build: speed up startup with V8 code cache

This patch speeds up the startup time and reduce the startup memory
footprint by using V8 code cache when comiling builtin modules.

The current approach is demonstrated in the `with-code-cache`
Makefile target (no corresponding Windows target at the moment).

1. Build the binary normally (`src/node_code_cache_stub.cc` is used),
  by now `internalBinding('code_cache')` is an empty object
2. Run `tools/generate_code_cache.js` with the binary, which generates
  the code caches by reading source code of builtin modules off source
  code exposed by `require('internal/bootstrap/cache').builtinSource`
  and then generate a C++ file containing static char arrays of the
  code cache, using a format similar to `node_javascript.cc`
3. Run `configure` with the `--code-cache-path` option so that
  the newly generated C++ file will be used when compiling the
  new binary. The generated C++ file will put the cache into
  the `internalBinding('code_cache')` object with the module
  ids as keys
4. The new binary tries to read the code cache from
  `internalBinding('code_cache')` and use it to compile
  builtin modules. If the cache is used, it will put the id
  into `require('internal/bootstrap/cache').compiledWithCache`
  for bookkeeping, otherwise the id will be pushed into
  `require('internal/bootstrap/cache').compiledWithoutCache`

This patch also added tests that verify the code cache is
generated and used when compiling builtin modules.

The binary with code cache:

- Is ~1MB bigger than the binary without code cahe
- Consumes ~1MB less memory during start up
- Starts up about 60% faster

PR-URL: https://github.com/nodejs/node/pull/21405
Reviewed-By: John-David Dalton <john.david.dalton@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gus Caplan <me@gus.host>

1 files changed, 8 insertions, 0 deletions

diff --git a/configure b/configure
index 1b3ff0162f..efb92701e2 100755
--- a/configure
+++ b/configure
@@ -491,6 +491,12 @@ parser.add_option('--without-snapshot',
     dest='without_snapshot',
     help=optparse.SUPPRESS_HELP)
 
+parser.add_option('--code-cache-path',
+    action='store',
+    dest='code_cache_path',
+    help='Use a file generated by tools/generate_code_cache.js to compile the'
+         ' code cache for builtin modules into the binary')
+
 parser.add_option('--without-ssl',
     action='store_true',
     dest='without_ssl',
@@ -983,6 +989,8 @@ def configure_node(o):
     o['variables']['debug_nghttp2'] = 'false'
 
   o['variables']['node_no_browser_globals'] = b(options.no_browser_globals)
+  if options.code_cache_path:
+    o['variables']['node_code_cache_path'] = options.code_cache_path
   o['variables']['node_shared'] = b(options.shared)
   node_module_version = getmoduleversion.get_version()