Files
scriptc/packages/runtime-pack-common/scripts/build.mjs
T
Malte Ubl dea883ff52 Link the runtime before the program and align runtime code
Linkers lay out code in input order, and executables linked the program
object first, so any change in program size shifted every runtime
function. The vendored archives build at -Os, which drops function
alignment, so the regex interpreter (lre_exec) landed at a different
offset within its cache line after every unrelated edit and swung
template-render by up to 17% and regex-logs by up to 8% on x86-64.

Executable inputs are now runtime objects, runtime archives, the
program object, its partitions, then FFI libraries. Generated code only
references runtime-object symbols, so single-pass GNU ld still resolves
every archive member; when FFI libraries are present, non-Darwin links
list the runtime archives again after them. The native-link-info input
order follows the same plan.

Vendored archives build with -falign-functions=64 on native targets.
On x86-64 the release runtime units do too: generated loops that call
runtime helpers otherwise swing by up to 13% with the program's
position relative to 16-byte-aligned helpers (numeric-kernels). arm64
keeps its runtime units unaligned, where the size cost is higher and
the effect was not measured.

A no-op 32-byte growth of the program object moved the baseline by
+10.8% (template-render, CI +9.3..+12.9%) and is neutral with this
change on every measured workload (Linux, 15 runs).
2026-10-08 15:22:27 -05:00

344 lines
14 KiB
JavaScript

#!/usr/bin/env node
import { execFile } from "node:child_process";
import { createHash } from "node:crypto";
import { availableParallelism, tmpdir } from "node:os";
import { copyFile, mkdir, mkdtemp, readFile, readdir, rm, stat, writeFile } from "node:fs/promises";
import { dirname, join, relative, sep } from "node:path";
import { fileURLToPath } from "node:url";
import { promisify } from "node:util";
import { createRuntimePackMatrix } from "../runtime-pack-matrix.mjs";
import { assertArtifactsExcludeStrings } from "./artifact-policy.mjs";
import { createDeterministicArchive } from "./archive.mjs";
import { installRuntimePack, withBuildLock } from "./build-state.mjs";
import { parallelMap } from "./parallel-map.mjs";
const run = promisify(execFile);
const packageRoot = process.env.SCRIPTC_RUNTIME_PACK_ROOT;
const configText = process.env.SCRIPTC_RUNTIME_PACK_CONFIG;
if (!packageRoot || !configText)
throw new Error("runtime-pack build requires package wrapper configuration");
const config = JSON.parse(configText);
const repoRoot = fileURLToPath(new URL("../../..", import.meta.url));
const runtimeRoot = join(repoRoot, "packages/runtime");
const runtimeSrc = join(runtimeRoot, "src");
const vendorRoot = join(runtimeRoot, "vendor");
const outputRoot = join(packageRoot, "artifacts");
const manifestPath = join(packageRoot, "runtime-pack.json");
const matrix = createRuntimePackMatrix(config);
async function build() {
const buildRoot = join(
packageRoot,
`.runtime-pack-build-${process.pid}-${Math.random().toString(36).slice(2)}`,
);
const stagedOutputRoot = join(buildRoot, "artifacts");
const stagedManifestPath = join(buildRoot, "runtime-pack.json");
const artifactPath = (path) =>
["artifacts", ...relative(stagedOutputRoot, path).split(sep)].join("/");
const sourcePathFlags = [
`-ffile-prefix-map=${buildRoot}=${packageRoot}`,
`-ffile-prefix-map=${repoRoot}=.`,
];
const packageManifest = JSON.parse(await readFile(join(packageRoot, "package.json"), "utf8"));
const compiler = process.env.CC ?? config.compiler ?? "clang";
const compilerArgs = config.compilerArgs ?? [];
const archiver = process.env.AR ?? config.archiver ?? "ar";
const archiverArgs = config.archiverArgs ?? [];
const commonFlags = [
...config.targetArgs,
...(config.compilerFlags ?? []),
"-std=c11",
...(config.threadArgs ?? []),
"-fno-math-errno",
"-fno-strict-aliasing",
...matrix.executable_section_elimination.compile_flags,
"-Wno-deprecated-declarations",
"-I",
runtimeSrc,
...(config.runtimeDefines ?? []).map((define) => `-D${define}`),
];
// Vendored archives build at -Os, which drops function alignment entirely,
// so their hot loops (the regex interpreter's above all) land wherever
// surrounding code puts them and run up to ~15% slower or faster as
// unrelated code changes size. Starting each vendored function on a
// cache-line boundary keeps their placement fixed; it costs size only in
// programs that link the archive. WASM code has no addresses to align.
const codeAlignment = config.platform === "wasi" ? [] : ["-falign-functions=64"];
// On x86-64 the runtime's own functions are aligned as well. Generated
// loops that call runtime helpers otherwise swing by up to ~14% with the
// helpers' offsets within their cache lines (numeric-kernels on Linux),
// and an x86 function already starts on a 16-byte boundary, so the extra
// padding is small. arm64 functions start on 4-byte boundaries, where the
// size cost is higher and the measured effect was not.
const runtimeAlignment = config.target.architecture === "x64" ? codeAlignment : [];
const quickjs = join(vendorRoot, "quickjs-ng");
const zlib = join(vendorRoot, "zlib");
const mbedtls = join(vendorRoot, "mbedtls");
const qjsSources = ["dtoa.c", "libregexp.c", "libunicode.c", "quickjs.c"];
const lreSources = ["libregexp.c", "libunicode.c"];
const zlibSources = [
"adler32.c",
"compress.c",
"crc32.c",
"deflate.c",
"infback.c",
"inffast.c",
"inflate.c",
"inftrees.c",
"trees.c",
"uncompr.c",
"zutil.c",
];
const sha256 = async (path) =>
createHash("sha256")
.update(await readFile(path))
.digest("hex");
const compile = async (source, output, flags) => {
await mkdir(dirname(output), { recursive: true });
// Zig emits DWARF by default even for optimized C. Packaged runtime
// objects omit source debug payload, matching clang's default; the
// compiler owns the program's development debug information.
await run(compiler, [
...compilerArgs,
...sourcePathFlags,
...flags,
"-g0",
"-c",
source,
"-o",
output,
]);
};
const parallel = async (items, task) => {
const width = Math.max(1, Math.min(8, availableParallelism()));
return parallelMap(items, width, task);
};
const archive = async (id, sources, sourceRoot, flags) => {
process.stdout.write(`building ${packageManifest.name} ${id} archive\n`);
const root = join(stagedOutputRoot, "vendor", id);
const objectRoot = join(root, "objects");
await parallel(sources, async (source) =>
compile(join(sourceRoot, source), join(objectRoot, source.replace(/\.c$/, ".o")), flags),
);
const output = join(root, `libscriptc-${id}.a`);
await createDeterministicArchive(
archiver,
output,
sources.map((source) => join(objectRoot, source.replace(/\.c$/, ".o"))),
archiverArgs,
);
await rm(objectRoot, { recursive: true, force: true });
return {
id,
path: artifactPath(output),
sha256: await sha256(output),
size: (await stat(output)).size,
};
};
await rm(buildRoot, { recursive: true, force: true });
try {
await mkdir(stagedOutputRoot, { recursive: true });
// Zig 0.16 creates a zero-byte `a.o` in its working directory for
// `zig cc --version`. Probe from a private temporary directory so a
// runtime-pack build never leaves that compiler byproduct in the package.
const versionProbeRoot = await mkdtemp(join(tmpdir(), "scriptc-runtime-pack-version-"));
let compilerVersion;
try {
compilerVersion = (
await run(compiler, [...compilerArgs, "--version"], {
cwd: versionProbeRoot,
})
).stdout
.split("\n", 1)[0]
.trim();
} finally {
await rm(versionProbeRoot, { recursive: true, force: true });
}
const flavors = {};
for (const [flavor, flavorSpec] of Object.entries(matrix.flavors)) {
process.stdout.write(`building ${packageManifest.name} ${flavor} runtime\n`);
// Zig emits DWARF by default, including descriptions of functions
// removed by section GC. Release packs must opt out explicitly.
const debugFlags = flavor.endsWith("release") ? ["-g0", ...runtimeAlignment] : [];
const units = await parallel(
flavorSpec.runtime_units ?? matrix.runtime_units,
async (unit) => {
const variants = [];
for (const baseVariant of unit.variants) {
const variant = {
...baseVariant,
defines: [...(flavorSpec.defines ?? []), ...baseVariant.defines],
};
const output = join(
stagedOutputRoot,
flavor,
"runtime",
variant.id,
unit.source.replace(/\.c$/, ".o"),
);
const includeFlags = [
...(unit.source === "scr_regex.c" || variant.defines.includes("SCR_DYNAMIC")
? ["-I", quickjs]
: []),
...(unit.source === "scr_tls.c" ? ["-I", join(mbedtls, "include")] : []),
...(unit.source === "scr_zlib.c" || unit.source === "scr_fetch.c"
? ["-I", zlib]
: []),
];
await compile(join(runtimeSrc, unit.source), output, [
...commonFlags,
flavorSpec.optimization,
...debugFlags,
...variant.defines.map((define) => `-D${define}`),
...includeFlags,
]);
variants.push({
id: variant.id,
when: variant.when,
defines: variant.defines,
path: artifactPath(output),
sha256: await sha256(output),
size: (await stat(output)).size,
});
}
return { source: unit.source, predicate: unit.predicate, variants };
},
);
flavors[flavor] = { optimization: flavorSpec.optimization, runtime_units: units };
}
const mbedtlsSources = (await readdir(join(mbedtls, "library")))
.filter((name) => !name.startsWith(".") && name.endsWith(".c"))
.sort();
// Vendored QuickJS reads `clock_gettime` for its monotonic clock. WASI
// exposes that declaration only when its process-clock emulation ABI is
// selected, so vendor sources inherit the target's runtime defines too.
const vendorTarget = [
...config.targetArgs,
...(config.compilerFlags ?? []),
"-g0",
...codeAlignment,
...(config.runtimeDefines ?? []).map((define) => `-D${define}`),
];
const requestedArchives = new Set(matrix.archives.map((entry) => entry.id));
const archives =
config.vendorArchives === false
? []
: [
...(requestedArchives.has("quickjs")
? [
await archive("quickjs", qjsSources, quickjs, [
...vendorTarget,
"-std=gnu11",
"-fvisibility=hidden",
"-funsigned-char",
"-DQUICKJS_NG_BUILD",
"-D_GNU_SOURCE",
"-DNDEBUG",
"-Os",
"-I",
quickjs,
]),
]
: []),
...(requestedArchives.has("libregexp")
? [
await archive("libregexp", lreSources, quickjs, [
...vendorTarget,
"-std=c11",
"-Os",
"-I",
quickjs,
]),
]
: []),
...(requestedArchives.has("zlib")
? [
await archive("zlib", zlibSources, zlib, [
...vendorTarget,
"-std=c11",
"-Os",
"-I",
zlib,
]),
]
: []),
...(requestedArchives.has("mbedtls")
? [
await archive("mbedtls", mbedtlsSources, join(mbedtls, "library"), [
...vendorTarget,
"-std=c11",
"-Os",
"-I",
join(mbedtls, "include"),
"-I",
join(mbedtls, "library"),
]),
]
: []),
];
await assertArtifactsExcludeStrings(stagedOutputRoot, config.forbiddenArtifactStrings ?? []);
const archiveSpecs = new Map(matrix.archives.map((entry) => [entry.id, entry]));
const licensed = [
[join(runtimeRoot, "LICENSE"), "artifacts/licenses/scriptc-runtime.txt", "Apache-2.0"],
[join(quickjs, "LICENSE"), "artifacts/licenses/quickjs-ng.txt", "MIT"],
[join(vendorRoot, "ryu", "LICENSE-Boost"), "artifacts/licenses/ryu.txt", "BSL-1.0"],
[
join(vendorRoot, "v8-number-radix", "LICENSE"),
"artifacts/licenses/v8-number-radix.txt",
"BSD-3-Clause",
],
[join(zlib, "LICENSE"), "artifacts/licenses/zlib.txt", "Zlib"],
[join(mbedtls, "LICENSE"), "artifacts/licenses/mbedtls.txt", "Apache-2.0"],
];
licensed.push([
join(vendorRoot, "unicode", "LICENSE"),
"artifacts/licenses/unicode.txt",
"Unicode-3.0",
]);
await Promise.all(
licensed.map(async ([source, destination]) => {
const output = join(buildRoot, destination);
await mkdir(dirname(output), { recursive: true });
await copyFile(source, output);
}),
);
const manifest = {
schema: "scriptc.runtime-pack.v1",
format: 1,
package: packageManifest.name,
version: packageManifest.version,
target: matrix.target,
runtime_abi: { version: 8, marker: "scr_runtime_abi_v8" },
compiler: { command: compiler, identity: compilerVersion, target: matrix.target.llvm_triple },
macros: {
executable: ["SCR_DYNAMIC", "SCR_TEXT_DECODER_LEGACY"],
excluded: ["SCR_RC_AUDIT", "SCR_ASAN_FIBERS"],
sanitizer: "external-toolchain-required",
},
flavors,
archives: archives.map((entry) => ({
...entry,
predicate: archiveSpecs.get(entry.id).predicate,
})),
system_libraries: matrix.system_libraries,
licenses: licensed.map(([, path, license]) => ({ path, license })),
};
await writeFile(stagedManifestPath, `${JSON.stringify(manifest, null, 2)}\n`);
const suffix = `${process.pid}-${Math.random().toString(36).slice(2)}`;
await installRuntimePack({
outputRoot,
manifestPath,
stagedOutputRoot,
stagedManifestPath,
backupRoot: join(packageRoot, `.runtime-pack-artifacts-backup-${suffix}`),
backupManifestPath: join(packageRoot, `.runtime-pack-manifest-backup-${suffix}`),
});
process.stdout.write(
`built ${packageManifest.name}@${packageManifest.version}: ${Object.keys(flavors).length} flavors, ${archives.length} vendor archives\n`,
);
} finally {
await rm(buildRoot, { recursive: true, force: true });
}
}
await withBuildLock(join(packageRoot, ".runtime-pack-build.lock"), build);