#!/usr/bin/env bash
# Build the core crate for wazero. No wasm-bindgen, no wasm-pack: the Go host
# provides no JS glue, so the module must be plain wasm32 with a C ABI.
set -euo pipefail
cd "$(dirname "$0")/.."
# Lint before building: disallowed-methods (clippy.toml) enforces the
# Doc-construction rule documented in core/src/lib.rs — Doc::new() and
# Doc::with_client_id() both draw entropy this build has no safe source
# for. A doc comment alone has been wrong, or gotten around, more than
# once; this is the actual enforcement.
cargo clippy --manifest-path core/Cargo.toml --all-targets -- -D warnings -D clippy::disallowed_methods
# --lib only: the wasm module shipped to wazero is the library crate. Any
# native tooling this crate ever grows under src/bin would not be part of
# that artifact and would not define the __getrandom_v03_custom symbol
# itself, so building it for wasm32 would fail to link -- it isn't meant to
# run there.
#
# --remap-path-prefix (x2): rustc embeds the absolute source path of every
# panic site (Location::caller()) into the binary. Left alone, that means
# the registry path of every dependency (which contains $HOME, so it
# leaks a username) and this worktree's own absolute path end up baked
# into slides_core.wasm -- so the artifact only reproduces byte-for-byte on
# the machine, and under the $HOME, that built it. The gate's `cmp`
# against the committed copy then fails everywhere else and misreports
# a stale artifact instead of a non-reproducible build. Remapping both
# roots to fixed placeholders makes the build's output independent of
# where it ran.
#
# Setting RUSTFLAGS here does not merge with .cargo/config.toml's
# target.wasm32-unknown-unknown.rustflags -- an env RUSTFLAGS replaces a
# config-file rustflags for the same target outright, it does not append
# to it. That config entry (--cfg getrandom_backend="custom") is what
# routes getrandom to our no-JS-import backend on wasm32; dropping it
# breaks the build (getrandom falls back to a backend wasm32-unknown-
# unknown doesn't support) rather than just losing the cfg silently. So
# it has to be repeated here alongside the remap flags.
registry_root="${CARGO_HOME:-$HOME/.cargo}/registry/src"
workspace_root="$(pwd)"
export RUSTFLAGS="--cfg getrandom_backend=\"custom\" --remap-path-prefix=${registry_root}=/cargo-registry-src --remap-path-prefix=${workspace_root}=/slides-core"
cargo build --release --manifest-path core/Cargo.toml --target wasm32-unknown-unknown --locked --lib
out="core/target/wasm32-unknown-unknown/release/slides_core.wasm"
[ -f "$out" ] || { echo "build-wasm: no artifact at $out" >&2; exit 1; }
echo "$out ($(wc -c < "$out") bytes)"