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digitalmars.D.bugs - [Issue 6552] New: Wrong fallthrough warning for CaseRange

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=6552

           Summary: Wrong fallthrough warning for CaseRange
           Product: D
           Version: D2
          Platform: Other
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: nobody puremagic.com
        ReportedBy: timon.gehr gmx.ch


--- Comment #0 from timon.gehr gmx.ch 2011-08-24 19:30:48 PDT ---
void main() {
    int c;
    switch (c) {
        case 1,2:
        case 3,4: break;
        default: break;
    }
}

Compile with warnings on, DMD v2.054:
tt.d(12): Error: switch case fallthrough - use 'goto case;' if intended

This warning is wrong.

For comparison, the equivalent code without CaseRanges passes even with
warnings on:

void main() {
    int c;
    switch (c) {
        case 1:
        case 2: break;
        default: break;
    }
}

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next sibling parent d-bugmail puremagic.com writes:
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SomeDude <lovelydear mailmetrash.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |lovelydear mailmetrash.com


--- Comment #1 from SomeDude <lovelydear mailmetrash.com> 2012-04-27 09:58:55
PDT ---
Compiles on 2.059

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--- Comment #2 from timon.gehr gmx.ch 2012-04-27 10:29:09 PDT ---
No, it does not. Check again with the correct compiler options. (you need -w)

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--- Comment #3 from SomeDude <lovelydear mailmetrash.com> 2012-04-27 15:07:07
PDT ---
Allright, I overlooked your comment.

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prev sibling next sibling parent d-bugmail puremagic.com writes:
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Andrej Mitrovic <andrej.mitrovich gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |pull, rejects-valid
                 CC|                            |andrej.mitrovich gmail.com
         AssignedTo|nobody puremagic.com        |andrej.mitrovich gmail.com


--- Comment #4 from Andrej Mitrovic <andrej.mitrovich gmail.com> 2013-02-17
13:47:59 PST ---
https://github.com/D-Programming-Language/dmd/pull/1673

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prev sibling next sibling parent d-bugmail puremagic.com writes:
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Stewart Gordon <smjg iname.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|pull, rejects-valid         |accepts-invalid,
                   |                            |diagnostic, spec
                 CC|                            |smjg iname.com


--- Comment #5 from Stewart Gordon <smjg iname.com> 2013-02-17 17:33:51 PST ---
The code is not valid per the current spec.

http://dlang.org/statement.html#SwitchStatement

CaseStatement:
    case ArgumentList : ScopeStatementList

ScopeStatementList:
    StatementListNoCaseNoDefault

StatementListNoCaseNoDefault:
    StatementNoCaseNoDefault
    StatementNoCaseNoDefault StatementListNoCaseNoDefault

By this spec,
    case 1,2: case 3,4: anything
is invalid.

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prev sibling next sibling parent d-bugmail puremagic.com writes:
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Andrej Mitrovic <andrej.mitrovich gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|accepts-invalid,            |pull, rejects-valid
                   |diagnostic, spec            |


--- Comment #6 from Andrej Mitrovic <andrej.mitrovich gmail.com> 2013-02-17
17:43:36 PST ---
(In reply to comment #5)
 The code is not valid per the current spec.
 
 http://dlang.org/statement.html#SwitchStatement
 
 CaseStatement:
     case ArgumentList : ScopeStatementList
 
 ScopeStatementList:
     StatementListNoCaseNoDefault
 
 StatementListNoCaseNoDefault:
     StatementNoCaseNoDefault
     StatementNoCaseNoDefault StatementListNoCaseNoDefault
 
 By this spec,
     case 1,2: case 3,4: anything
 is invalid.

I already said the spec was wrong and will have to be fixed. The OP code works without -w, and we're not about to break a ton of code because the spec is outdated (which is *very* common). -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
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--- Comment #7 from Stewart Gordon <smjg iname.com> 2013-02-17 18:07:37 PST ---
Where is the separate bug report about the spec being wrong?

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--- Comment #8 from Kenji Hara <k.hara.pg gmail.com> 2013-02-17 18:29:26 PST ---
(In reply to comment #7)
 Where is the separate bug report about the spec being wrong?

Opened. Issue 9529 - Switch Statement grammar bug for the chain of case statements -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
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--- Comment #9 from github-bugzilla puremagic.com 2013-02-17 19:34:01 PST ---
Commits pushed to master at https://github.com/D-Programming-Language/dmd

https://github.com/D-Programming-Language/dmd/commit/cac04a3dd38741205cac6b61400a7f91a8c8a36a
Fixes Issue 6552 - Invalid error on non-existent switch-case fallthrough.

https://github.com/D-Programming-Language/dmd/commit/631e980d134d7217ac3fe43809b625bc8f5bff9f
Merge pull request #1673 from AndrejMitrovic/Fix6552

 Issue 6552 - Invalid warning on non-existent switch case fallthrough.

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Andrej Mitrovic <andrej.mitrovich gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


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