Re: [PATCH] dist-xz: don't hard-code -9: honor setting of XZ_OPT

[Jim Meyering]

Ralf Wildenhues wrote:
> This patch is OK with a couple of minor nits below addressed.
>
> May I ask you to commit it on top of a fresh branch off of maint, and
> merge that to master?  Sorry for not stating that before, making you do

Sure.  What branch name would you like?

> double work, but that allows us to merge it to branch-1.11 later.
> I can otherwise also do this, if you just post the final patch.
> (The most painful part of this, thanks to git-merge-changelog, is
> merging NEWS correctly; I'm still pondering whether to write a merge
> driver for it or change the format to make it more suitable to branched
> development.)
>
> Based on Lasse's feedback, I'm wondering whether an xz default of -7 or
> -8 is not sufficient for most practical uses.  I can address this later
> though.

I agree.  Thanks.

> Please add @vindex entries for BZIP2 here, and XZ_OPT below.

Good point.
...
>> -    tardir=$(distdir) && $(am__tar) | bzip2 -9 -c >$(distdir).tar.bz2
>> +    tardir=$(distdir) && $(am__tar) \
>> +      | BZIP2=$${BZIP2--9} bzip2 -c >$(distdir).tar.bz2
>
> Let's still keep these on one line, because they will typically render
> ugly no matter where we split them: if AMTAR includes .../missing, then
> that will already be too long, and if it doesn't, then a split before or
> after && would be the most readable.  Below as well.

OK.

Here's the incremental:

diff --git a/doc/automake.texi b/doc/automake.texi
index f8f2d8f..60e450f 100644
--- a/doc/automake.texi
+++ b/doc/automake.texi
@@ -8458,6 +8458,7 @@ The Types of Distributions
 distributions in various formats.  Their targets are:

 @table @asis
address@hidden BZIP2
 @item @code{dist-bzip2}
 Generate a bzip2 tar archive of the distribution.  bzip2 archives are
 frequently smaller than gzipped archives.
@@ -8486,6 +8487,7 @@ The Types of Distributions
 Generate a shar archive of the distribution.
 @trindex dist-shar

address@hidden XZ_OPT
 @item @code{dist-xz}
 Generate an @samp{xz} tar archive of the distribution.  @command{xz}
 archives are frequently smaller than @command{bzip2}-compressed archives.
diff --git a/lib/am/distdir.am b/lib/am/distdir.am
index ad789df..185d34c 100644
--- a/lib/am/distdir.am
+++ b/lib/am/distdir.am
@@ -345,8 +345,7 @@ dist-gzip: distdir
 ?BZIP2?DIST_ARCHIVES += $(distdir).tar.bz2
 .PHONY: dist-bzip2
 dist-bzip2: distdir
-       tardir=$(distdir) && $(am__tar) \
-         | BZIP2=$${BZIP2--9} bzip2 -c >$(distdir).tar.bz2
+       tardir=$(distdir) && $(am__tar) | BZIP2=$${BZIP2--9} bzip2 -c 
>$(distdir).tar.bz2
        $(am__post_remove_distdir)

 ?LZIP?DIST_ARCHIVES += $(distdir).tar.lz
@@ -364,8 +363,7 @@ dist-lzma: distdir
 ?XZ?DIST_ARCHIVES += $(distdir).tar.xz
 .PHONY: dist-xz
 dist-xz: distdir
-       tardir=$(distdir) && $(am__tar) \
-         | XZ_OPT=$${XZ_OPT--9} xz -c >$(distdir).tar.xz
+       tardir=$(distdir) && $(am__tar) | XZ_OPT=$${XZ_OPT--9} xz -c 
>$(distdir).tar.xz
        $(am__post_remove_distdir)

 ?COMPRESS?DIST_ARCHIVES += $(distdir).tar.Z

Here's the merged result, including a summary and log that
also mention dist-bzip2:

>From 3b9a100b24b734cfd4cf934740c2694a0fc263c9 Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Sat, 2 Oct 2010 22:30:02 +0200
Subject: [PATCH] dist-xz, dist-bzip2: don't hard-code -9: honor envvar settings

* lib/am/distdir.am (dist-xz): Do not hard-code xz's -9: that
made it impossible to override.  Instead, use its XZ_OPT envvar,
defaulting to -9 if not defined.  Thus no change in behavior
when XZ_OPT is not set, and now, this rule honors the setting
of that envvar when it is set.  Suggested by Lasse Collin.
(dist-bzip2): Likewise for it's corresponding envvar: BZIP2.
* NEWS (Miscellaneous changes): Mention it.
* doc/automake.texi (The Types of Distributions): Describe the newly
enabled environment variables.
---
 NEWS              |    5 +++++
 doc/automake.texi |    9 +++++++++
 lib/am/distdir.am |    4 ++--
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/NEWS b/NEWS
index 121989f..c64ec14 100644
--- a/NEWS
+++ b/NEWS
@@ -17,6 +17,11 @@ New in 1.11a:

   - "make dist" can now create lzip-compressed tarballs.

+  - You may adjust the compression options used in dist-xz and dist-bzip2.
+    The default is still -9 for each, but you may specify a different
+    level via the XZ_OPT and BZIP2 envvars respectively.  E.g.,
+    "make dist-xz XZ_OPT=-7" or "make dist-xz BZIP2=-5"
+
   - Messages of types warning or error from `automake' and `aclocal' are now
     prefixed with the respective type, and presence of -Werror is noted.

diff --git a/doc/automake.texi b/doc/automake.texi
index 22c2f27..60e450f 100644
--- a/doc/automake.texi
+++ b/doc/automake.texi
@@ -8458,9 +8458,13 @@ The Types of Distributions
 distributions in various formats.  Their targets are:

 @table @asis
address@hidden BZIP2
 @item @code{dist-bzip2}
 Generate a bzip2 tar archive of the distribution.  bzip2 archives are
 frequently smaller than gzipped archives.
+By default, this rule makes @samp{bzip2} use a compression option of 
@option{-9}.
+To make it use a different one, set the @env{BZIP2} environment variable.
+For example, @samp{make dist-bzip2 BZIP2=-7}.
 @trindex dist-bzip2

 @item @code{dist-gzip}
@@ -8483,10 +8487,15 @@ The Types of Distributions
 Generate a shar archive of the distribution.
 @trindex dist-shar

address@hidden XZ_OPT
 @item @code{dist-xz}
 Generate an @samp{xz} tar archive of the distribution.  @command{xz}
 archives are frequently smaller than @command{bzip2}-compressed archives.
 The @samp{xz} format displaces the obsolete @samp{lzma} format.
+By default, this rule makes @samp{xz} use a compression option of @option{-9}.
+To make it use a different one, set the @env{XZ_OPT} environment variable.
+For example, run this command to use the default compression ratio, but
+with a progress indicator: @samp{make dist-xz XZ_OPT=-7e}.
 @trindex dist-xz

 @item @code{dist-zip}
diff --git a/lib/am/distdir.am b/lib/am/distdir.am
index a11d3a4..185d34c 100644
--- a/lib/am/distdir.am
+++ b/lib/am/distdir.am
@@ -345,7 +345,7 @@ dist-gzip: distdir
 ?BZIP2?DIST_ARCHIVES += $(distdir).tar.bz2
 .PHONY: dist-bzip2
 dist-bzip2: distdir
-       tardir=$(distdir) && $(am__tar) | bzip2 -9 -c >$(distdir).tar.bz2
+       tardir=$(distdir) && $(am__tar) | BZIP2=$${BZIP2--9} bzip2 -c 
>$(distdir).tar.bz2
        $(am__post_remove_distdir)

 ?LZIP?DIST_ARCHIVES += $(distdir).tar.lz
@@ -363,7 +363,7 @@ dist-lzma: distdir
 ?XZ?DIST_ARCHIVES += $(distdir).tar.xz
 .PHONY: dist-xz
 dist-xz: distdir
-       tardir=$(distdir) && $(am__tar) | xz -9 -c >$(distdir).tar.xz
+       tardir=$(distdir) && $(am__tar) | XZ_OPT=$${XZ_OPT--9} xz -c 
>$(distdir).tar.xz
        $(am__post_remove_distdir)

 ?COMPRESS?DIST_ARCHIVES += $(distdir).tar.Z
--
1.7.3.1.45.g9855b