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From 067a5105a76e51eebcdf7e7786d1f91040442d47 Mon Sep 17 00:00:00 2001
From: Michael Orlitzky <michael@orlitzky.com>
Date: Mon, 14 Aug 2023 13:23:09 -0400
Subject: makefiles/Makefile.top: dependencies for PRE_ and POST_TARGETS
The PRE_TARGETS and POST_TARGETS are supposed to be built before and
after $(OBJECTS), respectively -- at least according to the comments
in Makefile.top:
# List of targets to run before building $(OBJECT)
PRE_TARGETS :=
# List of targets to run after building $(OBJECT)
POST_TARGETS :=
The default target however builds them at the same time as $(OUTPUT),
# Default target
all: $(PRE_TARGETS) $(OUTPUT) $(POST_TARGETS)
where $(OUTPUT) basically just builds $(OBJECTS):
$(OUTPUT): $(BUILDDIR)/stamp $(OBJECTS)
...
As a result, there is a race condition when $(OBJECTS) truly requires
$(PRE_TARGETS), because they may be built at the same time. The same
problem arises the other way around with $(POST_TARGETS). As a
demonstration, one can try to build the libsvgtiny shared library
directly (note: the details are platform-dependent),
$ BD=build-x86_64-pc-linux-gnu-x86_64-pc-linux-gnu-release-lib-shared
$ make COMPONENT_TYPE=lib-shared "${BD}/libsvgtiny.so.0.1.7"
COMPILE: src/svgtiny.c
...
src/svgtiny.c:24:10: fatal error: autogenerated_colors.c: No such file or directory
24 | #include "autogenerated_colors.c"
| ^~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
This is because $(PRE_TARGETS) is not satisfied. In practice, this
condition seems hard to hit unintentionally, but it can happen if you
are building in parallel and extemely unlucky. A user discovered it in
Gentoo bug 711200.
The fix simply adds the stated dependencies on $(OBJECTS) and
$(POST_TARGETS) to guarantee the correct order.
---
makefiles/Makefile.top | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/makefiles/Makefile.top b/makefiles/Makefile.top
index 0b0fe22..2a41697 100644
--- a/makefiles/Makefile.top
+++ b/makefiles/Makefile.top
@@ -422,6 +422,16 @@ else
endif
endif
+ifneq ($(PRE_TARGETS),)
+# Ensure that PRE_TARGETS are built before OBJECTS.
+$(OBJECTS): $(PRE_TARGETS)
+endif
+
+ifneq ($(POST_TARGETS),)
+# Ensure that POST_TARGETS are built after OBJECTS.
+$(POST_TARGETS): $(OBJECTS)
+endif
+
###############################################################################
# Autogenerated, implied rules
###############################################################################
--
cgit v1.2.1
|
