I'm working on adding Autotools to a C++ library and test program. My Automake.am has:
lib_LTLIBRARIES = \ libcryptopp.la libcryptopp_la_SOURCES = \ cryptolib.cpp \ cpu.cpp \ integer.cpp \ <remaining files in alphabetical order> ... cpu.cpp needs additional flags to enable ISAs on IA-32, Aarch64 and Power7/Power8. According to https://www.gnu.org/software/automake/manual/html_node/Per_002dObject-Flags.html, I need to add an additional library: CPU_FLAG = -msse2 -msse3 -mssse3 libcpu_a_SOURCES = cpu.cpp libcpu_a_CXXFLAGS = $(CXXFLAGS) $(CPU_FLAG) Now that the objects are built we need to add libcpu.a back into libcryptopp.la in the exact position it would have been in if I could have specified per-object flags. The Automake manual gives an example of linking a program with disjoint libraries, but not adding the extraneous library back to the main (primary?) library at a particular position. The "in the exact position" is important. Because this is C++, we have to contend with Static Initialization Order Fiasco (https://isocpp.org/wiki/faq/ctors#static-init-order). We need the initializers for cryptlib.o to run first, then the initializers for cpu.o to run, then the initializers for integer.o to run. The remaining ones are "don't care". My question is, how do I add libcpu.a back into libcryptopp.la in that exact position it would have been in if I could have specified per-object flags? Thanks in advance, Jeff
