Re: [Boost.Test] linking with shared lib (cannot find main)

From: Andrew McFarlane (andrew.mcfarlane52_at_[hidden])
Date: 2020-02-29 04:55:44

Okay, so I've actually made considerable progress.

g++ can now find the main entry point and all my object files are being
compiled and placed where I want them. I'm even noticing the compilation
speedup from using the shared library, which is super cool.

I have (for the most part) transitioned my unit test translation units from
"automatic" to "manual". My current approach for manual test registration
is as follows:

- have an init_test_suite() function in each translation unit that: 1)
creates a test suite 2) adds all test cases from that translation unit to
the test suite 3) adds the test suite to the master test suite

- include test translation units in main.cpp

- have a register_test_suites() function in main.cpp that calls the
init_test_suite() function for each translation unit being tested

As one would expect from including a bunch of test translation units in
main.cpp (where several of them include files that are included by other
test translation units), I am running into redefinition errors. This does
not surprise me.

I am wondering: what would be a good modularized approach to calling the
init_test_suite() function defined in each of my test translation units
from main.cpp? Should I have test class header files with include guards,
and then include those files in main.cpp?

Sort of wondering what others have done in the past with manual test
registration to avoid redefinitions and maximize encapsulation.

Thanks in advance.

-AJ

On Fri, Feb 28, 2020 at 6:50 PM Andrew McFarlane <
andrew.mcfarlane52_at_[hidden]> wrote:

> Hi all,
>
> I have been using Boost.Test for about a month now. Big fan so far, except
> for the atrocious compilation times, hence why I am moving toward using the
> shared library.
>
> using b2 to build and install Boost.Test's libs was simple enough, though
> after making the noted changes here:
>
> https://www.boost.org/doc/libs/1_72_0/libs/test/doc/html/boost_test/adv_scenarios/shared_lib_customizations/entry_point.html
>
> to customize the module's entry point, g++ cannot find the main executable:
>
> Undefined symbols for architecture x86_64:
>
>   "_main", referenced from:
>
>      implicit entry/start for main executable
>
> ld: symbol(s) not found for architecture x86_64
>
> clang: error: linker command failed with exit code 1 (use -v to see
> invocation)
>
> make: *** [Guest_T] Error 1
>
> I tried digging through the docs for more information, but I came up short.
>
> For more context, I have written unit tests for each of my classes. For
> example, if my classes were A, B, and C, I would have A_T.cpp, B_T.cpp, and
> C_T.cpp for unit tests.
>
> - Should each of the unit tests have their own main() function? (I would
> think not..)
>
> - If not, how do I instruct g++ to first compile main.cpp before
> attempting to compile anything else?
>
> If you are curious, here are the contents of my Makefile:
>
> PROG := main
>
> CC := g++
>
> SDIR := ../src
>
> PKG_DIRS := $(shell ls $(SDIR))
>
> CXXFLAGS = -v -Wall -std=c++11 -I$(SDIR_TEST) \
>
> $(addprefix -I$(SDIR)/,$(PKG_DIRS)) -I$(BOOST_ROOT) \
>
> -L$(BOOST_LIBS) -Wl,-rpath,$(BOOST_LIBS) -lboost_unit_test_framework
>
> ODIR_TEST = ./bin
>
> SDIR_TEST = ./src
>
> OUTDIR = ./execs
>
> ODIR = ../sim/bin
>
>
> TEST_EXEC_NAMES = $(notdir $(basename $(wildcard $(SDIR_TEST)/*.cpp)))
>
>
> $(OUTDIR)/$(PROG) : $(SDIR_TEST)/main.cpp
>
>         $(CC) $(CXXFLAGS) -o $@ $<
>
>
> $(OUTDIR)/$(PROG) : $(TEST_EXEC_NAMES)
>
>         $(CC) $(CXXFLAGS) -o $@ $^
>
>
> % : $(SDIR_TEST)/%.cpp
>
>         $(CC) $(CXXFLAGS) -o $(OUTDIR)/$@ $^
>
> From what I can tell, g++ is failing to find the main the executable
> because it is attempting to compile one of my unit test files first. This
> may or may not be the case; either way, I would appreciate some help or
> direction as to what I should read to learn more about this.
>
> Let me know if you need more info.
>
> Thanks in advance.
>
> - AJ
>