feat: add 2-pass release build for Dynamic Dispatch table#119
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bdero wants to merge 9 commits intoshorebird/devfrom
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feat: add 2-pass release build for Dynamic Dispatch table#119bdero wants to merge 9 commits intoshorebird/devfrom
bdero wants to merge 9 commits intoshorebird/devfrom
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When building for arm64 Apple platforms with the linker enabled, run gen_snapshot twice: first in ELF mode to produce a temporary snapshot for analyze_snapshot to compute the DD table manifest, caller links, and slot mapping, then in assembly mode with --dd_slot_mapping to produce the final snapshot with indirect calls wired up. The DD table files (App.dd.link, App.dd_callers.link) are copied into the shorebird supplement directory alongside the existing link files so they can be bundled with releases and used during patch builds.
The 2-pass DD table build runs gen_snapshot in ELF mode before the main assembly pass. Update tests to expect this additional command.
The arm64 DD analysis pass delays the arm64 assembly, so x86_64 (which skips DD) completes its build first when both run concurrently via Future.wait.
Move the analyze_snapshot existence check before the gen_snapshot ELF pass so the entire DD computation is a no-op on standard Flutter SDKs that don't ship analyze_snapshot. This fixes iOS smoke test failures where gen_snapshot was being invoked unnecessarily in ELF mode. Also reverts test changes that are no longer needed since DD commands won't appear when analyze_snapshot doesn't exist in the test filesystem.
The arm64 build's async _computeDDTable() check (even a no-op when analyze_snapshot is absent) introduces an await that lets x86_64 reach gen_snapshot first in Future.wait. Reorder test expectations to match the actual interleaving: x86_64 before arm64 at each step.
The DD slot mapping now uses kernel_offset-based function matching (instead of function names). The base build must export an identity side file during gen_snapshot pass 1 and pass it to analyze_snapshot --compute_dd_slot_mapping. Without this, the DDSlotMapping has empty kernel_offset_to_slot and FinalizeIndirectStaticCallTable can't assign any DD slots, resulting in an empty DD table in the base snapshot.
Read SHOREBIRD_DD_MAX_BYTES from the environment to allow overriding the cascade limiter threshold. Defaults to 10000 if not set. An environment variable is used (rather than a command-line flag) so that older Flutter builds without DD table support silently ignore it.
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Updates dart_sdk_revision to include SIMARM64 simulator fixes (DoRedirectedCall, ClobberVolatileRegisters, Execute reason param) needed for ios_debug engine builds.
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The GN action for building the Rust updater via cargo declared only a stamp file as output. The library path referenced by libs[] was in the source tree, so Ninja couldn't map it to any build rule — causing "missing and no known rule to make it" for targets where the pre-built library didn't already exist (e.g. host_debug on macOS). Fix: the build_rust_updater.py script now copies the cargo-built library from the source tree to target_gen_dir, which is declared as an action output. This lets Ninja properly order the link step after the cargo build.
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Summary
analyze_snapshotto compute DD table manifest, caller links, and slot mapping--print_dd_function_identity_to) mapping each Code object's InstructionsTable index to its Function'skernel_offset, which is passed toanalyze_snapshot --compute_dd_slot_mappingvia--dd_function_identityfor kernel_offset-based function matching--dd_slot_mappingApp.dd.link,App.dd_callers.link) are copied into the supplement directory alongside existing link filesTest plan