I'm struggling with the last pieces of logic to make our Ada builder work as expectedly with variantdir. The problem is caused by the fact that the inflexible tools gnatbind and gnatlink doesn't allow the binder files to be placed in a directory other than the current one. This leaves me with two options:
Let gnatbind write the the binder files to topdir and then let gnatlink pick it from there. This may however cause race conditions if we want to allow simulatenous builds for different architectures and compiler versions which we want.
Modify the calls to gnatbind and gnatlink to temporarily go down to the build directory, in our case build/$ARCH/src-path. I successfully fixed the gnatbind step as this is explicitly called using a env.Execute from within the Ada builder. To try to fix the linking step I've modified the Program env using
env["LINKCOM"] = SCons.Action.Action(ada_linkcom)
where ada_linkcom is defined as
def ada_linkcom(source, target,env ):
....
return ret
where ret is a string describing what should be done in the shell. I need this to be a function it contains a bit complicated logic to convert paths from being relative to top-level to just containing their basenames.
This however fails with an error in scons-2.3.1/SCons/Executor.py on line 347 in function do_execute. Isn't env["LINKCOM"] allowed to be a function with ada_linkcom's signature?
No, it's not. You seem to think that 'env["LINKCOM"]' is what actually calls/executes the final build command, and that's not quite correct. Instead, environment variables like LINKCOM get expanded by the Executor/Builder for each specified Action, and are then executed.
You can have Python functions as Actions, and also use a so-called "generator" to create your Action strings on-the-fly. But you have to assign this Action to a Builder, and can't set it as an environment variable directly.
Please also have a look at the UserGuide ( http://www.scons.org/doc/production/HTML/scons-user.html ), especially section 18.4 "Builders That Execute Python Functions". Our basic guide for writing Builders and Tools might also prove to be helpful: http://www.scons.org/wiki/ToolsForFools
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I'm cross-compling with mingw and got this error:
undefined reference to `rpl_realloc'
After some searching I found this can be resolved as follows in configure.ac or as environment variables set prior to calling ./mingw64-configure:
ac_cv_func_malloc_0_nonnull=yes
ac_cv_func_realloc_0_nonnull=yes
What defines these macros, and as there any documentation on the subject? I couldn't find any...
What defines these macros, and as there any documentation on the subject?
Autoconf uses the ac_cv_ prefix for its "cache variables", in which it records the results of configuration tests it has performed. In the event that the same check is requested multiple times, these allow it to use the previously-determined result instead of performing the check again.
The general naming convention for these is documented in the Autoconf manual. The particular cache variable names you ask about are documented to cache the results of the Autoconf's AC_FUNC_MALLOC and AC_FUNC_REALLOC macros, respectively. That documentation also speaks to the rpl_realloc name.
It is allowed to use these variables in configure.ac to programmatically determine the results of those checks, but it is a relatively nasty hack to assign values to those variables directly. In this particular case, however, the error suggests that whoever prepared the autotooling for the project you're trying to build did a sloppy job of it. If fudging the cache variables gets you a successful build and a working program then that's a tempting and much easier alternative to actually fixing the project.
For work purposes I need to link against an object file generated by another program and found in its folder, the case is that I did not find information about this kind of linkage. I think that if I hardcode the paths and put the name-of-obj.o in front of the package_LDADD variable should work, but the case is that I don't want to do it that way.
If the object is not found I want the configure to fail and tell the user that the name-of-obj.o is missing.
I tried by using AC_LIBOBJ([name-of-obj.o]) but this will try to find in the root directory a name-of-obj.c and compile it.
Any tip or solution around this issue?
Thank you!
I need to link against an object file generated by another program and
found in its folder
What you describe is a very unusual requirement, not among those that the Autotools are designed to handle cleanly or easily. In particular, Autoconf has no mechanisms specifically applicable to searching for bare object files, as opposed to libraries, and Automake has no particular automation around including such objects when it links. Nevertheless, these tools do have enough general purpose functionality to do what you want; it just won't be as tidy as you might like.
I think that if I hardcode the paths and put the
name-of-obj.o in front of the package_LDADD variable should work, but
the case is that I don't want to do it that way.
I take it that it is the "hardcode the paths" part that you want to avoid. Adding an item to an appropriate LDADD variable is not negotiable; it is the right way to get your object included in the link.
If the object is not found I want the configure to fail and tell the
user that the name-of-obj.o is missing.
Well, then, the key thing appears to be to get configure to perform a search for your object file. Autoconf does not have a built-in mechanism to perform such a search, but it's just a macro-based shell-script generator, so you can write such a search in shell script + Autoconf, maybe something like this:
AC_MSG_CHECKING([for name-of-obj.o])
OTHER_LOCATION=
for my_dir in
/some/location/other_program/src
/another/location/other_program.12345/src
$srcdir/../relative/location/other_program/src; do
AS_IF([test -r "${my_dir}/name-of-obj.o"], [
# optionally, perform any desired test to check that the object is usable
# ... perhaps one using AC_LINK_IFELSE ...
# if it passes, then
OTHER_LOCATION=${my_dir}
break
])
done
# Check whether the object was in fact discovered, and act appropriately
AS_IF([test "x${OTHER_LOCATION}" = x], [
# Not found
AC_MSG_RESULT([not found])
AC_MSG_ERROR([Cannot configure without name-of-obj.o])
], [
AC_MSG_RESULT([${OTHER_LOCATION}/name-of-obj.o])
AC_SUBST([OTHER_LOCATION])
])
That's functional, but of course you could embellish, such as by providing for the package builder to specify a location to use via a command-line argument (AC_ARG_WITH(...)). And if you want to do this for multiple objects, then you would probably want to wrap up at least some of that into a custom macro.
The Automake side is much less involved. To get the object linked, you just need to add it to the appropriate LDADD variable, using the output variable created by the above, such as:
foo_LDADD = $(OTHER_LOCATION)/name-of-obj.o
Note that if you're building just one program target then you can use the general LDADD instead of foo_LDADD, but note that by default these are alternatives not complements.
With that said, this is a bad idea overall. If you want to link something that is not part of your project, then you should get it from an installed library. That can be a local, custom-built library, of course, so long as it is a library, not a bare object file, and it is installed. It can be a static library if you don't want to rely on or distribute a separate shared library.
On the other hand, if your project is part of a larger build, then the best approach is probably to integrate it into that build, maybe as a subproject. It would still be best to link a library instead of a bare object file, but in a subproject context it might make sense to use a lib that was not installed to the build system. In conjunction with a command-line argument that tells it where to find the wanted lib, this could make the needed Autoconf code much cleaner and clearer.
I have a #define ONB in a c file which (with several #ifndef...#endifs) changes many aspects of a programs behavior. Now I want to change the project makefile (or even better Makefile.am) so that if ONB is defined and some other options are set accordingly, it runs some special commands.
I searched the web but all i found was checking for environment variables... So is there a way to do this? Or I must change the c code to check for that in environment variables?(I prefer not changing the code because it is a really big project and i do not know everything about it)
Questions: My level is insufficient to ask in comments so I will have to ask here:
How and when is the define added to the target in the first place?
Do you essentially want a way to be able to post compile query the binaries to to determine if a particular define was used?
It would be helpful if you could give a concrete example, i.e. what are the special commands you want run, and what are the .c .h files involved?
Possible solution: Depending on what you need you could use LLVM tools to maybe generate and examine the AST of your code to see if a define is used. But this seems a little like over engineering.
Possible solution: You could also use #includes to pull in .c or header files and a conditional error be generated, or compile (to a .o), then if the compile fails you know it is defined or not. But this has it's own issues depending on how things are set-up in your make file.
I am having a design problem when using GNU Make.
My problem is the following:
I have 2 executables to compile.
These binaries need to be compiled for each compiler I list in a variable, let us call it COMPILERS.
After compiling the binaries, I need to run all binaries (all of them) several times and generate, for each of them, the times in a text file.
I must put all these files together, and generate a plot out of all that data.
So, for example, if I have 3 compilers to test, I would have 6 binaries, 6 * n_of_time_to_run_benchmark and a final output with all that data, in a single plot file.
The problem with this is that my usual way to approach binary compilation is to use CXX variable, CXXFLAGS, etc. But the CXX variable is supposed to change inside the same session, which looks inconsistent to me. An example of invocation would be:
make plot COMPILERS=clang++ g++
What I did is to just compile binaries separately every time I invoke make and per compiler, making use of CXX variable.
From a script I create a folder build-clang++ and compile, I create another folder build-g++ and compile, run all benchmarks, per folder for every couple of executables for same compiler. But for this I need an external script, and this is what I want to avoid, to be able to port to windows later more easily without duplicating scripts or installing more dependencies.
What is the best way to handle this:
Use another Makefile that calls this makefile with different configurations and use it as my "script" for generating the plot? This way the makefile looks like much more traditional to me, with his separate flags, etc.
Just create all targets directly inside same Make session?
To me it looks cleaner the script solution because a Makefile is usually written in a way that the compiler is a fixed variable that does not change in the whole session.
Thank you.
I am working on a project using the cmake build system. By default CMake has a nice framework for generating a single executable from a set of C/C++ code. The cmake function is called create_test_sourcelist. What it does is generate a C/C++ dispatcher with a single main entry point which will call other C/C++ code.
Therefore I have a bunch of C/C++ files with a function signature such as: int TestFunctionality1(int argc, char *argv[]), which I'd like to keep as-is, unless of course it means even more work.
How can I keep this system in place and start using BOOST_CHECK ? I could not figure out how to specify the actual main entry point is not called int main(int argc, char *argv[]).
My goal is have a framework for integration with Jenkins, since the project already uses Boost, I believe this should be doable without re-writing the existing CMake test suite and changing all tests into independent main function.
Unfortunately, it seems there is no straightforward and clean way to do that.
From one side the only useful function of create_test_sourcelist is to generate a test driver: a (stupid pretty simple, naive and with lack of abilities to hack/extend) C/C++ translation unit based on ${cmake-prefix}/share/cmake/Templates/TestDriver.cxx.in (and there is no way to select some other template).
From other side, Boost UTF offers its own test runner (which is equal to test driver in CMake's terminology), but in any variant (static, dynamic, single-header) it contains definition for main() some way or another (even in case of external test runner).
…so you end up with two main() functions and no ability to choose a single one.
Digging a little into sources of create_test_sourcelist I've really wonder why are they implemented it as a command and not as ordinal (extern) cmake module — it doesn't do any special (which can't be implemented using CMake language). This command is really stupid — it doesn't check that required functions are really exists (you'll get compile errors if smth wrong). There are no ways for flexible customization of output source file at all. All that is does is stripping paths and extensions from a list of source files and substitute it to mentioned template using ordinal configure_file()…
So, personally I see no reason to use it at all. It is why I've done the same (but better ;) job in the module mentioned in the comment above.
If you are still want to use that command, generated test driver completely useless if you want to use Boost UTF. You need to provide your own initialization function anyway (and it is not main()), where you can manually register your test cases into a master test suite (or organize your tests into some more complex tree). In that case there is absolutely no reason to use create_test_sourcelist! All what you can get from it is a list of sources that needs to be given to add_executable()… but it is much more easy to do w/ set()… This command even can't help you w/ list of test functions (list of filenames w/o extension actually) to call (it used internally and not exported). Do you still want to use that command??