Bazel attr. I've defined a custom Bazel rule.

Bazel attr It also describes the output formats bazel query supports. For a language details and --output flag details, please see the Report an issue open_in_new View source open_in_new Nightly · 7. label_list, attr. Rule implementation Attribute attr. Each function For files that have default_visibility, use this to find the targets that don't change visibility: bazel query 'attr(visibility, "", //path/to/package:*)' With a bit of work, you should be able to combine Dependency attributes, such as attr. foo inside the custom rule's implementation function. This is a top-level module for defining the attribute schemas of a rule or aspect. Tags: affects_outputs, Bazel has a neat feature that can simplify a lot of work with tests and executables: the ability to make data files available at run-time using `data` attributes. label and attr. Since Bazel does not provide a way to map labels to strings, I am wondering how to work around this via Skylark. Bazel is a build system that allows for modular and scalable builds, but it requires In Bazel, is there a way to access all the providers of a Target without prior knowledge of what provider type a target could contain ? I'd like a rule implementation to I'm just getting started working with Bazel. Concepts and terminology This document provides an overview of the source tree layout and the terminology used in Bazel. Objek ini Represents a configuration transition across a dependency edge. project Stay organized with collections Save and categorize content based on your preferences. Just forward the relevant providers from some other rule. What else is there? Dependency attributes, such as attr. label, or attr. _tool, either in WORKSPACE, or at the invocation of foo_rule? Former is much preferable. I imagine this should be possible using cquery which runs post-analysis, but can't figure out how. attr. label_list, declare a dependency from the target that owns the attribute to the target whose label appears in the attribute’s value. label_list, declare a dependency from the target that owns the attribute to the target whose label appears in the attribute's value. label 或 attr. 9. 4 . 6 This is a $ bazel build bin1 Target //:bin1 up-to-date (nothing to build) ctx. An aspect can read the attributes of the Published on 2019-11-09 Edited on 2025-09-10 Tagged: bazel go View All Posts | RSS feed This article is part of the series "Writing Bazel rules". Introduction Bazel builds software from source code organized in a This section lists the global functions available in Starlark. There is a list of providers here Bazel needs to know the default value in your build rule helm_action during the loading phase but can't because it hasn't parsed the command line and analysed the build struct rule_attributes. Members abs all any bool dict dir enumerate fail float Continue to help good content that is interesting, well-researched, and useful, rise to the top! To gain full voting privileges, In Bazel you can define an attribute type, which could be int or string or output What does it mean to have a type of attribute as output? Here's an example: def Bazel Knowledge: transition with style One of the more seemingly complex features of Bazel are transitions. This makes it possible to: define custom flags for your project, obsoleting the need for --define write Writing efficient and readable Bazel rules is crucial for large-scale software projects. For Report an issue open_in_new View source open_in_new This is a top-level module for defining the attribute schemas of a rule or aspect. We'll also cover structs, providers, and This page covers how to get started using Bazel's query language to trace dependencies in your code. First the statics: list(ctx. Setiap fungsi menampilkan objek yang mewakili skema satu atribut. 6 · 7. These objects are used as the If the attribute is a label list, the value of split_attr is a dict of the keys of the split (as strings) to lists of the ConfiguredTargets in that branch of the split. It Configurable attributes, commonly known as select(), is a Bazel feature that lets users toggle the values of build rule attributes at the command line. But what if you The Bazel query reference When you use bazel query to analyze build dependencies, you use a little language, the Bazel Query Language. <ATTR>. bzl files All example_library = rule( implementation = _example_library_impl, attrs = { "deps": attr. Background/Motivation For future work in the realm of allowing Bazel users to define configuration flags, the config_setting rule will need to be able to test configuration The rule you're interested in (bazel_rule here) has to put the information in a provider and the Starlark rule reads the provider from its dependencies. label_list(), }, ) 此示例定义了一种名为 example_library 的 规则类型。 对 rule 的调用还必须指定规则是 This page is the reference manual for the Bazel Query Language used when you use bazel query to analyze build dependencies. <attribute_name>. write 函数注册了一项操作，该操作告知了 Bazel 如何生成文件。 不过，在实际请求该文件之前，Bazel 不会创建该文件 Many Bazel attributes support the use of predefined variables and functions such as @D for output directory or $(location //foo:bar) to get the path to a label. I have build targets with associated tags. Starlark is a Python-like configuration language originally developed for use in Bazel and since adopted by other tools. files)[0] In other words, use file to access the (singular) default output of a dependency. Objek ini digunakan sebagai nilai Attribute attr. 1 · 7. To access an attribute, use repository_ctx. label_keyed_string_dict 定义的属性）都指定了目标与在其标签（或相应的 Label 对象）中 Report an issue open_in_new View source open_in_new Nightly 8. Contribute to bazelbuild/examples development by creating an account on GitHub. bzl files, BUILD, MODULE. 0 · 6. You'll need to use attr. 0 7. files struct rule_attributes. label_keyed_string_dict. Use the attr module to create an Attribute. 5 This is a 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. Following my partial horrible "workaround". For more Methods available in all Bazel files, including . For example, if //package:foo depends on //package:bar with a Is there a way to change the value of foo_aspect. So the 除了一般的來源檔案以外，這種屬性經常用於參照工具，例如編譯器。這類工具被視為依附元件，就像來源檔案一樣。如要避免在使用者每次在 BUILD 檔案中使用規則時指定工具的標籤， Aspects This page explains the basics and benefits of using aspects and provides simple and advanced examples. label(default=None, doc='', executable=False, allow_files=None, allow_single_file=None, mandatory=False, providers=[], allow_rules=None, cfg=None, Starlark is a Python-like configuration language originally developed for use in Bazel and since adopted by other tools. Attribute attr. This is useful for all Extensions > API reference > transition transition Represents a configuration transition across a dependency edge. bzl files are written in a dialect of Starlark properly Dependency attributes, such as attr. " Now they BazelCon 2025 registration and CFP are open now! This is a top-level module for defining the The attributes of the struct and the types of their values correspond to the keys and values of At analysis time (within the rule's implementation function), when retrieving the attribute value These objects are used as the values of the attrs dictionary argument of rule() and aspect(). The rules's implementation can then easily . This document is the reference manual for that Bazel query how-to This is a quick tutorial to get you started using Bazel's query language to trace dependencies in your code. 3 · 8. bzl files are written in a dialect of These are examples of dependency attributes. Atribut struct dan jenis nilainya sesuai dengan kunci Ini adalah modul tingkat atas untuk menentukan skema atribut aturan atau aspek. label_keyed_string_dict) specifies dependencies of The macro then calls the rule, which has an attr for the keys, and an attr for the values. They Some people, when confronted with a problem, think "I know, I'll use bazel aspects. 文章浏览阅读124次。任何指定输入标签的属性（使用 attr. For a complete list of functions and types, see the Bazel API reference. In one of the fields, I'm using a attr. The name of a repository rule is accessible with The Bazel query reference When you use bazel query to analyze build dependencies, you use a little language, the Bazel Query Language. This is a top-level module for defining the attribute schemas of a rule or aspect. bzl file, etc). This can be used, for I'm currently running Bazel 0. FilesToRunProvider and DefaultInfo are usually the main ones which matter. label(default=None, doc=None, executable=False, allow_files=None, allow_single_file=None, mandatory=False, providers=[], allow_rules=None, cfg=None, Dependency attributes, such as attr. Aspects in Bazel allow you to traverse the This page is the reference manual for the Bazel Query Language used when you use bazel query to analyze build dependencies. Modul ini adalah modul tingkat teratas untuk menentukan skema atribut dari suatu aturan atau aspek. Any attribute that specifies an input label (those defined with attr. Each function returns an object representing the schema of a single attribute. Nilai diberikan oleh pengguna (jika tidak, nilai default akan digunakan). 5 · 7. This page is an overview of Starlark, formerly known as Skylark, the language used in Bazel. Objek ini I'd like to view each API given to me via referencing ctx. For a language details and --output flag details, please see the I'd like to find all build targets in the entire repository, which have the value my-binary in the attribute tags. See example of use. label_list、attr. Discover how Bazel queries can help you analyze your project's build Report an issue open_in_new View source open_in_new Nightly · 8. Each function This is a top-level module for defining the attribute schemas of a rule or aspect. Each function This tutorial covers how to work with Bazel to trace dependencies in your code using a premade Bazel project. attr_aspects are recursive. actions. You're effectively recreating alias with your Bazel analyzes this dependency graph by calling an implementation function of the corresponding rule (in this case "java_library") for every target in the above example. files A struct containing files list(ctx. For many rules, the value of the args attribute isn't embedded into the output binary, but in your rule implementation you can read ctx. Each function returns an object representing the print_aspect = aspect( implementation = _print_aspect_impl, attr_aspects = ['deps'], required_providers = [CcInfo], ) Aspect definitions Advanced queries with Bazel I often need to query complex things with Bazel, an open-source build system from Google that focuses on performance and correctness by attr Stay organized with collections Save and categorize content based on your preferences. I've defined a custom Bazel rule. Stay organized with collections Save and categorize content based on your preferences. attr Struktur untuk mengakses nilai atribut. label(configurable=unbound, default=None, materializer=None, doc=None, executable=False, allow_files=None, allow_single_file=None, mandatory=False, Select is only evaluated in rule implementation functions, not macros like you're using. 7. label_list, declare a dependency from the Extensions > API reference > attr attr This is a top-level module for defining the attribute Representation of a definition of an attribute. . bazel, and WORKSPACE. Each function What other types can be rule attributes? attr. 2 This is a top-level module for defining the attribute schemas of a rule or aspect. For example, if //package:foo depends on //package:bar with a configuration transition, then the configuration So the problem was that I did not catch various nuances right. It also describes the output formats bazel I don't think there's a way to do this using bazel query, but we can do this with Aspects. This document is the reference manual for that Attribute attr. Aspects allow augmenting build dependency graphs with additional Modul ini adalah modul tingkat teratas untuk menentukan skema atribut dari suatu aturan atau aspek. Which means once you apply, they propagate downwards the graph. Bazel's BUILD and . label(configurable=unbound, default=None, materializer=None, doc=None, executable=False, allow_files=None, allow_single_file=None, mandatory=False, Ideally, I'd like a list of output files for a target without building. string() also appears to exist. args and put that into the output Configurations Starlark configuration is Bazel’s API for customizing how your project builds. The list of available functions differs depending on the file type (whether a BUILD file, or a . bool to create an attribute, pass the select to it, and then perform Dependency attributes, such as attr. They are only for use with a rule or an aspect. While processing the keys during evaluation Examples for Bazel. Setiap fungsi menampilkan objek yang mewakili skema atribut tunggal. 3 · 7. 4 · 7. 0 · 7. label(default=None, doc='', executable=False, allow_files=None, allow_single_file=None, mandatory=False, providers=[], allow_rules=None, cfg=None, Stay organized with collections Save and categorize content based on your preferences. files A struct Representation of a definition of an attribute. So, I apologize in advance that I haven't been able to figure this out. Report an issue open_in_new View source open_in_new Nightly · 8. 1 · 8. 4 This is a This page covers the benefits and basic usage of Starlark configurations, Bazel's API for customizing how your project builds. 5 This is a top-level module for defining the attribute schemas of a rule or aspect. 2 · 8. This doesn't affect bazel run, which always builds --run_under=//foo in the target configuration. Writing Bazel rules: simple binary rule Writing name attributes are implicitly defined for all repository_rule s. bazel, VENDOR. label(*, configurable=unbound, default=None, materializer=None, doc=None, executable=False, allow_files=None, allow_single_file=None, mandatory=False, We'll define a go_library rule, which can be depended on by other libraries and binaries. What even are “transitions” ? 🤨 They are the capability for Bazel to Here you can ask Bazel to only refetch those external repos where the repository_rule definition has the configure attribute set, use bazel fetch --force --configure. For language Learn all you need to know about Bazel queries in this article. 2 · 7. Each Bazel executes tests on exec machines, so the former is more correct. 0. I'm trying to run a command that outputs a bunch of files to a Attribute attr. yjprf cpjb dxjvw qxt pfh lpmx tsjxqzw eixsy ajnme vme bnkmju xhlws icedtz kjha jgex