Prepend the GraalVM LLVM Toolchain to PATH when installing gems

* Also add RbConfig::CONFIG['toolchain_path'] for other cases where it
  might be useful to access the toolchain `bin/` directory explicitly.

Author: eregon

CHANGELOG.md

@@ -18,6 +18,7 @@ Bug fixes:
 
 Compatibility:
 
+* Prepend the GraalVM LLVM Toolchain to `PATH` when installing gems (#1974).
 * Implemented `$LOAD_PATH.resolve_feature_path`.
 * Add `Pathname#/` alias to `Pathname#+` (#2178).
 * Fixed issue with large `Integer`s in `Math.log` (#2184).

lib/mri/mkmf.rb

@@ -55,6 +55,10 @@
   ENV['NOKOGIRI_USE_SYSTEM_LIBRARIES'] = 'true'
 end
 
+if defined?(::TruffleRuby) and Truffle::Boot.get_option('cexts-prepend-toolchain-to-path')
+  ENV['PATH'] = "#{RbConfig::CONFIG['toolchain_path']}:#{ENV['PATH']}"
+end
+
 class String
   # :stopdoc:
 

lib/truffle/rbconfig.rb

@@ -94,6 +94,8 @@ module RbConfig
   cext_dir = "#{prefix}/lib/cext"
   dlext = Truffle::Platform::DLEXT
 
+  toolchain_path = Truffle::Boot.toolchain_paths(:PATH)
+
   # Make C extensions use the same libssl as the one used for the openssl C extension
   if Truffle::Platform.darwin?
     require 'truffle/openssl-prefix'
@@ -187,6 +189,7 @@ module RbConfig
     'sysconfdir'        => "#{prefix}/etc", # doesn't exist, as in MRI
     'target_cpu'        => host_cpu,
     'target_os'         => host_os,
+    'toolchain_path'    => toolchain_path,
     'UNICODE_VERSION'   => '12.0.0',
     'UNICODE_EMOJI_VERSION' => '12.1',
     'warnflags'         => warnflags,

src/main/java/org/truffleruby/options/Options.java

@@ -103,6 +103,8 @@ public class Options {
     public final boolean CEXTS;
     /** --cexts-lock=true */
     public final boolean CEXT_LOCK;
+    /** --cexts-prepend-toolchain-to-path=true */
+    public final boolean CEXTS_PREPEND_TOOLCHAIN_TO_PATH;
     /** --keep-handles-alive=false */
     public final boolean CEXTS_KEEP_HANDLES_ALIVE;
     /** --options-log=false */
@@ -239,6 +241,7 @@ public Options(Env env, OptionValues options, LanguageOptions languageOptions) {
         BACKTRACE_ON_RESCUE = options.get(OptionsCatalog.BACKTRACE_ON_RESCUE_KEY);
         CEXTS = options.get(OptionsCatalog.CEXTS_KEY);
         CEXT_LOCK = options.get(OptionsCatalog.CEXT_LOCK_KEY);
+        CEXTS_PREPEND_TOOLCHAIN_TO_PATH = options.get(OptionsCatalog.CEXTS_PREPEND_TOOLCHAIN_TO_PATH_KEY);
         CEXTS_KEEP_HANDLES_ALIVE = options.get(OptionsCatalog.CEXTS_KEEP_HANDLES_ALIVE_KEY);
         OPTIONS_LOG = options.get(OptionsCatalog.OPTIONS_LOG_KEY);
         LOG_LOAD = options.get(OptionsCatalog.LOG_LOAD_KEY);
@@ -370,6 +373,8 @@ public Object fromDescriptor(OptionDescriptor descriptor) {
                 return CEXTS;
             case "ruby.cexts-lock":
                 return CEXT_LOCK;
+            case "ruby.cexts-prepend-toolchain-to-path":
+                return CEXTS_PREPEND_TOOLCHAIN_TO_PATH;
             case "ruby.keep-handles-alive":
                 return CEXTS_KEEP_HANDLES_ALIVE;
             case "ruby.options-log":

src/options.yml

@@ -109,6 +109,7 @@ EXPERT:
     # C extension options
     CEXTS: [cexts, boolean, true, Enable use of C extensions]
     CEXT_LOCK: [cexts-lock, boolean, true, Use a Global Lock when running C extensions]
+    CEXTS_PREPEND_TOOLCHAIN_TO_PATH: [cexts-prepend-toolchain-to-path, boolean, true, Prepend the GraalVM LLVM Toolchain to PATH when installing gems]
     CEXTS_KEEP_HANDLES_ALIVE: [keep-handles-alive, boolean, false, Keep handles for value wrappers alive forever]
 
     # Debugging the values of options

src/shared/java/org/truffleruby/shared/options/OptionsCatalog.java

@@ -67,6 +67,7 @@ public class OptionsCatalog {
     public static final OptionKey<Boolean> BACKTRACE_ON_RESCUE_KEY = new OptionKey<>(false);
     public static final OptionKey<Boolean> CEXTS_KEY = new OptionKey<>(true);
     public static final OptionKey<Boolean> CEXT_LOCK_KEY = new OptionKey<>(true);
+    public static final OptionKey<Boolean> CEXTS_PREPEND_TOOLCHAIN_TO_PATH_KEY = new OptionKey<>(true);
     public static final OptionKey<Boolean> CEXTS_KEEP_HANDLES_ALIVE_KEY = new OptionKey<>(false);
     public static final OptionKey<Boolean> OPTIONS_LOG_KEY = new OptionKey<>(false);
     public static final OptionKey<Boolean> LOG_LOAD_KEY = new OptionKey<>(false);
@@ -479,6 +480,13 @@ public class OptionsCatalog {
             .stability(OptionStability.EXPERIMENTAL)
             .build();
 
+    public static final OptionDescriptor CEXTS_PREPEND_TOOLCHAIN_TO_PATH = OptionDescriptor
+            .newBuilder(CEXTS_PREPEND_TOOLCHAIN_TO_PATH_KEY, "ruby.cexts-prepend-toolchain-to-path")
+            .help("Prepend the GraalVM LLVM Toolchain to PATH when installing gems")
+            .category(OptionCategory.EXPERT)
+            .stability(OptionStability.EXPERIMENTAL)
+            .build();
+
     public static final OptionDescriptor CEXTS_KEEP_HANDLES_ALIVE = OptionDescriptor
             .newBuilder(CEXTS_KEEP_HANDLES_ALIVE_KEY, "ruby.keep-handles-alive")
             .help("Keep handles for value wrappers alive forever")
@@ -1149,6 +1157,8 @@ public static OptionDescriptor fromName(String name) {
                 return CEXTS;
             case "ruby.cexts-lock":
                 return CEXT_LOCK;
+            case "ruby.cexts-prepend-toolchain-to-path":
+                return CEXTS_PREPEND_TOOLCHAIN_TO_PATH;
             case "ruby.keep-handles-alive":
                 return CEXTS_KEEP_HANDLES_ALIVE;
             case "ruby.options-log":
@@ -1367,6 +1377,7 @@ public static OptionDescriptor[] allDescriptors() {
             BACKTRACE_ON_RESCUE,
             CEXTS,
             CEXT_LOCK,
+            CEXTS_PREPEND_TOOLCHAIN_TO_PATH,
             CEXTS_KEEP_HANDLES_ALIVE,
             OPTIONS_LOG,
             LOG_LOAD,

test/truffle/cexts/backtraces/ext/backtraces/extconf.rb

@@ -3,23 +3,24 @@
 # Compile a real native library
 # Commands from src/main/c/truffleposix/Makefile
 
-so = RbConfig::CONFIG['SOEXT']
-cc = ENV['CC'] || 'cc'
+def command(*args)
+  $stderr.puts args.join(' ')
+  ret = system(*args)
+  raise unless ret
+end
 
 dir = File.expand_path('../..', __FILE__)
 name = "#{dir}/libnativetest"
+so = RbConfig::CONFIG['SOEXT']
+
+original_path = ENV['PATH'].delete_prefix("#{RbConfig::CONFIG['toolchain_path']}:")
+system_cc = find_executable('cc', original_path)
 
 cflags = %w[-Wall -Werror -fPIC -std=c99]
 ldflags = %w[-m64]
 
-def command(*args)
-  $stderr.puts args.join(' ')
-  ret = system(*args)
-  raise unless ret
-end
-
-command cc, '-o', "#{name}.o", '-c', *cflags, *ldflags, "#{name}.c"
-command cc, '-shared', *ldflags, '-o', "#{name}.#{so}", "#{name}.o"
+command system_cc, '-o', "#{name}.o", '-c', *cflags, *ldflags, "#{name}.c"
+command system_cc, '-shared', *ldflags, '-o', "#{name}.#{so}", "#{name}.o"
 
 $LIBS += " #{name}.#{so}"