[Issue 199] New: Label causes scope to collapse into parent

http://d.puremagic.com/issues/show_bug.cgi?id=199 Summary: Label causes scope to collapse into parent Product: D Version: 0.160 Platform: PC OS/Version: Windows Status: NEW Severity: normal Priority: P2 Component: DMD AssignedTo: bugzilla@digitalmars.com ReportedBy: ericanderton@yahoo.com When using a label directly before an anonymous scope (set of curly brackets), it causes the anonymous scope to behave as though its contents are declared in the parent scope directly. This causes variable names to collide should they share the same name between child and parent: void main(){ uint foo; x: { uint foo; } } test.d(5): declaration test.main.foo is already defined Adding '{}' immediately after the label seems to be a viable workaround. --

http://d.puremagic.com/issues/show_bug.cgi?id=199 ericanderton@yahoo.com changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |INVALID ------- Comment #1 from ericanderton@yahoo.com 2006-06-20 15:01 ------- DMD 0.161 disallows shadowing of local vars. So this is now a non-issue. --

http://d.puremagic.com/issues/show_bug.cgi?id=199 thomas-dloop@kuehne.cn changed: What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |REOPENED Resolution|INVALID | ------- Comment #2 from thomas-dloop@kuehne.cn 2006-06-29 08:42 ------- The scope is still being collapsed. Added to DStress as http://dstress.kuehne.cn/run/s/scope_13_A.d http://dstress.kuehne.cn/run/s/scope_13_B.d --

http://d.puremagic.com/issues/show_bug.cgi?id=199 davidl@126.com changed: What |Removed |Added ---------------------------------------------------------------------------- Status|REOPENED |RESOLVED Resolution| |WORKSFORME ------- Comment #3 from davidl@126.com 2007-01-22 23:52 ------- yeah, 1.0 doesn't allow shadowing of local var. it's not an issue anymore. and don't expect walter would fix the old revision --

http://d.puremagic.com/issues/show_bug.cgi?id=199 braddr@puremagic.com changed: What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |REOPENED Resolution|WORKSFORME | ------- Comment #4 from braddr@puremagic.com 2007-01-23 00:30 ------- David, I appreciate your trying to help, but this bug is NOT fixed. The scope_13_A test case that Thomas added is still failing. You can see that either by trying it yourself (which I just did), or looking at the test results here: http://dstress.kuehne.cn/www/dmd-1.00.html --

http://d.puremagic.com/issues/show_bug.cgi?id=199 smjg@iname.com changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |smjg@iname.com ------- Comment #5 from smjg@iname.com 2007-04-05 07:22 ------- On the basis of what you say, the compiler is behaving according to the spec, which states http://www.digitalmars.com/d/statement.html#LabeledStatement LabelledStatement: Identifier ':' NoScopeStatement I'd noticed it before. But since this bit of the spec is presumably not what was intended, I'm leaving this issue open. If there's any temptation to hit the INVALID button, it should be changed to an enhancement request instead. --

http://d.puremagic.com/issues/show_bug.cgi?id=199 bugzilla@digitalmars.com changed: What |Removed |Added ---------------------------------------------------------------------------- Status|REOPENED |RESOLVED Resolution| |WONTFIX ------- Comment #6 from bugzilla@digitalmars.com 2008-06-23 17:00 ------- Since the compiler is behaving according to spec, I don't want to change this because it could break existing code, and there doesn't seem to be a compelling reason to do so. --

http://d.puremagic.com/issues/show_bug.cgi?id=199 shro8822@vandals.uidaho.edu changed: What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |REOPENED Resolution|WONTFIX | ------- Comment #7 from shro8822@vandals.uidaho.edu 2008-06-23 17:09 ------- this still fail: http://dstress.kuehne.cn/run/s/scope_13_A.d --

May 29, 2013

[Issue 199] Label causes scope to collapse into parent

Posted by monarchdodra@gmail.com
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monarchdodra@gmail.com

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http://d.puremagic.com/issues/show_bug.cgi?id=199


monarchdodra@gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
                 CC|                            |monarchdodra@gmail.com
         Resolution|WONTFIX                     |


--- Comment #10 from monarchdodra@gmail.com 2013-05-29 03:00:58 PDT ---
According to this talk: http://forum.dlang.org/thread/ohctkdnupmbprglobwtc@forum.dlang.org#post-axonofactkyzpagilcbm:40forum.dlang.org

The spec does NOT state it should work that way.

Even if it did:
- Doing it this way buys nothing, as you get the same result simply by... not
typing the block
- Is bug prone (accidental labeling)
- Potentially creates different behavior from C code.

NB: The original example is wrong because of shadowing. But this one is more viable.

//----
void main()
{
    {
        uint foo;
    } end_first_block:

    {
        uint foo;
    } end_second_block:

    {
        uint foo; //main.d(12): Error: declaration main.main.foo is already
defined
    } end_third_block:

    return;
}
//----

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http://d.puremagic.com/issues/show_bug.cgi?id=199 bearophile_hugs@eml.cc changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |bearophile_hugs@eml.cc --- Comment #11 from bearophile_hugs@eml.cc 2013-05-29 03:10:51 PDT --- (In reply to comment #10) > - Potentially creates different behavior from C code. What are the conditions for it to create different behaviour? Maybe you can show two programs, in C and D, that behave differently. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------

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