Bazel external include path bazel file into manageable sections, particularly for monorepos: The root module can use the include directive to split its MODULE. bazel files, include cannot be used in non-root modules. The following optional features can improve the hygiene of a C++ project. . h is in a different package (//include). At this stage, the source archives of the dependencies are not fetched yet; so if the MODULE. Follow these guidelines for include paths: Make all include paths relative to the workspace directory. This page contains resources that help you use Bazel with C++ projects. Working with Bazel. e. Jun 13, 2018 · Bazel requires that C++ build rules declare all header files that the sources depend on. If you'd like the repo rule or module extension to be sensitive to the path's existence, use the watch() method on the context object. Jul 2, 2022 · The absolute path to this folder; The path of the symlink used to access this folder from the workspace root. bazel file into multiple segments. It links to a tutorial, build rules, and other information specific to building C++ projects with Bazel. Note that accessing this field does not cause the path to be watched. Returns true if the file or directory denoted by this path exists. Apr 14, 2025 · Report an issue open_in_new View source open_in_new Nightly · 8. External dependencies are all downloaded to a directory under the subdirectory external in Oct 9, 2015 · What Austin said is correct. (parent directory). The issue here is, the external library is dynamic and we can not modify it. g. Dec 21, 2017 · In the case that the offending #include <> is inside a generated (i. / in the include path). To force a re-download, use bazel sync. Bzlmod is the codename of the new external dependency system introduced in Bazel 5. Apr 14, 2025 · During dependency resolution, the MODULE. directory /path/to C at version 1. Bazel can depend on targets from other projects. Avoid using UNIX directory shortcuts, such as . (current directory) or . C++ and Bazel. 6 · 7. we have a requirement to have "-Wconditional-uninitialized" flag to give a warning if some variable is initialized based on some condition which is absolutely fine. This yields two problems: The integrator has to search the whole library for the build information. 2 to build the app. In your WORKSPACE file define a new_local_repository with the path attribute set to /usr/local and the build_file pointing to a BUILD file local to the workspace, for example: Apr 14, 2025 · bool path. h) and STL (e. Toolchain features. You cannot directly include include/build. Do you have any suggestions? By default, Bazel will only re-download external dependencies if their definition changes. Apr 14, 2025 · Splitting up a very large MODULE. build Aug 2, 2024 · The problem here is, that I am not able to define the header paths adequately in the BUILD file of the external library. 0 · 7. exists. 0. h. h because build. Use quoted includes (#include "foo/bar/baz. Layout. Only exceptions are the "default" header files, such as POSIX system headers (e. I think that (2) follows this pattern: bazel-my-project/external. bazel file load s another file, there is no way for Bazel to actually fetch that file without fetching the entire source archive. The following resources will help you work with Bazel on C++ projects: Tutorial: Building a C++ project; C++ common use cases; C/C++ rules Apr 14, 2025 · Report an issue open_in_new View source open_in_new Nightly · 8. And bazel has no chances to recognize errors with the used -I copt flags. get_child. , patches or BUILD files) are also taken into account by bazel. 5. stdio. For the same reason we don't allow load s in MODULE. 0 and another include C at 2. Sometimes you cannot (or do not want to) root include paths at the workspace root. See full list on bazel. 2 · 8. So, is there any way by which I can avoid the external warnings popping up in my build and being treated as errors? Adding include paths. bazel file of all referenced external dependencies are fetched from registries. I want my code to be modular, so I am trying to avoid #include statements with relative or long absolute paths. David Apr 14, 2025 · For legacy or third_party code that requires includes pointing outside the project repository, such as external repository includes requiring a prefix, use the include_prefix and strip_include_prefix arguments on the cc_library rule target. via genrule) header, and the include path is relative to the root of the workspace, then this technique doesn't seem to be possible (would require . Here you will find some of the most common use cases for building C++ projects with Bazel. bazel rc content is like this: build --features=external_include_paths build --repo_env=BAZEL_CXXOPTS Working with external dependencies. For example, suppose you have the following directory structure: Nov 9, 2021 · I'm struggling to understand the logic of how includes work in Bazel targets. Caching Nov 18, 2019 · As a workaround you could add a cc_library for a new_local_repository that wraps a view on /usr/local. 1 · 8. Existing libraries might already have an include directory that doesn't match its path in your workspace. <iostream>) -- they are needed so frequently that Bazel doesn't require you to declare them. How can I get these paths from the Bazel CLI? Mar 10, 2022 · Now, when I try to include the external library's header file, the build is failing as that header file is containing the warnings. Changes to files referenced in the definition (e. Jul 13, 2022 · i have a c++ application and i am using clang + Bazel 5. h") for non-system headers, not angle-brackets (#include <foo/bar/baz. Suppose I Apr 14, 2025 · Include paths. You would need to add a include/BUILD and add a cc_library target that //a and //b can depend on in order to use build. h>). knaud mkc kecdwz lqrks jlnw ygyui jptugk iylr kvkir dlycajx uhvw qjq xgwlgf myyxt omrydg