This avoids the requirement of putting the code image in a
section/segment which is both writable and executable, which is good
for security and avoids trouble with systems like iOS which disallow
such things.
The implementation relies on relative addressing such that the offset
of the desired address is fixed as a compile-time constant relative to
the start of the memory area of interest (e.g. the code image, heap
image, or thunk table). At runtime, the base pointer to the memory
area is retrieved from the thread structure and added to the offset to
compute the final address. Using the thread pointer allows us to
generate read-only, position-independent code while avoiding the use
of IP-relative addressing, which is not available on all
architectures.
This monster commit is the first step towards supporting
cross-architecture bootimage builds. The challenge is to build a heap
and code image for the target platform where the word size and
endianess may differ from those of the build architecture. That means
the memory layout of objects may differ due to alignment and size
differences, so we can't just copy objects into the heap image
unchanged; we must copy field by field, resizing values, reversing
endianess and shifting offsets as necessary.
This commit also removes POD (plain old data) type support from the
type generator because it added a lot of complication and little
value.
Recent versions of Cygwin's GCC no longer support the -mno-cygwin flag
(compilation works, but linking fails). However, Cygwin now includes
mingw64-i686-gcc, mingw64-x86_64-gcc, and related packages, so we use
those compilers instead. This has the added benefit that we can build
native x86_64 binaries on Cygwin now.
This will break the build for old Cygwin installs, so it will be
necessary to upgrade Cygwin and install the aforementioned packages to
build Avian going forward.
Added JavaVM to include path. Also allow dynamically building with
different SDK versions through the OSX_SDK_VERSION and OSX_SDK_SYSROOT
environment variables (these default to the previosly hardcoded value of
10.4 and 10.4u respectively).
OpenJDK's compile.c and Avian's compile.cpp were both being compiled
to compile.o, which led to a conflict when building libavian.a. We
now append "-openjdk" to the object file name for OpenJDK code to
avoid such conflicts.
This primarily required additions to classpath-openjdk.cpp to
intercept ZipFile, ZipEntry, and JarFile native methods to consult
embedded encryption policy jars when required.
While we can use Linux's jni.h to cross compile the i386 Mac OS build,
that doesn't work for the PowerPC one. Now we use the proper
/System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Headers/jni.h
from the sysroot instead.
This test covers the case where a local stack slot is first used to
store an object reference and later to store a subroutine return
address. Unfortunately, this confuses the VM's stack mapping code;
I'll be working on a fix for that next.
The new test requires generating bytecode from scratch, since there's
no reliable way to get javac to generate the code we want. Since we
already had primitive bytecode construction code in Proxy.java, I
factored it out so we can reuse it in Subroutine.java.
This mainly involves some makefile ugliness to work around bugs in the
native Windows OpenJDK code involving conflicting static and
not-static declarations which GCC 4.0 and later justifiably reject but
MSVC tolerates.
* add libnet.so and libnio.so to built-in libraries for openjdk-src build
* implement sun.misc.Unsafe.park/unpark
* implement JVM_SetClassSigners/JVM_GetClassSigners
* etc.
