Bug 9178 - subscript operator on typedef'ed reference fails
Summary: subscript operator on typedef'ed reference fails
Alias: None
Product: gdb
Classification: Unclassified
Component: varobj (show other bugs)
Version: unknown
: P3 enhancement
Target Milestone: ---
Assignee: Jim Blandy
Depends on:
Reported: 2006-01-23 23:58 UTC by schaudhu
Modified: 2008-12-18 20:56 UTC (History)
3 users (show)

See Also:
Last reconfirmed:

jimb.gdb-binop-ref-typedef.patch (834 bytes, application/octet-stream)
, schaudhu

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Description schaudhu 2006-01-23 23:58:01 UTC
[Converted from Gnats 2073]

Attempting to display the results of a subscript operator call on a reference that has been typedef'ed displays the error "cannot subscript something of type CLASSNAME".  This is 100% reproducible in the environments specified.  Using either -gdb and -gstabs+ flags makes no difference.


SunOS 5.8 Generic_108528-29 sun4u sparc SUNW,Sun-Fire-V210, gcc-3.4.4/4.0.0, gdb-6.4

The following code demonstrates the error:

#include <iostream>

class Foo

    int value;


    Foo( const int val ) { value = val; }
    int operator[]( const int i ) const { return value; }

typedef Foo Bar;

int main()
    Foo foo1( 123 );
    std::cout << foo1[ 0 ] << std::endl;

    // In the debugger, type print foo1[ 0 ]: NO PROBLEM

    Foo &foo2 = foo1;
    std::cout << foo2[ 0 ] << std::endl;

    // In the debugger, type print foo2[ 0 ]: NO PROBLEM

    Bar &bar1 = foo1;
    std::cout << bar1[ 0 ] << std::endl;

    // In the debugger, type print bar1[ 0 ]: ERROR!
    // cannot subscript something of type `Foo'

    Bar bar2( 321 );
    std::cout << bar2[ 0 ] << std::endl;

    // In the debugger, type print bar2[ 0 ]: NO PROBLEM

    return 0;
Comment 1 Jim Blandy 2006-01-24 07:30:39 UTC
Responsible-Changed-From-To: unassigned->jimb
Responsible-Changed-Why: I think I know what this is.  I sure hope so, or else I'll have to get into the C++ code.
Comment 2 Jim Blandy 2006-01-24 07:43:24 UTC
State-Changed-From-To: open->feedback
State-Changed-Why: Could you try the attached patch?
Comment 3 soumya.chaudhuri 2006-01-24 15:44:10 UTC
From: "Chaudhuri, Soumya" <soumya.chaudhuri@blackrock.com>
To: <gdb-gnats@sources.redhat.com>
Subject: Re: varobj/2073: subscript operator on typedef'ed reference fails
Date: Tue, 24 Jan 2006 10:44:10 -0500

 The patch fixes the issue.  Thanks!
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Comment 4 Jim Blandy 2006-01-25 06:43:31 UTC
State-Changed-From-To: feedback->closed
State-Changed-Why: Fix committed to trunk.