From 067a5105a76e51eebcdf7e7786d1f91040442d47 Mon Sep 17 00:00:00 2001 From: Michael Orlitzky 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