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-rw-r--r--lib/Bytecode/Reader/Reader.cpp478
1 files changed, 478 insertions, 0 deletions
diff --git a/lib/Bytecode/Reader/Reader.cpp b/lib/Bytecode/Reader/Reader.cpp
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+++ b/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: Make error message outputs be configurable depending on an option?
+// TODO: Allow passing in an option to ignore the symbol table
+//
+//===------------------------------------------------------------------------===
+
+#include "llvm/Bytecode/Reader.h"
+#include "llvm/Bytecode/Format.h"
+#include "llvm/Module.h"
+#include "llvm/BasicBlock.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/ConstPoolVals.h"
+#include "llvm/iOther.h"
+#include "ReaderInternals.h"
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <algorithm>
+
+bool BytecodeParser::getTypeSlot(const Type *Ty, unsigned &Slot) {
+ if (Ty->isPrimitiveType()) {
+ Slot = Ty->getPrimitiveID();
+ } else {
+ TypeMapType::iterator I = TypeMap.find(Ty);
+ if (I == TypeMap.end()) return true; // Didn't find type!
+ Slot = I->second;
+ }
+ //cerr << "getTypeSlot '" << Ty->getName() << "' = " << Slot << endl;
+ 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 << endl;
+
+ const Value *D = getValue(Type::TypeTy, ID, false);
+ if (D == 0) return 0;
+
+ assert(D->getType() == Type::TypeTy &&
+ D->getValueType() == Value::ConstantVal);
+
+
+ return ((const ConstPoolType*)D)->getValue();;
+}
+
+bool BytecodeParser::insertValue(Value *Def, vector<ValueList> &ValueTab) {
+ unsigned type;
+ if (getTypeSlot(Def->getType(), type)) return true;
+
+ if (ValueTab.size() <= type)
+ ValueTab.resize(type+1, ValueList());
+
+ //cerr << "insertValue Values[" << type << "][" << ValueTab[type].size()
+ // << "] = " << Def << endl;
+
+ if (type == Type::TypeTyID && Def->getValueType() == Value::ConstantVal) {
+ const Type *Ty = ((const ConstPoolType*)Def)->getValue();
+ unsigned ValueOffset = FirstDerivedTyID;
+
+ if (&ValueTab == &Values) // Take into consideration module level types
+ ValueOffset += ModuleValues[type].size();
+
+ if (TypeMap.find(Ty) == TypeMap.end())
+ TypeMap[Ty] = ValueTab[type].size()+ValueOffset;
+ }
+
+ ValueTab[type].push_back(Def);
+
+ return false;
+}
+
+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; // TODO: true
+
+ if (type == Type::TypeTyID) { // The 'type' plane has implicit values
+ 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;
+ }
+
+ if (ModuleValues.size() > type) {
+ if (ModuleValues[type].size() > Num)
+ 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::LabelTyID: d = new BBPHolder(Ty, oNum); break;
+ case Type::MethodTyID:
+ cerr << "Creating method pholder! : " << type << ":" << oNum << " "
+ << Ty->getName() << endl;
+ d = new MethPHolder(Ty, oNum);
+ insertValue(d, LateResolveModuleValues);
+ return d;
+ default: d = new DefPHolder(Ty, oNum); break;
+ }
+
+ assert(d != 0 && "How did we not make something?");
+ if (insertValue(d, LateResolveValues)) return 0;
+ return d;
+}
+
+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()->getName()
+ << ">:" << 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 *Def;
+ if (ParseInstruction(Buf, EndBuf, Def)) {
+ delete BB;
+ return true;
+ }
+
+ if (Def == 0) { delete BB; return true; }
+ if (insertValue(Def, Values)) { delete BB; return true; }
+
+ BB->getInstList().push_back(Def);
+ }
+
+ return false;
+}
+
+bool BytecodeParser::ParseSymbolTable(const uchar *&Buf, const uchar *EndBuf) {
+ 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;
+
+ for (unsigned i = 0; i < NumEntries; i++) {
+ // Symtab entry: [def slot #][name]
+ unsigned slot;
+ if (read_vbr(Buf, EndBuf, slot)) return true;
+ string Name;
+ if (read(Buf, EndBuf, Name, false)) // Not aligned...
+ return true;
+
+ Value *D = getValue(Ty, slot, false); // Find mapping...
+ if (D == 0) return true;
+ D->setName(Name);
+ }
+ }
+
+ return Buf > EndBuf;
+}
+
+
+bool BytecodeParser::ParseMethod(const uchar *&Buf, const uchar *EndBuf,
+ Module *C) {
+ // Clear out the local values table...
+ Values.clear();
+ if (MethodSignatureList.empty()) return true; // Unexpected method!
+
+ const MethodType *MTy = MethodSignatureList.front().first;
+ unsigned MethSlot = MethodSignatureList.front().second;
+ MethodSignatureList.pop_front();
+ Method *M = new Method(MTy);
+
+ const MethodType::ParamTypes &Params = MTy->getParamTypes();
+ for (MethodType::ParamTypes::const_iterator It = Params.begin();
+ It != Params.end(); It++) {
+ MethodArgument *MA = new MethodArgument(*It);
+ if (insertValue(MA, Values)) { delete M; return true; }
+ M->getArgumentList().push_back(MA);
+ }
+
+ while (Buf < EndBuf) {
+ unsigned Type, Size;
+ const uchar *OldBuf = Buf;
+ if (readBlock(Buf, EndBuf, Type, Size)) { delete M; return true; }
+
+ switch (Type) {
+ case BytecodeFormat::ConstantPool:
+ if (ParseConstantPool(Buf, Buf+Size, M->getConstantPool(), Values)) {
+ cerr << "Error reading constant pool!\n";
+ delete M; return true;
+ }
+ break;
+
+ case BytecodeFormat::BasicBlock: {
+ BasicBlock *BB;
+ if (ParseBasicBlock(Buf, Buf+Size, BB) ||
+ insertValue(BB, Values)) {
+ cerr << "Error parsing basic block!\n";
+ delete M; return true; // Parse error... :(
+ }
+
+ M->getBasicBlocks().push_back(BB);
+ break;
+ }
+
+ case BytecodeFormat::SymbolTable:
+ if (ParseSymbolTable(Buf, Buf+Size)) {
+ cerr << "Error reading method symbol table!\n";
+ delete M; return true;
+ }
+ break;
+
+ default:
+ Buf += Size;
+ if (OldBuf > Buf) return true; // Wrap around!
+ break;
+ }
+ if (align32(Buf, EndBuf)) {
+ delete M; // Malformed bc file, read past end of block.
+ return true;
+ }
+ }
+
+ if (postResolveValues(LateResolveValues) ||
+ postResolveValues(LateResolveModuleValues)) {
+ delete M; return true; // Unresolvable references!
+ }
+
+ Value *MethPHolder = getValue(MTy, MethSlot, false);
+ assert(MethPHolder && "Something is broken no placeholder found!");
+ assert(MethPHolder->getValueType() == Value::MethodVal && "Not a method?");
+
+ unsigned type; // Type slot
+ assert(!getTypeSlot(MTy, type) && "How can meth type not exist?");
+ getTypeSlot(MTy, type);
+
+ C->getMethodList().push_back(M);
+
+ // Replace placeholder with the real method pointer...
+ ModuleValues[type][MethSlot] = M;
+
+ // If anyone is using the placeholder make them use the real method instead
+ MethPHolder->replaceAllUsesWith(M);
+
+ // We don't need the placeholder anymore!
+ delete MethPHolder;
+
+ return false;
+}
+
+bool BytecodeParser::ParseModuleGlobalInfo(const uchar *&Buf, const uchar *End,
+ Module *C) {
+
+ if (!MethodSignatureList.empty()) return true; // Two ModuleGlobal blocks?
+
+ // Read the method signatures for all of the methods that are coming, and
+ // create fillers in the Value tables.
+ unsigned MethSignature;
+ if (read_vbr(Buf, End, MethSignature)) return true;
+ while (MethSignature != Type::VoidTyID) { // List is terminated by Void
+ const Type *Ty = getType(MethSignature);
+ if (!Ty || !Ty->isMethodType()) {
+ cerr << "Method not meth type! ";
+ if (Ty) cerr << Ty->getName(); else cerr << MethSignature; cerr << endl;
+ return true;
+ }
+
+ // 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 *Def = new MethPHolder(Ty, 0);
+ insertValue(Def, ModuleValues);
+
+ // Figure out which entry of its typeslot it went into...
+ unsigned TypeSlot;
+ if (getTypeSlot(Def->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...
+ //
+ MethodSignatureList.push_back(make_pair((const MethodType*)Ty, SlotNo));
+ if (read_vbr(Buf, End, MethSignature)) return true;
+ }
+
+ if (align32(Buf, End)) return true;
+
+ // 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 *&C) {
+
+ unsigned Type, Size;
+ if (readBlock(Buf, EndBuf, Type, Size)) return true;
+ if (Type != BytecodeFormat::Module || Buf+Size != EndBuf)
+ return true; // Hrm, not a class?
+
+ MethodSignatureList.clear(); // Just in case...
+
+ // Read into instance variables...
+ if (read_vbr(Buf, EndBuf, FirstDerivedTyID)) return true;
+ if (align32(Buf, EndBuf)) return true;
+
+ C = new Module();
+
+ while (Buf < EndBuf) {
+ const uchar *OldBuf = Buf;
+ if (readBlock(Buf, EndBuf, Type, Size)) { delete C; return true; }
+ switch (Type) {
+ case BytecodeFormat::ModuleGlobalInfo:
+ if (ParseModuleGlobalInfo(Buf, Buf+Size, C)) {
+ cerr << "Error reading class global info section!\n";
+ delete C; return true;
+ }
+ break;
+
+ case BytecodeFormat::ConstantPool:
+ if (ParseConstantPool(Buf, Buf+Size, C->getConstantPool(), ModuleValues)) {
+ cerr << "Error reading class constant pool!\n";
+ delete C; return true;
+ }
+ break;
+
+ case BytecodeFormat::Method: {
+ if (ParseMethod(Buf, Buf+Size, C)) {
+ delete C; return true; // Error parsing method
+ }
+ break;
+ }
+
+ case BytecodeFormat::SymbolTable:
+ if (ParseSymbolTable(Buf, Buf+Size)) {
+ cerr << "Error reading class symbol table!\n";
+ delete C; return true;
+ }
+ break;
+
+ default:
+ cerr << "Unknown class block: " << Type << endl;
+ Buf += Size;
+ if (OldBuf > Buf) return true; // Wrap around!
+ break;
+ }
+ if (align32(Buf, EndBuf)) { delete C; return true; }
+ }
+
+ if (!MethodSignatureList.empty()) // Expected more methods!
+ return true;
+ 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))
+ return 0; // Invalid signature!
+
+ Module *Result;
+ if (ParseModule(Buf, EndBuf, Result)) return 0;
+ return Result;
+}
+
+
+Module *ParseBytecodeBuffer(const uchar *Buffer, unsigned Length) {
+ BytecodeParser Parser;
+ return Parser.ParseBytecode(Buffer, Buffer+Length);
+}
+
+// Parse and return a class file...
+//
+Module *ParseBytecodeFile(const string &Filename) {
+ struct stat StatBuf;
+ Module *Result = 0;
+
+ if (Filename != string("-")) { // Read from a file...
+ int FD = open(Filename.data(), O_RDONLY);
+ if (FD == -1) return 0;
+
+ if (fstat(FD, &StatBuf) == -1) { close(FD); return 0; }
+
+ int Length = StatBuf.st_size;
+ if (Length == 0) { close(FD); return 0; }
+ uchar *Buffer = (uchar*)mmap(0, Length, PROT_READ,
+ MAP_PRIVATE, FD, 0);
+ if (Buffer == (uchar*)-1) { close(FD); return 0; }
+
+ BytecodeParser Parser;
+ Result = Parser.ParseBytecode(Buffer, Buffer+Length);
+
+ munmap((char*)Buffer, Length);
+ close(FD);
+ } 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) { free(FileData); return 0; }
+
+#define ALIGN_PTRS 1
+#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!");
+ free(FileData);
+ memcpy(Buf, FileData, FileSize);
+#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
+ }
+
+ return Result;
+}
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