Re: pattern rules example

[Thien-Thi Nguyen]

() Ralf Wildenhues <address@hidden>
() Wed, 18 Aug 2010 07:02:07 +0200

   Format conversion seems like a good idea, ideally one that's
   about free formats and using free and portable tools?

Hi Ralf,

Sorry for the long delay.  Please find below a patch, rebased
onto 68e694113, that takes into account your suggestions.  It
bears only the slightest resemblance to previous iterations.
Comments welcome!  In particular, i don't know how widespread
oggenc is, or if there is a more GNUish alternative.

_____________________________________________________________________

>From 0e4ec03ceaf2f67a62f3f2a3a168ce7236f77212 Mon Sep 17 00:00:00 2001
From: Thien-Thi Nguyen <address@hidden>
Date: Wed, 18 May 2011 16:53:33 +0200
Subject: [PATCH] doc: mention ext reversal on pattern- to suffix-rule conversion

* doc/automake.texi (Suffixes): Mention order reversal when
converting GNU make pattern rule to Automake suffix rule;
add example; add xref to GNU make manual.
(Multiple Outputs): Add xref to "Suffixes".
---
 ChangeLog         |   10 +++++++++-
 doc/automake.texi |   31 ++++++++++++++++++++++++++++++-
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index b3a1e7e..a26e4ec 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2011-05-18  Thien-Thi Nguyen  <address@hidden>
+
+       doc: mention ext reversal on pattern- to suffix-rule conversion
+       * doc/automake.texi (Suffixes): Mention order reversal when
+       converting GNU make pattern rule to Automake suffix rule;
+       add example; add xref to GNU make manual.
+       (Multiple Outputs): Add xref to "Suffixes".
+
 2011-05-15  Stefano Lattarini  <address@hidden>
 
        testsuite: be more cross-compile friendly
@@ -306,7 +314,7 @@
        * tests/python5b.test: Likewise.
        * tests/specflg-dummy.test: Likewise.
        * tests/yacc-dist-nobuild-subdir.test: Likewise.
-       
+
 2011-04-12  Stefano Lattarini  <address@hidden>
 
        coverage: test for automake bug#8485 (known regression)
diff --git a/doc/automake.texi b/doc/automake.texi
index 5dd1099..ddb197b 100644
--- a/doc/automake.texi
+++ b/doc/automake.texi
@@ -9672,6 +9672,35 @@ @node Suffixes
 @code{SUFFIXES} go at the start of the generated suffixes list, followed
 by Automake generated suffixes not already in the list.
 
+Another thing to keep in mind if converting a GNU @command{make}
address@hidden rule} to an Automake suffix rule is to reverse the
+order of the prerequisite and target suffixes.  For example, to
+convert a @acronym{WAV} format audio file to another in
address@hidden format:
+
address@hidden
address@hidden
+# GNU make pattern rule, not portable
+%.ogg : %.wav
+        oggenc -o $@@ $<
address@hidden group
+
address@hidden
+# Automake suffix rule, portable, backwards
+.ogg.wav:
+        oggenc -o $@@ $<
address@hidden group
+
address@hidden
+# Automake suffix rule, portable, correct
+.wav.ogg:
+        oggenc -o $@@ $<
address@hidden group
address@hidden example
+
address@hidden
address@hidden Examples, , Pattern Rule Examples, make, The GNU Make Manual}.
+
 @node Multilibs
 @section Support for Multilibs
 
@@ -11772,7 +11801,7 @@ @node Multiple Outputs
 (@pxref{Pattern Examples, , Pattern Rule Examples, make, The GNU Make
 Manual}).  We do not discuss pattern rules here because they are not
 portable, but they can be convenient in packages that assume GNU
address@hidden
address@hidden  @xref{Suffixes}.
 
 
 @node Hard-Coded Install Paths
-- 
1.6.3.2