I have C++ header file dependencies that I specify in my waf script with the includes=... parameter to bld.program().
I know the waf build configuration sees the includes because my program compiles correctly.
However, when I change a header file, waf does not detect the change. That is, when I run waf build after changing the contents of an included header, nothing gets recompiled.
Isn't waf supposed to determine #include "..." dependencies automatically?
How can I troubleshoot this?
I have looked in the build/c4che directory to see if I could make sense of the configuration files stored there. Mention of "include" in the waf generated .py files is suspiciously absent.
I am using waf version 1.9.0.
I have also tried this with waf 1.8.19 and got the same result.
EDIT: I replaced my original complicated wscript with the much simpler one listed below, and I still get the same behavior.
Here is my wscript:
top = '.'
out = 'build'
CXXFLAGS = ['-fopenmp', '-Wall', '-Werror', '-std=c++11', '-Wl,--no-as-needed']
def options(ctx):
ctx.load('compiler_cxx')
def configure(ctx):
ctx.load('compiler_cxx')
ctx.env.CXXFLAGS = CXXFLAGS
def build(ctx):
ctx.program(source="test_config_parser.cpp", target="test_config_parser", includes=["../include"], lib=['pthread', 'gomp'])
Your problem is that you use includes out of the project's directory. By default waf does not use external includes as dependencies (like system includes) to speed up things. Solutions I know of :
1/
Organize your project to have your include directory under the waf top directory :
top_dir/
wscript
include/
myinclude.h
sources/
mysource.cpp
2/
Change top directory. I think top = .. should work (not tested).
3/
Tell waf to go absolute by adding this lines at the beginning of build():
waflib.Tools.c_preproc.go_absolute=True
waflib.Tools.c_preproc.standard_includes=[]
4/
Use gcc dependencies by loading the gccdeps waf module.
Solution 1/ is probably the best.
By the way I prefer to have my build directory out of the source tree. Use out = ../build in your wscript, if you want to build out of the source tree.
my2c
Related
please take a look at the bin-win target in my repository here:
https://github.com/thinlizzy/bazelexample/blob/master/demo/BUILD#L28
it seems to be properly packing the executable inside a file named bin-win.tar.gz, but I still have some questions:
1- in my machine, the file is being generated at this directory:
C:\Users\John\AppData\Local\Temp_bazel_John\aS4O8v3V\execroot__main__\bazel-out\x64_windows-fastbuild\bin\demo
which makes finding the tar.gz file a cumbersome task.
The question is how can I make my bin-win target to move the file from there to a "better location"? (perhaps defined by an environment variable or a cmd line parameter/flag)
2- how can I include more files with my executable? My actual use case is I want to supply data files and some DLLs together with the executable. Should I use a filegroup() rule and refer its name in the "srcs" attribute as well?
2a- for the DLLs, is there a way to make a filegroup() rule to interpret environment variables? (e.g: the directories of the DLLs)
Thanks!
Look for the bazel-bin and bazel-genfiles directories in your workspace. These are actually junctions (directory symlinks) that Bazel updates after every build. If you bazel build //:demo, you can access its output as bazel-bin\demo.
(a) You can also set TMP and TEMP in your environment to point to e.g. c:\tmp. Bazel will pick those up instead of C:\Users\John\AppData\Local\Temp, so the full path for the output directory (that bazel-bin points to) will be c:\tmp\aS4O8v3V\execroot\__main__\bazel-out\x64_windows-fastbuild\bin.
(b) Or you can pass the --output_user_root startup flag, e.g. bazel--output_user_root=c:\tmp build //:demo. That will have the same effect as (a).
There's currently no way to get rid of the _bazel_John\aS4O8v3V\execroot part of the path.
Yes, I think you need to put those files in pkg_tar.srcs. Whether you use a filegroup() rule is irrelevant; filegroup just lets you group files together, so you can refer to the group by name, which is useful when you need to refer to the same files in multiple rules.
2.a. I don't think so.
Problem
I wonder how to inform bazel about dependencies unknown at declaration time, but known at build time (a.k.a implicit dependencies, dynamic dependencies, ...). For instance when compiling C++ sources, the .cpp source file will depends on some header files and this information is not available when writing the BUILD file. It needs to be retrieve at build time. Whatever is the solution to get the information (dry-run, generating depfile, parsing stdout), it needs to be done at build time and the information need to be retrieved to bazel build graph.
Since skylark does not allow to do I/O, for instance to read a generated depfile or to parse stdout result containing a dependency list, I have no clue on how to deal with it.
Behind implicit dependencies, I am looking for correct incremental build.
Example
To experiment this problem I have created a simple tool, just_a_tool.exe which takes an input file, read a list of file from it, and concatenate the content of all these file to an output file.
command line example:
just_a_tool.exe --input input.txt --depfile dep.d output.txt
dep.d contains the list of all the read files.
Issue
If I change the content of test1.txt, test2.txt, or test3.txt, bazel does not rebuild output.txt file. Of course, because it does not know there were dependencies.
Example files
just_a_tool.bzl
def _impl(ctx):
exec_path = "C:/Code/JustATool/just_a_tool.exe"
for f in ctx.attr.source.files:
source_path = f.path
output_path = ctx.outputs.out.path
dep_file = ctx.actions.declare_file("dep.d")
args = ["--input", source_path, "--dep_file", dep_file.path, output_path]
ctx.actions.run(
outputs=[ctx.outputs.out, dep_file],
executable=exec_path,
inputs=ctx.attr.source.files,
arguments=args
)
jat_convert = rule(
implementation = _impl,
attrs = {
"source" : attr.label(mandatory=True, allow_files=True, single_file=True)
},
outputs = {"out": "%{name}.txt"}
)
BUILD
load("//tool:just_a_tool.bzl", "jat_convert")
jat_convert(
name="my_output",
source=":input.txt"
)
input.txt
test1.txt
test2.txt
test3.txt
Goal
I want to do correct and fast incremental build for the following situation:
Generate reflection data from C++ sources, this custom tool execution depends on header file included in my source files.
Use a internal tool to build asset file which can include other files
Run a custom preprocessor on my shaders allowing a #include feature
Thanks!
Bazel's extension language doesn't support creating actions with a dynamic set of inputs, where this set depends on the output of a previous action. In other words, custom rules cannot run an action, read the action's output, then create actions with those inputs or update (or prune the set of) inputs of already created actions.
Instead I suggest adding attribute(s) to your rule where the user can declare the set of files that the sources may include. I call this "the universe of headers". The actions you create depend on this user-defined universe, so the set of action inputs is completely defined. Of course this means these actions potentially depend on more files than the cpp files, which they process, include.
This approach is analogous to how the cc_* rules work: a file in cc_*.srcs can include other files in the srcs of the same rule and from hdrs of dependencies, but nothing else. Thus the union of srcs + hdrs of (direct & transitive) dependencies defines the universe of header files that a cpp file may include.
Context
I am writing a repository rule that invokes another Bazel project. My current approach is to build the additional project as a deploy jar. I would like a user to be able to instantiate the rule like:
jar_path = some/relative/path
my_rule(name = "something", p_arg="m_arg", binary=jar_path)
and then given the jar_path and the arguments, I would like the repository rule to execute the following command in the shell:
java -jar $(SOME_JAR) $(ARGUMENTS_PROVIDED_BY_RULE)
Problem
First, it's unclear how best to accomplish the deploy jar approach. So far, I have attempt two different approaches, with varying levels of success. For examples, I have skimmed through the scala_rules, the maven_rules, and the skylark cookbook.
Second, and more importantly, I am not sure whether the deploy jar is the best route to accomplishing my goals. Again, my interest is to invoke a target from an external Bazel project, that is currently hosted on github. (So feasibly, I could try to fetch the project using the http_archive rule).
Below, I describe the attempts I have made.
Approach 1
My first approach involved trying to execute the command using the command field in ctx.action. I tried various enumerations of
java -jar {computed_absolute_path_of_deploy_jar} {args_passed_from_instantiation}.
My biggest issue here was with determining the absolute path of the deploy jar. The file's root path, would contain some additional information. For example, it would like something like this.
/abs/olute/path[ something ]/rela/tive/path
As a side note, I'm not sure if this is a bug/nit, but the File.root.path, evaluated to None, despite File.none not being None.
My first approach involved was to was to try to use skylark [ctx.binary]
Approach 2
Next thing I tried was to mimic the input binary example from the docs. This was also unsuccessful. The issue was that the actual binary could not be found. Here is how I configured it.
First, I relaxed the repository rule into a regular skylark rule.
def _test_binary(ctx):
ctx.action(
....
arguments = [ctx.attr.p_arg],
executable = ctx.executable.binary)
test_binary = rule(
...
attrs = {
"binary":attr.label(mandatory=True, cfg="host", allow_files=True, executable=True),
...
}
Then, in my external project, I loaded the skylark rule into the WORKSPACE file. Finally, I called the macro from one of my BUILD files as follows:
load("#something_rule//:something_rule.bzl", "test_binary")
test_binary(name = "hello", p_arg = "hello", binary = "script.sh")
The script is a one line java -jar something_deploy.jar -- -arg:$1, and is in the same directory as the BUILD file.
Bazel complains that src/script.sh does not exist. I presume because it is looking for the file in /private/var/tmp/-bazel_username/somehash/relative_path. In response, I tried to pass the absolute path, which is not allowed.
Cheers.
It looks like you're mixing up repository rules with build extensions ("normal" rules). A good rule of thumb is:
Repository rules are for getting sources onto your system or symlinking them to a place Bazel can see them.
Build extension are for everything else: compiling, copying files, running binaries, etc.
I don't actually think you need to use either, for this. You say that the other project is on GitHub, so you can add the following to your WORKSPACE file:
http_archive(
name = "other_project",
...
)
Then, in your BUILD file:
genrule(
name = "run-a-jar",
srcs = ["#other_project//some/relative:path"],
cmd = "java -jar $(location #other_project//some/relative:path) -- arg1 arg2 > $#",
outs = ["jar-output"],
)
You shouldn't need to use the _deploy.jar target, since you're not moving the jar out of its project (_deploy.jar is useful when you need to relocate it).
Other things from your question:
I'm not sure if this is a bug/nit, but the File.root.path, evaluated to None,
Are you sure it didn't evaluate to ""? The path is relative to the execution root, so for sources, it will always be "" (for outputs, it'll be bazel-out/local-fastbuild/bin or similar).
Bazel complains that src/script.sh does not exist.
Passing -s to Bazel can really help debugging Skylark rules. You can see exactly where it is looking.
I've got an iOS framework that has a dependency on the (presumably Google maintained) pod called '!ProtoCompiler'. In order to build my framework I'm going to need it in the sandbox. So, I have a genrule and can try to include it with
src = glob(['Pods/!ProtoCompiler/**/*']) but I get the following error:
ERROR: BUILD:2:1: //Foo:framework-debug: invalid label 'Pods/!ProtoCompiler/google/protobuf/any.proto' in element 1118 of attribute 'srcs' in 'genrule' rule: invalid target name 'Pods/!ProtoCompiler/google/protobuf/any.proto': target names may not contain '!'.
As is, this seems like a total blocker for me using bazel to do this build. I don't have the ability to rename the pod directory as far as I can tell. As far as I can tell, the ! prohibition is supposed to be for target labels, is there any way I can specify that this is just a file, not a label? Or are those two concepts completely melded in bazel?
(Also, if I get this to work I'm worried about the fact that this produces a .framework directory and it seems like rules are expected to produces files only. Maybe I'll zip it up and then unzip it as part of the build of the test harness.)
As far as I can tell, the ! prohibition is supposed to be for target
labels, is there any way I can specify that this is just a file, not a
label? Or are those two concepts completely melded in bazel?
They are mostly molded.
Bazel associates a label with all source files in a package that appear in BUILD files, so that you can write srcs=["foo.cc", "//bar:baz.cc"] in a build rule and it'll work regardless of foo.cc and baz.cc being a source file, a generated file, or a build rule's name that produces files suitable for this particular srcs attribute.
That said you can of course have any file in the package, but if the name won't allow Bazel to derive a label from it, then you can't reference them in the BUILD file. Since glob is evaluated during loading and is expanded to a list of labels, using glob won't work around this limitation.
(...) it seems like rules are expected to produces files only. Maybe
I'll zip it up and then unzip it as part of the build of the test
harness.
Yes, that's the usual approach.
currently I'm trying to port a million-sloc legacy project from dull .cmd scripts to SCons. Parts of it are VC++, others are Delphi. Creating SConscripts for the C++ pieces was a breeze.
To build the delphi part I've written a very simple builder which detects whether it is a program or library project. Calling the builder after chaining via SConscript makes scons to call dcc32 $subdir/project.dpr what misleads dcc32 to look for units in the current directory instead of the $subdir.
Is there a way to tell scons to enter the $subdir before executing commands residing in the sconscript or should I fix it within the builder?
Thank you in advance
SCons already changes to the directory of sub-directory SConscripts when reading them, so it looks like the problem is going to have to be fixed in the actual builder.
Once the scripts are parsed, and SCons is running the build commands, it stays in the top-level directory. Commands are then issued using path names relative to that top-level directory. The way to change this behavior is to use the chdir keyword in your Builder.
The example from the scons man page is as follows:
b = Builder(action='build < ${SOURCE.file} > ${TARGET.file}',
chdir=1)
env = Environment(BUILDERS = {'MyBuild' : b})
env.MyBuild('sub/dir/foo.out', 'sub/dir/foo.in')
You need to specify the .file component as the use of chdir does not change the names passed to the builder, i.e. they are still relative to the top-level directory.