I'm using SCons to build a very large project, with many buildable sub-projects. I can easily use keyword commands like scons group=ai to build the AI sub-projects with if statements (choosing the right SConscripts based on the keyword command), but I want to make it as easy as possible for others to use scons. Ideally, I'd like to use it like so: scons ai to build the AI components. However, the only single-word command functionality I've found in SCons so far is aliasing, and all the examples are about changing the target. This is not what I want. Since I have a very large project with multiple sub-SConscript files to build the subprojects, I want to call the SConscripts selectively. I've tried code like so:
env.Alias("ai", SConscript("ai/SConscript", 'env'))
but this calls the AI SConscript every time, regardless of whether I use the "ai" alias or a different one. Does anyone know if it is possible to use aliasing this way to selectively call SConscripts based on the alias?
As you mentioned, the Alias() function is only used for targets. I can think of 2 ways to solve this
Alias() can be called multiple times for the same alias with different targets, so you could call it for all targets in each SConscript, then you could build everything in a SConscript. Here's an example of what I mean:
ai/SConscript:
# targets, etc
env.Alias("ai", target1)
env.Alias("ai", target2)
...
env.Alias("ai", targetn)
Another option would be to put some logic in your root SConstruct so it only calls sub-project SConscript's based on a command line argument. This option would require you to use a command line argument of this form: group=ai
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Question
In ninja, I can compile a single C++ file by running ninja path/to/my/object.file.o.
Is there a way to achieve the same in bazel?
Use case / Background
During refactoring, in particular when changing interfaces in .hpp files, I usually want to focus on one single complex user of the interface first. I want to iterate on that one user until my refactoring works as expected on complex_user.cpp and I am happy with the new interfaces. Only afterwards, I want to adjust all other users. I hence want to get the compiler errors / warnings only from my complex_user.cpp file while ignoring all other places where .hpp might be included
Try --save_temps. bazel build --save_temps //my:library will give you the .o, .s, and similar files for only the targets listed on the command line.
--compile_one_dependency is designed for a similar use case, if you want to specify the target to build by the .cpp file instead of specifying a particular cc_library.
You need to implement a custom-made rule cc_object_file. Since the Bazel cc_rules are open source you can use this as a starting point.
I am writing a C++ program using gtkmm as the window library and autotools as my build system. In my Makefile.am, I install the icon as follows:
icondir = $(datadir)/icons/hicolor/scalable/apps
icon_DATA = $(top_srcdir)/appname.svg
EDIT: changed from prefix to datadir
This results in appname.svg being copied to $(datadir)/icons/hicolor/scalable/apps when the program is installed. In my C++ code, I would like to access the icon at runtime for a window decoration:
string iconPath = DATADIR + "/icons/hicolor/scalable/apps/appname.svg";
// do stuff with the icon
I am unsure how to go about obtaining DATADIR for this purpose. I could use relative paths, but then moving the binary would break the icon, which seems evident of hackery. I figure that there should be a special way to handle icons separate from general data, since people can install 3rd party icon packs. So, I have two questions:
What is the standard way of installing and using icons with autotools/C++/gtkmm?
Edit: gtkmm has an IconTheme class that is the standard way to use icons in gtkmm. It appears that I add_resource_path() (for which I still need the installation prefix), and then I can use the library to obtain the icon by name.
What is the general method with autotools/C++ to access the autotools installation prefix?
To convey data determined by configure to your source files, the primary methods available are to write them in a header that your sources #include or to define them as macros on the compiler command line. These are handled most conveniently via the AC_DEFINE Autoconf macro. Under some circumstances, you might also consider converting source files to templates for configure to process, but except inasmuch as Autoconf itself uses an internal version of that technique to build config.h (when that is requested), I wouldn't normally recommend it.
HOWEVER, the installation prefix and other installation directories are special cases. They are not finally set until you actually run make. Even if you set them via the configure's command-line options, you can still override that by specifying different values on the make command line. Thus, it is not safe to rely on AC_DEFINE for this particular purpose, and in fact, doing so may not work at all (will not work for prefix itself).
Instead, you should specify the appropriate macro definition in a command-line option that is evaluated at make time. You can do this for all targets being built by setting the AM_CPPFLAGS variable in your Makefile.am files, as demonstrated in another answer. That particular example sets the specified symbol to be a macro that expands to a C string literal containing the prefix. Alternatively, you could consider defining the whole icon directory as a symbol. If you need it only for one target out of several then you might prefer setting the appropriate onetarget_CPPFLAGS variable.
As an aside, do note that $(prefix)/icons/hicolor/scalable/apps is a nonstandard choice for the installation directory for your icon. That will typically resolve to something like /usr/local/icons/hicolor/scalable/apps. The conventional choice would be $(datadir)/icons/hicolor/scalable/apps, which will resolve to something like /usr/local/share/icons/hicolor/scalable/apps.
In your Makefile.am, use the following
AM_CPPFLAGS = -DPREFIX='"$(prefix)"'
See Defining Directories in autoconf's manual.
I have a project consisting of a set of makefiles that CANNOT be run with make --jobs=N because the dependencies are not specified tightly enough for make to correctly execute the recipes in correct order (ie I get race conditions).
I am currently using Huddle, by Electric-Cloud.com, and it does exactly what I need: it parses the makefile and then executes the jobs in parallel and accounts for the unspecified dependencies.
Question: is there a free or free-er thing that does this?
Yes I know I could re-write the makefiles but project management says "no way".
UPDATE #1
I understand that I'll have to do some work to get functionality similar to Electric-Cloud's functionality.
I know that Electric-Cloud parses the makefile(s) to find the dependencies so wouldn't the same thing be accomplished using makedepend?
I'm thinking:
Run makedepend on existing makefiles
Feed in the output using include <makedepend.output>
make all --jobs=64
UPDATE 2
Turns out makedepend is specific to C/C++: it merely runs the pre-processor on source files and parses any #include statements; not what I need.
I need what this guy is asking for:
Build a makefile dependency / inheritance tree
UPDATE 3
The makefile "dependency graph generator" actually already exists
http://plindenbaum.blogspot.com/2012/11/visualizing-dependencies-of-makefile.html?m=1
but that's not going to help me.
Many of my recipes create directories which are used by other targets' recipes, effectively making them implicit prerequisites.
The graph dependency tool at above URL works by parsing the build log's statements but those statements don't indicate the implicit dependencies.
Even if I try to run my makefile with --dry-run, the build fails because some of the recipes that aren't executed - cause it's a dry run - create directories that other invocations of make need simply to 'pretend execute' a recipe.
UPDATE 4
Electric-Cloud has made Huddle - 4 local cores, non-clustered - free for anyone forever.
Furthermore, they output an .xml file that lists each job's dependencies so I can use it to fix my makefiles compatible so they're compatible with the --jobs option.
I am currently using Huddle, by Electric-Cloud.com, and it does exactly what I need: it parses the makefile and then executes the jobs in parallel and accounts for the unspecified dependencies.
I actually don't know about these tools, but can't you provide them with a super makefile under your control, that clarifies the inner dependencies of the various targets?
You probably just have to add some indirection level for these (imported?) projects directory structure and another Makefile.
I'm still struggling with waf for setting up different set of flags for subprojects.
I have a structure like this, in which superproject recursed to the subprojects:
superproject/wscript
libproject/wscript
progproject/wscript
The problem is that both subprojects progrproject and libproject use boost tool.
I want that both projects check for boost at configuration time, since I want the projects to be self-contained when they are built independently.
I have to do something like this to not overwrite flags for boost between subprojects:
#In libproject
cfg.check_boost('regex', uselib_store='BOOST_LIBPROJECT')
#In progrpoject
cfg.check_boost('program_options', uselib_store='BOOST_PROGPROJECT')
This has the side-effect of making options --boost-libsand --boost-includesdefaults not to work anymore.
Actually, I would like to use the default BOOST store for both, but one seems to overwrite the other in _cache.py file. If I build the projects alone and separate, this problem does not happen. I think setting another environment is not a solution (right?)
since this makes the command to become ./waf build_libproject or similar, which is not what I want.
I want:
./waf configure build
to run correctly without workarounding with different stores or preventive flag name changing.
What is the correct way to do it?
I am converting a project from autotools to waf with the hope that it can be easily compiled in windows as well.
I am using a super project with two children folders that are 2 projects.
One of them is a library, the other, a program, like this:
superproject/wscript
superproject/libraryproject/wscript
superproject/programproject/wscript
It seems that waf has terrible support for subprojects. I have a wscript in each of these directories.
I recurse from superproject into the 2 other projects, but the _cache.py file is shared for both projects. This has the following side effects (issues):
When using the boost tool, I had to use it like this to avoid name collisions:
# In library project
cfg.check_boost('boost_program_options', uselib_store='BOOST_LIBRARYPROJECT')
# In program project
cfg.check_boost('boost_program_options', uselib_store='BOOST_PROGRAMPROJECT')
boost-libs and boost-includes command line options are also lost by default, so I have to set them manually, like this:
cfg.env.LIBPATH_BOOST_PROGRAMPROJECT = cfg.options.boost_libs
...
The _cache.py file is overwritten by the programproject/wscript, loosing all the configuration for the flags.
Questions:
Is there any good way to nest projects and avoid at least issue 2?
Is there any reasonable way to avoid both that doesn't require a script and building projects separately?
Configuration file is not written twice.
My mistake was to do this:
cfg.env = ConfigSet()
I wanted a new and clean ConfigSet but doing that in both projects made the first set of flags to be lost.
Since the environment seems to be shared among all project configurations, is it good style to name the variables with custom names? For example, instead of using:
cfg.check_boost('program_options')
Should I use:
cfg.check_boost('program_options', uselib_store='BOOST_MYPROGRAMPROJECT')
Is this good style or it's usually done in another way?
Can be done in a cleaner way deriving ConfigSets?