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decomp.cpp
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/*******************************************************************************
* Copyright (c) 1991, 2019 IBM Corp. and others
*
* This program and the accompanying materials are made available under
* the terms of the Eclipse Public License 2.0 which accompanies this
* distribution and is available at https://www.eclipse.org/legal/epl-2.0/
* or the Apache License, Version 2.0 which accompanies this distribution and
* is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the following
* Secondary Licenses when the conditions for such availability set
* forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
* General Public License, version 2 with the GNU Classpath
* Exception [1] and GNU General Public License, version 2 with the
* OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] http://openjdk.java.net/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
*******************************************************************************/
#include <string.h>
#include "j9.h"
#include "j9protos.h"
#include "j9consts.h"
#include "j9cp.h"
#include "rommeth.h"
#include "jilconsts.h"
#include "jitprotos.h"
#include "j9protos.h"
#include "stackwalk.h"
#include "MethodMetaData.h"
#include "pcstack.h"
#include "ut_j9codertvm.h"
#include "jitregmap.h"
#include "pcstack.h"
#include "VMHelpers.hpp"
#include "OMR/Bytes.hpp"
extern "C" {
/* Generic rounding macro - result is a UDATA */
#define ROUND_TO(granularity, number) OMR::align((UDATA)(number), granularity)
typedef struct {
J9JITExceptionTable * metaData;
J9Method * method;
UDATA * bp;
UDATA * a0;
UDATA * unwindSP;
UDATA * sp;
UDATA argCount;
J9Method * literals;
J9I2JState i2jState;
UDATA * j2iFrame;
UDATA preservedRegisterValues[J9SW_JIT_CALLEE_PRESERVED_SIZE];
UDATA previousFrameBytecodes;
UDATA notifyFramePop;
UDATA resolveFrameFlags;
} J9JITDecompileState;
/* OSR result codes */
#define OSR_OK 0
#define OSR_OUT_OF_MEMORY 1
/* Bit values for J9OSRFrame->flags */
#define J9OSRFRAME_NOTIFY_FRAME_POP 1
typedef struct {
J9VMThread *targetThread;
J9JITExceptionTable *metaData;
void *jitPC;
UDATA resolveFrameFlags;
UDATA *objectArgScanCursor;
UDATA *objectTempScanCursor;
J9JITStackAtlas *gcStackAtlas;
J9Method *method;
U_8 *liveMonitorMap;
U_16 numberOfMapBits;
void *inlineMap;
void *inlinedCallSite;
J9OSRFrame *osrFrame;
} J9OSRData;
extern void _fsdSwitchToInterpPatchEntry(void *);
extern void _fsdRestoreToJITPatchEntry(void *);
J9_EXTERN_BUILDER_SYMBOL(jitExitInterpreter0);
J9_EXTERN_BUILDER_SYMBOL(jitExitInterpreter1);
J9_EXTERN_BUILDER_SYMBOL(jitExitInterpreterD);
J9_EXTERN_BUILDER_SYMBOL(jitExitInterpreterF);
J9_EXTERN_BUILDER_SYMBOL(jitExitInterpreterJ);
J9_EXTERN_BUILDER_SYMBOL(jitDecompileOnReturn0);
J9_EXTERN_BUILDER_SYMBOL(jitDecompileOnReturn1);
J9_EXTERN_BUILDER_SYMBOL(jitDecompileOnReturnD);
J9_EXTERN_BUILDER_SYMBOL(jitDecompileOnReturnF);
J9_EXTERN_BUILDER_SYMBOL(jitDecompileOnReturnJ);
J9_EXTERN_BUILDER_SYMBOL(jitDecompileOnReturnL);
J9_EXTERN_BUILDER_SYMBOL(jitReportExceptionCatch);
J9_EXTERN_BUILDER_SYMBOL(jitDecompileAtExceptionCatch);
J9_EXTERN_BUILDER_SYMBOL(jitDecompileAtCurrentPC);
J9_EXTERN_BUILDER_SYMBOL(jitDecompileBeforeMethodMonitorEnter);
J9_EXTERN_BUILDER_SYMBOL(jitDecompileBeforeReportMethodEnter);
J9_EXTERN_BUILDER_SYMBOL(jitDecompileAfterAllocation);
J9_EXTERN_BUILDER_SYMBOL(jitDecompileAfterMonitorEnter);
J9_EXTERN_BUILDER_SYMBOL(executeCurrentBytecodeFromJIT);
J9_EXTERN_BUILDER_SYMBOL(enterMethodMonitorFromJIT);
J9_EXTERN_BUILDER_SYMBOL(reportMethodEnterFromJIT);
J9_EXTERN_BUILDER_SYMBOL(handlePopFramesFromJIT);
static J9OSRFrame* findOSRFrameAtInlineDepth(J9OSRBuffer *osrBuffer, UDATA inlineDepth);
static void jitFramePopNotificationAdded(J9VMThread * currentThread, J9StackWalkState * walkState, UDATA inlineDepth);
static void decompPrintMethod(J9VMThread * currentThread, J9Method * method);
static UDATA decompileAllFrameIterator(J9VMThread * currentThread, J9StackWalkState * walkState);
static J9JITDecompilationInfo * deleteDecompilationForExistingFrame(J9VMThread * decompileThread, J9JITDecompilationInfo * info);
static J9JITDecompilationInfo * addDecompilation(J9VMThread * currentThread, J9StackWalkState * walkState, UDATA reason);
static void removeAllBreakpoints(J9VMThread * currentThread);
static void buildBytecodeFrame(J9VMThread *currentThread, J9OSRFrame *osrFrame);
static void buildInlineStackFrames(J9VMThread *currentThread, J9JITDecompileState *decompileState, J9JITDecompilationInfo *decompRecord, UDATA inlineDepth, J9OSRFrame *osrFrame);
static void performDecompile(J9VMThread * currentThread, J9JITDecompileState * decompileState, J9JITDecompilationInfo * decompRecord, J9OSRFrame *osrFrame, UDATA numberOfFrames);
static void decompileOuterFrame(J9VMThread * currentThread, J9JITDecompileState * decompileState, J9JITDecompilationInfo * decompRecord, J9OSRFrame *osrFrame);
static void markMethodBreakpointed(J9VMThread * currentThread, J9JITBreakpointedMethod * breakpointedMethod);
static UDATA codeBreakpointAddedFrameIterator(J9VMThread * currentThread, J9StackWalkState * walkState);
static void decompileAllMethodsInAllStacks(J9VMThread * currentThread, UDATA reason);
static void markMethodUnbreakpointed(J9VMThread * currentThread, J9JITBreakpointedMethod * breakpointedMethod);
static void reinstallAllBreakpoints(J9VMThread * currentThread);
static UDATA decompileMethodFrameIterator(J9VMThread * currentThread, J9StackWalkState * walkState);
static void deleteAllDecompilations(J9VMThread * currentThread, UDATA reason, J9Method * method);
static void freeDecompilationRecord(J9VMThread * decompileThread, J9JITDecompilationInfo * info, UDATA retain);
static UDATA osrAllFramesSize(J9VMThread *currentThread, J9JITExceptionTable *metaData, void *jitPC, UDATA resolveFrameFlags);
static UDATA performOSR(J9VMThread *currentThread, J9StackWalkState *walkState, J9OSRBuffer *osrBuffer, U_8 *osrScratchBuffer, UDATA scratchBufferSize, UDATA jitStackFrameSize, UDATA *mustDecompile);
static UDATA* jitLocalSlotAddress(J9VMThread * currentThread, J9StackWalkState *walkState, UDATA slot, UDATA inlineDepth);
static void jitResetAllMethods(J9VMThread *currentThread);
static void fixStackForNewDecompilation(J9VMThread * currentThread, J9StackWalkState * walkState, J9JITDecompilationInfo *info, UDATA reason, J9JITDecompilationInfo **link);
static UDATA roundedOSRScratchBufferSize(J9VMThread * currentThread, J9JITExceptionTable *metaData, void *jitPC);
static j9object_t* getObjectSlotAddress(J9OSRData *osrData, U_16 slot);
static UDATA createMonitorEnterRecords(J9VMThread *currentThread, J9OSRData *osrData);
static UDATA initializeOSRFrame(J9VMThread *currentThread, J9OSRData *osrData);
static UDATA initializeOSRBuffer(J9VMThread *currentThread, J9OSRBuffer *osrBuffer, J9OSRData *osrData);
static UDATA getPendingStackHeight(J9VMThread *currentThread, U_8 *interpreterPC, J9Method *ramMethod, UDATA resolveFrameFlags);
static J9JITDecompilationInfo* jitAddDecompilationForFramePop(J9VMThread * currentThread, J9StackWalkState * walkState);
static J9JITDecompilationInfo* fetchAndUnstackDecompilationInfo(J9VMThread *currentThread);
static void fixSavedPC(J9VMThread *currentThread, J9JITDecompilationInfo *decompRecord);
static void dumpStack(J9VMThread *currentThread, char const *msg);
static J9ROMNameAndSignature* getNASFromInvoke(U_8 *bytecodePC, J9ROMClass *romClass);
/**
* Get the J9ROMNameAndSignature for an invoke bytecode.
*
* @param[in] bytecodePC the PC of the invoke
* @param[in] romClass the J9ROMClass containing the invoke bytecode
*
* @return the J9ROMNameAndSignature referenced by the invoke
*/
static J9ROMNameAndSignature*
getNASFromInvoke(U_8 *bytecodePC, J9ROMClass *romClass)
{
U_16 cpIndex = *(U_16*)(bytecodePC + 1);
J9ROMNameAndSignature* nameAndSig = NULL;
U_8 bytecode = *bytecodePC;
if (JBinvokedynamic == bytecode) {
/* Convert from callSites table index to actual cpIndex by probing the
* J9ROMClass->callSiteData table. That data is layed out as:
* callSiteCount x SRP to: J9ROMNameAndSignature, callSiteCount x U16, bsmCount x J9BSMData
*/
J9SRP *callSiteData = (J9SRP *) J9ROMCLASS_CALLSITEDATA(romClass);
nameAndSig = SRP_PTR_GET(callSiteData + cpIndex, J9ROMNameAndSignature*);
} else {
switch(bytecode) {
case JBinvokeinterface2:
cpIndex = *(U_16*)(bytecodePC + 3);
break;
case JBinvokestaticsplit:
cpIndex = *(J9ROMCLASS_STATICSPLITMETHODREFINDEXES(romClass) + cpIndex);
break;
case JBinvokespecialsplit:
cpIndex = *(J9ROMCLASS_SPECIALSPLITMETHODREFINDEXES(romClass) + cpIndex);
break;
}
J9ROMMethodRef * romMethodRef = ((J9ROMMethodRef *) &(J9_ROM_CP_FROM_ROM_CLASS(romClass)[cpIndex]));
nameAndSig = J9ROMMETHODREF_NAMEANDSIGNATURE(romMethodRef);
}
return nameAndSig;
}
/**
* Pop the top of the decompilation stack.
*
* @param[in] currentThread the current J9VMThread
*
* @return the top element from the decompilation stack
*/
static J9JITDecompilationInfo*
fetchAndUnstackDecompilationInfo(J9VMThread *currentThread)
{
J9JITDecompilationInfo *decompRecord = currentThread->decompilationStack;
currentThread->decompilationStack = decompRecord->next;
return decompRecord;
}
/**
* Restore the PC from a decompilation record to its original location.
*
* @param[in] currentThread the current J9VMThread
* @param[in] decompRecord the decompilation record
*/
static void
fixSavedPC(J9VMThread *currentThread, J9JITDecompilationInfo *decompRecord)
{
*decompRecord->pcAddress = decompRecord->pc;
}
/**
* If the verbose stack dumper is enabled, dump the stack of the current thread.
*
* @param[in] currentThread the current J9VMThread
* @param[in] msg the header message for the stack dump
*/
static void
dumpStack(J9VMThread *currentThread, char const *msg)
{
J9JavaVM *vm = currentThread->javaVM;
if (NULL != vm->verboseStackDump) {
vm->verboseStackDump(currentThread, msg);
}
}
static void
decompPrintMethod(J9VMThread * currentThread, J9Method * method)
{
PORT_ACCESS_FROM_VMC(currentThread);
J9UTF8 * className = J9ROMCLASS_CLASSNAME(UNTAGGED_METHOD_CP(method)->ramClass->romClass);
J9ROMMethod * romMethod = J9_ROM_METHOD_FROM_RAM_METHOD(method);
J9UTF8 * name = J9ROMMETHOD_NAME(romMethod);
J9UTF8 * sig = J9ROMMETHOD_SIGNATURE(romMethod);
Trc_Decomp_printMethod(currentThread, method, J9UTF8_LENGTH(className), J9UTF8_DATA(className), J9UTF8_LENGTH(name), J9UTF8_DATA(name), J9UTF8_LENGTH(sig), J9UTF8_DATA(sig));
}
static void
jitResetAllMethods(J9VMThread *currentThread)
{
J9JavaVM * vm = currentThread->javaVM;
J9InternalVMFunctions *vmFuncs = vm->internalVMFunctions;
J9Class * clazz = NULL;
J9ClassWalkState state;
/* First mark every compiled method for retranslation and invalidate the translation */
clazz = vmFuncs->allClassesStartDo(&state, vm, NULL);
while (clazz != NULL) {
J9Method *method = clazz->ramMethods;
U_32 methodCount = clazz->romClass->romMethodCount;
while (methodCount != 0) {
if (0 == ((UDATA)method->extra & J9_STARTPC_NOT_TRANSLATED)) {
/* Do not reset JIT INLs (currently in FSD there are no compiled JNI natives) */
if (0 == (J9_ROM_METHOD_FROM_RAM_METHOD(method)->modifiers & J9AccNative)) {
J9JITExceptionTable *metaData = vm->jitConfig->jitGetExceptionTableFromPC(currentThread, (UDATA) method->extra);
if (NULL != metaData) {
/* 0xCC is the "int3" instruction on x86.
* This will cause a crash if this instruction is executed.
* On other platforms, this will have unknown behaviour (likely a crash).
*/
*(U_8*)method->extra = 0xCC;
}
vmFuncs->initializeMethodRunAddress(currentThread, method);
}
}
method += 1;
methodCount -= 1;
}
clazz = vmFuncs->allClassesNextDo(&state);
}
vmFuncs->allClassesEndDo(&state);
/* Now fix all the JIT vTables */
clazz = vmFuncs->allClassesStartDo(&state, vm, NULL);
while (clazz != NULL) {
/* Interface classes do not have vTables, so skip them */
if (!J9ROMCLASS_IS_INTERFACE(clazz->romClass)) {
UDATA *vTableWriteCursor = JIT_VTABLE_START_ADDRESS(clazz);
J9VTableHeader *vTableHeader = J9VTABLE_HEADER_FROM_RAM_CLASS(clazz);
J9Method **vTableReadCursor = J9VTABLE_FROM_HEADER(vTableHeader);
UDATA vTableSize = vTableHeader->size;
/* Put invalid entries in the obsolete JIT vTables and reinitialize the current ones */
if (J9_IS_CLASS_OBSOLETE(clazz)) {
while (0 != vTableSize) {
*vTableWriteCursor = (UDATA)-1;
vTableWriteCursor -= 1;
vTableSize -= 1;
}
} else {
while (0 != vTableSize) {
J9Method *method = *vTableReadCursor;
vTableReadCursor += 1;
vmFuncs->fillJITVTableSlot(currentThread, vTableWriteCursor, method);
vTableWriteCursor -= 1;
vTableSize -= 1;
}
}
}
clazz = vmFuncs->allClassesNextDo(&state);
}
vmFuncs->allClassesEndDo(&state);
}
#if (defined(J9VM_INTERP_HOT_CODE_REPLACEMENT)) /* priv. proto (autogen) */
J9JITDecompilationInfo *
jitCleanUpDecompilationStack(J9VMThread * currentThread, J9StackWalkState * walkState, UDATA dropCurrentFrame)
{
PORT_ACCESS_FROM_VMC(currentThread);
J9JITDecompilationInfo * current;
J9JITDecompilationInfo * currentFrameDecompile = NULL;
current = currentThread->decompilationStack;
while (current != walkState->decompilationStack) {
J9JITDecompilationInfo * temp = current;
if (!dropCurrentFrame) {
if (current->bp == walkState->bp) {
currentFrameDecompile = current;
break;
}
}
current = current->next;
freeDecompilationRecord(currentThread, temp, FALSE);
}
currentThread->decompilationStack = current;
return currentFrameDecompile;
}
#endif /* J9VM_INTERP_HOT_CODE_REPLACEMENT (autogen) */
void
jitCodeBreakpointAdded(J9VMThread * currentThread, J9Method * method)
{
PORT_ACCESS_FROM_VMC(currentThread);
J9JITConfig * jitConfig = currentThread->javaVM->jitConfig;
J9JITBreakpointedMethod * breakpointedMethod;
J9JITBreakpointedMethod * breakpointedMethods = jitConfig->breakpointedMethods;
J9VMThread * loopThread;
/* Called under exclusive access, so no mutex required */
Trc_Decomp_jitCodeBreakpointAdded_Entry(currentThread, method);
decompPrintMethod(currentThread, method);
breakpointedMethod = breakpointedMethods;
while (breakpointedMethod) {
if (breakpointedMethod->method == method) {
++(breakpointedMethod->count);
Trc_Decomp_jitCodeBreakpointAdded_incCount(currentThread, breakpointedMethod->count);
return;
}
breakpointedMethod = breakpointedMethod->link;
}
Trc_Decomp_jitCodeBreakpointAdded_newEntry(currentThread);
breakpointedMethod = (J9JITBreakpointedMethod *) j9mem_allocate_memory(sizeof(J9JITBreakpointedMethod), OMRMEM_CATEGORY_JIT);
if (!breakpointedMethod) {
j9tty_printf(PORTLIB, "\n*** alloc failure in jitPermanentBreakpointAdded ***\n");
Assert_Decomp_breakpointFailed();
}
breakpointedMethod->link = breakpointedMethods;
jitConfig->breakpointedMethods = breakpointedMethod;
breakpointedMethod->method = method;
breakpointedMethod->count = 1;
markMethodBreakpointed(currentThread, breakpointedMethod);
Trc_Decomp_jitCodeBreakpointAdded_hasBeenTranslated(currentThread, breakpointedMethod->hasBeenTranslated);
loopThread = currentThread;
do {
J9StackWalkState walkState;
walkState.userData1 = method;
walkState.flags = J9_STACKWALK_ITERATE_FRAMES | J9_STACKWALK_SKIP_INLINES | J9_STACKWALK_VISIBLE_ONLY | J9_STACKWALK_ITERATE_HIDDEN_JIT_FRAMES | J9_STACKWALK_MAINTAIN_REGISTER_MAP;
walkState.skipCount = 0;
walkState.frameWalkFunction = codeBreakpointAddedFrameIterator;
walkState.walkThread = loopThread;
currentThread->javaVM->walkStackFrames(currentThread, &walkState);
} while ((loopThread = loopThread->linkNext) != currentThread);
Trc_Decomp_jitCodeBreakpointAdded_Exit(currentThread);
}
void
jitCodeBreakpointRemoved(J9VMThread * currentThread, J9Method * method)
{
PORT_ACCESS_FROM_VMC(currentThread);
J9JITConfig * jitConfig = currentThread->javaVM->jitConfig;
J9JITBreakpointedMethod ** previous = &(jitConfig->breakpointedMethods);
J9JITBreakpointedMethod * breakpointedMethod;
/* Called under exclusive access, so no mutex required */
Trc_Decomp_jitCodeBreakpointRemoved_Entry(currentThread, method);
decompPrintMethod(currentThread, method);
while ((breakpointedMethod = *previous) != NULL) {
if (breakpointedMethod->method == method) {
UDATA count;
if ( (count = --(breakpointedMethod->count)) == 0) {
Trc_Decomp_jitCodeBreakpointAdded_fixingMethods(currentThread);
markMethodUnbreakpointed(currentThread, breakpointedMethod);
*previous = breakpointedMethod->link;
j9mem_free_memory(breakpointedMethod);
deleteAllDecompilations(currentThread, JITDECOMP_CODE_BREAKPOINT, method);
}
Trc_Decomp_jitCodeBreakpointRemoved_decCount(currentThread, count);
return;
}
previous = &(breakpointedMethod->link);
}
Trc_Decomp_jitCodeBreakpointAdded_Failed(currentThread);
}
static UDATA
codeBreakpointAddedFrameIterator(J9VMThread * currentThread, J9StackWalkState * walkState)
{
/* Decompile JIT frames running the breakpointed method */
if (walkState->jitInfo && (walkState->method == (J9Method *) walkState->userData1)) {
addDecompilation(currentThread, walkState, JITDECOMP_CODE_BREAKPOINT);
}
return J9_STACKWALK_KEEP_ITERATING;
}
#if (defined(J9VM_INTERP_HOT_CODE_REPLACEMENT)) /* priv. proto (autogen) */
void
jitHotswapOccurred(J9VMThread * currentThread)
{
/* We have exclusive */
Trc_Decomp_jitHotswapOccurred_Entry(currentThread);
/* Remove all breakpoints before resetting the methods */
removeAllBreakpoints(currentThread);
/* Find every method which has been translated and mark it for retranslation */
jitResetAllMethods(currentThread);
/* Reinstall the breakpoints */
reinstallAllBreakpoints(currentThread);
/* Mark every JIT method in every stack for decompilation */
decompileAllMethodsInAllStacks(currentThread, JITDECOMP_HOTSWAP);
Trc_Decomp_jitHotswapOccurred_Exit(currentThread);
}
#endif /* J9VM_INTERP_HOT_CODE_REPLACEMENT (autogen) */
void
jitDecompileMethod(J9VMThread * currentThread, J9JITDecompilationInfo * decompRecord)
{
J9JITDecompileState decompileState;
J9StackWalkState walkState;
J9OSRBuffer *osrBuffer = &decompRecord->osrBuffer;
UDATA numberOfFrames = osrBuffer->numberOfFrames;
J9OSRFrame *osrFrame = (J9OSRFrame*)(osrBuffer + 1);
/* Collect the required information from the stack - top visible frame is the decompile frame */
walkState.flags = J9_STACKWALK_ITERATE_FRAMES | J9_STACKWALK_SKIP_INLINES | J9_STACKWALK_VISIBLE_ONLY | J9_STACKWALK_MAINTAIN_REGISTER_MAP | J9_STACKWALK_ITERATE_HIDDEN_JIT_FRAMES | J9_STACKWALK_SAVE_STACKED_REGISTERS;
walkState.skipCount = 0;
walkState.frameWalkFunction = decompileMethodFrameIterator;
walkState.walkThread = currentThread;
walkState.userData1 = &decompileState;
walkState.userData2 = NULL;
currentThread->javaVM->walkStackFrames(currentThread, &walkState);
performDecompile(currentThread, &decompileState, decompRecord, osrFrame, numberOfFrames);
freeDecompilationRecord(currentThread, decompRecord, TRUE);
}
/**
* Find the pending stack height for a frame.
*
* @param[in] *currentThread current thread
* @param[in] *interpreterP the bytecoded PC
* @param[in] *method the J9Method
* @param[in] resolveFrameFlags the flags of the preceding resolve frame, or 0 if not preceded by a resolve frame
*
* @return the pending stack height
*/
static UDATA
getPendingStackHeight(J9VMThread *currentThread, U_8 *interpreterPC, J9Method *ramMethod, UDATA resolveFrameFlags)
{
UDATA pendingStackHeight = 0;
/* If the JIT frame has not been built, the pending stack height is 0. If we're at an exception catch,
* the height is 0 because the decompile return point will push the pending exception.
*/
UDATA resolveFrameType = resolveFrameFlags & J9_STACK_FLAGS_JIT_FRAME_SUB_TYPE_MASK;
switch(resolveFrameType) {
case J9_STACK_FLAGS_JIT_STACK_OVERFLOW_RESOLVE_FRAME:
case J9_STACK_FLAGS_JIT_EXCEPTION_CATCH_RESOLVE:
break;
default:
J9ROMClass *romClass = J9_CLASS_FROM_METHOD(ramMethod)->romClass;
J9ROMMethod * originalROMMethod = getOriginalROMMethod(ramMethod);
UDATA offsetPC = interpreterPC - J9_BYTECODE_START_FROM_RAM_METHOD(ramMethod);
J9JavaVM *vm = currentThread->javaVM;
J9InternalVMFunctions *vmFuncs = vm->internalVMFunctions;
J9PortLibrary *portLibrary = vm->portLibrary;
U_8 bytecode = *interpreterPC;
/* Use the stack mapper to determine the pending stack height */
pendingStackHeight = (UDATA)vmFuncs->j9stackmap_StackBitsForPC(portLibrary, offsetPC, romClass, originalROMMethod, NULL, 0, NULL, NULL, NULL);
/* All invokes consider their arguments not to be pending - remove the arguments from the pending stack */
switch(bytecode) {
case JBinvokevirtual:
case JBinvokespecial:
case JBinvokespecialsplit:
case JBinvokeinterface:
case JBinvokeinterface2:
case JBinvokehandle:
case JBinvokehandlegeneric:
/* Remove implicit receiver from pending stack */
pendingStackHeight -= 1;
/* Intentional fall-through */
case JBinvokedynamic:
case JBinvokestatic:
case JBinvokestaticsplit:
/* Remove arguments from pending stack */
pendingStackHeight -= getSendSlotsFromSignature(J9UTF8_DATA(J9ROMNAMEANDSIGNATURE_SIGNATURE(getNASFromInvoke(interpreterPC, romClass))));
break;
}
/* Reduce the pending stack height for the resolve special cases */
switch (resolveFrameType) {
case J9_STACK_FLAGS_JIT_MONITOR_ENTER_RESOLVE:
/* Decompile after monitorenter completes. Remove the object from the pending stack. */
pendingStackHeight -= 1;
break;
case J9_STACK_FLAGS_JIT_ALLOCATION_RESOLVE:
/* Decompile after allocation completes. The JIT has not mapped the bytecode parameters in the pending stack */
switch (bytecode) {
case JBanewarray:
case JBnewarray: /* 1 slot (size) stacked */
pendingStackHeight -= 1;
break;
case JBmultianewarray: /* Dimensions stacked (number of dimensions is 3 bytes from the multianewarray) */
pendingStackHeight -= interpreterPC[3];
break;
default: /* JBnew - no stacked parameters*/
break;
}
}
}
Assert_CodertVM_true((IDATA)pendingStackHeight >= 0);
Trc_Decomp_decompileMethodFrameIterator_pendingCount(currentThread, pendingStackHeight);
return pendingStackHeight;
}
static UDATA
decompileMethodFrameIterator(J9VMThread * currentThread, J9StackWalkState * walkState)
{
J9JITDecompileState * decompileState = (J9JITDecompileState *) walkState->userData1;
Trc_Decomp_decompileMethodFrameIterator_Entry(currentThread);
/* If the decompile frame has already been passed, record the final information and stop walking */
if (walkState->userData2) {
if (walkState->jitInfo) {
UDATA * valueCursor = decompileState->preservedRegisterValues;
UDATA ** mapCursor = (UDATA **) &(walkState->registerEAs);
UDATA i;
decompileState->previousFrameBytecodes = FALSE;
for (i = 0; i < J9SW_JIT_CALLEE_PRESERVED_SIZE; ++i) {
UDATA regNumber = jitCalleeSavedRegisterList[i];
*(valueCursor++) = *(mapCursor[regNumber]);
}
Trc_Decomp_decompileMethodFrameIterator_previousIsJIT(currentThread);
} else {
Trc_Decomp_decompileMethodFrameIterator_previousIsBC(currentThread);
decompileState->previousFrameBytecodes = TRUE;
}
return J9_STACKWALK_STOP_ITERATING;
} else {
/* Current frame is the decompile frame - collect the preliminary info */
J9JITExceptionTable *metaData = walkState->jitInfo;
J9Method *method = walkState->method;
decompileState->metaData = metaData;
decompileState->method = method;
decompileState->sp = walkState->sp;
decompileState->argCount = walkState->outgoingArgCount;
Trc_Decomp_decompileMethodFrameIterator_outgoingArgCount(currentThread, decompileState->argCount);
decompileState->bp = walkState->bp;
decompileState->a0 = walkState->arg0EA;
decompileState->literals = method;
decompileState->unwindSP = walkState->unwindSP;
decompileState->j2iFrame = walkState->j2iFrame;
memcpy(&(decompileState->i2jState), walkState->i2jState, sizeof(J9I2JState));
decompileState->resolveFrameFlags = walkState->resolveFrameFlags;
/* Walk the next frame regardless of its visibility */
walkState->userData2 = (void *) 1;
walkState->flags &= ~J9_STACKWALK_VISIBLE_ONLY;
}
Trc_Decomp_decompileMethodFrameIterator_Exit(currentThread);
return J9_STACKWALK_KEEP_ITERATING;
}
/**
* Push a bytecode frame based on an OSR frame. Assumes that a bytecode frame
* (either pure or J2I) is already on the top of stack.
*
* @param[in] *currentThread current thread
* @param[in] *osrFrame the OSR frame from which to copy the information
*/
static void
buildBytecodeFrame(J9VMThread *currentThread, J9OSRFrame *osrFrame)
{
J9Method *method = osrFrame->method;
U_8 *bytecodePC = osrFrame->bytecodePCOffset + J9_BYTECODE_START_FROM_RAM_METHOD(method);
UDATA numberOfLocals = osrFrame->numberOfLocals;
UDATA maxStack = osrFrame->maxStack;
UDATA pendingStackHeight = osrFrame->pendingStackHeight;
UDATA *locals = ((UDATA*)(osrFrame + 1)) + maxStack;
UDATA *pending = locals - pendingStackHeight;
UDATA *sp = currentThread->sp;
UDATA *a0 = currentThread->arg0EA;
U_8 *pc = currentThread->pc;
J9Method *literals = currentThread->literals;
UDATA *newA0 = sp - 1;
J9SFStackFrame *stackFrame = NULL;
/* Push the locals */
sp -= numberOfLocals;
memcpy(sp, locals, numberOfLocals * sizeof(UDATA));
/* Push the stack frame */
stackFrame = (J9SFStackFrame*)sp - 1;
stackFrame->savedPC = pc;
stackFrame->savedCP = literals;
stackFrame->savedA0 = a0;
/* Push the pendings */
sp = (UDATA*)stackFrame - pendingStackHeight;
memcpy(sp, pending, pendingStackHeight * sizeof(UDATA));
/* Update the root values in the J9VMThread */
currentThread->arg0EA = newA0;
currentThread->pc = bytecodePC;
currentThread->literals = method;
currentThread->sp = sp;
}
/**
* Recursive helper for decompiling inlined frames.
*
* @param[in] *currentThread current thread
* @param[in] *decompileState the decompilation state copied from the stack walk
* @param[in] *decompRecord the decompilation record
* @param[in] inlineDepth the depth of inlining, 0 for the outer frame
* @param[in] *osrFrame the OSR frame from which to copy the information
*/
static void
buildInlineStackFrames(J9VMThread *currentThread, J9JITDecompileState *decompileState, J9JITDecompilationInfo *decompRecord, UDATA inlineDepth, J9OSRFrame *osrFrame)
{
J9JavaVM *vm = currentThread->javaVM;
J9MonitorEnterRecord *firstEnterRecord = osrFrame->monitorEnterRecords;
J9Method *method = osrFrame->method;
if (0 == inlineDepth) {
decompileOuterFrame(currentThread, decompileState, decompRecord, osrFrame);
} else {
J9OSRFrame *nextOSRFrame = (J9OSRFrame*)((U_8*)osrFrame + osrFrameSize(method));
buildInlineStackFrames(currentThread, decompileState, decompRecord, inlineDepth - 1, nextOSRFrame);
buildBytecodeFrame(currentThread, osrFrame);
}
/* Fix all of the monitor enter records for this frame to point to the new arg0EA.
* Filter out the record for the syncObject in synchronized methods. Only one such
* record will ever be detected in any frame. Link the remaining records into the list.
*/
if (NULL != firstEnterRecord) {
J9MonitorEnterRecord listHead;
J9MonitorEnterRecord *lastEnterRecord = &listHead;
J9MonitorEnterRecord *enterRecord = firstEnterRecord;
UDATA *arg0EA = currentThread->arg0EA;
j9object_t syncObject = NULL;
if (J9_ROM_METHOD_FROM_RAM_METHOD(method)->modifiers & J9AccSynchronized) {
syncObject = *(j9object_t*)(arg0EA - osrFrame->numberOfLocals + 1);
}
listHead.next = firstEnterRecord;
do {
J9MonitorEnterRecord *nextRecord = enterRecord->next;
if (enterRecord->object == syncObject) {
syncObject = NULL; /* Make sure syncObject isn't matched more than once */
lastEnterRecord->next = nextRecord;
pool_removeElement(currentThread->monitorEnterRecordPool, enterRecord);
} else {
enterRecord->arg0EA = CONVERT_TO_RELATIVE_STACK_OFFSET(currentThread, arg0EA);
lastEnterRecord = enterRecord;
}
enterRecord = nextRecord;
} while (NULL != enterRecord);
lastEnterRecord->next = currentThread->monitorEnterRecords;
currentThread->monitorEnterRecords = listHead.next;
}
/* If this frame has a notify frame pop pending, set the bit */
if (osrFrame->flags & J9OSRFRAME_NOTIFY_FRAME_POP) {
UDATA *bp = currentThread->arg0EA - osrFrame->numberOfLocals;
Trc_Decomp_performDecompile_addedPopNotification(currentThread, bp);
*bp |= J9SF_A0_REPORT_FRAME_POP_TAG;
}
}
/**
* Perform decompilation after gather information from the stack walk.
*
* @param[in] *currentThread current thread
* @param[in] *decompileState the decompilation state copied from the stack walk
* @param[in] *decompRecord the decompilation record
* @param[in] *osrFrame the first OSR frame to rebuild
* @param[in] numberOfFrames the total number of frames to rebuild
*/
static void
performDecompile(J9VMThread *currentThread, J9JITDecompileState *decompileState, J9JITDecompilationInfo *decompRecord, J9OSRFrame *osrFrame, UDATA numberOfFrames)
{
J9JavaVM *vm = currentThread->javaVM;
UDATA outgoingArgs[255];
UDATA outgoingArgCount = decompileState->argCount;
UDATA inlineDepth = numberOfFrames - 1;
Trc_Decomp_performDecompile_Entry(currentThread);
dumpStack(currentThread, "before decompilation");
if (FALSE == decompRecord->usesOSR) {
/* Not compiled with OSR - copy stack slots from JIT frame into OSR frame */
UDATA *jitTempBase = ((UDATA *) (((U_8 *) decompileState->bp) + ((J9JITStackAtlas *) decompileState->metaData->gcStackAtlas)->localBaseOffset)) + decompileState->metaData->tempOffset;
UDATA *osrTempBase = ((UDATA*)(osrFrame + 1)) + osrFrame->maxStack;
J9ROMMethod * romMethod = J9_ROM_METHOD_FROM_RAM_METHOD(osrFrame->method);
UDATA argCount = J9_ARG_COUNT_FROM_ROM_METHOD(romMethod);
UDATA tempCount = osrFrame->numberOfLocals - argCount;
UDATA pendingStackHeight = osrFrame->pendingStackHeight;
/* Decompiling without OSR means old-style single-frame FSD */
Assert_CodertVM_true(vm->jitConfig->fsdEnabled);
Assert_CodertVM_true(1 == numberOfFrames);
/* The pending slots immediately precede the temps in both the OSR frame and the JIT frame, so copy them all at once */
memcpy(osrTempBase - pendingStackHeight, jitTempBase - pendingStackHeight, (tempCount + pendingStackHeight) * sizeof(UDATA));
}
/* Temporarily copy the outgoing arguments to the C stack */
memcpy(outgoingArgs, decompileState->sp, outgoingArgCount * sizeof(UDATA));
/* Rebuild the interpreter stack frames */
buildInlineStackFrames(currentThread, decompileState, decompRecord, inlineDepth, osrFrame);
/* Push the outgoing arguments onto the java stack */
currentThread->sp -= outgoingArgCount;
memcpy(currentThread->sp, outgoingArgs, outgoingArgCount * sizeof(UDATA));
Trc_Decomp_performDecompile_Exit(currentThread, currentThread->sp);
}
/**
* Decompile the outer (and possibly only) frame.
*
* @param[in] *currentThread current thread
* @param[in] *decompileState the decompilation state copied from the stack walk
* @param[in] *decompRecord the decompilation record
* @param[in] *osrFrame the OSR frame from which to copy the information
*/
static void
decompileOuterFrame(J9VMThread * currentThread, J9JITDecompileState * decompileState, J9JITDecompilationInfo * decompRecord, J9OSRFrame *osrFrame)
{
UDATA * newTempBase;
UDATA * oldTempBase;
UDATA * newPendingBase;
UDATA * oldPendingBase;
UDATA * stackFrame;
UDATA * newSP;
J9Method *method = osrFrame->method;
J9ROMMethod * romMethod = J9_ROM_METHOD_FROM_RAM_METHOD(method);
UDATA argCount = J9_ARG_COUNT_FROM_ROM_METHOD(romMethod);
UDATA numberOfLocals = osrFrame->numberOfLocals;
UDATA tempCount = numberOfLocals - argCount;
U_8 ** jitReturnPCAddress = (U_8 **) &(((J9JITFrame *) (decompileState->bp))->returnPC);
U_8 * jitReturnPC = *jitReturnPCAddress;
UDATA * currentJ2iFrame = decompileState->j2iFrame;
UDATA pendingStackHeight = osrFrame->pendingStackHeight;
oldTempBase = ((UDATA*)(osrFrame + 1)) + osrFrame->maxStack;
/* Determine the shape of the new stack frame */
newTempBase = decompileState->a0 - numberOfLocals + 1;
if (decompileState->previousFrameBytecodes) {
/* Use the I2J returnSP in this case in order to account for the possible 8-alignment of the I2J args */
UDATA * correctTempBase = UNTAG2(decompileState->i2jState.returnSP, UDATA *) - numberOfLocals;
/* If the args were moved for alignment, copy them back to their original position */
if (newTempBase != correctTempBase) {
UDATA * newA0 = correctTempBase + numberOfLocals - 1;
memmove(correctTempBase + tempCount, newTempBase + tempCount, argCount * sizeof(UDATA));
newTempBase = correctTempBase;
decompileState->a0 = newA0;
}
stackFrame = (UDATA *) (((U_8 *) newTempBase) - sizeof(J9SFStackFrame));
} else {
stackFrame = (UDATA *) (((U_8 *) newTempBase) - sizeof(J9SFJ2IFrame));
}
newPendingBase = stackFrame - pendingStackHeight;
oldPendingBase = oldTempBase - pendingStackHeight;
newSP = newPendingBase;
/* If the JIT stack frame has not been constructed, don't attempt to read from it */
UDATA resolveFrameType = decompileState->resolveFrameFlags & J9_STACK_FLAGS_JIT_FRAME_SUB_TYPE_MASK;
if (J9_STACK_FLAGS_JIT_STACK_OVERFLOW_RESOLVE_FRAME == resolveFrameType) {
Trc_Decomp_performDecompile_monitorNotEntered(currentThread);
/* Temps have not been pushed yet - zero them and set up the sync object (if any) */
memset(newTempBase, 0, tempCount * sizeof(UDATA));
if (romMethod->modifiers & J9AccSynchronized) {
if (romMethod->modifiers & J9AccStatic) {
newTempBase[0] = (UDATA)J9VM_J9CLASS_TO_HEAPCLASS(J9_CLASS_FROM_METHOD(method));
} else {
newTempBase[0] = *(decompileState->a0);
}
} else if (J9ROMMETHOD_IS_NON_EMPTY_OBJECT_CONSTRUCTOR(romMethod)) {
newTempBase[0] = *(decompileState->a0);
}
} else {
/* Copy the temps to their new location */
memcpy(newTempBase, oldTempBase, tempCount * sizeof(UDATA));
}
/* Copy pending pushes */
memcpy(newPendingBase, oldPendingBase, pendingStackHeight * sizeof(UDATA));
/* Create the stack frame, either a pure bytecode frame or a J2I frame, depending on the previous frame. */
if (decompileState->previousFrameBytecodes) {
J9SFStackFrame * bytecodeFrame = (J9SFStackFrame *) stackFrame;
Trc_Decomp_performDecompile_buildingBCFrame(currentThread, stackFrame);
bytecodeFrame->savedPC = decompileState->i2jState.pc;
bytecodeFrame->savedCP = decompileState->i2jState.literals;
bytecodeFrame->savedA0 = decompileState->i2jState.a0;
} else {
J9SFJ2IFrame * j2iFrame = (J9SFJ2IFrame *) stackFrame;
char * returnChar;
J9JITDecompilationInfo * info;
Trc_Decomp_performDecompile_buildingJ2IFrame(currentThread, stackFrame);
memcpy(&(j2iFrame->i2jState), &(decompileState->i2jState), sizeof(J9I2JState));
memcpy(&(j2iFrame->J9SW_LOWEST_MEMORY_PRESERVED_REGISTER), decompileState->preservedRegisterValues, J9SW_JIT_CALLEE_PRESERVED_SIZE * sizeof(UDATA));
j2iFrame->specialFrameFlags = J9_STACK_FLAGS_JIT_CALL_IN_FRAME | J9_STACK_FLAGS_JIT_CALL_IN_TYPE_J2_I;
j2iFrame->returnAddress = jitReturnPC;
j2iFrame->previousJ2iFrame = currentJ2iFrame;
currentJ2iFrame = (UDATA *) &(j2iFrame->taggedReturnSP);
returnChar = (char *) J9UTF8_DATA(J9ROMMETHOD_SIGNATURE(romMethod));
while (*returnChar++ != ')') ;
switch(*returnChar) {
case 'V':
j2iFrame->exitPoint = J9_BUILDER_SYMBOL(jitExitInterpreter0);
break;
case 'D':
j2iFrame->exitPoint = J9_BUILDER_SYMBOL(jitExitInterpreterD);
break;
case 'F':
j2iFrame->exitPoint = J9_BUILDER_SYMBOL(jitExitInterpreterF);
break;
case 'J':
#ifdef J9VM_ENV_DATA64
case '[':
case 'L':
#endif
j2iFrame->exitPoint = J9_BUILDER_SYMBOL(jitExitInterpreterJ);
break;
default:
j2iFrame->exitPoint = J9_BUILDER_SYMBOL(jitExitInterpreter1);
break;
}
#ifdef J9SW_NEEDS_JIT_2_INTERP_CALLEE_ARG_POP
j2iFrame->taggedReturnSP = (UDATA *) (((U_8 *) (((UDATA *) (j2iFrame + 1)) + argCount + tempCount)));
#else
j2iFrame->taggedReturnSP = (UDATA *) (((U_8 *) (((UDATA *) (j2iFrame + 1)) + tempCount)));
#endif
/* If the next thing on the decompilation stack used to point to the return address save slot in the decompiled JIT frame, point it to the slot in the J2I frame. */
if ((info = currentThread->decompilationStack) != NULL) {
if (info->pcAddress == jitReturnPCAddress) {
Trc_Decomp_performDecompile_fixingDecompStack(currentThread, info, info->pcAddress, &(j2iFrame->returnAddress), info->pc);
info->pcAddress = &(j2iFrame->returnAddress);
}
}
}
/* Fill in vmThread values for bytecode execution */
currentThread->pc = osrFrame->bytecodePCOffset + J9_BYTECODE_START_FROM_RAM_METHOD(osrFrame->method);
currentThread->literals = decompileState->literals;
currentThread->arg0EA = decompileState->a0;
currentThread->sp = newSP;
currentThread->j2iFrame = currentJ2iFrame;
/* If the outer framed failed a method monitor enter, hide the interpreted version to prevent exception throw
* from exiting the monitor that was never entered.
*/
if (J9_STACK_FLAGS_JIT_FAILED_METHOD_MONITOR_ENTER_RESOLVE == resolveFrameType) {
newTempBase[-1] |= J9SF_A0_INVISIBLE_TAG;
}
}
/**
* Fix the java stack to account for a newly-added decompilation. This involves modifying
* the return address in the stack which would be used to return to the frame for which the
* decompilation was added.
*
* @param[in] *currentThread current thread
* @param[in] *walkState stack walk state (already at the OSR point)
* @param[in] *info the new decompilation record
* @param[in] reason the reason for the decompilation
* @param[in] **link pointer to the next pointer of the previous decompilation record
* (this may be the root of the decompilation stack)
*/
static void
fixStackForNewDecompilation(J9VMThread * currentThread, J9StackWalkState * walkState, J9JITDecompilationInfo *info, UDATA reason, J9JITDecompilationInfo **link)
{
J9JavaVM* vm = currentThread->javaVM;
U_8 ** pcStoreAddress = walkState->pcAddress;
/* Fill in the decompilation record and link it into the stack */
info->pcAddress = walkState->pcAddress;
info->bp = walkState->bp;
info->method = walkState->method;
info->reason = reason;
info->pc = walkState->pc;
info->next = *link;
*link = info;
/* Slam the return address to point to the appropriate decompile */
if (0 != walkState->resolveFrameFlags) {