From dc57b99bb8281f5cc746d9a41e4670c770df15cc Mon Sep 17 00:00:00 2001
From: Chris Seaton <chris.seaton@oracle.com>
Date: Mon, 7 Aug 2017 13:34:45 +0100
Subject: [PATCH] Logic to automatically find Graal if it's built as a sibling

---
 doc/contributor/workflow.md |  6 ++++--
 tool/jt.rb                  | 20 ++++++++++++++++----
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/doc/contributor/workflow.md b/doc/contributor/workflow.md
index 6b126e783411..21e3622df217 100644
--- a/doc/contributor/workflow.md
+++ b/doc/contributor/workflow.md
@@ -142,10 +142,12 @@ $ export GRAALVM_BIN=.../graalvm-0.nn/bin/java
 $ jt ruby --graal -e 'p Truffle.graal?'
 ```
 
-To run with Graal built from source, set `GRAAL_HOME`.
+To run with Graal built from source, set `GRAAL_HOME`. Or it will be
+automatically found if it is cloned into the same directory as `truffleruby`, it
+is built, and you are not using a binary suite for Truffle.
 
 ```bash
-$ export GRAAL_HOME=.../graal-core
+$ export GRAAL_HOME=.../graal
 $ jt ruby --graal ...
 ```
 
diff --git a/tool/jt.rb b/tool/jt.rb
index ce6efac93c6c..9c933e5eadc4 100755
--- a/tool/jt.rb
+++ b/tool/jt.rb
@@ -85,8 +85,12 @@ def self.find_graal_javacmd_and_options
         "--module-path=#{jvmci_graal_home}/../truffle/mxbuild/modules/com.oracle.truffle.truffle_api.jar:#{jvmci_graal_home}/mxbuild/modules/com.oracle.graal.graal_core.jar"
       ]
       options = ['--no-bootclasspath']
-    elsif graal_home
-      graal_home = File.expand_path(graal_home, TRUFFLERUBY_DIR)
+    elsif graal_home || auto_graal_home = find_auto_graal_home
+      if graal_home
+        graal_home = File.expand_path(graal_home, TRUFFLERUBY_DIR)
+      else
+        graal_home = auto_graal_home
+      end
       output, _ = ShellUtils.mx('-v', '-p', graal_home, 'vm', '-version', :err => :out, capture: true)
       command_line = output.lines.select { |line| line.include? '-version' }
       if command_line.size == 1
@@ -105,6 +109,14 @@ def self.find_graal_javacmd_and_options
     end
     [javacmd, vm_args.map { |arg| "-J#{arg}" } + options]
   end
+  
+  def self.find_auto_graal_home
+    sibling_compiler = File.expand_path('../graal/compiler', TRUFFLERUBY_DIR)
+    return nil unless Dir.exist?(sibling_compiler)
+    return nil unless File.exist?("#{sibling_compiler}/mxbuild/dists/graal-compiler.jar")
+    return nil if Dir.exist?("#{TRUFFLERUBY_DIR}/mx.imports/binary/truffle")
+    sibling_compiler
+  end
 
   def self.which(binary)
     ENV["PATH"].split(File::PATH_SEPARATOR).each do |dir|
@@ -381,7 +393,7 @@ def help
       jt rebuild                                     clean, sforceimports, and build
       jt dis <file>                                  finds the bc file in the project, disassembles, and returns new filename
       jt run [options] args...                       run JRuby with args
-          --graal         use Graal (set either GRAALVM_BIN or GRAAL_HOME)
+          --graal         use Graal (set either GRAALVM_BIN, JVMCI_BIN or GRAAL_HOME, or have graal built as a sibling)
               --stress    stress the compiler (compile immediately, foreground compilation, compilation exceptions are fatal)
           --js            add Graal.js to the classpath (set GRAAL_JS_JAR)
           --asm           show assembly (implies --graal)
@@ -404,7 +416,7 @@ def help
           --syslog        runs syslog tests
           --openssl       runs openssl tests
           --aot           use AOT TruffleRuby image (set AOT_BIN)
-          --graal         use Graal (set either GRAALVM_BIN, JVMCI_BIN or GRAAL_HOME)
+          --graal         use Graal (set either GRAALVM_BIN, JVMCI_BIN or GRAAL_HOME, or have graal built as a sibling)
       jt test specs                                  run all specs
       jt test specs fast                             run all specs except sub-processes, GC, sleep, ...
       jt test spec/ruby/language                     run specs in this directory