diff --git a/src/share/vm/ci/ciField.cpp b/src/share/vm/ci/ciField.cpp index bd80ebbdebfa207b22b7cdc7869cedf6e152e253..39a5651dc68c9e73de31eeb055ab0ac23938b1f6 100644 --- a/src/share/vm/ci/ciField.cpp +++ b/src/share/vm/ci/ciField.cpp @@ -161,6 +161,18 @@ ciField::ciField(fieldDescriptor *fd): _known_to_link_with(NULL) { "bootstrap classes must not create & cache unshared fields"); } +static bool trust_final_non_static_fields(ciInstanceKlass* holder) { + if (holder == NULL) + return false; + if (holder->name() == ciSymbol::java_lang_System()) + // Never trust strangely unstable finals: System.out, etc. + return false; + // Even if general trusting is disabled, trust system-built closures in these packages. + if (holder->is_in_package("java/dyn") || holder->is_in_package("sun/dyn")) + return true; + return TrustFinalNonStaticFields; +} + void ciField::initialize_from(fieldDescriptor* fd) { // Get the flags, offset, and canonical holder of the field. _flags = ciFlags(fd->access_flags()); @@ -172,7 +184,7 @@ void ciField::initialize_from(fieldDescriptor* fd) { if (!this->is_static()) { // A field can be constant if it's a final static field or if it's // a final non-static field of a trusted class ({java,sun}.dyn). - if (_holder->is_in_package("java/dyn") || _holder->is_in_package("sun/dyn")) { + if (trust_final_non_static_fields(_holder)) { _is_constant = true; return; } diff --git a/src/share/vm/runtime/globals.hpp b/src/share/vm/runtime/globals.hpp index 5ea78ccb7b2ae6bcd5a60759fd79012b88f0ac5c..3c41d0d69c2b201950027fb3601e62ca75c4e4bd 100644 --- a/src/share/vm/runtime/globals.hpp +++ b/src/share/vm/runtime/globals.hpp @@ -3370,6 +3370,9 @@ class CommandLineFlags { diagnostic(bool, OptimizeMethodHandles, true, \ "when constructing method handles, try to improve them") \ \ + experimental(bool, TrustFinalNonStaticFields, false, \ + "trust final non-static declarations for constant folding") \ + \ experimental(bool, EnableInvokeDynamic, false, \ "recognize the invokedynamic instruction") \ \