--- /dev/null
+//===- BitcodeReader.cpp - Internal BitcodeReader implementation ----------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This header defines the BitcodeReader class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "BitcodeReader.h"
+#include "llvm/Bitcode/BitstreamReader.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Module.h"
+using namespace llvm;
+
+/// ConvertToString - Convert a string from a record into an std::string, return
+/// true on failure.
+static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
+ std::string &Result) {
+ if (Record.size() < Idx+1 || Record.size() < Record[Idx]+Idx+1)
+ return true;
+
+ for (unsigned i = 0, e = Record[Idx]; i != e; ++i)
+ Result += (char)Record[Idx+i+1];
+ return false;
+}
+
+static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
+ switch (Val) {
+ default: // Map unknown/new linkages to external
+ case 0: return GlobalValue::ExternalLinkage;
+ case 1: return GlobalValue::WeakLinkage;
+ case 2: return GlobalValue::AppendingLinkage;
+ case 3: return GlobalValue::InternalLinkage;
+ case 4: return GlobalValue::LinkOnceLinkage;
+ case 5: return GlobalValue::DLLImportLinkage;
+ case 6: return GlobalValue::DLLExportLinkage;
+ case 7: return GlobalValue::ExternalWeakLinkage;
+ }
+}
+
+static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
+ switch (Val) {
+ default: // Map unknown visibilities to default.
+ case 0: return GlobalValue::DefaultVisibility;
+ case 1: return GlobalValue::HiddenVisibility;
+ }
+}
+
+
+const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
+ // If the TypeID is in range, return it.
+ if (ID < TypeList.size())
+ return TypeList[ID].get();
+ if (!isTypeTable) return 0;
+
+ // The type table allows forward references. Push as many Opaque types as
+ // needed to get up to ID.
+ while (TypeList.size() <= ID)
+ TypeList.push_back(OpaqueType::get());
+ return TypeList.back().get();
+}
+
+
+bool BitcodeReader::ParseTypeTable(BitstreamReader &Stream) {
+ if (Stream.EnterSubBlock())
+ return Error("Malformed block record");
+
+ if (!TypeList.empty())
+ return Error("Multiple TYPE_BLOCKs found!");
+
+ SmallVector<uint64_t, 64> Record;
+ unsigned NumRecords = 0;
+
+ // Read all the records for this type table.
+ while (1) {
+ unsigned Code = Stream.ReadCode();
+ if (Code == bitc::END_BLOCK) {
+ if (NumRecords != TypeList.size())
+ return Error("Invalid type forward reference in TYPE_BLOCK");
+ return Stream.ReadBlockEnd();
+ }
+
+ if (Code == bitc::ENTER_SUBBLOCK) {
+ // No known subblocks, always skip them.
+ Stream.ReadSubBlockID();
+ if (Stream.SkipBlock())
+ return Error("Malformed block record");
+ continue;
+ }
+
+ if (Code == bitc::DEFINE_ABBREVS) {
+ assert(0 && "Abbrevs not implemented yet!");
+ }
+
+ // Read a record.
+ Record.clear();
+ const Type *ResultTy = 0;
+ switch (Stream.ReadRecord(Code, Record)) {
+ default: // Default behavior: unknown type.
+ ResultTy = 0;
+ break;
+ case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
+ // TYPE_CODE_NUMENTRY contains a count of the number of types in the
+ // type list. This allows us to reserve space.
+ if (Record.size() < 1)
+ return Error("Invalid TYPE_CODE_NUMENTRY record");
+ TypeList.reserve(Record[0]);
+ continue;
+ case bitc::TYPE_CODE_META: // TYPE_CODE_META: [metacode]...
+ // No metadata supported yet.
+ if (Record.size() < 1)
+ return Error("Invalid TYPE_CODE_META record");
+ continue;
+
+ case bitc::TYPE_CODE_VOID: // VOID
+ ResultTy = Type::VoidTy;
+ break;
+ case bitc::TYPE_CODE_FLOAT: // FLOAT
+ ResultTy = Type::FloatTy;
+ break;
+ case bitc::TYPE_CODE_DOUBLE: // DOUBLE
+ ResultTy = Type::DoubleTy;
+ break;
+ case bitc::TYPE_CODE_LABEL: // LABEL
+ ResultTy = Type::LabelTy;
+ break;
+ case bitc::TYPE_CODE_OPAQUE: // OPAQUE
+ ResultTy = 0;
+ break;
+ case bitc::TYPE_CODE_INTEGER: // INTEGER: [width]
+ if (Record.size() < 1)
+ return Error("Invalid Integer type record");
+
+ ResultTy = IntegerType::get(Record[0]);
+ break;
+ case bitc::TYPE_CODE_POINTER: // POINTER: [pointee type]
+ if (Record.size() < 1)
+ return Error("Invalid POINTER type record");
+ ResultTy = PointerType::get(getTypeByID(Record[0], true));
+ break;
+ case bitc::TYPE_CODE_FUNCTION: {
+ // FUNCTION: [vararg, retty, #pararms, paramty N]
+ if (Record.size() < 3 || Record.size() < Record[2]+3)
+ return Error("Invalid FUNCTION type record");
+ std::vector<const Type*> ArgTys;
+ for (unsigned i = 0, e = Record[2]; i != e; ++i)
+ ArgTys.push_back(getTypeByID(Record[3+i], true));
+
+ // FIXME: PARAM TYS.
+ ResultTy = FunctionType::get(getTypeByID(Record[1], true), ArgTys,
+ Record[0]);
+ break;
+ }
+ case bitc::TYPE_CODE_STRUCT: { // STRUCT: [ispacked, #elts, eltty x N]
+ if (Record.size() < 2 || Record.size() < Record[1]+2)
+ return Error("Invalid STRUCT type record");
+ std::vector<const Type*> EltTys;
+ for (unsigned i = 0, e = Record[1]; i != e; ++i)
+ EltTys.push_back(getTypeByID(Record[2+i], true));
+ ResultTy = StructType::get(EltTys, Record[0]);
+ break;
+ }
+ case bitc::TYPE_CODE_ARRAY: // ARRAY: [numelts, eltty]
+ if (Record.size() < 2)
+ return Error("Invalid ARRAY type record");
+ ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
+ break;
+ case bitc::TYPE_CODE_VECTOR: // VECTOR: [numelts, eltty]
+ if (Record.size() < 2)
+ return Error("Invalid VECTOR type record");
+ ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
+ break;
+ }
+
+ if (NumRecords == TypeList.size()) {
+ // If this is a new type slot, just append it.
+ TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
+ ++NumRecords;
+ } else if (ResultTy == 0) {
+ // Otherwise, this was forward referenced, so an opaque type was created,
+ // but the result type is actually just an opaque. Leave the one we
+ // created previously.
+ ++NumRecords;
+ } else {
+ // Otherwise, this was forward referenced, so an opaque type was created.
+ // Resolve the opaque type to the real type now.
+ assert(NumRecords < TypeList.size() && "Typelist imbalance");
+ const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
+
+ // Don't directly push the new type on the Tab. Instead we want to replace
+ // the opaque type we previously inserted with the new concrete value. The
+ // refinement from the abstract (opaque) type to the new type causes all
+ // uses of the abstract type to use the concrete type (NewTy). This will
+ // also cause the opaque type to be deleted.
+ const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
+
+ // This should have replaced the old opaque type with the new type in the
+ // value table... or with a preexisting type that was already in the system.
+ // Let's just make sure it did.
+ assert(TypeList[NumRecords-1].get() != OldTy &&
+ "refineAbstractType didn't work!");
+ }
+ }
+}
+
+
+bool BitcodeReader::ParseTypeSymbolTable(BitstreamReader &Stream) {
+ if (Stream.EnterSubBlock())
+ return Error("Malformed block record");
+
+ SmallVector<uint64_t, 64> Record;
+
+ // Read all the records for this type table.
+ std::string TypeName;
+ while (1) {
+ unsigned Code = Stream.ReadCode();
+ if (Code == bitc::END_BLOCK)
+ return Stream.ReadBlockEnd();
+
+ if (Code == bitc::ENTER_SUBBLOCK) {
+ // No known subblocks, always skip them.
+ Stream.ReadSubBlockID();
+ if (Stream.SkipBlock())
+ return Error("Malformed block record");
+ continue;
+ }
+
+ if (Code == bitc::DEFINE_ABBREVS) {
+ assert(0 && "Abbrevs not implemented yet!");
+ }
+
+ // Read a record.
+ Record.clear();
+ switch (Stream.ReadRecord(Code, Record)) {
+ default: // Default behavior: unknown type.
+ break;
+ case bitc::TST_ENTRY_CODE: // TST_ENTRY: [typeid, namelen, namechar x N]
+ if (ConvertToString(Record, 1, TypeName))
+ return Error("Invalid TST_ENTRY record");
+ unsigned TypeID = Record[0];
+ if (TypeID >= TypeList.size())
+ return Error("Invalid Type ID in TST_ENTRY record");
+
+ TheModule->addTypeName(TypeName, TypeList[TypeID].get());
+ TypeName.clear();
+ break;
+ }
+ }
+}
+
+
+bool BitcodeReader::ParseModule(BitstreamReader &Stream,
+ const std::string &ModuleID) {
+ // Reject multiple MODULE_BLOCK's in a single bitstream.
+ if (TheModule)
+ return Error("Multiple MODULE_BLOCKs in same stream");
+
+ if (Stream.EnterSubBlock())
+ return Error("Malformed block record");
+
+ // Otherwise, create the module.
+ TheModule = new Module(ModuleID);
+
+ SmallVector<uint64_t, 64> Record;
+ std::vector<std::string> SectionTable;
+
+ // Read all the records for this module.
+ while (!Stream.AtEndOfStream()) {
+ unsigned Code = Stream.ReadCode();
+ if (Code == bitc::END_BLOCK)
+ return Stream.ReadBlockEnd();
+
+ if (Code == bitc::ENTER_SUBBLOCK) {
+ switch (Stream.ReadSubBlockID()) {
+ default: // Skip unknown content.
+ if (Stream.SkipBlock())
+ return Error("Malformed block record");
+ break;
+ case bitc::TYPE_BLOCK_ID:
+ if (ParseTypeTable(Stream))
+ return true;
+ break;
+ case bitc::TYPE_SYMTAB_BLOCK_ID:
+ if (ParseTypeSymbolTable(Stream))
+ return true;
+ break;
+ }
+ continue;
+ }
+
+ if (Code == bitc::DEFINE_ABBREVS) {
+ assert(0 && "Abbrevs not implemented yet!");
+ }
+
+ // Read a record.
+ switch (Stream.ReadRecord(Code, Record)) {
+ default: break; // Default behavior, ignore unknown content.
+ case bitc::MODULE_CODE_VERSION: // VERSION: [version#]
+ if (Record.size() < 1)
+ return Error("Malformed MODULE_CODE_VERSION");
+ // Only version #0 is supported so far.
+ if (Record[0] != 0)
+ return Error("Unknown bitstream version!");
+ break;
+ case bitc::MODULE_CODE_TRIPLE: { // TRIPLE: [strlen, strchr x N]
+ std::string S;
+ if (ConvertToString(Record, 0, S))
+ return Error("Invalid MODULE_CODE_TRIPLE record");
+ TheModule->setTargetTriple(S);
+ break;
+ }
+ case bitc::MODULE_CODE_DATALAYOUT: { // DATALAYOUT: [strlen, strchr x N]
+ std::string S;
+ if (ConvertToString(Record, 0, S))
+ return Error("Invalid MODULE_CODE_DATALAYOUT record");
+ TheModule->setDataLayout(S);
+ break;
+ }
+ case bitc::MODULE_CODE_ASM: { // ASM: [strlen, strchr x N]
+ std::string S;
+ if (ConvertToString(Record, 0, S))
+ return Error("Invalid MODULE_CODE_ASM record");
+ TheModule->setModuleInlineAsm(S);
+ break;
+ }
+ case bitc::MODULE_CODE_DEPLIB: { // DEPLIB: [strlen, strchr x N]
+ std::string S;
+ if (ConvertToString(Record, 0, S))
+ return Error("Invalid MODULE_CODE_DEPLIB record");
+ TheModule->addLibrary(S);
+ break;
+ }
+ case bitc::MODULE_CODE_SECTIONNAME: { // SECTIONNAME: [strlen, strchr x N]
+ std::string S;
+ if (ConvertToString(Record, 0, S))
+ return Error("Invalid MODULE_CODE_SECTIONNAME record");
+ SectionTable.push_back(S);
+ break;
+ }
+ // GLOBALVAR: [type, isconst, initid,
+ // linkage, alignment, section, visibility, threadlocal]
+ case bitc::MODULE_CODE_GLOBALVAR: {
+ if (Record.size() < 8)
+ return Error("Invalid MODULE_CODE_GLOBALVAR record");
+ const Type *Ty = getTypeByID(Record[0]);
+ if (!isa<PointerType>(Ty))
+ return Error("Global not a pointer type!");
+ Ty = cast<PointerType>(Ty)->getElementType();
+
+ bool isConstant = Record[1];
+ GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
+ unsigned Alignment = (1 << Record[4]) >> 1;
+ std::string Section;
+ if (Record[5]) {
+ if (Record[5]-1 >= SectionTable.size())
+ return Error("Invalid section ID");
+ Section = SectionTable[Record[5]-1];
+ }
+ GlobalValue::VisibilityTypes Visibility = GetDecodedVisibility(Record[6]);
+ bool isThreadLocal = Record[7];
+
+ GlobalVariable *NewGV =
+ new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule);
+ NewGV->setAlignment(Alignment);
+ if (!Section.empty())
+ NewGV->setSection(Section);
+ NewGV->setVisibility(Visibility);
+ NewGV->setThreadLocal(isThreadLocal);
+
+ // TODO: Add to value table.
+ // TODO: remember initializer/global pair for later substitution.
+ break;
+ }
+ // FUNCTION: [type, callingconv, isproto, linkage, alignment, section,
+ // visibility]
+ case bitc::MODULE_CODE_FUNCTION: {
+ if (Record.size() < 7)
+ return Error("Invalid MODULE_CODE_FUNCTION record");
+ const Type *Ty = getTypeByID(Record[0]);
+ if (!isa<PointerType>(Ty))
+ return Error("Function not a pointer type!");
+ const FunctionType *FTy =
+ dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
+ if (!FTy)
+ return Error("Function not a pointer to function type!");
+
+ Function *Func = new Function(FTy, GlobalValue::ExternalLinkage,
+ "", TheModule);
+
+ Func->setCallingConv(Record[1]);
+ Func->setLinkage(GetDecodedLinkage(Record[3]));
+ Func->setAlignment((1 << Record[4]) >> 1);
+ if (Record[5]) {
+ if (Record[5]-1 >= SectionTable.size())
+ return Error("Invalid section ID");
+ Func->setSection(SectionTable[Record[5]-1]);
+ }
+ Func->setVisibility(GetDecodedVisibility(Record[6]));
+
+ // TODO: Add to value table.
+ // TODO: remember initializer/global pair for later substitution.
+ break;
+ }
+ }
+ Record.clear();
+ }
+
+ return Error("Premature end of bitstream");
+}
+
+
+bool BitcodeReader::ParseBitcode(unsigned char *Buf, unsigned Length,
+ const std::string &ModuleID) {
+ TheModule = 0;
+
+ if (Length & 3)
+ return Error("Bitcode stream should be a multiple of 4 bytes in length");
+
+ BitstreamReader Stream(Buf, Buf+Length);
+
+ // Sniff for the signature.
+ if (Stream.Read(8) != 'B' ||
+ Stream.Read(8) != 'C' ||
+ Stream.Read(4) != 0x0 ||
+ Stream.Read(4) != 0xC ||
+ Stream.Read(4) != 0xE ||
+ Stream.Read(4) != 0xD)
+ return Error("Invalid bitcode signature");
+
+ // We expect a number of well-defined blocks, though we don't necessarily
+ // need to understand them all.
+ while (!Stream.AtEndOfStream()) {
+ unsigned Code = Stream.ReadCode();
+
+ if (Code != bitc::ENTER_SUBBLOCK)
+ return Error("Invalid record at top-level");
+
+ unsigned BlockID = Stream.ReadSubBlockID();
+
+ // We only know the MODULE subblock ID.
+ if (BlockID == bitc::MODULE_BLOCK_ID) {
+ if (ParseModule(Stream, ModuleID))
+ return true;
+ } else if (Stream.SkipBlock()) {
+ return Error("Malformed block record");
+ }
+ }
+
+ return false;
+}
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