Integrate bazel resource_sets into the build actions

[novas0x2a]

This is an attempt to make parallelization of builds safer by telling bazel what resources an action will consume. By default, Bazel allocates 1 CPU and 250M of RAM, and this makes the current methods of parallelization (i.e. --action_env=CMAKE_BUILD_PARALLEL_LEVEL=16) pretty unpleasant, since bazel won't know and will happily schedule 160 cores worth of actions on a 10-core machine.

This is currently up to get early feedback; some things that are missing are:

• Tests
• Docs
• env priority ordering (i.e. make sure local overrides global)
• meson / autotools
• Also depends on feat: expand the usefulness of resource_sets bazel-lib#1235 merging and being released.

Related to #329

A description of the intended workflow here is:

• target owners add resource_size=tiny|small|medium|large|enormous as they see fit.
  • these sizes map to default cpu/ram allocations (see code) which affect both the resource_set and the underlying build system's parallelization controls (e.g. CMAKE_BUILD_PARALLEL_LEVEL)
• Someone running a build can:
  • override the defaults for what (e.g.) "large" means to either fit within a smaller machine or allow taking advantage of a larger one, by setting new values for @rules_foreign_cc//foreign_cc/settings:size_$size_(cpu|mem)
  • override the global default for targets without resource_size keys with @rules_foreign_cc//foreign_cc/settings:size_default

Currently, changing the values of these settings does invalidate the cache.

[Copilot]

Pull request overview

This PR integrates Bazel resource_sets into build actions to enable safer parallelization. By specifying resource consumption, Bazel can properly schedule builds instead of over-scheduling when build systems use parallel compilation (e.g., CMAKE_BUILD_PARALLEL_LEVEL).

Changes:

• Adds new resource_sets module that defines size classes (tiny/small/medium/large/enormous) with CPU and memory allocations
• Updates framework.bzl and built_tools_framework.bzl to set resource_set and environment variables for parallel builds
• Adds bazel_lib dependency (with temporary archive_override) for resource_set_for function
• Updates dependency versions for platforms, bazel_features, bazel_skylib, rules_cc, rules_shell, and aspect_rules_lint

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
foreign_cc/private/resource_sets.bzl	New module defining size classes, settings creation, and resource set computation logic
foreign_cc/settings/BUILD.bazel	New file that creates build settings for resource size configuration
foreign_cc/private/framework.bzl	Integrates SIZE_ATTRIBUTES and sets resource_set/env vars for cc_external_rule actions
foreign_cc/built_tools/private/built_tools_framework.bzl	Integrates SIZE_ATTRIBUTES and sets resource_set/env vars for built tool actions
toolchains/private/BUILD.bazel	Example usage: sets cmake_tool to "medium" resource size
foreign_cc/repositories.bzl	Adds bazel_lib dependency and updates versions for platforms, bazel_features, bazel_skylib, rules_cc, rules_shell
MODULE.bazel	Updates dependency versions and adds temporary archive_override for bazel_lib pending upstream PR
WORKSPACE.bazel	Updates aspect_rules_lint and switches from aspect_bazel_lib to bazel_lib

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[Copilot]

Pull request overview

Copilot reviewed 11 out of 12 changed files in this pull request and generated 5 comments.

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[Copilot]

The documentation string could be improved for clarity. Consider adding line breaks or formatting to make the two main points more distinct. The reference to settings labels at the end could also be more specific about how to use them.

Suggested change

	"Set the approximate size of this build. This does two things:" +
	"1. Sets the environment variables to tell the underlying build system " +
	" the requested parallelization; examples are CMAKE_BUILD_PARALLEL_LEVEL " +
	" for cmake or MAKEFLAGS for autotools. " +
	"2. Sets the resource_set attribute on the action to tell bazel how many cores " +
	" are being used, so it schedules appropriately." +
	"The sizes map to labels, which can be used to override the meaning of the sizes. See " +
	"@rules_foreign_cc//foreign_cc/settings:size_{size}_{cpu|mem}"
	"Set the approximate size of this build. This does two things:\n\n"
	"1. Sets environment variables to tell the underlying build system the\n"
	" requested level of parallelism; examples are CMAKE_BUILD_PARALLEL_LEVEL\n"
	" for CMake or MAKEFLAGS for autotools.\n"
	"2. Sets the resource_set attribute on the action to tell Bazel how many\n"
	" cores and how much memory are being used, so it can schedule\n"
	" appropriately.\n\n"
	"Each size value maps to build-setting labels that control the CPU and\n"
	"memory assigned to that size. You can override the meaning of a size by\n"
	"changing the values of the labels\n"
	"@rules_foreign_cc//foreign_cc/settings:size_<size>_cpu and\n"
	"@rules_foreign_cc//foreign_cc/settings:size_<size>_mem."

[Copilot]

Only the cmake_tool has resource_size set to "medium" while other built tools (make_tool on line 23, ninja_tool on line 86, meson_tool on line 113, and pkgconfig_tool on line 159) don't have resource_size specified. For consistency and to fully realize the benefits of this feature, consider whether these other build tools should also have appropriate resource_size values set. For example, building make, ninja, or pkgconfig from source could also benefit from resource allocation hints.