Bazel macro example Overriding repositories from the command line. Tests should be in a matching Send feedback Macros Stay organized with collections Save and categorize content based on your preferences. java_proto_library, java_lite_proto_library and cc_proto_library are rules For example, if a macro-defined target is not visible to its own package or to the finalizer macro's definition, and is not delegated to the finalizer, the finalizer cannot see such a target. When built, the rule generates some configuration and runs Sphinx to produce an HTML site, ready for manual inspection. Load visibility Report an issue open_in_new View source open_in_new Nightly · 8. General. See general comments about deps at Typical attributes defined by most build rules. 0 License, and code samples are licensed under the Apache 2. java"]), deps = [; The name of the library should be the name of the directory containing the BUILD file. Supported OS identifiers are linux, macos, windows, freebsd, and openbsd. proto files that are already linked into proto runtimes, such as any. Then: the macro which generates the test and target under test should should be named _test_foo (_test_provider_contents) its test rule type should be named foo_test (provider_contents_test) the label of the target of this rule type should be foo_test (provider_contents_test) For an example, consider rules_k8s, the Kubernetes rules for Bazel. h: %. Defining. command_line Report an issue open_in_new View source open_in_new Nightly · 8. h. This is used for . Members For example, you may want to generate or preprocess a source file, or compress a binary. proto_library is a language-agnostic rule that describes relations between . The WORKSPACE file is already disabled in Bazel 8 (late 2024) and will be removed in Bazel 9 (late 2025). If you need to know the package name (for example, which BUILD file is calling the macro), use the function native. Example bazel test invocation for Go tests. Resources. Macros don’t give additional power, they are just used for encapsulation and code reuse. 6 7. cpp source files (inputs). 4. Starlark is a language that defines how software is built, and as such it is both a programming and a configuration language. Luckily, there is a Bazel extension for building Rust projects: rules_rust. Configurable attributes, commonly known as select(), is a Bazel feature that lets users toggle the values of build rule attributes at the command line. Attributes Represents a configuration transition across a dependency edge. Aliasing may be of help in large repositories (Example. As above, but with a Bazel currently provides rules for Java, JavaLite and C++. Even though there aren’t any Go sources to build in the root directory, let’s write a Bazel Rules: Macros. Before learning the more advanced concepts, first: For example, target G is normally built with copts = []. allowlist_different_package: Label; default is None. Gazelle generates Bazel BUILD files, so that I don’t have to write them all myself, and updates the Bazel files after changes are done to Go source files. Examples for Bazel bazel. Let’s suppose you need to run a tool as part of your build. * Bazel also supports the Sky Query engine which automatically kicks in with a specific set of options used with query. The sources should be a non-recursive glob of all Java files in the directory. For example, if //package:foo depends on //package:bar with a configuration transition, then the configuration of these two targets will differ: //package:bar's transition will be determined by that of //package:foo, as subject to the function defined by a transition object. Buildifier makes a distinction between a standalone comment and a comment attached to an element. The API will become more stable when the Python rules are moved out of Report an issue open_in_new View source open_in_new Nightly 8. Additional query reference This mechanism can also be used to join diamonds. cpp file to include #define to enable this macro. generate the API whenever mymessage. Enabling this flag is equivalent to using --config=linux on Linux, --config=windows on Windows, etc. Overview Rules Symbolic macros Legacy macros Depsets Aspects Repository rules Example rules Distributing rules Share your custom rules to your project or the Bazel community. Docker images can be generated with different rules. 4 A context object that is passed to the implementation function for a rule or aspect. h, which in turn is allowed to include baz-impl. Due to the shortcomings of WORKSPACE, Bzlmod is replacing the legacy WORKSPACE system. The generated files are listed in the outs attribute of the rule. For example, if I have the following BUILD file: java_library (name = "directory-name", srcs = glob (["*. Label resolution in macros. Recommended rules. blacklisted_protos: List of labels; default is []. package_relative_label(), converts the input into a Label in the context of the package currently being constructed. Macros also help with the reuse of code and are converted to concrete Bazel rules. The implementation function should then call Configurable build attributes. 1 Report an issue open_in_new View source open_in_new Nightly · 8. This function may only be called while evaluating a BUILD file and the macros it directly or indirectly calls; it Report an issue open_in_new View source open_in_new Nightly · 8. cc: %. A label is a unique identifier that points to a The inclusion checking rules only apply to direct inclusions. In this tutorial, you are Currently i need to change my . package_name(). To override a declared repository with a local repository from the command line, use the --override_repository flag. I would like to extend the bundle macro to accept a list of bundles in addition to a list of components and package all of the components directly-included or included in one of its included bundles. The Bazel ecosystem has a growing and evolving set of rules to support popular languages and packages. Rules give you more A collection of examples of how to use the Bazel build system. You can get help by Report an issue open_in_new View source open_in_new Nightly · 8. Converts the input string into a Label object, in the context of the package currently being initialized (that is, the BUILD file for which the current macro is executing). For example, a C++ binary rule might: Take a set of . 5 7. bzl files are written in a dialect of Starlark properly known as the "Build Language", though it is often simply referred to as "Starlark", alias(name, actual, compatible_with, deprecation, features, package_metadata, restricted_to, tags, target_compatible_with, testonly, visibility)The alias rule creates another name a rule can be referred to as. build/start point to code in this repository: Macros are special StarkLark functions used exclusively in the loading phase that we can use to make rules more convenient for users. Converts a label string into a Label object, in the context of the package where the calling . A configuration transition maps the transformation from one configured target to another within the build graph. If you use an incoming-edge transition, you can put a For example, consider rules_k8s, the Kubernetes rules for Bazel. Configurable attributes, commonly known as select(), is a Bazel feature that lets users toggle the values of BUILD rule attributes at the command line. If you need to support older Bazel versions take a look at Creating a Legacy Macro. Setting up a WORKSPACE. For example, //foo/bar specifies the package having that name and which lives in the same repository as the package group. For the authoritative specification Report an issue open_in_new View source open_in_new Nightly · 8. This page covers the basics of using macros and includes typical use cases, debugging, and conventions. 3) For module extension repos: module_name~version~extension_name~repo_name (Example. For a complete list of functions and types, see the Bazel API reference. This guide helps you migrate your project to Bzlmod and A macro that instantiates a build rule converting a DSLX source file to an IR file. This makes the label of the library shorter, that is use "//package" instead of "//package:package". Invoking this value during package construction time will instantiate the macro, and cause the macro's implementation function to be evaluated (in a separate context, different from the Calls to rules and macros. With the launch of Bazel 8. Technically, the compilation of a . For practical use cases, see the Bazel Query How-To. Skip to content. Important: Transitions have memory and performance impact. Rules give Report an issue open_in_new View source open_in_new Nightly · 8. Macros are defined in . In this tutorial, you are going to create a legacy macro that resizes an image. If your priority is results that match a specific bazel invocation’s flags and fancy output formats aren’t too important to you, then cquery is the better choice. For a language details and --output flag details, please see the reference manuals, Bazel query reference and Bazel cquery reference. Intro # Bazel’s evaluation model includes three phases: As a contrived but simple example, let’s create a macro that will provide a reasonable default for the name of the output file. If the input is already a Label, it is returned unchanged. proto files. All such macros are either defined in or re-exported from //infra-sk/index. This page covers basic style guidelines for Starlark and also includes information on macros and rules. rs scripts, automatically converting Cargo dependencies to Bazel and a lot more. Much of Bazel's strength comes from the ability to define new rules that can be used by others. Bazel's BUILD and . For example, bundling the application with rules_webpack Example of using Bazel to cross compile a library that depends on a procedural macro - wildarch/bazel_proc_macro_example Some of these examples are explained also in the presentation Introduction to Bazel to build C++ and Python. Symbolic macros are available by default in Bazel 8. e. proto changes) using Bazel? Using Labels to Identify and Build Specific Targets. Here is a selection of recommended rules: Android; C For example, if the host OS is Linux and you run bazel build, Bazel picks up lines starting with build:linux. 6 · 7. This can be used to subtract a set of targets from the set specified by the preceding Bazel is a powerful yet complicated system, and it can be intimidating to newcomers. 4 7. Starlark is a Python-like configuration language originally developed for use in Bazel and since adopted by other tools. 0 License. While this attribute is currently optional, it will become required when the Python rules are moved out of Bazel itself. This section uses the terms macro and rule interchangeably when referring Report an issue open_in_new View source open_in_new Nightly · 8. In the example above foo. For example, foo/bar/wiz is equivalent to //foo/bar:wiz (if there is a package foo/bar) or to //foo:bar/wiz (if there is a package foo). Introductory tutorials Some tutorials under https://bazel. It supports handling Rust toolchains, building Rust libraries, binaries and proc_macro crates, running build. Use a load statement to import a symbol from an extension. In addition to specifying the correct version of Rust, Bazel also uses labels to identify and build specific targets within the project. A rule defines a series of actions that Bazel performs on inputs to produce a set of outputs, which are referenced in providers returned by the rule's implementation function. In particular, package_group and test_suite cannot be aliased. Is there a way that i can provide this alongwith bazel build command ? One option would be to Creating a macro. . query, by contrast, runs over the results of Bazel's loading phase, Understand concepts like rules and macros to extend Bazel's capabilities. While the Bazel user guide and user manual preach the benefits of giving Bazel full control over your build process by rewriting all Some things to keep in mind when writing genrules: A genrule needs to know all its input files and output files (srcs and outs attributes)It needs to know the tools it's going to use in the command (exec_tools attribute). Bazel 5 deprecation. Report an issue open_in_new View source open_in_new Nightly · 8. 4 Macros; Depsets; Aspects; Repository rules; Configuring; Platforms; Toolchains; Execution groups; 8. If you want to do anything more complicated, for example add support for a new programming language, consider creating a rule. In GNU make, I would do (simplified example): %. List of examples: Bazel with third party dependencies; Basic C++ example; Basic code coverage computation for C++; Basic Python example; Bazel Macros: Generate cpp files using Python; Explicitly declare autodetected C++ toolchain when Attributes; name: Name; required. 2 A callable Starlark value representing a symbolic macro; in other words, the return value of macro(). Check out the documentation on macros for more details. The macro also instantiates the 'enable_generated_file_wrapper' function. This can be used, for example, for a multiplatform library that automatically chooses the appropriate implementation for the def my_macro (name, visibility = None): native. package_relative_label(input). Use that function to Contribute to SamB/bazel-examples development by creating an account on GitHub. It achieves this by running over the results of Bazel's analysis phase, which integrates these effects. ; Run g++ on the 0x01 背景 上篇中已经介绍了bazel的基本工作原理和相关的概念。这篇将继续介绍下，现有的makefile构建工程如何切换到bazel构建系统。 bazel提供了丰富的扩展方式，当然也支持从目前的makefile过渡到bazel构建。 再次说明下其特性： 多语言支持，并且支持扩展到任何语 For example, you may want to generate or preprocess a source file, or compress a binary. 1 · 8. For example if A and B had the same dependency but call it by different names, those dependencies can be joined in myproject/WORKSPACE. For example, consider rules_k8s, the Kubernetes rules for Bazel. No code will be generated for files in the srcs attribute of blacklisted_protos. build. It also describes the output formats bazel query supports. bzl source file lives. Save and categorize content based on your preferences. Rules give you more Under the hood the tools will be the same as Angular Architect but now coordinated by Bazel. bzl files, and not in BUILD files. This page describes the recommended, native, and non-native Bazel rules. So, if your priority is speed and over-approximation of results isn’t a problem, query is your engine. The distinction is important when doing automated changes (for example, to keep or remove a comment when deleting a rule). proto. The implementation function is similar to a WORKSPACE macro, except that it gets a module_ctx object, which grants access to the dependency graph and all pertinent tags. Usage. @bazel_skylib~1. For macros, a related function, native. 3 · 7. In this tutorial, we are For example, you may want to generate or preprocess a source file, or compress a binary. Report an issue open_in_new View source open_in_new Nightly 8. You can do things like taking in the attributes you care about and creating the rule ( bazel_rule in your example) within the macro, so that the macro has the attribute value, but this Label Label(input). existing_rules()-based legacy macro will also be unable to see such a target. By A collection of examples of how to use the Bazel build system. Label native. 0, we're announcing the upcoming deprecation Report an issue open_in_new View source open_in_new Nightly · 8. Suppose we have the following target: In this example, a “docs” target is created, just as though the macro were a standard, single Bazel rule. 2. 0 · 7. $< How can I accomplish the same (i. This can be used, for example, for a multiplatform library that automatically chooses the appropriate implementation for the For example, you may want to generate or preprocess a source file, or compress a binary. Or, you can swap out some of the tools, essentially making your own custom, incremental build system for Angular just with a few lines of Bazel's macros. cc file may transitively include any header file in the hdrs or srcs in any cc_library in the transitive deps closure. However, an Symbolic macros are available by default in Bazel 8. This can be used, for example, for a multiplatform library that automatically chooses the appropriate implementation for the architecture, or for a feature-configurable binary that can be customized The default visibility of the top-level rule targets and symbolic macros in this package — that is, the targets and symbolic macros that are not themselves declared inside a symbolic macro. These can be used, Attributes; name: Name; required. Bazel extensions are files ending in . If a comment is not attached to a specific element, use an empty line after it. It provides access to the information and methods needed to analyze the current target. Use; Predefined variables; Predefined genrule variables; Predefined source/output path variables; Custom variables "Make" variables are a special class of expandable string variables available to attributes marked as "Subject to 'Make variable' substitution". Bazel 更倾向于将主代码库中的软件包放在工作区根目录下。 此选项用于指定用于搜索给定软件包的 BUILD 文件的一组目录。 Bazel 会通过搜索软件包路径来查找软件包。这是一个以英文冒号分隔的 Bazel 目录有序列表，每个目录都是部分源代码树的根目录。 IMPORTANT: This tutorial is for symbolic macros – the new macro system introduced in Bazel 8. For . Macros are suitable Macros Macro creation. For example, if //package:foo depends on //package:bar with a configuration transition, then the configuration of //package:bar (and its dependencies) will be //package:foo's configuration plus the changes Report an issue open_in_new View source open_in_new Nightly · 8. cc_library (name = name, srcs = ["main. 0 7. An executable example of symbolic macros can be found in the examples repository. cc %. When built, the rule generates some configuration and runs Sphinx to produce an HTML site, ready for manual inspection Macros, for example, can't change their behavior based on the chosen branch, and bazel query can only make conservative guesses about a target's configurable dependencies. A macro is a function called from the BUILD file that can instantiate rules. 0. This page describes how to extend the BUILD language using macros and rules. This page is an overview of Starlark, formerly known as Skylark, the language used in Bazel. As a contrived but simple example, let’s 上一节讨论了对外部仓库的依赖。本节将对 Bazel 的规则展开讨论，并以尝试创建自定义规则。相关概念宏 (Macros) 与规则 (Rules)宏：实例化规则的函数。当我们需要在 BUILD 文件中重复使用一些功能时可以定义宏。规 A macro can't read attributes of a target (roughly, macros are evaluated at build file loading time, and attributes are evaluated later at analysis time). 0 6. Aliasing only works for "regular" targets. deps: List of labels; default is []. cc"], visibility = visibility,). Macros are suitable for simple tasks. See this FAQ for more on using select() with rules and macros. For example, you may want to generate or preprocess a source file, or compress a binary. For details, see the Google Developers Site Policies . These tools can be other things that need to be built, like binary targets (cc_binary, java_binary, sh_binary, py_binary, etc), or they can be pre-compiled I'm using Bazel and Google's protocol buffers. Readme About Bazel Getting started User guide Reference Extending Community Versioned docs 8. Example: An IR conversion with a top entity The first line of the WORKSPACE file gives the project a name, and the rest loads the dependencies on rules_go and Gazelle. The macro instantiates a rule that converts a DSLX source file to an IR file. In this tutorial, you are going to create a symbolic macro that resizes an image. h, which may include baz. Our front-end code is built and tested using a set of custom Bazel macros built on top of rules provided by the rules_js and rules_ts rulesets. Note, however, that a native. The exact variable names expanded is an unstable API and is subject to change. In this tutorial, you are going to create a macro that resizes an image. However, an Report an issue open_in_new View source open_in_new Nightly · 8. However, an config_setting (name = "my_config", flag_values = {"//example:favorite_flavor": "MANGO"}) User-defined transitions. 5 5. This attribute should be used to list other sh_library rules that provide interpreted program source code depended on For example, a JUnit test method would be named testFoo. You can use an outgoing-edge user-defined transition as detailed in Brian's answer, but one thing to note is that if the test target is built / run on its own (as a top-level target explicitly, or captured by a target pattern like //, //:all, //:*, or if a target depends on it directly), then it won't get the configuration transition. I want to add a Bazel rule so I can generate the C++ API from the . 2021-12-30 • edited 2022-01-06. If the given value is already a Label, it is returned unchanged. Rules give you more For example, you may want to generate or preprocess a source file, or compress a binary. If target P depends on target G, and I run bazel build :P, I want both targets to be built with copts = You might want to create macros to bundle the wrapper rules along with the corresponding cc_library. Attributes Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4. 4 · 7. Imagine that you need to run a tool as part of your build. The list of "library" targets to be aggregated into this target. Since legacy macros are Report an issue open_in_new View source open_in_new Nightly · 8. In particular, it lets the implementation function access the current target's label, attributes, For example, consider rules_k8s, the Kubernetes rules for Bazel. In this Report an issue open_in_new View source open_in_new Nightly · 8. Note that native can only be used in . cquery is a variant of query that correctly handles select() and build options' effects on the build graph. Some Imagine that you need to run a tool as part of your build. A unique name for this target. Suppose you have the following target: In this example, a "docs" target is created, just as though the macro were a standard, single Bazel rule. Navigation Menu Example cookbook. Macros are mainly used for encapsulation and code reuse of existing rules and other macros. bzl files by calling the macro() function with two required parameters: attrs and implementation. This page is the reference manual for the Bazel Query Language used when you use bazel query to analyze build dependencies. Many Bazel commands accept a list of target patterns as arguments, and they all honor the prefix negation operator -. proto protoc --cpp_out=. . Rules give you more For example, consider rules_k8s, the Kubernetes rules for Bazel. Represents a configuration transition across a dependency edge. For example, docker builds are easier to accomplish . Using bzlmod; How to generate source code from a rule and include it in a library; [Macro writing] Using Symbolic Macros; CI: About. In this case the compiler may read Let’s see what it will take to build and test this workspace with Bazel. Where this document mentions macros, it's referring to symbolic macros. Transitions define configuration changes between rules. cc is allowed to include bar. bzl. 5 · 7. This can be used, for example, for a multiplatform library that automatically chooses the appropriate implementation for the I have two macros/targets: component and bundle (which packages several components). You will use Starlark to write BUILD files, macros, For example, their arguments are typed like rule attributes, and the author decides which attributes permit select()s based on whether the macro needs to examine that value or pass it through. This page covers how to get started using Bazel's query language to trace dependencies in your code. For more information about the language, see Starlark's GitHub repo. In this tutorial, you are going to create a symbolic macro that resizes an image. zaavqntu mkqhe uryr ecqte eesrn lsx slyv nncvgu viq gvyxibt ucben grhdk wnpwr qiyo tahjz