Use the system libyaml for psych as it is faster for warmup

* And it has similar peak performance.
* See #2089

Author: eregon

CHANGELOG.md

@@ -98,6 +98,7 @@ Performance:
 * Marking of native structures wrapped in objects is now done on C call exit to reduce memory overhead (@aardvark179).
 * Splitting (copying) of call targets has been optimized by implementing `cloneUninitialized()` (@andrykonchin, @eregon).
 * `Process.pid` is now cached per process like `$$` (#2882, @horakivo)
+* Use the system `libyaml` for `psych` to improve warmup when parsing YAML (#2089, @eregon).
 
 Changes:
 

README.md

@@ -103,6 +103,7 @@ environment, for example, by unmounting system filesystems such as `/dev/shm`.
 
 * [make and gcc](doc/user/installing-llvm.md) for building C and C++ extensions
 * [libssl](doc/user/installing-libssl.md) for the `openssl` C extension
+* [libyaml](doc/user/installing-libyaml.md) for the `psych` C extension
 * [zlib](doc/user/installing-zlib.md) for the `zlib` C extension
 
 Without these dependencies, many libraries including RubyGems will not work.

ci.jsonnet

@@ -228,12 +228,14 @@ local part_definitions = {
       packages+: {
         binutils: ">=2.30",
         ruby: "==" + mri_version,
+        libyaml: "==0.2.5",
       },
     },
 
     local linux_aarch64_deps = common.deps.sulong + {
       packages+: {
         ruby: "==3.0.2",
+        libyaml: "==0.2.5",
       },
     },
 

doc/user/installing-libyaml.md

@@ -0,0 +1,39 @@
+---
+layout: docs-experimental
+toc_group: ruby
+link_title: Installing LibYAML
+permalink: /reference-manual/ruby/InstallingLibYAML/
+---
+# Installing LibYAML
+
+TruffleRuby requires to have `libyaml` installed, much like CRuby 3.2+ and Psych 5+.
+
+### Fedora-based: RHEL, Oracle Linux, etc
+
+```bash
+sudo dnf install libyaml-devel
+```
+
+### Debian-based: Ubuntu, etc
+
+```bash
+sudo apt-get install libyaml-dev
+```
+
+### macOS
+
+#### Homebrew
+
+We recommend installing libssl via [Homebrew](https://brew.sh).
+
+```bash
+brew install libyaml
+```
+
+#### MacPorts
+
+MacPorts should also work but is not actively tested.
+
+```bash
+sudo port install libyaml
+```

lib/truffle/truffle/libyaml-prefix.rb

@@ -0,0 +1,41 @@
+# Copyright (c) 2023 Oracle and/or its affiliates. All rights reserved. This
+# code is released under a tri EPL/GPL/LGPL license. You can use it,
+# redistribute it and/or modify it under the terms of the:
+#
+# Eclipse Public License version 2.0, or
+# GNU General Public License version 2, or
+# GNU Lesser General Public License version 2.1.
+
+# Set LIBYAML_PREFIX in ENV to find the libyaml headers
+
+search_homebrew = -> homebrew {
+  if prefix = "#{homebrew}/opt/libyaml" and Dir.exist?(prefix)
+    prefix
+  end
+}
+
+if Truffle::Platform.darwin? && !ENV['LIBYAML_PREFIX']
+  default_homebrew_prefix = Truffle::System.host_cpu == 'aarch64' ? '/opt/homebrew' : '/usr/local'
+  if prefix = search_homebrew.call(default_homebrew_prefix)
+    # found
+  else
+    homebrew = `brew --prefix 2>/dev/null`.strip
+    homebrew = nil unless $?.success? and !homebrew.empty? and Dir.exist?(homebrew)
+
+    if homebrew and prefix = search_homebrew.call(homebrew)
+      # found
+    elsif Dir.exist?('/opt/local/include/libyaml') # MacPorts
+      prefix = '/opt/local'
+    end
+  end
+
+  if prefix
+    ENV['LIBYAML_PREFIX'] = prefix
+  else
+    abort 'Could not find libyaml headers, install via Homebrew or MacPorts or set LIBYAML_PREFIX'
+  end
+end
+
+if libyaml_prefix = ENV['LIBYAML_PREFIX']
+  Truffle::Debug.log_config("Found libyaml in #{libyaml_prefix}")
+end

src/main/c/Makefile

@@ -159,11 +159,10 @@ rbconfig-sizeof/sizeof.$(DLEXT): rbconfig-sizeof/Makefile rbconfig-sizeof/sizes.
 	$(Q) cd rbconfig-sizeof && $(MAKE) $(MKMF_MAKEFILE_SUBPROCESS_FLAGS)
 
 # psych
-# Always use the bundled libyaml, as we want it as bitcode and avoid extra handles
 psych/Makefile: psych/extconf.rb $(EXTCONF_DEPS)
-	$(Q) cd psych && $(RUBY) extconf.rb --enable-bundled-libyaml || $(IF_EXTCONF_FAIL)
+	$(Q) cd psych && $(RUBY) extconf.rb || $(IF_EXTCONF_FAIL)
 
-psych/psych.$(DLEXT): psych/Makefile psych/*.c psych/*.h psych/yaml/*.c psych/yaml/*.h
+psych/psych.$(DLEXT): psych/Makefile psych/*.c psych/*.h
 	$(Q) cd psych && $(MAKE) $(MKMF_MAKEFILE_SUBPROCESS_FLAGS)
 
 # debug bundled gem

src/main/c/psych/extconf.rb

@@ -5,8 +5,18 @@
 
 # :stopdoc:
 
-dir_config 'libyaml'
+if defined?(::TruffleRuby)
+  require 'truffle/libyaml-prefix'
+  dir_config('libyaml', ENV['LIBYAML_PREFIX'])
+else
+  dir_config 'libyaml'
+end
 
+if defined?(::TruffleRuby)
+  # From https://github.com/ruby/psych/blob/v5.0.0/ext/psych/extconf.rb#L42-L43
+  find_header('yaml.h') or abort "yaml.h not found"
+  find_library('yaml', 'yaml_get_version') or abort "libyaml not found"
+else
 if enable_config("bundled-libyaml", false) || !(find_header('yaml.h') && find_library('yaml', 'yaml_get_version'))
   # Embed libyaml since we could not find it.
 
@@ -35,6 +45,7 @@
   find_header 'yaml.h'
   have_header 'config.h'
 end
+end
 
 create_makefile 'psych' do |mk|
   mk << "YAML_H = #{header}".strip << "\n"