From: Tom Tromey <tromey@redhat.com>
Date: Thu, 1 Oct 1998 01:31:05 +0000 (+0000)
Subject: 	* depend2.am (%.o): Handle deleted header file problem.
X-Git-Tag: Release-1-3d~57
X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=d81bb6d82ddef6b15ab1b51a2dc51781b8f23173;p=automake.git

	* depend2.am (%.o): Handle deleted header file problem.
	(%.lo): Likewise.
---

diff --git a/ChangeLog b/ChangeLog
index 9c8c1ce1..5dfbc93a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 Thu Oct  1 00:51:51 1998  Tom Tromey  <tromey@cygnus.com>
 
+	* depend2.am (%.o): Handle deleted header file problem.
+	(%.lo): Likewise.
+
 	* texinfos.am (install-info-am): Handle case where INFO_DEPS is
 	empty.  Reported by Andrew Cagney.
 	(uninstall-info): Likewise.
diff --git a/NEWS b/NEWS
index 3dd3bb18..d9d1d2e1 100644
--- a/NEWS
+++ b/NEWS
@@ -4,6 +4,7 @@ New in 1.3b:
 * Support for latest autoconf, including support for objext
 * Can now put `.' in SUBDIRS to control build order
 * `include' command
+* Dependency tracking no long susceptible to deleted header file problem
 * Bug fixes
 
 New in 1.3:
diff --git a/depend2.am b/depend2.am
index 09cb938d..7e4c6a3f 100644
--- a/depend2.am
+++ b/depend2.am
@@ -26,12 +26,30 @@
 ##   -MM, not -M (despite what the docs say).
 ## - Using -M directly means running the compiler twice (even worse
 ##   than renaming).
-	$(@PFX@COMPILE) -Wp,-MD,.deps/$(*F).P -c $<
+	$(@PFX@COMPILE) -Wp,-MD,.deps/$(*F).p -c $<
+## This next piece of magic avoids the `deleted header file' problem.
+## The problem is that when a header file which appears in a .P file
+## is deleted, the dependency causes make to die (because there is
+## typically no way to rebuild the header).  We avoid this by adding
+## dummy dependencies for each header file.  Too bad gcc doesn't do
+## this for us directly.
+	@-tr '\\ ' '\n\n' < .deps/$(*F).p \
+## The very first nondeleted line is always the primary source file.
+## No need for that, so we remove it too via `1d'.
+	  | sed -e '/^$$/ d' -e '/:$$/ d' -e 1d -e 's/$$/:/' > .deps/$(*F).P; \
+	rm .deps/$(*F).p
 
 %.lo: %@EXT@
 	@echo '$(LT@PFX@COMPILE) -c $<'; \
 ## See above to understand implementation weirdness.
 	$(LT@PFX@COMPILE) -Wp,-MD,.deps/$(*F).p -c $<
 	@-sed -e 's/^\([^:]*\)\.o:/\1.lo \1.o:/' \
-	  < .deps/$(*F).p > .deps/$(*F).P
-	@-rm -f .deps/$(*F).p
+	  < .deps/$(*F).p > .deps/$(*F).P; \
+## See above to understand deleted header file trick.
+	tr '\\ ' '\n\n' < .deps/$(*F).p \
+## The very first nondeleted line is always the primary source file.
+## No need for that, so we remove it too via `1d'.
+	  | sed -e '/^$$/ d' -e '/:$$/ d' -e 1d -e 's/$$/:/' \
+## Note subtle difference: here we append to the .P file.
+	    >> .deps/$(*F).P; \
+	rm -f .deps/$(*F).p
diff --git a/lib/am/depend2.am b/lib/am/depend2.am
index 09cb938d..7e4c6a3f 100644
--- a/lib/am/depend2.am
+++ b/lib/am/depend2.am
@@ -26,12 +26,30 @@
 ##   -MM, not -M (despite what the docs say).
 ## - Using -M directly means running the compiler twice (even worse
 ##   than renaming).
-	$(@PFX@COMPILE) -Wp,-MD,.deps/$(*F).P -c $<
+	$(@PFX@COMPILE) -Wp,-MD,.deps/$(*F).p -c $<
+## This next piece of magic avoids the `deleted header file' problem.
+## The problem is that when a header file which appears in a .P file
+## is deleted, the dependency causes make to die (because there is
+## typically no way to rebuild the header).  We avoid this by adding
+## dummy dependencies for each header file.  Too bad gcc doesn't do
+## this for us directly.
+	@-tr '\\ ' '\n\n' < .deps/$(*F).p \
+## The very first nondeleted line is always the primary source file.
+## No need for that, so we remove it too via `1d'.
+	  | sed -e '/^$$/ d' -e '/:$$/ d' -e 1d -e 's/$$/:/' > .deps/$(*F).P; \
+	rm .deps/$(*F).p
 
 %.lo: %@EXT@
 	@echo '$(LT@PFX@COMPILE) -c $<'; \
 ## See above to understand implementation weirdness.
 	$(LT@PFX@COMPILE) -Wp,-MD,.deps/$(*F).p -c $<
 	@-sed -e 's/^\([^:]*\)\.o:/\1.lo \1.o:/' \
-	  < .deps/$(*F).p > .deps/$(*F).P
-	@-rm -f .deps/$(*F).p
+	  < .deps/$(*F).p > .deps/$(*F).P; \
+## See above to understand deleted header file trick.
+	tr '\\ ' '\n\n' < .deps/$(*F).p \
+## The very first nondeleted line is always the primary source file.
+## No need for that, so we remove it too via `1d'.
+	  | sed -e '/^$$/ d' -e '/:$$/ d' -e 1d -e 's/$$/:/' \
+## Note subtle difference: here we append to the .P file.
+	    >> .deps/$(*F).P; \
+	rm -f .deps/$(*F).p