demandimport: delay loading for "from a import b" with absolute_import
Before this patch, "from a import b" doesn't delay loading module "b",
if absolute_import is enabled, even though "from . import b" does.
For example:
- it is assumed that extension X has "from P import M" for module M
under package P with absolute_import feature
- if importing module M is already delayed before loading extension
X, loading module M in extension X is delayed until actually
referring
util, cmdutil, scmutil or so of Mercurial itself should be
imported by "from . import M" style before loading extension X
- otherwise, module M is loaded immediately at loading extension X,
even if extension X itself isn't used at that "hg" command invocation
Some minor modules (e.g. filemerge or so) of Mercurial itself
aren't imported by "from . import M" style before loading
extension X. And of course, external libraries aren't, too.
This might cause startup performance problem of hg command, because
many bundled extensions already enable absolute_import feature.
To delay loading module for "from a import b" with absolute_import
feature, this patch does below in "from a (or .a) import b" with
absolute_import case:
1. import root module of "name" by system built-in __import__
(referred as _origimport)
2. recurse down the module chain for hierarchical "name"
This logic can be shared with non absolute_import
case. Therefore, this patch also centralizes it into chainmodules().
3. and fall through to process elements in "fromlist" for the leaf
module of "name"
Processing elements in "fromlist" is executed in the code path
after "if _pypy: .... else: ..." clause. Therefore, this patch
replaces "if _pypy:" with "elif _pypy:" to share it.
At 4f1144c3c72b introducing original "work around" for "from a import
b" case, elements in "fromlist" were imported with "level=level". But
"level" might be grater than 1 (e.g. level=2 in "from .. import b"
case) at demandimport() invocation, and importing direct sub-module in
"fromlist" with level grater than 1 causes unexpected result.
IMHO, this seems main reason of "errors for unknown reason" described
in 4f1144c3c72b, and we don't have to worry about it, because this
issue was already fixed by 78d05778907b.
This is reason why this patch removes "errors for unknown reasons"
comment.
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
>
> [phases]
> publish=False
>
> [alias]
> tglog = log -G --template "{rev}: '{desc}' {branches}\n"
> EOF
$ hg init a
$ cd a
$ hg unbundle "$TESTDIR/bundles/rebase.hg"
adding changesets
adding manifests
adding file changes
added 8 changesets with 7 changes to 7 files (+2 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg up tip
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo I > I
$ hg ci -AmI
adding I
$ hg tglog
@ 8: 'I'
|
o 7: 'H'
|
| o 6: 'G'
|/|
o | 5: 'F'
| |
| o 4: 'E'
|/
| o 3: 'D'
| |
| o 2: 'C'
| |
| o 1: 'B'
|/
o 0: 'A'
$ cd ..
Version with only two heads (to allow default destination to work)
$ hg clone -q -u . a a2heads -r 3 -r 8
These fail:
$ hg clone -q -u . a a0
$ cd a0
$ hg rebase -s 8 -d 7
nothing to rebase
[1]
$ hg rebase --continue --abort
abort: cannot use both abort and continue
[255]
$ hg rebase --continue --collapse
abort: cannot use collapse with continue or abort
[255]
$ hg rebase --continue --dest 4
abort: abort and continue do not allow specifying revisions
[255]
$ hg rebase --base 5 --source 4
abort: cannot specify both a source and a base
[255]
$ hg rebase --rev 5 --source 4
abort: cannot specify both a revision and a source
[255]
$ hg rebase --base 5 --rev 4
abort: cannot specify both a revision and a base
[255]
$ hg rebase --base 6
abort: branch 'default' has 3 heads - please rebase to an explicit rev
(run 'hg heads .' to see heads)
[255]
$ hg rebase --rev '1 & !1' --dest 8
empty "rev" revision set - nothing to rebase
[1]
$ hg rebase --source '1 & !1' --dest 8
empty "source" revision set - nothing to rebase
[1]
$ hg rebase --base '1 & !1' --dest 8
empty "base" revision set - can't compute rebase set
[1]
$ hg rebase --dest 8
nothing to rebase - working directory parent is also destination
[1]
$ hg rebase -b . --dest 8
nothing to rebase - e7ec4e813ba6 is both "base" and destination
[1]
$ hg up -q 7
$ hg rebase --dest 8 --traceback
nothing to rebase - working directory parent is already an ancestor of destination e7ec4e813ba6
[1]
$ hg rebase --dest 8 -b.
nothing to rebase - "base" 02de42196ebe is already an ancestor of destination e7ec4e813ba6
[1]
$ hg rebase --dest '1 & !1'
abort: empty revision set
[255]
These work:
Rebase with no arguments (from 3 onto 8):
$ cd ..
$ hg clone -q -u . a2heads a1
$ cd a1
$ hg up -q -C 3
$ hg rebase
rebasing 1:42ccdea3bb16 "B"
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a1/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)
$ hg tglog
@ 6: 'D'
|
o 5: 'C'
|
o 4: 'B'
|
o 3: 'I'
|
o 2: 'H'
|
o 1: 'F'
|
o 0: 'A'
Try to rollback after a rebase (fail):
$ hg rollback
no rollback information available
[1]
$ cd ..
Rebase with base == '.' => same as no arguments (from 3 onto 8):
$ hg clone -q -u 3 a2heads a2
$ cd a2
$ hg rebase --base .
rebasing 1:42ccdea3bb16 "B"
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a2/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)
$ hg tglog
@ 6: 'D'
|
o 5: 'C'
|
o 4: 'B'
|
o 3: 'I'
|
o 2: 'H'
|
o 1: 'F'
|
o 0: 'A'
$ cd ..
Rebase with dest == branch(.) => same as no arguments (from 3 onto 8):
$ hg clone -q -u 3 a a3
$ cd a3
$ hg rebase --dest 'branch(.)'
rebasing 1:42ccdea3bb16 "B"
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a3/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)
$ hg tglog
@ 8: 'D'
|
o 7: 'C'
|
o 6: 'B'
|
o 5: 'I'
|
o 4: 'H'
|
| o 3: 'G'
|/|
o | 2: 'F'
| |
| o 1: 'E'
|/
o 0: 'A'
$ cd ..
Specify only source (from 2 onto 8):
$ hg clone -q -u . a2heads a4
$ cd a4
$ hg rebase --source 'desc("C")'
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a4/.hg/strip-backup/5fddd98957c8-f9244fa1-backup.hg (glob)
$ hg tglog
o 6: 'D'
|
o 5: 'C'
|
@ 4: 'I'
|
o 3: 'H'
|
o 2: 'F'
|
| o 1: 'B'
|/
o 0: 'A'
$ cd ..
Specify only dest (from 3 onto 6):
$ hg clone -q -u 3 a a5
$ cd a5
$ hg rebase --dest 6
rebasing 1:42ccdea3bb16 "B"
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a5/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)
$ hg tglog
@ 8: 'D'
|
o 7: 'C'
|
o 6: 'B'
|
| o 5: 'I'
| |
| o 4: 'H'
| |
o | 3: 'G'
|\|
| o 2: 'F'
| |
o | 1: 'E'
|/
o 0: 'A'
$ cd ..
Specify only base (from 1 onto 8):
$ hg clone -q -u . a2heads a6
$ cd a6
$ hg rebase --base 'desc("D")'
rebasing 1:42ccdea3bb16 "B"
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a6/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)
$ hg tglog
o 6: 'D'
|
o 5: 'C'
|
o 4: 'B'
|
@ 3: 'I'
|
o 2: 'H'
|
o 1: 'F'
|
o 0: 'A'
$ cd ..
Specify source and dest (from 2 onto 7):
$ hg clone -q -u . a a7
$ cd a7
$ hg rebase --source 2 --dest 7
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a7/.hg/strip-backup/5fddd98957c8-f9244fa1-backup.hg (glob)
$ hg tglog
o 8: 'D'
|
o 7: 'C'
|
| @ 6: 'I'
|/
o 5: 'H'
|
| o 4: 'G'
|/|
o | 3: 'F'
| |
| o 2: 'E'
|/
| o 1: 'B'
|/
o 0: 'A'
$ cd ..
Specify base and dest (from 1 onto 7):
$ hg clone -q -u . a a8
$ cd a8
$ hg rebase --base 3 --dest 7
rebasing 1:42ccdea3bb16 "B"
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a8/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)
$ hg tglog
o 8: 'D'
|
o 7: 'C'
|
o 6: 'B'
|
| @ 5: 'I'
|/
o 4: 'H'
|
| o 3: 'G'
|/|
o | 2: 'F'
| |
| o 1: 'E'
|/
o 0: 'A'
$ cd ..
Specify only revs (from 2 onto 8)
$ hg clone -q -u . a2heads a9
$ cd a9
$ hg rebase --rev 'desc("C")::'
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a9/.hg/strip-backup/5fddd98957c8-f9244fa1-backup.hg (glob)
$ hg tglog
o 6: 'D'
|
o 5: 'C'
|
@ 4: 'I'
|
o 3: 'H'
|
o 2: 'F'
|
| o 1: 'B'
|/
o 0: 'A'
$ cd ..
Rebasing both a single revision and a merge in one command
$ hg clone -q -u . a aX
$ cd aX
$ hg rebase -r 3 -r 6 --dest 8
rebasing 3:32af7686d403 "D"
rebasing 6:eea13746799a "G"
saved backup bundle to $TESTTMP/aX/.hg/strip-backup/eea13746799a-ad273fd6-backup.hg (glob)
$ cd ..
Test --tool parameter:
$ hg init b
$ cd b
$ echo c1 > c1
$ hg ci -Am c1
adding c1
$ echo c2 > c2
$ hg ci -Am c2
adding c2
$ hg up -q 0
$ echo c2b > c2
$ hg ci -Am c2b
adding c2
created new head
$ cd ..
$ hg clone -q -u . b b1
$ cd b1
$ hg rebase -s 2 -d 1 --tool internal:local
rebasing 2:e4e3f3546619 "c2b" (tip)
note: rebase of 2:e4e3f3546619 created no changes to commit
saved backup bundle to $TESTTMP/b1/.hg/strip-backup/e4e3f3546619-b0841178-backup.hg (glob)
$ hg cat c2
c2
$ cd ..
$ hg clone -q -u . b b2
$ cd b2
$ hg rebase -s 2 -d 1 --tool internal:other
rebasing 2:e4e3f3546619 "c2b" (tip)
saved backup bundle to $TESTTMP/b2/.hg/strip-backup/e4e3f3546619-b0841178-backup.hg (glob)
$ hg cat c2
c2b
$ cd ..
$ hg clone -q -u . b b3
$ cd b3
$ hg rebase -s 2 -d 1 --tool internal:fail
rebasing 2:e4e3f3546619 "c2b" (tip)
unresolved conflicts (see hg resolve, then hg rebase --continue)
[1]
$ hg summary
parent: 1:56daeba07f4b
c2
parent: 2:e4e3f3546619 tip
c2b
branch: default
commit: 1 modified, 1 unresolved (merge)
update: (current)
phases: 3 draft
rebase: 0 rebased, 1 remaining (rebase --continue)
$ hg resolve -l
U c2
$ hg resolve -m c2
(no more unresolved files)
continue: hg rebase --continue
$ hg graft --continue
abort: no graft in progress
(continue: hg rebase --continue)
[255]
$ hg rebase -c --tool internal:fail
rebasing 2:e4e3f3546619 "c2b" (tip)
note: rebase of 2:e4e3f3546619 created no changes to commit
saved backup bundle to $TESTTMP/b3/.hg/strip-backup/e4e3f3546619-b0841178-backup.hg (glob)
$ hg rebase -i
abort: interactive history editing is supported by the 'histedit' extension (see "hg --config extensions.histedit= help -e histedit")
[255]
$ hg rebase --interactive
abort: interactive history editing is supported by the 'histedit' extension (see "hg --config extensions.histedit= help -e histedit")
[255]
$ cd ..
No common ancestor
$ hg init separaterepo
$ cd separaterepo
$ touch a
$ hg commit -Aqm a
$ hg up -q null
$ touch b
$ hg commit -Aqm b
$ hg rebase -d 0
nothing to rebase from d7486e00c6f1 to 3903775176ed
[1]
$ cd ..