-
Notifications
You must be signed in to change notification settings - Fork 6k
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
organize snapshot/BUILD.gn targets and fix create_arm_gen_snapshot #28345
organize snapshot/BUILD.gn targets and fix create_arm_gen_snapshot #28345
Conversation
In GN, if the target has the same name as the directory it's in, then the target name can be omitted when depending on it, so instead of depending on |
@zanderso Thanks for the explanation! |
When performing artifact lookups for Artifact.genSnapshot, a TargetPlatform is used to determine the name of the tool, typically `gen_snapshot_$TARGET_ARCH`. Formerly, this tool was always named `gen_snapshot`. The astute reader may ask "but Chris, didn't we support TWO target architectures on iOS and therefore need TWO gen_snapshot binaries?" Yes, we did support both armv7 and arm64 target architectures on iOS. No, we didn't have two gen_snapshot binaries. At the time, the bitness of the gen_snapshot tool needed to match the bitness of the target architecture. As such we did *build* two gen_snapshots: * A 32-bit x86 binary that emitted armv7 AOT code * A 64-bit x64 binary that emitted arm64 AOT code However, to avoid having to do a lot of work plumbing through suffixed gen_snapshot names, the author of that work elected to "cleverly" lipo the two together into a single multi-architecture macOS binary. See: flutter/engine#4948 This was later remediated over the course of several patches, including: See: flutter#37445 See: flutter/engine#10430 See: flutter/engine#22818 However, there were still cases (notably --local-engine workflows in the tool) where we weren't computing the target platform and thus referenced the generic gen_snapshot tool. See: flutter#38933 Fixed in: flutter/engine#28345 The test removed in this PR, which ensured that null SnapshotType.platform was supported was introduced in flutter#11924 as a followup to flutter#11820 when the snapshotting logic was originally extracted to the `GenSnapshot` class. Since there are no longer any cases where TargetPlatform isn't passed when looking up Artifacts.genSnapshot, we can safely make the platform non-nullable and remove the test. This is pre-factoring towrards the removal of the generic gen_snapshot artifact, which is pre-factoring towards the goal of building gen_snapshot binaries with an arm64 host architecture, and eliminate the need to use Rosetta during iOS and macOS Flutter builds. Issue: flutter#101138 Issue: flutter#103386
When performing artifact lookups for `Artifact.genSnapshot` for macOS desktop builds, a `TargetPlatform` is used to determine the name of the tool, typically `gen_snapshot_$TARGET_ARCH`. Formerly, this tool was always named `gen_snapshot`. The astute reader may ask "but Chris, didn't we support TWO target architectures on iOS and therefore need TWO `gen_snapshot` binaries?" Yes, we did support both armv7 and arm64 target architectures on iOS. But no, we didn't initially have two `gen_snapshot` binaries. We did *build* two `gen_snapshots`: * A 32-bit x86 binary that emitted armv7 AOT code * A 64-bit x64 binary that emitted arm64 AOT code At the time, the bitness of the `gen_snapshot` tool needed to match the bitness of the target architecture, and to avoid having to do a lot of work plumbing through suffixed `gen_snapshot` names, the author of that work (who, as evidenced by this patch, is still paying for his code crimes) elected to "cleverly" lipo the two together into a single multi-architecture macOS binary still named `gen_snapshot`. See: flutter/engine#4948 This was later remediated over the course of several patches, including: * flutter/engine#10430 * flutter/engine#22818 * #37445 However, there were still cases (notably `--local-engine` workflows in the tool) where we weren't computing the target platform and thus referenced the generic `gen_snapshot` tool. See: #38933 Fixed in: flutter/engine#28345 The test removed in this PR, which ensured that null `SnapshotType.platform` was supported was introduced in #11924 as a followup to #11820 when the snapshotting logic was originally extracted to the `GenSnapshot` class, and most invocations still passed a null target platform. Since there are no longer any cases where `TargetPlatform` isn't passed when looking up `Artifact.genSnapshot`, we can safely make the platform non-nullable and remove the test. This is pre-factoring towards the removal of the generic `gen_snapshot` artifact from the macOS host binaries (which are currently unused since we never pass a null `TargetPlatform`), which is pre-factoring towards the goal of building `gen_snapshot` binaries with an arm64 host architecture, and eliminate the need to use Rosetta during iOS and macOS Flutter builds. Part of: #101138 Umbrella issue: #103386 Umbrella issue: #69157 No new tests since the behaviour is enforced by the compiler.
When performing artifact lookups for `Artifact.genSnapshot` for macOS desktop builds, a `TargetPlatform` is used to determine the name of the tool, typically `gen_snapshot_$TARGET_ARCH`. Formerly, this tool was always named `gen_snapshot`. The astute reader may ask "but Chris, didn't we support TWO target architectures on iOS and therefore need TWO `gen_snapshot` binaries?" Yes, we did support both armv7 and arm64 target architectures on iOS. But no, we didn't initially have two `gen_snapshot` binaries. We did *build* two `gen_snapshots`: * A 32-bit x86 binary that emitted armv7 AOT code * A 64-bit x64 binary that emitted arm64 AOT code At the time, the bitness of the `gen_snapshot` tool needed to match the bitness of the target architecture, and to avoid having to do a lot of work plumbing through suffixed `gen_snapshot` names, the author of that work (who, as evidenced by this patch, is still paying for his code crimes) elected to "cleverly" lipo the two together into a single multi-architecture macOS binary still named `gen_snapshot`. See: flutter/engine#4948 This was later remediated over the course of several patches, including: * flutter/engine#10430 * flutter/engine#22818 * flutter#37445 However, there were still cases (notably `--local-engine` workflows in the tool) where we weren't computing the target platform and thus referenced the generic `gen_snapshot` tool. See: flutter#38933 Fixed in: flutter/engine#28345 The test removed in this PR, which ensured that null `SnapshotType.platform` was supported was introduced in flutter#11924 as a followup to flutter#11820 when the snapshotting logic was originally extracted to the `GenSnapshot` class, and most invocations still passed a null target platform. Since there are no longer any cases where `TargetPlatform` isn't passed when looking up `Artifact.genSnapshot`, we can safely make the platform non-nullable and remove the test. This is pre-factoring towards the removal of the generic `gen_snapshot` artifact from the macOS host binaries (which are currently unused since we never pass a null `TargetPlatform`), which is pre-factoring towards the goal of building `gen_snapshot` binaries with an arm64 host architecture, and eliminate the need to use Rosetta during iOS and macOS Flutter builds. Part of: flutter#101138 Umbrella issue: flutter#103386 Umbrella issue: flutter#69157 No new tests since the behaviour is enforced by the compiler.
create_arm_gen_snapshot
into this new group target.This also fixes flutter/flutter#38933
The current code has
create_arm_gen_snapshot
insidesource_set("snapshot")
, which doesn't seem to be run at all.I couldn't find any deps to
source_set("snapshot")
in the code base. Maybe we should just removesource_set("snapshot")
? @zandersoPre-launch Checklist
writing and running engine tests.
///
).If you need help, consider asking for advice on the #hackers-new channel on Discord.