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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package jdk.tools.jaotc;
import jdk.tools.jaotc.binformat.BinaryContainer;
import jdk.tools.jaotc.binformat.Symbol;
import jdk.vm.ci.code.site.Call;
import jdk.vm.ci.hotspot.HotSpotResolvedJavaMethod;
/**
* Symbol for a regular Java call. This method also creates additional relocations for {@code .plt}
* to {@code .got} and {@code .got} to {@code .plt}.
*/
final class JavaCallSiteRelocationSymbol extends CallSiteRelocationSymbol {
private static final byte[] zeroSlot = new byte[8];
// -1 represents Universe::non_oop_word() value
private static final byte[] minusOneSlot;
static {
String archStr = System.getProperty("os.arch").toLowerCase();
if (archStr.equals("aarch64")) {
// AArch64 is a special case: it uses 48-bit addresses.
byte[] nonOopWord = {-1, -1, -1, -1, -1, -1, 0, 0};
minusOneSlot = nonOopWord;
} else {
byte[] nonOopWord = {-1, -1, -1, -1, -1, -1, -1, -1};
minusOneSlot = nonOopWord;
}
}
JavaCallSiteRelocationSymbol(CompiledMethodInfo mi, Call call, CallSiteRelocationInfo callSiteRelocation, BinaryContainer binaryContainer) {
super(createPltEntrySymbol(binaryContainer, mi, call, callSiteRelocation));
StubInformation stub = getStub(mi, call);
addRelocations(mi, stub, binaryContainer, call, callSiteRelocation);
}
/**
* Returns a unique symbol name with the {@code suffix} appended.
*/
private static String relocationSymbolName(String suffix, CompiledMethodInfo mi, Call call, CallSiteRelocationInfo callSiteRelocation) {
return "M" + mi.getCodeId() + "_" + call.pcOffset + "_" + callSiteRelocation.targetSymbol + "_" + suffix;
}
private static Symbol createPltEntrySymbol(BinaryContainer binaryContainer, CompiledMethodInfo mi, Call call, CallSiteRelocationInfo callSiteRelocation) {
String symbolName = relocationSymbolName("plt.entry", mi, call, callSiteRelocation);
StubInformation stub = getStub(mi, call);
return createCodeContainerSymbol(binaryContainer, symbolName, stub.getOffset());
}
private static StubInformation getStub(CompiledMethodInfo mi, Call call) {
HotSpotResolvedJavaMethod callTarget = (HotSpotResolvedJavaMethod) call.target;
String callTargetSymbol = JavaMethodInfo.uniqueMethodName(callTarget) + ".at." + call.pcOffset;
return mi.getStubFor(callTargetSymbol);
}
/**
* Add all the required relocations.
*/
private static void addRelocations(CompiledMethodInfo mi, StubInformation stub, BinaryContainer binaryContainer, Call call, CallSiteRelocationInfo callSiteRelocation) {
final boolean isVirtualCall = CallInfo.isVirtualCall(mi, call);
final int gotStartOffset = binaryContainer.appendExtLinkageGotBytes(zeroSlot, 0, zeroSlot.length);
if (isVirtualCall) {
// Nothing.
} else {
// For c2i stub we need slot with -1 value.
binaryContainer.appendExtLinkageGotBytes(minusOneSlot, 0, minusOneSlot.length);
}
// Add relocation to GOT cell for call resolution jump.
// This GOT cell will be initialized during JVM startup with address
// of JVM runtime call resolution function.
String gotSymbolName = "got." + getResolveSymbolName(mi, call);
Symbol gotSymbol = binaryContainer.getGotSymbol(gotSymbolName);
addExternalPltToGotRelocation(binaryContainer, gotSymbol, stub.getResolveJumpOffset());
// Add relocation to resolve call jump instruction address for GOT cell.
// This GOT cell will be initialized with address of resolution jump instruction and
// will be updated with call destination address by JVM runtime call resolution code.
String pltJmpSymbolName = relocationSymbolName("plt.jmp", mi, call, callSiteRelocation);
addCodeContainerRelocation(binaryContainer, pltJmpSymbolName, stub.getResolveJumpStart(), gotStartOffset);
// Add relocation to GOT cell for dispatch jump.
// The dispatch jump loads destination address from this GOT cell.
String gotEntrySymbolName = relocationSymbolName("got.entry", mi, call, callSiteRelocation);
addExtLinkageGotContainerRelocation(binaryContainer, gotEntrySymbolName, gotStartOffset, stub.getDispatchJumpOffset());
// Virtual call needs initial -1 value for Klass pointer.
// Non virtual call needs initial 0 value for Method pointer to call c2i adapter.
byte[] slot = isVirtualCall ? minusOneSlot : zeroSlot;
final int gotMetaOffset = binaryContainer.appendExtLinkageGotBytes(slot, 0, slot.length);
// Add relocation to GOT cell for move instruction (Klass* for virtual, Method* otherwise).
String gotMoveSymbolName = relocationSymbolName("got.move", mi, call, callSiteRelocation);
addExtLinkageGotContainerRelocation(binaryContainer, gotMoveSymbolName, gotMetaOffset, stub.getMovOffset());
if (isVirtualCall) {
// Nothing.
} else {
// Add relocation to GOT cell for c2i adapter jump.
// The c2i jump instruction loads destination address from this GOT cell.
// This GOT cell is initialized with -1 and will be updated
// by JVM runtime call resolution code.
String gotC2ISymbolName = relocationSymbolName("got.c2i", mi, call, callSiteRelocation);
addExtLinkageGotContainerRelocation(binaryContainer, gotC2ISymbolName, gotStartOffset + 8, stub.getC2IJumpOffset());
}
}
/**
* Returns the name of the resolve method for this particular call.
*/
private static String getResolveSymbolName(CompiledMethodInfo mi, Call call) {
String resolveSymbolName;
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