Recursive make is dangerously stupid. There are better tools, but not everyone has realized.
In a system using recursive make, two rules invoke recursive make for different rulesof the same directory.
Unfortunately, these rukes are not parallelizable. The nonrecursive makefile knows this, but the separate recursive make invocations do not.
I.e. recursive make can break parallel make -j.
Thursday, June 21, 2012
how-can-mercurial-or-any-other-dvcs-recognize-partially-overlapped-histories
http://stackoverflow.com/questions/11146096/how-can-mercurial-or-any-other-dvcs-recognize-partially-overlapped-histories
Q: is there any way in Mercurial to usefully merge two repositories
whrrer the lines of history are similar, but not identical?
E.g. where one rep has coarse grain revisions 0,1,2
and the other has fine graun revisions 0, 0.1, 0.2, 1, 1.1, 1.2, 2,
and come up with a single history?
Rather than a mess of branches and heads, which is what I get when I try using what I know of Mercurial?
Or the even fancier
Repo1: 0, 1, 1.1, 1.2, 2
Repo 2: 0, 0.1, 0.2, 1, 2, 3
Merge: 0, 0.1, 0.2, 1, 1.1, 1.2 2, 3
In more detail:
What I want is a merge that can recognize when file contents are the same,
or which can recognize that two lines of history are similar, although not all versions in one line
are in the other,
and give something like:
o=o changesets with same file contents on different historical lines
o | (line1)
| | changeset: 2:2a02e67e7b5d
| | user: Andy Glew
| | date: Thu Jun 21 12:40:15 2012 -0700
| | summary: 2
| o (line2)
| | changeset: 8:089179dde80a
| | user: Andy Glew
| | date: Thu Jun 21 12:40:15 2012 -0700
| | summary: 2
| |
| o changeset: 7:615416921e33
| | user: Andy Glew
| | date: Thu Jun 21 12:40:14 2012 -0700
| | summary: 1.2
| |
| o changeset: 6:a43a88065141
| | user: Andy Glew
| | date: Thu Jun 21 12:40:14 2012 -0700
| | summary: 1.1
| |
| |
o=o changesets with same file contents on different historical lines
o | (line1)
| | changeset: 1:93cbae111269
| | user: Andy Glew
| | date: Thu Jun 21 12:40:13 2012 -0700
| | summary: 1
| o (line2)
| | changeset: 5:fef4050e0162
| | user: Andy Glew
| | date: Thu Jun 21 12:40:12 2012 -0700
| | summary: 1
| |
| o changeset: 4:b51fbedc72e5
| | user: Andy Glew
| | date: Thu Jun 21 12:40:12 2012 -0700
| | summary: 0.2
| |
| o changeset: 3:45b7f64b2a23
| | parent: 0:c80bc10826be
| | user: Andy Glew
| | date: Thu Jun 21 12:40:12 2012 -0700
| | summary: 0.1
| |
| |
|/
|
o changeset: 0:c80bc10826be
user: Andy Glew
date: Thu Jun 21 12:40:11 2012 -0700
summary: 0
I can imagine that possibly a merge changeset would be necessary at the o=o points.
But I would like to have it recognized automatically.
Here's an example of how such a history would be created.
Contrived in this example, but something siomilar is happening to me in real-life,
when a project wants coarse grain commits, but where I want to preserve the fine grain ciommits
(as well as the coarse grain stuff released to the project).
[glew@mipscs587 ~/hack/hg-granularity] 900$ bash 12:39:54>. ./eg
% set verbose
% mkdir hg-repo
% cd hg-repo
% ./hg-repo
% hg init
% echo 0 > a
% hg add a
% hg ci -m0 a
% cd ..
% hg clone hg-repo fine
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
% hg clone hg-repo coarse
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
% cd fine
./fine
% echo 0.1 > a; hg ci -m0.1
% echo 0.2 > a; hg ci -m0.2
% echo 1 > a; hg ci -m1
% cat a
1
% hg push default
pushing to /home/glew/hack/hg-granularity/hg-repo
searching for changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
% hg glog
@ changeset: 3:fef4050e0162
| tag: tip
| user: Andy Glew
| date: Thu Jun 21 12:40:12 2012 -0700
| summary: 1
|
o changeset: 2:b51fbedc72e5
| user: Andy Glew
| date: Thu Jun 21 12:40:12 2012 -0700
| summary: 0.2
|
o changeset: 1:45b7f64b2a23
| user: Andy Glew
| date: Thu Jun 21 12:40:12 2012 -0700
| summary: 0.1
|
o changeset: 0:c80bc10826be
user: Andy Glew
date: Thu Jun 21 12:40:11 2012 -0700
summary: 0
% cd ../coarse
% cp ../fine/a .
% cat a
1
% hg ci -m1
% hg glog
@ changeset: 1:93cbae111269
| tag: tip
| user: Andy Glew
| date: Thu Jun 21 12:40:13 2012 -0700
| summary: 1
|
o changeset: 0:c80bc10826be
user: Andy Glew
date: Thu Jun 21 12:40:11 2012 -0700
summary: 0
% cd ../fine
% echo 1.1 > a; hg ci -m1.1
% echo 1.2 > a; hg ci -m1.2
% echo 2 > a; hg ci -m2
% cat a
2
% hg push default
pushing to /home/glew/hack/hg-granularity/hg-repo
searching for changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
% hg glog
@ changeset: 6:089179dde80a
| tag: tip
| user: Andy Glew
| date: Thu Jun 21 12:40:15 2012 -0700
| summary: 2
|
o changeset: 5:615416921e33
| user: Andy Glew
| date: Thu Jun 21 12:40:14 2012 -0700
| summary: 1.2
|
o changeset: 4:a43a88065141
| user: Andy Glew
| date: Thu Jun 21 12:40:14 2012 -0700
| summary: 1.1
|
o changeset: 3:fef4050e0162
| user: Andy Glew
| date: Thu Jun 21 12:40:12 2012 -0700
| summary: 1
|
o changeset: 2:b51fbedc72e5
| user: Andy Glew
| date: Thu Jun 21 12:40:12 2012 -0700
| summary: 0.2
|
o changeset: 1:45b7f64b2a23
| user: Andy Glew
| date: Thu Jun 21 12:40:12 2012 -0700
| summary: 0.1
|
o changeset: 0:c80bc10826be
user: Andy Glew
date: Thu Jun 21 12:40:11 2012 -0700
summary: 0
% cd ../coarse
% cp ../fine/a .
% cat a
2
% hg ci -m2
% hg glog
@ changeset: 2:2a02e67e7b5d
| tag: tip
| user: Andy Glew
| date: Thu Jun 21 12:40:15 2012 -0700
| summary: 2
|
o changeset: 1:93cbae111269
| user: Andy Glew
| date: Thu Jun 21 12:40:13 2012 -0700
| summary: 1
|
o changeset: 0:c80bc10826be
user: Andy Glew
date: Thu Jun 21 12:40:11 2012 -0700
summary: 0
OK, so now I have a fine grain history in the fine repo,
and a coarse grain history in the coarse repo. I wouldf like to merge them.
(Firget that the coarse is a subset of the fine: I can easily contrive exanples where they are not).
Simply pushing the coarse graon history gives a warning.
I will opush it later,
but first I will try merging in a separate clone.
% hg push default
pushing to /home/glew/hack/hg-granularity/hg-repo
searching for changes
abort: push creates new remote head 2a02e67e7b5d!
(you should pull and merge or use push -f to force)
% cd ..
% hg clone coarse merge-fine-and-coarse
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
% cd merge-fine-and-coarse/
./merge-fine-and-coarse/
% hg glog
@ changeset: 2:2a02e67e7b5d
| tag: tip
| user: Andy Glew
| date: Thu Jun 21 12:40:15 2012 -0700
| summary: 2
|
o changeset: 1:93cbae111269
| user: Andy Glew
| date: Thu Jun 21 12:40:13 2012 -0700
| summary: 1
|
o changeset: 0:c80bc10826be
user: Andy Glew
date: Thu Jun 21 12:40:11 2012 -0700
summary: 0
% hg pull ../hg-repo
pulling from ../hg-repo
searching for changes
adding changesets
adding manifests
adding file changes
added 6 changesets with 6 changes to 1 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
% hg heads
changeset: 8:089179dde80a
tag: tip
user: Andy Glew
date: Thu Jun 21 12:40:15 2012 -0700
summary: 2
changeset: 2:2a02e67e7b5d
user: Andy Glew
date: Thu Jun 21 12:40:15 2012 -0700
summary: 2
Here is the merge.
Notice that the pairs
o changeset: 8:089179dde80a
| @ changeset: 2:2a02e67e7b5d
and
o changeset: 5:fef4050e0162
| o changeset: 1:93cbae111269
have the same file contents,
one from the coartse and the other from the fine repo.
But the Mercurial history graph does not reflect this.
% hg glog
o changeset: 8:089179dde80a
| tag: tip
| user: Andy Glew
| date: Thu Jun 21 12:40:15 2012 -0700
| summary: 2
|
o changeset: 7:615416921e33
| user: Andy Glew
| date: Thu Jun 21 12:40:14 2012 -0700
| summary: 1.2
|
o changeset: 6:a43a88065141
| user: Andy Glew
| date: Thu Jun 21 12:40:14 2012 -0700
| summary: 1.1
|
o changeset: 5:fef4050e0162
| user: Andy Glew
| date: Thu Jun 21 12:40:12 2012 -0700
| summary: 1
|
o changeset: 4:b51fbedc72e5
| user: Andy Glew
| date: Thu Jun 21 12:40:12 2012 -0700
| summary: 0.2
|
o changeset: 3:45b7f64b2a23
| parent: 0:c80bc10826be
| user: Andy Glew
| date: Thu Jun 21 12:40:12 2012 -0700
| summary: 0.1
|
| @ changeset: 2:2a02e67e7b5d
| | user: Andy Glew
| | date: Thu Jun 21 12:40:15 2012 -0700
| | summary: 2
| |
| o changeset: 1:93cbae111269
|/ user: Andy Glew
| date: Thu Jun 21 12:40:13 2012 -0700
| summary: 1
|
o changeset: 0:c80bc10826be
user: Andy Glew
date: Thu Jun 21 12:40:11 2012 -0700
summary: 0
% hg diff -r 2a02e67e7b5d -r 089179dde80a
So I'll try a merge
% hg merge -r 8
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
% hg ci -m'merge of fine and coarse at 2'
Better -
this shows that
o changeset: 8:089179dde80a
| @ changeset: 2:2a02e67e7b5d
are a convergence point,
although an extra dummy changesrt was necessary.
But it does not show the commonality between
o changeset: 5:fef4050e0162
| o changeset: 1:93cbae111269
Here's the merged graph
% hg glog
@ changeset: 9:328db8187d31
|\ tag: tip
| | parent: 2:2a02e67e7b5d
| | parent: 8:089179dde80a
| | user: Andy Glew
| | date: Thu Jun 21 12:43:51 2012 -0700
| | summary: merge of fine and coarse at 2
| |
| o changeset: 8:089179dde80a
| | user: Andy Glew
| | date: Thu Jun 21 12:40:15 2012 -0700
| | summary: 2
| |
| o changeset: 7:615416921e33
| | user: Andy Glew
| | date: Thu Jun 21 12:40:14 2012 -0700
| | summary: 1.2
| |
| o changeset: 6:a43a88065141
| | user: Andy Glew
| | date: Thu Jun 21 12:40:14 2012 -0700
| | summary: 1.1
| |
| o changeset: 5:fef4050e0162
| | user: Andy Glew
| | date: Thu Jun 21 12:40:12 2012 -0700
| | summary: 1
| |
| o changeset: 4:b51fbedc72e5
| | user: Andy Glew
| | date: Thu Jun 21 12:40:12 2012 -0700
| | summary: 0.2
| |
| o changeset: 3:45b7f64b2a23
| | parent: 0:c80bc10826be
| | user: Andy Glew
| | date: Thu Jun 21 12:40:12 2012 -0700
| | summary: 0.1
| |
o | changeset: 2:2a02e67e7b5d
| | user: Andy Glew
| | date: Thu Jun 21 12:40:15 2012 -0700
| | summary: 2
| |
o | changeset: 1:93cbae111269
|/ user: Andy Glew
| date: Thu Jun 21 12:40:13 2012 -0700
| summary: 1
|
o changeset: 0:c80bc10826be
user: Andy Glew
date: Thu Jun 21 12:40:11 2012 -0700
summary: 0
How about another merge?
% hg update -r 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
% hg merge -r 5
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
% hg ci -m'merge of fine and coarse at 1'
created new head
% hg glog
@ changeset: 10:cca7fec90d3f
|\ tag: tip
| | parent: 1:93cbae111269
| | parent: 5:fef4050e0162
| | user: Andy Glew
| | date: Thu Jun 21 12:45:03 2012 -0700
| | summary: merge of fine and coarse at 1
| |
| | o changeset: 9:328db8187d31
| | |\ parent: 2:2a02e67e7b5d
| | | | parent: 8:089179dde80a
| | | | user: Andy Glew
| | | | date: Thu Jun 21 12:43:51 2012 -0700
| | | | summary: merge of fine and coarse at 2
| | | |
| | | o changeset: 8:089179dde80a
| | | | user: Andy Glew
| | | | date: Thu Jun 21 12:40:15 2012 -0700
| | | | summary: 2
| | | |
| | | o changeset: 7:615416921e33
| | | | user: Andy Glew
| | | | date: Thu Jun 21 12:40:14 2012 -0700
| | | | summary: 1.2
| | | |
| +---o changeset: 6:a43a88065141
| | | user: Andy Glew
| | | date: Thu Jun 21 12:40:14 2012 -0700
| | | summary: 1.1
| | |
| o | changeset: 5:fef4050e0162
| | | user: Andy Glew
| | | date: Thu Jun 21 12:40:12 2012 -0700
| | | summary: 1
| | |
| o | changeset: 4:b51fbedc72e5
| | | user: Andy Glew
| | | date: Thu Jun 21 12:40:12 2012 -0700
| | | summary: 0.2
| | |
| o | changeset: 3:45b7f64b2a23
| | | parent: 0:c80bc10826be
| | | user: Andy Glew
| | | date: Thu Jun 21 12:40:12 2012 -0700
| | | summary: 0.1
| | |
+---o changeset: 2:2a02e67e7b5d
| | user: Andy Glew
| | date: Thu Jun 21 12:40:15 2012 -0700
| | summary: 2
| |
o | changeset: 1:93cbae111269
|/ user: Andy Glew
| date: Thu Jun 21 12:40:13 2012 -0700
| summary: 1
|
o changeset: 0:c80bc10826be
user: Andy Glew
date: Thu Jun 21 12:40:11 2012 -0700
summary: 0
This is not right. It has established a new head, whereas
what we wanted was some way of indicating that
o changeset: 5:fef4050e0162
| o changeset: 1:93cbae111269
are the same.
OK, switch back to the original coarse
% cd ../coarse
% hg push default
pushing to /home/glew/hack/hg-granularity/hg-repo
searching for changes
abort: push creates new remote head 2a02e67e7b5d!
(you should pull and merge or use push -f to force)
% hg push -f default
pushing to /home/glew/hack/hg-granularity/hg-repo
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files (+1 heads)
% hg glog
@ changeset: 2:2a02e67e7b5d
| tag: tip
| user: Andy Glew
| date: Thu Jun 21 12:40:15 2012 -0700
| summary: 2
|
o changeset: 1:93cbae111269
| user: Andy Glew
| date: Thu Jun 21 12:40:13 2012 -0700
| summary: 1
|
o changeset: 0:c80bc10826be
user: Andy Glew
date: Thu Jun 21 12:40:11 2012 -0700
summary: 0
% cd ../hg-repo/
% hg glog
o changeset: 8:2a02e67e7b5d
| tag: tip
| user: Andy Glew
| date: Thu Jun 21 12:40:15 2012 -0700
| summary: 2
|
o changeset: 7:93cbae111269
| parent: 0:c80bc10826be
| user: Andy Glew
| date: Thu Jun 21 12:40:13 2012 -0700
| summary: 1
|
| o changeset: 6:089179dde80a
| | user: Andy Glew
| | date: Thu Jun 21 12:40:15 2012 -0700
| | summary: 2
| |
| o changeset: 5:615416921e33
| | user: Andy Glew
| | date: Thu Jun 21 12:40:14 2012 -0700
| | summary: 1.2
| |
| o changeset: 4:a43a88065141
| | user: Andy Glew
| | date: Thu Jun 21 12:40:14 2012 -0700
| | summary: 1.1
| |
| o changeset: 3:fef4050e0162
| | user: Andy Glew
| | date: Thu Jun 21 12:40:12 2012 -0700
| | summary: 1
| |
| o changeset: 2:b51fbedc72e5
| | user: Andy Glew
| | date: Thu Jun 21 12:40:12 2012 -0700
| | summary: 0.2
| |
| o changeset: 1:45b7f64b2a23
|/ user: Andy Glew
| date: Thu Jun 21 12:40:12 2012 -0700
| summary: 0.1
|
@ changeset: 0:c80bc10826be
user: Andy Glew
date: Thu Jun 21 12:40:11 2012 -0700
summary: 0
% echo This is not right
This is not right
What I want is a merge that can recognize when file contents are the same,
or which can recognize that two lines of history are similar, although not all versions in one line
are in the other,
and give something like:
o=o changesets with same file contents on different historical lines
o | (line1)
| | changeset: 2:2a02e67e7b5d
| | user: Andy Glew
| | date: Thu Jun 21 12:40:15 2012 -0700
| | summary: 2
| o (line2)
| | changeset: 8:089179dde80a
| | user: Andy Glew
| | date: Thu Jun 21 12:40:15 2012 -0700
| | summary: 2
| |
| o changeset: 7:615416921e33
| | user: Andy Glew
| | date: Thu Jun 21 12:40:14 2012 -0700
| | summary: 1.2
| |
| o changeset: 6:a43a88065141
| | user: Andy Glew
| | date: Thu Jun 21 12:40:14 2012 -0700
| | summary: 1.1
| |
| |
o=o changesets with same file contents on different historical lines
o | (line1)
| | changeset: 1:93cbae111269
| | user: Andy Glew
| | date: Thu Jun 21 12:40:13 2012 -0700
| | summary: 1
| o (line2)
| | changeset: 5:fef4050e0162
| | user: Andy Glew
| | date: Thu Jun 21 12:40:12 2012 -0700
| | summary: 1
| |
| o changeset: 4:b51fbedc72e5
| | user: Andy Glew
| | date: Thu Jun 21 12:40:12 2012 -0700
| | summary: 0.2
| |
| o changeset: 3:45b7f64b2a23
| | parent: 0:c80bc10826be
| | user: Andy Glew
| | date: Thu Jun 21 12:40:12 2012 -0700
| | summary: 0.1
| |
| |
|/
|
o changeset: 0:c80bc10826be
user: Andy Glew
date: Thu Jun 21 12:40:11 2012 -0700
summary: 0
I can imagine that possibly a merge changeset would be necessary at the o=o points.
But I would like to have it recognized automatically.
Heck, forget "recognized". I would like to have a way that I can recognize it manually, but have it represented in Mercurial.
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