| //===---------------------------------------------------------------------===// |
| // General notes |
| //===---------------------------------------------------------------------===// |
| |
| VMKit is the composition of three libraries: |
| 1) MVM: mostly a garbage collector |
| 2) JnJVM: a Java Virtual Machine implemented with MVM and LLVM |
| 3) N3: a CLI implementation with MVM and LLVM |
| |
| |
| You must first patch llvm with vmkit-llvm-svn.patch if you're with SVN, or |
| vmkit-llvm-2.2.patch if you're with 2.2. |
| |
| |
| JnJVM and N3 work on Linux/x86 (note that you may have to disable SSE on some |
| architecture), and mostly work on Linux/PPC (there are some errors with |
| floating points). Portage to Darwin has been done some time ago, so it should |
| not be too hard. |
| |
| JnJVM and N3 use GCC's unwinding library (libgcc_s.so). |
| |
| There are mainly two options in the ./configure script |
| --with-gnu-classpath-local-prefix: the local build of GNU classpath |
| --with-llvm: the local build of LLVM |
| |
| Running make on the root tree will produce three executables: |
| 1) lib/Mvm/main: a command line tool to load virtual machines dynamically |
| 2) lib/JnJVM/main: running the JnJVM like any other JVM |
| 3) lib/N3/main: running N3 like CLR |
| |
| JnJVM and N3 have their own README notes. N3 requires to patch pnet-0.7.4. |
| |
| |
| //===---------------------------------------------------------------------===// |
| // LLVM patch |
| //===---------------------------------------------------------------------===// |
| |
| The patched files are: |
| - include/llvm/Target/TargetOptions.h: new option SizedMemoryCode to know |
| before emitting the size of the code |
| - include/llvm/CodeGen/SizeEmitter.h: new file |
| - include/llvm/CodeGen/MachineCodeEmitter.h: uses virtual methods to implement |
| SizeEmitter |
| - lib/CodeGen/LLVMTargetMachine.cpp: enables SizeEmitter if SiedMemoryCode is |
| true |
| - lib/CogeGen/SizeEmitter.cpp: new file |
| - lib/Target/PowerPC/PPCInstrInfo.td: being able to load extern symbols (probably |
| a bug fix in LLVM) |
| - lib/Target/PowerPC/PPCJITInfo.cpp: adds Dwarf debugging output to callbacks, |
| and makes the patching code thread-safe |
| - lib/Target/PowerPC/PPCISelLowering.cpp: lowers external symbol, and comments |
| double word alignment (TODO in TOT) |
| - lib/ExecutionEngine/JIT/JITEmitter.cpp: helpers for SizedMemoryCode, make the |
| JIT more thread-safe wrt Java (which can execute code when looking for a |
| class) |
| - lib/ExecutionEngine/ExecutionEngine.cpp: Don't check existing mappings (check |
| if TOT is correct) |
| - lib/VMCore/AsmWriter.cpp: enables printing of Ghost functions |
| (for debugging purposes) |
| - lib/Target/X86/X86JITInfo.cpp: enables Dwarf debugging output to callbacks |
| |
| //===---------------------------------------------------------------------===// |
| // TODOs |
| //===---------------------------------------------------------------------===// |
| |
| - Merge LLVM patch with TOT |
| - A compiler/system dependency interface |
| - A better autoconf support |
| - Remove old, historical references and files |
| - Currently old object are allocated by MVM'GC. Make some classes |
| hand-allocated. |
| - Port to Darwin |
| - Improve exception handling performance: it's currently ugly and inefficient |
| |
| //===---------------------------------------------------------------------===// |
| // Disclaimer |
| //===---------------------------------------------------------------------===// |
| |
| JnJVM, N3 and MVM were developed with "having functional virtual machines as |
| quick as possible" in mind. The usage of mixed C/C++ and the absence of clean |
| interfaces, is due to the initial developers lazyness. But now that the VMs |
| run, things should go better. |
| |
