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llvm-project/llvm/lib/Bytecode/Reader/Reader.cpp

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//===- Reader.cpp - Code to read bytecode files ---------------------------===//
//
// This library implements the functionality defined in llvm/Bytecode/Reader.h
//
// Note that this library should be as fast as possible, reentrant, and
// threadsafe!!
//
// TODO: Return error messages to caller instead of printing them out directly.
// TODO: Allow passing in an option to ignore the symbol table
//
//===----------------------------------------------------------------------===//
#include "ReaderInternals.h"
#include "llvm/Bytecode/Reader.h"
#include "llvm/Bytecode/Format.h"
#include "llvm/Module.h"
#include "llvm/Constants.h"
#include "llvm/iPHINode.h"
#include "llvm/iOther.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#include <algorithm>
using std::cerr;
using std::pair;
using std::make_pair;
bool BytecodeParser::getTypeSlot(const Type *Ty, unsigned &Slot) {
if (Ty->isPrimitiveType()) {
Slot = Ty->getPrimitiveID();
} else {
// Check the method level types first...
TypeValuesListTy::iterator I = find(MethodTypeValues.begin(),
MethodTypeValues.end(), Ty);
if (I != MethodTypeValues.end()) {
Slot = FirstDerivedTyID+ModuleTypeValues.size()+
(&*I - &MethodTypeValues[0]);
} else {
I = find(ModuleTypeValues.begin(), ModuleTypeValues.end(), Ty);
if (I == ModuleTypeValues.end()) return true; // Didn't find type!
Slot = FirstDerivedTyID + (&*I - &ModuleTypeValues[0]);
}
}
//cerr << "getTypeSlot '" << Ty->getName() << "' = " << Slot << "\n";
return false;
}
const Type *BytecodeParser::getType(unsigned ID) {
const Type *T = Type::getPrimitiveType((Type::PrimitiveID)ID);
if (T) return T;
//cerr << "Looking up Type ID: " << ID << "\n";
const Value *D = getValue(Type::TypeTy, ID, false);
if (D == 0) return 0;
return cast<Type>(D);
}
int BytecodeParser::insertValue(Value *Val, std::vector<ValueList> &ValueTab) {
unsigned type;
if (getTypeSlot(Val->getType(), type)) return -1;
assert(type != Type::TypeTyID && "Types should never be insertValue'd!");
if (ValueTab.size() <= type)
ValueTab.resize(type+1, ValueList());
//cerr << "insertValue Values[" << type << "][" << ValueTab[type].size()
// << "] = " << Val << "\n";
ValueTab[type].push_back(Val);
return ValueTab[type].size()-1;
}
Value *BytecodeParser::getValue(const Type *Ty, unsigned oNum, bool Create) {
unsigned Num = oNum;
unsigned type; // The type plane it lives in...
if (getTypeSlot(Ty, type)) return 0;
if (type == Type::TypeTyID) { // The 'type' plane has implicit values
assert(Create == false);
const Type *T = Type::getPrimitiveType((Type::PrimitiveID)Num);
if (T) return (Value*)T; // Asked for a primitive type...
// Otherwise, derived types need offset...
Num -= FirstDerivedTyID;
// Is it a module level type?
if (Num < ModuleTypeValues.size())
return (Value*)ModuleTypeValues[Num].get();
// Nope, is it a method level type?
Num -= ModuleTypeValues.size();
if (Num < MethodTypeValues.size())
return (Value*)MethodTypeValues[Num].get();
return 0;
}
if (type < ModuleValues.size()) {
if (Num < ModuleValues[type].size())
return ModuleValues[type][Num];
Num -= ModuleValues[type].size();
}
if (Values.size() > type && Values[type].size() > Num)
return Values[type][Num];
if (!Create) return 0; // Do not create a placeholder?
Value *d = 0;
switch (Ty->getPrimitiveID()) {
case Type::FunctionTyID:
cerr << "Creating method pholder! : " << type << ":" << oNum << " "
<< Ty->getName() << "\n";
d = new FunctionPHolder(Ty, oNum);
if (insertValue(d, LateResolveModuleValues) == -1) return 0;
return d;
case Type::LabelTyID:
d = new BBPHolder(Ty, oNum);
break;
default:
d = new ValPHolder(Ty, oNum);
break;
}
assert(d != 0 && "How did we not make something?");
if (insertValue(d, LateResolveValues) == -1) return 0;
return d;
}
/// getConstantValue - Just like getValue, except that it returns a null pointer
/// only on error. It always returns a constant (meaning that if the value is
/// defined, but is not a constant, that is an error). If the specified
/// constant hasn't been parsed yet, a placeholder is defined and used. Later,
/// after the real value is parsed, the placeholder is eliminated.
///
Constant *BytecodeParser::getConstantValue(const Type *Ty, unsigned Slot) {
if (Value *V = getValue(Ty, Slot, false))
return dyn_cast<Constant>(V); // If we already have the value parsed...
GlobalRefsType::iterator I = GlobalRefs.find(make_pair(Ty, Slot));
if (I != GlobalRefs.end()) {
BCR_TRACE(5, "Previous forward ref found!\n");
return cast<Constant>(I->second);
} else {
// Create a placeholder for the constant reference and
// keep track of the fact that we have a forward ref to recycle it
BCR_TRACE(5, "Creating new forward ref to a constant!\n");
Constant *C = new ConstPHolder(Ty, Slot);
// Keep track of the fact that we have a forward ref to recycle it
GlobalRefs.insert(make_pair(make_pair(Ty, Slot), C));
return C;
}
}
bool BytecodeParser::postResolveValues(ValueTable &ValTab) {
bool Error = false;
for (unsigned ty = 0; ty < ValTab.size(); ++ty) {
ValueList &DL = ValTab[ty];
unsigned Size;
while ((Size = DL.size())) {
unsigned IDNumber = getValueIDNumberFromPlaceHolder(DL[Size-1]);
Value *D = DL[Size-1];
DL.pop_back();
Value *NewDef = getValue(D->getType(), IDNumber, false);
if (NewDef == 0) {
Error = true; // Unresolved thinger
cerr << "Unresolvable reference found: <"
<< D->getType()->getDescription() << ">:" << IDNumber << "!\n";
} else {
// Fixup all of the uses of this placeholder def...
D->replaceAllUsesWith(NewDef);
// Now that all the uses are gone, delete the placeholder...
// If we couldn't find a def (error case), then leak a little
delete D; // memory, 'cause otherwise we can't remove all uses!
}
}
}
return Error;
}
bool BytecodeParser::ParseBasicBlock(const uchar *&Buf, const uchar *EndBuf,
BasicBlock *&BB) {
BB = new BasicBlock();
while (Buf < EndBuf) {
Instruction *Inst;
if (ParseInstruction(Buf, EndBuf, Inst,
/*HACK*/BB)) {
delete BB;
return true;
}
if (Inst == 0) { delete BB; return true; }
if (insertValue(Inst, Values) == -1) { delete BB; return true; }
BB->getInstList().push_back(Inst);
BCR_TRACE(4, Inst);
}
return false;
}
bool BytecodeParser::ParseSymbolTable(const uchar *&Buf, const uchar *EndBuf,
SymbolTable *ST) {
while (Buf < EndBuf) {
// Symtab block header: [num entries][type id number]
unsigned NumEntries, Typ;
if (read_vbr(Buf, EndBuf, NumEntries) ||
read_vbr(Buf, EndBuf, Typ)) return true;
const Type *Ty = getType(Typ);
if (Ty == 0) return true;
BCR_TRACE(3, "Plane Type: '" << Ty << "' with " << NumEntries <<
" entries\n");
for (unsigned i = 0; i < NumEntries; ++i) {
// Symtab entry: [def slot #][name]
unsigned slot;
if (read_vbr(Buf, EndBuf, slot)) return true;
std::string Name;
if (read(Buf, EndBuf, Name, false)) // Not aligned...
return true;
Value *D = getValue(Ty, slot, false); // Find mapping...
if (D == 0) {
BCR_TRACE(3, "FAILED LOOKUP: Slot #" << slot << "\n");
return true;
}
BCR_TRACE(4, "Map: '" << Name << "' to #" << slot << ":" << D;
if (!isa<Instruction>(D)) cerr << "\n");
D->setName(Name, ST);
}
}
if (Buf > EndBuf) return true;
return false;
}
void BytecodeParser::ResolveReferencesToValue(Value *NewV, unsigned Slot) {
GlobalRefsType::iterator I = GlobalRefs.find(make_pair(NewV->getType(),Slot));
if (I == GlobalRefs.end()) return; // Never forward referenced?
BCR_TRACE(3, "Mutating forward refs!\n");
Value *VPH = I->second; // Get the placeholder...
// Loop over all of the uses of the Value. What they are depends
// on what NewV is. Replacing a use of the old reference takes the
// use off the use list, so loop with !use_empty(), not the use_iterator.
while (!VPH->use_empty()) {
Constant *C = cast<Constant>(VPH->use_back());
unsigned numReplaced = C->mutateReferences(VPH, NewV);
assert(numReplaced > 0 && "Supposed user wasn't really a user?");
if (GlobalValue* GVal = dyn_cast<GlobalValue>(NewV)) {
// Remove the placeholder GlobalValue from the module...
GVal->getParent()->getGlobalList().remove(cast<GlobalVariable>(VPH));
}
}
delete VPH; // Delete the old placeholder
GlobalRefs.erase(I); // Remove the map entry for it
}
bool BytecodeParser::ParseMethod(const uchar *&Buf, const uchar *EndBuf,
Module *C) {
// Clear out the local values table...
Values.clear();
if (FunctionSignatureList.empty()) {
Error = "Function found, but FunctionSignatureList empty!";
return true; // Unexpected method!
}
const PointerType *PMTy = FunctionSignatureList.back().first; // PtrMeth
const FunctionType *MTy = dyn_cast<FunctionType>(PMTy->getElementType());
if (MTy == 0) return true; // Not ptr to method!
unsigned isInternal;
if (read_vbr(Buf, EndBuf, isInternal)) return true;
unsigned MethSlot = FunctionSignatureList.back().second;
FunctionSignatureList.pop_back();
Function *M = new Function(MTy, isInternal != 0);
BCR_TRACE(2, "METHOD TYPE: " << MTy << "\n");
const FunctionType::ParamTypes &Params = MTy->getParamTypes();
Function::aiterator AI = M->abegin();
for (FunctionType::ParamTypes::const_iterator It = Params.begin();
It != Params.end(); ++It, ++AI) {
if (insertValue(AI, Values) == -1) {
Error = "Error reading method arguments!\n";
delete M; return true;
}
}
while (Buf < EndBuf) {
unsigned Type, Size;
const uchar *OldBuf = Buf;
if (readBlock(Buf, EndBuf, Type, Size)) {
Error = "Error reading Function level block!";
delete M; return true;
}
switch (Type) {
case BytecodeFormat::ConstantPool:
BCR_TRACE(2, "BLOCK BytecodeFormat::ConstantPool: {\n");
if (ParseConstantPool(Buf, Buf+Size, Values, MethodTypeValues)) {
delete M; return true;
}
break;
case BytecodeFormat::BasicBlock: {
BCR_TRACE(2, "BLOCK BytecodeFormat::BasicBlock: {\n");
BasicBlock *BB;
if (ParseBasicBlock(Buf, Buf+Size, BB) ||
insertValue(BB, Values) == -1) {
delete M; return true; // Parse error... :(
}
M->getBasicBlockList().push_back(BB);
break;
}
case BytecodeFormat::SymbolTable:
BCR_TRACE(2, "BLOCK BytecodeFormat::SymbolTable: {\n");
if (ParseSymbolTable(Buf, Buf+Size, M->getSymbolTableSure())) {
delete M; return true;
}
break;
default:
BCR_TRACE(2, "BLOCK <unknown>:ignored! {\n");
Buf += Size;
if (OldBuf > Buf) return true; // Wrap around!
break;
}
BCR_TRACE(2, "} end block\n");
if (align32(Buf, EndBuf)) {
Error = "Error aligning Function level block!";
delete M; // Malformed bc file, read past end of block.
return true;
}
}
if (postResolveValues(LateResolveValues) ||
postResolveValues(LateResolveModuleValues)) {
Error = "Error resolving method values!";
delete M; return true; // Unresolvable references!
}
Value *FunctionPHolder = getValue(PMTy, MethSlot, false);
assert(FunctionPHolder && "Something is broken no placeholder found!");
assert(isa<Function>(FunctionPHolder) && "Not a function?");
unsigned type; // Type slot
assert(!getTypeSlot(MTy, type) && "How can meth type not exist?");
getTypeSlot(PMTy, type);
C->getFunctionList().push_back(M);
// Replace placeholder with the real method pointer...
ModuleValues[type][MethSlot] = M;
// Clear out method level types...
MethodTypeValues.clear();
// If anyone is using the placeholder make them use the real method instead
FunctionPHolder->replaceAllUsesWith(M);
// We don't need the placeholder anymore!
delete FunctionPHolder;
ResolveReferencesToValue(M, MethSlot);
return false;
}
bool BytecodeParser::ParseModuleGlobalInfo(const uchar *&Buf, const uchar *End,
Module *Mod) {
if (!FunctionSignatureList.empty()) {
Error = "Two ModuleGlobalInfo packets found!";
return true; // Two ModuleGlobal blocks?
}
// Read global variables...
unsigned VarType;
if (read_vbr(Buf, End, VarType)) return true;
while (VarType != Type::VoidTyID) { // List is terminated by Void
// VarType Fields: bit0 = isConstant, bit1 = hasInitializer,
// bit2 = isInternal, bit3+ = slot#
const Type *Ty = getType(VarType >> 3);
if (!Ty || !isa<PointerType>(Ty)) {
Error = "Global not pointer type! Ty = " + Ty->getDescription();
return true;
}
const PointerType *PTy = cast<const PointerType>(Ty);
const Type *ElTy = PTy->getElementType();
Constant *Initializer = 0;
if (VarType & 2) { // Does it have an initalizer?
// Do not improvise... values must have been stored in the constant pool,
// which should have been read before now.
//
unsigned InitSlot;
if (read_vbr(Buf, End, InitSlot)) return true;
Value *V = getValue(ElTy, InitSlot, false);
if (V == 0) return true;
Initializer = cast<Constant>(V);
}
// Create the global variable...
GlobalVariable *GV = new GlobalVariable(ElTy, VarType & 1, VarType & 4,
Initializer);
int DestSlot = insertValue(GV, ModuleValues);
if (DestSlot == -1) return true;
Mod->getGlobalList().push_back(GV);
ResolveReferencesToValue(GV, (unsigned)DestSlot);
BCR_TRACE(2, "Global Variable of type: " << PTy->getDescription()
<< " into slot #" << DestSlot << "\n");
if (read_vbr(Buf, End, VarType)) return true;
}
// Read the method signatures for all of the methods that are coming, and
// create fillers in the Value tables.
unsigned FnSignature;
if (read_vbr(Buf, End, FnSignature)) return true;
while (FnSignature != Type::VoidTyID) { // List is terminated by Void
const Type *Ty = getType(FnSignature);
if (!Ty || !isa<PointerType>(Ty) ||
!isa<FunctionType>(cast<PointerType>(Ty)->getElementType())) {
Error = "Function not ptr to func type! Ty = " + Ty->getDescription();
return true;
}
// We create methods by passing the underlying FunctionType to create...
Ty = cast<PointerType>(Ty)->getElementType();
// When the ModuleGlobalInfo section is read, we load the type of each
// method and the 'ModuleValues' slot that it lands in. We then load a
// placeholder into its slot to reserve it. When the method is loaded, this
// placeholder is replaced.
// Insert the placeholder...
Value *Val = new FunctionPHolder(Ty, 0);
if (insertValue(Val, ModuleValues) == -1) return true;
// Figure out which entry of its typeslot it went into...
unsigned TypeSlot;
if (getTypeSlot(Val->getType(), TypeSlot)) return true;
unsigned SlotNo = ModuleValues[TypeSlot].size()-1;
// Keep track of this information in a linked list that is emptied as
// methods are loaded...
//
FunctionSignatureList.push_back(
make_pair(cast<const PointerType>(Val->getType()), SlotNo));
if (read_vbr(Buf, End, FnSignature)) return true;
BCR_TRACE(2, "Function of type: " << Ty << "\n");
}
if (align32(Buf, End)) return true;
// Now that the function signature list is set up, reverse it so that we can
// remove elements efficiently from the back of the vector.
std::reverse(FunctionSignatureList.begin(), FunctionSignatureList.end());
// This is for future proofing... in the future extra fields may be added that
// we don't understand, so we transparently ignore them.
//
Buf = End;
return false;
}
bool BytecodeParser::ParseModule(const uchar *Buf, const uchar *EndBuf,
Module *&Mod) {
unsigned Type, Size;
if (readBlock(Buf, EndBuf, Type, Size)) return true;
if (Type != BytecodeFormat::Module || Buf+Size != EndBuf) {
Error = "Expected Module packet!";
return true; // Hrm, not a class?
}
BCR_TRACE(0, "BLOCK BytecodeFormat::Module: {\n");
FunctionSignatureList.clear(); // Just in case...
// Read into instance variables...
if (read_vbr(Buf, EndBuf, FirstDerivedTyID)) return true;
if (align32(Buf, EndBuf)) return true;
BCR_TRACE(1, "FirstDerivedTyID = " << FirstDerivedTyID << "\n");
TheModule = Mod = new Module();
while (Buf < EndBuf) {
const uchar *OldBuf = Buf;
if (readBlock(Buf, EndBuf, Type, Size)) { delete Mod; return true;}
switch (Type) {
case BytecodeFormat::ConstantPool:
BCR_TRACE(1, "BLOCK BytecodeFormat::ConstantPool: {\n");
if (ParseConstantPool(Buf, Buf+Size, ModuleValues, ModuleTypeValues)) {
delete Mod; return true;
}
break;
case BytecodeFormat::ModuleGlobalInfo:
BCR_TRACE(1, "BLOCK BytecodeFormat::ModuleGlobalInfo: {\n");
if (ParseModuleGlobalInfo(Buf, Buf+Size, Mod)) {
delete Mod; return true;
}
break;
case BytecodeFormat::Function: {
BCR_TRACE(1, "BLOCK BytecodeFormat::Function: {\n");
if (ParseMethod(Buf, Buf+Size, Mod)) {
delete Mod; return true; // Error parsing function
}
break;
}
case BytecodeFormat::SymbolTable:
BCR_TRACE(1, "BLOCK BytecodeFormat::SymbolTable: {\n");
if (ParseSymbolTable(Buf, Buf+Size, Mod->getSymbolTableSure())) {
delete Mod; return true;
}
break;
default:
Error = "Expected Module Block!";
Buf += Size;
if (OldBuf > Buf) return true; // Wrap around!
break;
}
BCR_TRACE(1, "} end block\n");
if (align32(Buf, EndBuf)) { delete Mod; return true; }
}
if (!FunctionSignatureList.empty()) { // Expected more methods!
Error = "Function expected, but bytecode stream at end!";
return true;
}
BCR_TRACE(0, "} end block\n\n");
return false;
}
Module *BytecodeParser::ParseBytecode(const uchar *Buf, const uchar *EndBuf) {
LateResolveValues.clear();
unsigned Sig;
// Read and check signature...
if (read(Buf, EndBuf, Sig) ||
Sig != ('l' | ('l' << 8) | ('v' << 16) | 'm' << 24)) {
Error = "Invalid bytecode signature!";
return 0; // Invalid signature!
}
Module *Result;
if (ParseModule(Buf, EndBuf, Result)) return 0;
return Result;
}
Module *ParseBytecodeBuffer(const unsigned char *Buffer, unsigned Length) {
BytecodeParser Parser;
return Parser.ParseBytecode(Buffer, Buffer+Length);
}
// Parse and return a class file...
//
Module *ParseBytecodeFile(const std::string &Filename, std::string *ErrorStr) {
struct stat StatBuf;
Module *Result = 0;
if (Filename != std::string("-")) { // Read from a file...
int FD = open(Filename.c_str(), O_RDONLY);
if (FD == -1) {
if (ErrorStr) *ErrorStr = "Error opening file!";
return 0;
}
if (fstat(FD, &StatBuf) == -1) { close(FD); return 0; }
int Length = StatBuf.st_size;
if (Length == 0) {
if (ErrorStr) *ErrorStr = "Error stat'ing file!";
close(FD); return 0;
}
uchar *Buffer = (uchar*)mmap(0, Length, PROT_READ,
MAP_PRIVATE, FD, 0);
if (Buffer == (uchar*)-1) {
if (ErrorStr) *ErrorStr = "Error mmapping file!";
close(FD); return 0;
}
BytecodeParser Parser;
Result = Parser.ParseBytecode(Buffer, Buffer+Length);
munmap((char*)Buffer, Length);
close(FD);
if (ErrorStr) *ErrorStr = Parser.getError();
} else { // Read from stdin
size_t FileSize = 0;
int BlockSize;
uchar Buffer[4096], *FileData = 0;
while ((BlockSize = read(0, Buffer, 4))) {
if (BlockSize == -1) { free(FileData); return 0; }
FileData = (uchar*)realloc(FileData, FileSize+BlockSize);
memcpy(FileData+FileSize, Buffer, BlockSize);
FileSize += BlockSize;
}
if (FileSize == 0) {
if (ErrorStr) *ErrorStr = "Standard Input empty!";
free(FileData); return 0;
}
#define ALIGN_PTRS 0
#if ALIGN_PTRS
uchar *Buf = (uchar*)mmap(0, FileSize, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
assert((Buf != (uchar*)-1) && "mmap returned error!");
memcpy(Buf, FileData, FileSize);
free(FileData);
#else
uchar *Buf = FileData;
#endif
BytecodeParser Parser;
Result = Parser.ParseBytecode(Buf, Buf+FileSize);
#if ALIGN_PTRS
munmap((char*)Buf, FileSize); // Free mmap'd data area
#else
free(FileData); // Free realloc'd block of memory
#endif
if (ErrorStr) *ErrorStr = Parser.getError();
}
return Result;
}
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