdb-datadir=/usr/local/share/gdb (relocatable)
--with-jit-reader-dir=/usr/local/lib/gdb (relocatable)
--without-libunwind-ia64
--with-lzma
--with-python=/usr
--without-guile
--with-separate-debug-dir=/usr/local/lib/debug (relocatable)
--with-zlib
--without-babeltrace
(Relocatable means the directory can be moved with the GDB installation
tree, and GDB will still find it.)
The code was compiled using:
$ arm-cortexa8-linux-gnueabi-gcc --version
arm-cortexa8-linux-gnueabi-gcc (OSELAS.Toolchain-2012.12.1
linaro-4.7-2012.11) 4.7.3 20121106 (prerelease)
Copyright (C) 2012 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
GDB itself was compiled with:
$ gcc --version
gcc (Debian 4.9.0-7) 4.9.0
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Thank you very much!
Emílio
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Re: Displaying structure members named like C keywords.
I could not reproduce the problem here. Would you mind providing the
structure declaration, or at least a reproducer?
Hello Sergio,
thank you very much for your prompt answer!
Here is the declaration of the structure:
typedef struct param_t {
const char* name;
type_t type;
short not_available : 1;
short rlevel : 4;
short wlevel : 4;
union {
struct {
void* get_fct;
void* set_fct;
void* gsv_fct;
int32_t polling_default;
int32_t polling_min;
} natural;
struct {
unsigned short paramc;
struct param_t* paramv;
} complex;
struct {
void (*cmd_fct)();
void (*wrap)(void (*cmd_fct)(), p_id cmd, const variant_t*
argv, size_t argc, variant_t* res);
} cmd;
struct {
type_t type;
struct param_t *link;
} alias;
} info;
struct param_t* parent;
void* user_data;
} param_t;
extern param_t* const g_global_paramv;
Regards
Emílio
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