Call plus ensure does not properly initialize all temps #3969
Description
Environment
JRuby master as of today.
Expected Behavior
@subbuss added a pass to only initialize variables (to nil) that would not otherwise be initialized before they need to be read.
Actual Behavior
The pass in question does not appear to be handling some cases correctly. The following fails to compile in JIT because there are uninitialized variables:
Caused by: java.lang.VerifyError: Bad local variable type
Exception Details:
Location:
blah.RUBY$method$raw$0(Lorg/jruby/runtime/ThreadContext;Lorg/jruby/parser/StaticScope;Lorg/jruby/runtime/builtin/IRubyObject;[Lorg/jruby/runtime/builtin/IRubyObject;Lorg/jruby/runtime/Block;Lorg/jruby/RubyModule;Ljava/lang/String;)Lorg/jruby/runtime/builtin/IRubyObject; @89: aload
Reason:
Type top (current frame, locals[10]) is not assignable to reference type
Current Frame:
bci: @89
flags: { }
locals: { 'org/jruby/runtime/ThreadContext', 'org/jruby/parser/StaticScope', 'org/jruby/runtime/builtin/IRubyObject', '[Lorg/jruby/runtime/builtin/IRubyObject;', 'org/jruby/runtime/Block', 'org/jruby/RubyModule', 'java/lang/String', top, 'org/jruby/runtime/builtin/IRubyObject', 'org/jruby/runtime/builtin/IRubyObject', top, top, top, 'java/lang/Throwable', 'org/jruby/runtime/builtin/IRubyObject' }
stack: { 'org/jruby/runtime/ThreadContext', 'org/jruby/runtime/builtin/IRubyObject', 'org/jruby/runtime/builtin/IRubyObject' }
I believe this fails to verify because the JVM knows that calls can raise exceptions, and with an ensure block it might branch to code that reads the saved value before it is written. Unfortunately, the following patch seems to break something (though it does seem to help):
diff --git a/core/src/main/java/org/jruby/ir/dataflow/analyses/DefinedVariableNode.java b/core/src/main/java/org/jruby/ir/dataflow/analyses/DefinedVariableNode.java
index 2098b34..c07647d 100644
--- a/core/src/main/java/org/jruby/ir/dataflow/analyses/DefinedVariableNode.java
+++ b/core/src/main/java/org/jruby/ir/dataflow/analyses/DefinedVariableNode.java
@@ -97,7 +97,7 @@ public class DefinedVariableNode extends FlowGraphNode<DefinedVariablesProblem,
tmp.set(problem.getDFVar(v));
}
- if (!tmp.get(problem.getDFVar(v))) {
+ if (!tmp.get(problem.getDFVar(v)) || i.getOperation().canRaiseException()) {
// System.out.println("Variable " + v + " in instr " + i + " in " + basicBlock + " isn't defined!");
undefinedVars.add(v);
}When I apply this patch and try to run with -X+C (force compile on load) I get the following output:
$ jruby -Xjit.logging -Xjit.logging.verbose -X+C -e 1
2016-06-14T19:36:12.234-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/java.rb
2016-06-14T19:36:12.313-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/java/java_utilities.rb
2016-06-14T19:36:12.322-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/java/core_ext.rb
2016-06-14T19:36:12.398-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/java/core_ext/module.rb
2016-06-14T19:36:12.468-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/java/core_ext/object.rb
2016-06-14T19:36:12.474-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/java/java_ext.rb
2016-06-14T19:36:12.579-05:00 [main] INFO Ruby : done compiling target script: file:/Users/headius/projects/jruby/lib/jruby.jar!/jruby/jruby.rb
2016-06-14T19:36:12.658-05:00 [main] INFO Ruby : done compiling target script: file:/Users/headius/projects/jruby/lib/jruby.jar!/jruby/kernel.rb
2016-06-14T19:36:12.683-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/jruby/type.rb
2016-06-14T19:36:12.726-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/signal.rb
2016-06-14T19:36:12.795-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/kernel.rb
2016-06-14T19:36:12.824-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/proc.rb
2016-06-14T19:36:12.838-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/process.rb
2016-06-14T19:36:12.861-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/jruby/process_util.rb
2016-06-14T19:36:12.886-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/jruby/type.rb
2016-06-14T19:36:13.039-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/enumerator.rb
2016-06-14T19:36:13.113-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/enumerable.rb
2016-06-14T19:36:13.133-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/io.rb
2016-06-14T19:36:13.149-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/time.rb
2016-06-14T19:36:13.251-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/gc.rb
2016-06-14T19:36:13.292-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/range.rb
2016-06-14T19:36:13.298-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/load_error.rb
2016-06-14T19:36:13.345-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/file.rb
2016-06-14T19:36:13.354-05:00 [main] INFO Ruby : done compiling target script: file:/Users/headius/projects/jruby/lib/jruby.jar!/jruby/preludes.rb
2016-06-14T19:36:13.363-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/prelude.rb
2016-06-14T19:36:13.369-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/enc_prelude.rb
2016-06-14T19:36:13.382-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/unicode_normalize.rb
2016-06-14T19:36:13.391-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/gem_prelude.rb
2016-06-14T19:36:13.652-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems.rb
2016-06-14T19:36:13.667-05:00 [main] INFO Ruby : done compiling target script: uri:classloader:/jruby/kernel/rbconfig.rb
2016-06-14T19:36:13.682-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/compatibility.rb
2016-06-14T19:36:13.723-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/defaults.rb
2016-06-14T19:36:13.745-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/deprecate.rb
2016-06-14T19:36:13.778-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/errors.rb
2016-06-14T19:36:14.437-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/specification.rb
2016-06-14T19:36:14.488-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/version.rb
2016-06-14T19:36:14.568-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/requirement.rb
2016-06-14T19:36:14.650-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/platform.rb
2016-06-14T19:36:14.699-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/basic_specification.rb
2016-06-14T19:36:14.742-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/stub_specification.rb
2016-06-14T19:36:14.758-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/util/list.rb
2016-06-14T19:36:14.888-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/exceptions.rb
2016-06-14T19:36:15.043-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/defaults/jruby.rb
2016-06-14T19:36:15.123-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/config_file.rb
2016-06-14T19:36:15.198-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/user_interaction.rb
2016-06-14T19:36:15.222-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/util.rb
2016-06-14T19:36:15.300-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/io/console.rb
2016-06-14T19:36:15.323-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/io/bsd_console.rb
2016-06-14T19:36:15.325-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/ffi.rb
2016-06-14T19:36:15.354-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/ffi/ffi.rb
2016-06-14T19:36:15.428-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/ffi/platform.rb
2016-06-14T19:36:15.453-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/ffi/types.rb
2016-06-14T19:36:15.613-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/jar_install_post_install_hook.rb
2016-06-14T19:36:15.619-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/jars/post_install_hook.rb
2016-06-14T19:36:15.728-05:00 [main] INFO Ruby : done compiling target script: /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/dependency.rb
TypeError: wrong argument type NilClass (expected Regexp)
sub! at org/jruby/RubyString.java:2383
sub at org/jruby/RubyString.java:2358
block in register_default_spec at /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems.rb:1188
each at org/jruby/RubyArray.java:1593
register_default_spec at /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems.rb:1186
block in load_defaults at /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/specification.rb:874
block in each_spec at /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/specification.rb:821
block in each_gemspec at /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/specification.rb:743
each at org/jruby/RubyArray.java:1593
block in each_gemspec at /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/specification.rb:742
each at org/jruby/RubyArray.java:1593
each_gemspec at /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/specification.rb:741
each_spec at /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/specification.rb:819
load_defaults at /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/specification.rb:871
<top> at /Users/headius/projects/jruby/lib/ruby/stdlib/rubygems.rb:1321
require at org/jruby/RubyKernel.java:942
<top> at uri:classloader:/jruby/kernel/gem_prelude.rb:3
load at org/jruby/RubyKernel.java:960
<top> at file:/Users/headius/projects/jruby/lib/jruby.jar!/jruby/preludes.rb:4
@subbuss Is my patch wrong?