pjs/ef/Compiler/CodeGenerator/NativeFormatter.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
//
// NativeFormatter.cpp
//
// Scott M. Silver
//
// Actually output native code for a function to memory (from the NativeCodeCache).
//
// Summary
//
// A NativeFormatter takes an InstructionEmitter (a per/method data structure) and a Method
// (a runtime representation of a method) and actually outputs the native representation
// of the function out to memory. Memory is acquired from the NativeCodeCache.
//
// Each function has the following structural layout:
//
// ControlNodes Formatted Correlation
// PreMethod
// ckBegin Prolog
// ckReturn Epilog
// ckEnd PostMethod
//
// Prolog and Epilog are normal entry and exit points from a function. Note that even
// if a function does not return a value a ckReturn node must exist.
// PreMethod and PostMethod are invented pieces of code/data which may be used
// for debuggers or stack inspection (eg. MacsBug symbols, TraceBack tables, etc...)
#include "NativeFormatter.h"
#include "ControlGraph.h"
#include "InstructionEmitter.h"
#include "NativeCodeCache.h"
#include "ExceptionTable.h"
#ifdef DEBUG
#include "JavaVM.h" // to insert breakpoints in jitted code
#endif
UT_DEFINE_LOG_MODULE(ExceptionMatrix);
//-----------------------------------------------------------------------------------------------------------
// format
//
// Actually output the native instructions of a method out to memory
// acquired from the cache.
//
// outInfo: Normally temporal information about the formatting the function
// mainly used for debugging purposes
void* NativeFormatter::
format(Method& inMethod, FormattedCodeInfo* outInfo)
{
// now setup a FormattedCodeInfo with collected data about the method
FormattedCodeInfo fci;
fci.method = &inMethod;
// Need policy before any formatting can be done
mFormatter.initStackFrameInfo();
mFormatter.calculatePrologEpilog(inMethod, fci.prologSize, fci.epilogSize);
mFormatter.calculatePrePostMethod(inMethod, fci.preMethodSize, fci.postMethodSize);
// potentially shortens or lengthens branches
fci.bodySize = resolveBranches(fci.prologSize, fci.epilogSize);
// actually grab some memory for this method
Uint32 methodSize = fci.preMethodSize + fci.bodySize + fci.postMethodSize;
#ifdef DEBUG
#if defined(XP_PC) || defined(LINUX)
DebugDesc *bps;
Uint32 nbps;
nbps = VM::theVM.getExecBreakPoints(bps);
bool hasInt3 = false;
bool foundBreakPoint = false;
for (Uint32 index = 0; index < nbps; index++)
if (inMethod.isSelf(bps[index].className, bps[index].methodName, bps[index].sig)) {
methodSize++; // for int 3
fci.methodStart = NativeCodeCache::getCache().acquireMemory(methodSize);
*fci.methodStart++ = 0xcc;
hasInt3 = true;
foundBreakPoint = true;
break;
}
if (!foundBreakPoint)
fci.methodStart = NativeCodeCache::getCache().acquireMemory(methodSize);
#else
fci.methodStart = NativeCodeCache::getCache().acquireMemory(methodSize);
#endif
#else
fci.methodStart = NativeCodeCache::getCache().acquireMemory(methodSize);
#endif
// build the exception table
// FIX FIX FIX
// for now just grab some memory
Pool* tempPool = new Pool();
ExceptionTable& eTable = buildExceptionTable(fci.methodStart, tempPool);
DEBUG_LOG_ONLY(eTable.print(UT_LOG_MODULE(ExceptionMatrix)));
DEBUG_LOG_ONLY(eTable.printFormatted(UT_LOG_MODULE(ExceptionMatrix), nodes, nNodes, false));
// fci is now valid
mFormatter.beginFormatting(fci);
// dump out the function to memory
outputNativeToMemory(fci.methodStart, fci);
// make an entry point for this function
MethodDescriptor md(inMethod);
mFormatter.endFormatting(fci);
#if defined(DEBUG) && (defined(XP_PC) || defined(LINUX))
if (hasInt3)
fci.methodStart--;
#endif
PlatformTVector functionDescriptor;
functionDescriptor.setTVector(mFormatter.createTransitionVector(fci));
fci.methodEnd = fci.methodStart + methodSize;
#ifdef WIN32
// temporarily check this invariant
assert((fci.methodStart + methodSize) == (functionDescriptor.getFunctionAddress() + methodSize));
#endif
// Eventually we may wish to have choose different GPR/FPR save procedures and local store sizes for
// different nodes in the control graph. Correspondingly the restore policies in an exception unwind
// can vary by control node -- ie they are not necessarily the same across the whole method.
// For now we will give each method the same info, but we reserve the right later to make this optimisation.
// FIX for mow, NativeCodeCache::mapMemoryToMethod caches a copy of the policy
StackFrameInfo& policy = mFormatter.getStackFrameInfo();
NativeCodeCache::getCache().mapMemoryToMethod(md, functionDescriptor, fci.methodEnd, &eTable, policy);
if (outInfo)
*outInfo = fci;
#ifdef DEBUG_LOG
// debugging stuff
if(VM::theVM.getEmitHTML())
dumpMethodToHTML(fci, eTable);
#endif
// return the entry point
return (fci.methodStart);
}
// outputNativeToMemory
// actually ouput this method to memory starting at inWhere.
// inInfo contains some precalculated information about the method
// which is useful in its formatting.
void NativeFormatter::
outputNativeToMemory(void* inWhere, const FormattedCodeInfo& inInfo)
{
Uint32 curOffset;
char* nextMemory = (char*) inWhere;
assert(nodes[0]->hasControlKind(ckBegin));
assert(nodes[nNodes-1]->hasControlKind(ckEnd));
// first output the PreMethod
mFormatter.formatPreMethodToMemory(nextMemory, inInfo);
nextMemory += inInfo.preMethodSize;
mFormatter.formatPrologToMemory(nextMemory);
nextMemory += inInfo.prologSize;
curOffset = inInfo.prologSize;
for (Uint32 n = 0; n < nNodes; n++)
{
InstructionList& instructions = nodes[n]->getInstructions();
for(InstructionList::iterator i = instructions.begin(); !instructions.done(i); i = instructions.advance(i))
{
Instruction& curInstruction = instructions.get(i);
curInstruction.formatToMemory(nextMemory, curOffset, mFormatter);
curOffset += curInstruction.getFormattedSize(mFormatter);
nextMemory += curInstruction.getFormattedSize(mFormatter);
}
if (nodes[n]->hasControlKind(ckReturn))
{ mFormatter.formatEpilogToMemory(nextMemory);
curOffset += inInfo.epilogSize;
nextMemory += inInfo.epilogSize;
}
}
// Now end with the PostMethod
mFormatter.formatPostMethodToMemory(nextMemory, inInfo);
//nextMemory += inInfo.preMethodSize;
}
// accumulateSize
//
// Accumulate the size of the the formatted (ie in-memory) representation
// of each Instruction in this ControlNode. ckBegin and ckReturn nodes
// include the prolog and epilog size, respectively.
Uint32 NativeFormatter::
accumulateSize(ControlNode& inNode, Uint32 inPrologSize, Uint32 inEpilogSize)
{
Uint32 accum;
InstructionList& instructions = inNode.getInstructions();
accum = 0;
for(InstructionList::iterator i = instructions.begin(); !instructions.done(i); i = instructions.advance(i))
accum += instructions.get(i).getFormattedSize(mFormatter);
if (inNode.hasControlKind(ckReturn))
accum += inEpilogSize;
else if (inNode.hasControlKind(ckBegin))
accum += inPrologSize;
return (accum);
}
// resolveBranches
//
// for each node in the scheduled ControlNodes
// assign a native offset to each ControlNode.
// decisions to make short/long branches would normally be made
// here. returns the size of the formatted method. including
// epilog and prolog. The PreMethod and PostMethod are not
// considered here.
Uint32 NativeFormatter::
resolveBranches(Uint32 inPrologSize, Uint32 inEpilogSize)
{
Uint32 accumSize;
accumSize = 0;
for (Uint32 i = 0; i < nNodes; i++)
{
ControlNode& node = *nodes[i];
Uint32 formattedSize;
node.setNativeOffset(accumSize);
// fix-me this should be a function of the list, ie the list
// should maintain the size of the instructions in it
formattedSize = accumulateSize(node, inPrologSize, inEpilogSize);
accumSize += formattedSize;
}
// make long/short branch decisions here
return (accumSize);
}
// buildExceptionTable
// In: start of method
// pool to create table in
// Out: the Exception Table
// #define DEBUG_GENERATE_EXCEPTION_MATRIX
// Debugging code to print out a matrix of exception handlers
// Ugly -- farm out to a class, time permitting
#ifdef DEBUG_GENERATE_EXCEPTION_MATRIX
#define DEBUG_SET_UP_EXCEPTION_MATRIX \
UT_LOG(ExceptionMatrix, PR_LOG_ALWAYS, ("\n\nBuilding Exception Table\n")); \
assert(nNodes < 100); /* dumb check */ \
int _exceptionMatrix[100][100]; \
Uint32 _rows, _cols; \
for(_rows = 0; _rows < nNodes; _rows++) \
for(_cols = 0; _cols < nNodes; _cols++) \
_exceptionMatrix[_rows][_cols] = 0; \
Uint32 _addorder = 1;
#define DEBUG_ADD_ENTRY_TO_EXCEPTION_MATRIX \
_exceptionMatrix[node->dfsNum][e->getTarget().dfsNum] = _addorder++;
#define DEBUG_PRINT_EXCEPTION_MATRIX \
/* print header */ \
UT_LOG(ExceptionMatrix, PR_LOG_ALWAYS, ("\n\nException Matrix\n ")); \
for(_cols = 0; _cols < nNodes; _cols++) \
UT_LOG(ExceptionMatrix, PR_LOG_ALWAYS, ("N%02d ", nodes[_cols]->dfsNum)); \
UT_LOG(ExceptionMatrix, PR_LOG_ALWAYS, ("\n")); \
/* print rows */ \
for(_rows = 0; _rows < nNodes; _rows++) \
{ \
UT_LOG(ExceptionMatrix, PR_LOG_ALWAYS, (" N%02d: ", nodes[_rows]->dfsNum)); \
for(_cols = 0; _cols < nNodes; _cols++) \
{ \
_addorder = _exceptionMatrix[nodes[_rows]->dfsNum][nodes[_cols]->dfsNum]; \
if(_addorder != 0) \
UT_LOG(ExceptionMatrix, PR_LOG_ALWAYS, (" %02d ", _addorder)); \
else \
UT_LOG(ExceptionMatrix, PR_LOG_ALWAYS, (" - ")); \
} \
UT_LOG(ExceptionMatrix, PR_LOG_ALWAYS, ("\n")); \
} \
UT_LOG(ExceptionMatrix, PR_LOG_ALWAYS, ("\n\n\n"));
#else
#define DEBUG_SET_UP_EXCEPTION_MATRIX
#define DEBUG_ADD_ENTRY_TO_EXCEPTION_MATRIX
#define DEBUG_PRINT_EXCEPTION_MATRIX
#endif // DEBUG_GENERATE_EXCEPTION_MATRIX
ExceptionTable& NativeFormatter::
buildExceptionTable(Uint8* methodStart, Pool* inPool)
{
Uint32 i;
DEBUG_SET_UP_EXCEPTION_MATRIX;
ExceptionTableBuilder eBuilder(methodStart);
for (i = 0; i < nNodes; i++) // iterate through nodes in scheduled order
{
ControlNode* node = nodes[i];
ControlKind kind = node->getControlKind();
if(kind == ckExc || kind == ckAExc || kind == ckThrow)
{ // has exception
ControlNode::ExceptionExtra& excExtra = node->getExceptionExtra();
const Class **exceptionClass = excExtra.handlerFilters + excExtra.nHandlers;
if (kind == ckAExc)
eBuilder.addAEntry(node->getNativeOffset());
// iterate through exception edges
Uint32 startIndex = 0; // start extending exceptions from beginning of table
ControlEdge *e = node->getSuccessorsEnd();
for (Uint32 exceptNum = 0; exceptNum < excExtra.nHandlers; exceptNum++)
{
e--; // move to previous handler edge
exceptionClass--; // move to previous handler filter
assert(&(e->getSource()) == node);
if(e->getTarget().getControlKind() != ckEnd) // only interested in exceptions handled locally
{
// assert(e->getTarget().getControlKind() == ckCatch); // targets of exception edges must be End or Catch nodes
ExceptionTableEntry ete; // container for exception info passing
ete.pStart = node->getNativeOffset();
ete.pEnd = nodes[i+1]->getNativeOffset(); // points to byte after 'node'
ete.pHandler = e->getTarget().getNativeOffset();
ete.pExceptionType = *exceptionClass;
UT_LOG(ExceptionMatrix, PR_LOG_ALWAYS, ("N%02d->N%02d ", node->dfsNum, e->getTarget().dfsNum));
eBuilder.addEntry(startIndex, ete); // note that startIndex is passed by reference
DEBUG_ADD_ENTRY_TO_EXCEPTION_MATRIX;
}
}
}
}
DEBUG_PRINT_EXCEPTION_MATRIX;
DEBUG_ONLY(eBuilder.checkInOrder());
// copy table into new (efficient) storage and insert into NativeCodeCache
ExceptionTable* eTable = new(*inPool) ExceptionTable(eBuilder, *inPool);
return (*eTable);
}