From: Julien Rioux <jrioux@physics.utoronto.ca>
Date: Tue, 7 Feb 2012 16:51:16 +0000 (-0500)
Subject: Build: Use order-only prerequisites in lilypond-book chain rule.
X-Git-Tag: release/2.15.31-1~49
X-Git-Url: https://git.donarmstrong.com/?a=commitdiff_plain;h=0bb3eb14a16a605ca202dacbf657bdbe5dc94ebf;p=lilypond.git

Build: Use order-only prerequisites in lilypond-book chain rule.

The chain rule makes sure that only one instance of lilypond-book
is running at once. However, it also adds superficial dependencies
between manuals. We can avoid this using GNU make's order-only
syntax for prerequisites, which adds a pipe (|) character in front.
---

diff --git a/make/ly-rules.make b/make/ly-rules.make
index 0461e1b9c6..418d1b9f03 100644
--- a/make/ly-rules.make
+++ b/make/ly-rules.make
@@ -9,9 +9,10 @@ $(outdir)/%.latex: %.doc $(INIT_LY_SOURCES) $(SCHEME_SOURCES)
 
 
 # This allows -j make option while making sure only one lilypond-book instance
-# is running at the same time
+# is running at the same time, using GNU make's order-only prerequisites so
+# as to not create superficial dependencies between unrelated manuals.
 define CHAIN_RULE
-$(i)
+| $(i)
 $(i): 
 endef