Initial revision
llvm-svn: 2
diff --git a/llvm/lib/Bytecode/Writer/Writer.cpp b/llvm/lib/Bytecode/Writer/Writer.cpp
new file mode 100644
index 0000000..d03c945
--- /dev/null
+++ b/llvm/lib/Bytecode/Writer/Writer.cpp
@@ -0,0 +1,182 @@
+//===-- Writer.cpp - Library for writing VM bytecode files -------*- C++ -*--=//
+//
+// This library implements the functionality defined in llvm/Bytecode/Writer.h
+//
+// This library uses the Analysis library to figure out offsets for
+// variables in the method tables...
+//
+// Note that this file uses an unusual technique of outputting all the bytecode
+// to a vector of unsigned char's, then copies the vector to an ostream. The
+// reason for this is that we must do "seeking" in the stream to do back-
+// patching, and some very important ostreams that we want to support (like
+// pipes) do not support seeking. :( :( :(
+//
+// The choice of the vector data structure is influenced by the extremely fast
+// "append" speed, plus the free "seek"/replace in the middle of the stream.
+//
+// Note that the performance of this library is not terribly important, because
+// it shouldn't be used by JIT type applications... so it is not a huge focus
+// at least. :)
+//
+//===----------------------------------------------------------------------===//
+
+#include "WriterInternals.h"
+#include "llvm/Module.h"
+#include "llvm/Method.h"
+#include "llvm/BasicBlock.h"
+#include "llvm/ConstPoolVals.h"
+#include "llvm/SymbolTable.h"
+#include "llvm/DerivedTypes.h"
+#include <string.h>
+#include <algorithm>
+
+BytecodeWriter::BytecodeWriter(vector<unsigned char> &o, const Module *M)
+ : Out(o), Table(M, false) {
+
+ outputSignature();
+
+ // Emit the top level CLASS block.
+ BytecodeBlock ModuleBlock(BytecodeFormat::Module, Out);
+
+ // Output largest ID of first "primitive" type:
+ output_vbr((unsigned)Type::FirstDerivedTyID, Out);
+ align32(Out);
+
+ // Do the whole module now!
+ processModule(M);
+
+ // If needed, output the symbol table for the class...
+ if (M->hasSymbolTable())
+ outputSymbolTable(*M->getSymbolTable());
+}
+
+// TODO: REMOVE
+#include "llvm/Assembly/Writer.h"
+
+bool BytecodeWriter::processConstPool(const ConstantPool &CP, bool isMethod) {
+ BytecodeBlock *CPool = new BytecodeBlock(BytecodeFormat::ConstantPool, Out);
+
+ unsigned NumPlanes = Table.getNumPlanes();
+
+ for (unsigned pno = 0; pno < NumPlanes; pno++) {
+ const vector<const Value*> &Plane = Table.getPlane(pno);
+ if (Plane.empty()) continue; // Skip empty type planes...
+
+ unsigned ValNo = 0; // Don't reemit module constants
+ if (isMethod) ValNo = Table.getModuleLevel(pno);
+
+ unsigned NumConstants = 0;
+ for (unsigned vn = ValNo; vn < Plane.size(); vn++)
+ if (Plane[vn]->getValueType() == Value::ConstantVal)
+ NumConstants++;
+
+ if (NumConstants == 0) continue; // Skip empty type planes...
+
+ // Output type header: [num entries][type id number]
+ //
+ output_vbr(NumConstants, Out);
+
+ // Output the Type ID Number...
+ int Slot = Table.getValSlot(Plane.front()->getType());
+ assert (Slot != -1 && "Type in constant pool but not in method!!");
+ output_vbr((unsigned)Slot, Out);
+
+ //cerr << "NC: " << NumConstants << " Slot = " << hex << Slot << endl;
+
+ for (; ValNo < Plane.size(); ValNo++) {
+ const Value *V = Plane[ValNo];
+ if (V->getValueType() == Value::ConstantVal) {
+ //cerr << "Serializing value: <" << V->getType() << ">: "
+ // << ((const ConstPoolVal*)V)->getStrValue() << ":"
+ // << Out.size() << "\n";
+ outputConstant((const ConstPoolVal*)V);
+ }
+ }
+ }
+
+ delete CPool; // End bytecode block section!
+
+ if (!isMethod) { // The ModuleInfoBlock follows directly after the c-pool
+ assert(CP.getParent()->getValueType() == Value::ModuleVal);
+ outputModuleInfoBlock((const Module*)CP.getParent());
+ }
+
+ return false;
+}
+
+void BytecodeWriter::outputModuleInfoBlock(const Module *M) {
+ BytecodeBlock ModuleInfoBlock(BytecodeFormat::ModuleGlobalInfo, Out);
+
+ // Output the types of the methods in this class
+ Module::MethodListType::const_iterator I = M->getMethodList().begin();
+ while (I != M->getMethodList().end()) {
+ int Slot = Table.getValSlot((*I)->getType());
+ assert(Slot != -1 && "Module const pool is broken!");
+ assert(Slot >= Type::FirstDerivedTyID && "Derived type not in range!");
+ output_vbr((unsigned)Slot, Out);
+ I++;
+ }
+ output_vbr((unsigned)Table.getValSlot(Type::VoidTy), Out);
+ align32(Out);
+}
+
+bool BytecodeWriter::processMethod(const Method *M) {
+ BytecodeBlock MethodBlock(BytecodeFormat::Method, Out);
+
+ Table.incorporateMethod(M);
+
+ if (ModuleAnalyzer::processMethod(M)) return true;
+
+ // If needed, output the symbol table for the method...
+ if (M->hasSymbolTable())
+ outputSymbolTable(*M->getSymbolTable());
+
+ Table.purgeMethod();
+ return false;
+}
+
+
+bool BytecodeWriter::processBasicBlock(const BasicBlock *BB) {
+ BytecodeBlock MethodBlock(BytecodeFormat::BasicBlock, Out);
+ return ModuleAnalyzer::processBasicBlock(BB);
+}
+
+void BytecodeWriter::outputSymbolTable(const SymbolTable &MST) {
+ BytecodeBlock MethodBlock(BytecodeFormat::SymbolTable, Out);
+
+ for (SymbolTable::const_iterator TI = MST.begin(); TI != MST.end(); TI++) {
+ SymbolTable::type_const_iterator I = MST.type_begin(TI->first);
+ SymbolTable::type_const_iterator End = MST.type_end(TI->first);
+ int Slot;
+
+ if (I == End) continue; // Don't mess with an absent type...
+
+ // Symtab block header: [num entries][type id number]
+ output_vbr(MST.type_size(TI->first), Out);
+
+ Slot = Table.getValSlot(TI->first);
+ assert(Slot != -1 && "Type in symtab, but not in table!");
+ output_vbr((unsigned)Slot, Out);
+
+ for (; I != End; I++) {
+ // Symtab entry: [def slot #][name]
+ Slot = Table.getValSlot(I->second);
+ assert (Slot != -1 && "Value in symtab but not in method!!");
+ output_vbr((unsigned)Slot, Out);
+ output(I->first, Out, false); // Don't force alignment...
+ }
+ }
+}
+
+void WriteBytecodeToFile(const Module *C, ostream &Out) {
+ assert(C && "You can't write a null class!!");
+
+ vector<unsigned char> Buffer;
+
+ // This object populates buffer for us...
+ BytecodeWriter BCW(Buffer, C);
+
+ // Okay, write the vector out to the ostream now...
+ Out.write(&Buffer[0], Buffer.size());
+ Out.flush();
+}