[dmd-beta] cherry-picking regression fixes for point releases

[Daniel Murphy]

There has been a _lot_ of code churn since the release was branched,
and hopefully there will be even more shortly after the next release.
Now is certainly not the easiest time to start backporting regression
fixes.

That said, InlineScanVisitor::visitCallExp is equivalent to
CallExp::inlineScan.  Working on line numbers is not going to help you
here, and neither is plain function names.  Depending on how far you
want to go, the pull request that did the refactoring should be
obvious in git blame and _should_ make it clear where everything was
moved to.  A 'cheat' option is to select a small chunk of old code and
see if it appears in the new version.  Comments are especially good
for this as they are likely to survive visitor refactorings unchanged.

Or, ask the pull author to backport.

On Thu, Apr 3, 2014 at 1:33 PM, Andrew Edwards <edwards.ac at gmail.com> wrote:
> The case was made that it is absolutely necessary to retain the release
> branches in order to simplify preparation for point releases. And, while I
> initially argued against it, I do not see how it is possible to create the
> point release without doing so. However I strongly believe that resolutions
> to these regressions should first be implemented the oldest supported
> version (currently 2.065.1) and then merged forward to master. My reasoning?
> Read on!
>
> I conducted a search on bugzilla for all regressions RESOLVED as FIXED after
> 2014-02-23 using the following:
>
> http://d.puremagic.com/issues/buglist.cgi?bug_severity=regression&bug_status=RESOLVED&chfield=resolution&chfieldfrom=2014-02-23&chfieldto=Now&chfieldvalue=FIXED&columnlist=changeddate%2Cbug_severity%2Cpriority%2Cop_sys%2Cassigned_to_realname%2Cbug_status%2Cresolution%2Cshort_desc&query_format=advanced&resolution=FIXED&order=changeddate%2Cresolution%2Cassigned_to%2Cbug_id&query_based_on=
>
> I figured I'd cherry-pick each into the 2.065 branch (starting the the
> oldest) as long as they were marked as regressions to v2.065.0 or older.
> Note that this approach does not correctly identify all regressions that
> needs to be included in a point release (see issue #12264 which is also
> fixes #12262). Anyway, I commenced by checking out the branch and issuing
> the command:
>
>     git cherry-pick -m 1 53bec85
>
> This specific pick is the merger of pull request #3339 which resolves (Issue
> 12243 - "ICE: cannot append 'char' to 'string'" with -inline). Immediately I
> encountered a merge conflict so I investigated the resolution and came
> across the following:
>
> The pull essentially changes lines 1420 through 1425 of src/inline.c [a part
> of visitCallExp(CallExp*, Expression*) implementation]
>
> From ---------->
>
>         if (eresult && e->type->ty != Tvoid &&
>             !e->type->equals(eresult->type) &&
>             eresult->type->hasWild() && !e->type->hasWild())
>          {
>             eresult = eresult->copy();
>             eresult->type = e->type;
>          }
>
> To ---------->
>
>         if (eresult && e->type->ty != Tvoid)
>          {
>             Expression *ex = eresult;
>             while (ex->op == TOKcomma)
>             {
>                 ex->type = e->type;
>                 ex = ((CommaExp *)ex)->e2;
>             }
>             ex->type = e->type;
>          }
>
> So far so good. Now cross-reference this to the version of src/inline.c from
> v2.065.0 and you will find that the function visitCallExp() does not exist.
> Further the function resident at the same location in the older version of
> the file [Expression * SliceExp::inlineScan(InlineScanState *iss){}] does
> not exist anywhere in the newer version (neither is any of a number of
> inlineScan() related implementations surrounding it). As such, it is not
> possible to pick this fix in preparation for v2.065.1.
>
> What is the proper resolution for this problem in the context of the 2.065
> branch?
>
>
>
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