From: "Willgerodt, Felix" <felix.willgerodt@intel.com>
To: "gdb@sourceware.org" <gdb@sourceware.org>
Subject: C++ nested class bug/questions
Date: Tue, 22 Jun 2021 11:27:37 +0000 [thread overview]
Message-ID: <391f40b3730d4f2486b3fcd324cf4c31@intel.com> (raw)
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Hello everyone,
I was debugging a program similar to the one attached and noticed a couple
of unexpected things happening. I compiled it with ”-g -O0” and g++ 11.1.0
(clang showed similar behaviour) and saw this:
(gdb) bt
#0 DF::vvv (this=0x7fffffffd120) at foo.cc:11
#1 0x0000555555555180 in foo () at foo.cc:16
#2 0x00005555555551a7 in main () at foo.cc:20
(gdb) ptype abcd
type = class DF::FFFF {
private:
int ffff;
}
(gdb) ptype FFFF
No symbol "FFFF" in current context.
(gdb) ptype DF::
FFFF vvv()
(gdb) ptype DF::FFFF
There is no field named FFFF
(gdb) ptype 'DF::FFFF'
type = class DF::FFFF {
private:
int ffff;
}
(gdb)
(The fourth command shows tab completion.)
The problems I see are:
1) I think it shouldn’t be DF::FFFF.
2) 'ptype FFFF’ should just work as it is in the current scope.
3) There shouldn’t be a need to quote DF:FFFF, right? Although that might just be a side-effect here.
4) The fact that a suggestion from tab completion doesn’t work is annoying. This is probably also be a side-effect.
Before debugging this further, I wanted to see if there are any comments/suggestions.
Am I even right about point 1? I couldn’t really find anything definitive
in my favourite cpp reference on this type of nesting. g++ and clang output FFFF as
foo()::DF::vvv()::FFFF as far as I can see.
I don’t see any obvious problems in the dwarf that is produced.
Thanks,
Felix
Intel Deutschland GmbH
Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de <http://www.intel.de>
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[-- Attachment #2: foo.cc --]
[-- Type: application/octet-stream, Size: 227 bytes --]
void foo(void) {
class DF {
public:
int a;
int b;
int vvv() {
class FFFF {
int ffff;
};
FFFF abcd;
return 1;
}
};
DF x;
int a = x.vvv();
}
int main(void) {
foo();
}
next reply other threads:[~2021-06-22 11:27 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-22 11:27 Willgerodt, Felix [this message]
2021-06-22 19:01 ` Simon Marchi
2021-06-23 13:59 ` Willgerodt, Felix
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