1 //===-- Writer.cpp - Library for converting LLVM code to C ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This library converts LLVM code to C code, compilable by GCC and other C
13 //===----------------------------------------------------------------------===//
15 #include "CTargetMachine.h"
16 #include "llvm/Constants.h"
17 #include "llvm/DerivedTypes.h"
18 #include "llvm/Module.h"
19 #include "llvm/Instructions.h"
20 #include "llvm/Pass.h"
21 #include "llvm/PassManager.h"
22 #include "llvm/SymbolTable.h"
23 #include "llvm/Intrinsics.h"
24 #include "llvm/Analysis/ConstantsScanner.h"
25 #include "llvm/Analysis/FindUsedTypes.h"
26 #include "llvm/Analysis/LoopInfo.h"
27 #include "llvm/CodeGen/IntrinsicLowering.h"
28 #include "llvm/Transforms/Scalar.h"
29 #include "llvm/Target/TargetMachineRegistry.h"
30 #include "llvm/Support/CallSite.h"
31 #include "llvm/Support/CFG.h"
32 #include "llvm/Support/GetElementPtrTypeIterator.h"
33 #include "llvm/Support/InstVisitor.h"
34 #include "llvm/Support/Mangler.h"
35 #include "llvm/ADT/StringExtras.h"
36 #include "llvm/Support/MathExtras.h"
37 #include "llvm/Config/config.h"
44 // Register the target.
45 RegisterTarget<CTargetMachine> X("c", " C backend");
47 /// NameAllUsedStructs - This pass inserts names for any unnamed structure
48 /// types that are used by the program.
50 class CBackendNameAllUsedStructs : public ModulePass {
51 void getAnalysisUsage(AnalysisUsage &AU) const {
52 AU.addRequired<FindUsedTypes>();
55 virtual const char *getPassName() const {
56 return "C backend type canonicalizer";
59 virtual bool runOnModule(Module &M);
62 /// CWriter - This class is the main chunk of code that converts an LLVM
63 /// module to a C translation unit.
64 class CWriter : public FunctionPass, public InstVisitor<CWriter> {
66 IntrinsicLowering &IL;
69 const Module *TheModule;
70 std::map<const Type *, std::string> TypeNames;
72 std::map<const ConstantFP *, unsigned> FPConstantMap;
74 CWriter(std::ostream &o, IntrinsicLowering &il) : Out(o), IL(il) {}
76 virtual const char *getPassName() const { return "C backend"; }
78 void getAnalysisUsage(AnalysisUsage &AU) const {
79 AU.addRequired<LoopInfo>();
83 virtual bool doInitialization(Module &M);
85 bool runOnFunction(Function &F) {
86 LI = &getAnalysis<LoopInfo>();
88 // Get rid of intrinsics we can't handle.
91 // Output all floating point constants that cannot be printed accurately.
92 printFloatingPointConstants(F);
94 // Ensure that no local symbols conflict with global symbols.
95 F.renameLocalSymbols();
98 FPConstantMap.clear();
102 virtual bool doFinalization(Module &M) {
109 std::ostream &printType(std::ostream &Out, const Type *Ty,
110 const std::string &VariableName = "",
111 bool IgnoreName = false);
113 void writeOperand(Value *Operand);
114 void writeOperandInternal(Value *Operand);
117 void lowerIntrinsics(Function &F);
119 bool nameAllUsedStructureTypes(Module &M);
120 void printModule(Module *M);
121 void printModuleTypes(const SymbolTable &ST);
122 void printContainedStructs(const Type *Ty, std::set<const StructType *> &);
123 void printFloatingPointConstants(Function &F);
124 void printFunctionSignature(const Function *F, bool Prototype);
126 void printFunction(Function &);
127 void printBasicBlock(BasicBlock *BB);
128 void printLoop(Loop *L);
130 void printConstant(Constant *CPV);
131 void printConstantArray(ConstantArray *CPA);
133 // isInlinableInst - Attempt to inline instructions into their uses to build
134 // trees as much as possible. To do this, we have to consistently decide
135 // what is acceptable to inline, so that variable declarations don't get
136 // printed and an extra copy of the expr is not emitted.
138 static bool isInlinableInst(const Instruction &I) {
139 // Always inline setcc instructions, even if they are shared by multiple
140 // expressions. GCC generates horrible code if we don't.
141 if (isa<SetCondInst>(I)) return true;
143 // Must be an expression, must be used exactly once. If it is dead, we
144 // emit it inline where it would go.
145 if (I.getType() == Type::VoidTy || !I.hasOneUse() ||
146 isa<TerminatorInst>(I) || isa<CallInst>(I) || isa<PHINode>(I) ||
147 isa<LoadInst>(I) || isa<VAArgInst>(I) || isa<VANextInst>(I))
148 // Don't inline a load across a store or other bad things!
151 // Only inline instruction it it's use is in the same BB as the inst.
152 return I.getParent() == cast<Instruction>(I.use_back())->getParent();
155 // isDirectAlloca - Define fixed sized allocas in the entry block as direct
156 // variables which are accessed with the & operator. This causes GCC to
157 // generate significantly better code than to emit alloca calls directly.
159 static const AllocaInst *isDirectAlloca(const Value *V) {
160 const AllocaInst *AI = dyn_cast<AllocaInst>(V);
161 if (!AI) return false;
162 if (AI->isArrayAllocation())
163 return 0; // FIXME: we can also inline fixed size array allocas!
164 if (AI->getParent() != &AI->getParent()->getParent()->getEntryBlock())
169 // Instruction visitation functions
170 friend class InstVisitor<CWriter>;
172 void visitReturnInst(ReturnInst &I);
173 void visitBranchInst(BranchInst &I);
174 void visitSwitchInst(SwitchInst &I);
175 void visitInvokeInst(InvokeInst &I) {
176 assert(0 && "Lowerinvoke pass didn't work!");
179 void visitUnwindInst(UnwindInst &I) {
180 assert(0 && "Lowerinvoke pass didn't work!");
182 void visitUnreachableInst(UnreachableInst &I);
184 void visitPHINode(PHINode &I);
185 void visitBinaryOperator(Instruction &I);
187 void visitCastInst (CastInst &I);
188 void visitSelectInst(SelectInst &I);
189 void visitCallInst (CallInst &I);
190 void visitShiftInst(ShiftInst &I) { visitBinaryOperator(I); }
192 void visitMallocInst(MallocInst &I);
193 void visitAllocaInst(AllocaInst &I);
194 void visitFreeInst (FreeInst &I);
195 void visitLoadInst (LoadInst &I);
196 void visitStoreInst (StoreInst &I);
197 void visitGetElementPtrInst(GetElementPtrInst &I);
198 void visitVANextInst(VANextInst &I);
199 void visitVAArgInst (VAArgInst &I);
201 void visitInstruction(Instruction &I) {
202 std::cerr << "C Writer does not know about " << I;
206 void outputLValue(Instruction *I) {
207 Out << " " << Mang->getValueName(I) << " = ";
210 bool isGotoCodeNecessary(BasicBlock *From, BasicBlock *To);
211 void printPHICopiesForSuccessor(BasicBlock *CurBlock,
212 BasicBlock *Successor, unsigned Indent);
213 void printBranchToBlock(BasicBlock *CurBlock, BasicBlock *SuccBlock,
215 void printIndexingExpression(Value *Ptr, gep_type_iterator I,
216 gep_type_iterator E);
220 /// This method inserts names for any unnamed structure types that are used by
221 /// the program, and removes names from structure types that are not used by the
224 bool CBackendNameAllUsedStructs::runOnModule(Module &M) {
225 // Get a set of types that are used by the program...
226 std::set<const Type *> UT = getAnalysis<FindUsedTypes>().getTypes();
228 // Loop over the module symbol table, removing types from UT that are
229 // already named, and removing names for structure types that are not used.
231 SymbolTable &MST = M.getSymbolTable();
232 for (SymbolTable::type_iterator TI = MST.type_begin(), TE = MST.type_end();
234 SymbolTable::type_iterator I = TI++;
235 if (const StructType *STy = dyn_cast<StructType>(I->second)) {
236 // If this is not used, remove it from the symbol table.
237 std::set<const Type *>::iterator UTI = UT.find(STy);
245 // UT now contains types that are not named. Loop over it, naming
248 bool Changed = false;
249 unsigned RenameCounter = 0;
250 for (std::set<const Type *>::const_iterator I = UT.begin(), E = UT.end();
252 if (const StructType *ST = dyn_cast<StructType>(*I)) {
253 while (M.addTypeName("unnamed"+utostr(RenameCounter), ST))
261 // Pass the Type* and the variable name and this prints out the variable
264 std::ostream &CWriter::printType(std::ostream &Out, const Type *Ty,
265 const std::string &NameSoFar,
267 if (Ty->isPrimitiveType())
268 switch (Ty->getTypeID()) {
269 case Type::VoidTyID: return Out << "void " << NameSoFar;
270 case Type::BoolTyID: return Out << "bool " << NameSoFar;
271 case Type::UByteTyID: return Out << "unsigned char " << NameSoFar;
272 case Type::SByteTyID: return Out << "signed char " << NameSoFar;
273 case Type::UShortTyID: return Out << "unsigned short " << NameSoFar;
274 case Type::ShortTyID: return Out << "short " << NameSoFar;
275 case Type::UIntTyID: return Out << "unsigned " << NameSoFar;
276 case Type::IntTyID: return Out << "int " << NameSoFar;
277 case Type::ULongTyID: return Out << "unsigned long long " << NameSoFar;
278 case Type::LongTyID: return Out << "signed long long " << NameSoFar;
279 case Type::FloatTyID: return Out << "float " << NameSoFar;
280 case Type::DoubleTyID: return Out << "double " << NameSoFar;
282 std::cerr << "Unknown primitive type: " << *Ty << "\n";
286 // Check to see if the type is named.
287 if (!IgnoreName || isa<OpaqueType>(Ty)) {
288 std::map<const Type *, std::string>::iterator I = TypeNames.find(Ty);
289 if (I != TypeNames.end()) return Out << I->second << " " << NameSoFar;
292 switch (Ty->getTypeID()) {
293 case Type::FunctionTyID: {
294 const FunctionType *MTy = cast<FunctionType>(Ty);
295 std::stringstream FunctionInnards;
296 FunctionInnards << " (" << NameSoFar << ") (";
297 for (FunctionType::param_iterator I = MTy->param_begin(),
298 E = MTy->param_end(); I != E; ++I) {
299 if (I != MTy->param_begin())
300 FunctionInnards << ", ";
301 printType(FunctionInnards, *I, "");
303 if (MTy->isVarArg()) {
304 if (MTy->getNumParams())
305 FunctionInnards << ", ...";
306 } else if (!MTy->getNumParams()) {
307 FunctionInnards << "void";
309 FunctionInnards << ")";
310 std::string tstr = FunctionInnards.str();
311 printType(Out, MTy->getReturnType(), tstr);
314 case Type::StructTyID: {
315 const StructType *STy = cast<StructType>(Ty);
316 Out << NameSoFar + " {\n";
318 for (StructType::element_iterator I = STy->element_begin(),
319 E = STy->element_end(); I != E; ++I) {
321 printType(Out, *I, "field" + utostr(Idx++));
327 case Type::PointerTyID: {
328 const PointerType *PTy = cast<PointerType>(Ty);
329 std::string ptrName = "*" + NameSoFar;
331 if (isa<ArrayType>(PTy->getElementType()))
332 ptrName = "(" + ptrName + ")";
334 return printType(Out, PTy->getElementType(), ptrName);
337 case Type::ArrayTyID: {
338 const ArrayType *ATy = cast<ArrayType>(Ty);
339 unsigned NumElements = ATy->getNumElements();
340 return printType(Out, ATy->getElementType(),
341 NameSoFar + "[" + utostr(NumElements) + "]");
344 case Type::OpaqueTyID: {
345 static int Count = 0;
346 std::string TyName = "struct opaque_" + itostr(Count++);
347 assert(TypeNames.find(Ty) == TypeNames.end());
348 TypeNames[Ty] = TyName;
349 return Out << TyName << " " << NameSoFar;
352 assert(0 && "Unhandled case in getTypeProps!");
359 void CWriter::printConstantArray(ConstantArray *CPA) {
361 // As a special case, print the array as a string if it is an array of
362 // ubytes or an array of sbytes with positive values.
364 const Type *ETy = CPA->getType()->getElementType();
365 bool isString = (ETy == Type::SByteTy || ETy == Type::UByteTy);
367 // Make sure the last character is a null char, as automatically added by C
368 if (isString && (CPA->getNumOperands() == 0 ||
369 !cast<Constant>(*(CPA->op_end()-1))->isNullValue()))
374 // Keep track of whether the last number was a hexadecimal escape
375 bool LastWasHex = false;
377 // Do not include the last character, which we know is null
378 for (unsigned i = 0, e = CPA->getNumOperands()-1; i != e; ++i) {
379 unsigned char C = cast<ConstantInt>(CPA->getOperand(i))->getRawValue();
381 // Print it out literally if it is a printable character. The only thing
382 // to be careful about is when the last letter output was a hex escape
383 // code, in which case we have to be careful not to print out hex digits
384 // explicitly (the C compiler thinks it is a continuation of the previous
385 // character, sheesh...)
387 if (isprint(C) && (!LastWasHex || !isxdigit(C))) {
389 if (C == '"' || C == '\\')
396 case '\n': Out << "\\n"; break;
397 case '\t': Out << "\\t"; break;
398 case '\r': Out << "\\r"; break;
399 case '\v': Out << "\\v"; break;
400 case '\a': Out << "\\a"; break;
401 case '\"': Out << "\\\""; break;
402 case '\'': Out << "\\\'"; break;
405 Out << (char)(( C/16 < 10) ? ( C/16 +'0') : ( C/16 -10+'A'));
406 Out << (char)(((C&15) < 10) ? ((C&15)+'0') : ((C&15)-10+'A'));
415 if (CPA->getNumOperands()) {
417 printConstant(cast<Constant>(CPA->getOperand(0)));
418 for (unsigned i = 1, e = CPA->getNumOperands(); i != e; ++i) {
420 printConstant(cast<Constant>(CPA->getOperand(i)));
427 // isFPCSafeToPrint - Returns true if we may assume that CFP may be written out
428 // textually as a double (rather than as a reference to a stack-allocated
429 // variable). We decide this by converting CFP to a string and back into a
430 // double, and then checking whether the conversion results in a bit-equal
431 // double to the original value of CFP. This depends on us and the target C
432 // compiler agreeing on the conversion process (which is pretty likely since we
433 // only deal in IEEE FP).
435 static bool isFPCSafeToPrint(const ConstantFP *CFP) {
438 sprintf(Buffer, "%a", CFP->getValue());
440 if (!strncmp(Buffer, "0x", 2) ||
441 !strncmp(Buffer, "-0x", 3) ||
442 !strncmp(Buffer, "+0x", 3))
443 return atof(Buffer) == CFP->getValue();
446 std::string StrVal = ftostr(CFP->getValue());
448 while (StrVal[0] == ' ')
449 StrVal.erase(StrVal.begin());
451 // Check to make sure that the stringized number is not some string like "Inf"
452 // or NaN. Check that the string matches the "[-+]?[0-9]" regex.
453 if ((StrVal[0] >= '0' && StrVal[0] <= '9') ||
454 ((StrVal[0] == '-' || StrVal[0] == '+') &&
455 (StrVal[1] >= '0' && StrVal[1] <= '9')))
456 // Reparse stringized version!
457 return atof(StrVal.c_str()) == CFP->getValue();
462 // printConstant - The LLVM Constant to C Constant converter.
463 void CWriter::printConstant(Constant *CPV) {
464 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
465 switch (CE->getOpcode()) {
466 case Instruction::Cast:
468 printType(Out, CPV->getType());
470 printConstant(CE->getOperand(0));
474 case Instruction::GetElementPtr:
476 printIndexingExpression(CE->getOperand(0), gep_type_begin(CPV),
480 case Instruction::Select:
482 printConstant(CE->getOperand(0));
484 printConstant(CE->getOperand(1));
486 printConstant(CE->getOperand(2));
489 case Instruction::Add:
490 case Instruction::Sub:
491 case Instruction::Mul:
492 case Instruction::Div:
493 case Instruction::Rem:
494 case Instruction::SetEQ:
495 case Instruction::SetNE:
496 case Instruction::SetLT:
497 case Instruction::SetLE:
498 case Instruction::SetGT:
499 case Instruction::SetGE:
500 case Instruction::Shl:
501 case Instruction::Shr:
503 printConstant(CE->getOperand(0));
504 switch (CE->getOpcode()) {
505 case Instruction::Add: Out << " + "; break;
506 case Instruction::Sub: Out << " - "; break;
507 case Instruction::Mul: Out << " * "; break;
508 case Instruction::Div: Out << " / "; break;
509 case Instruction::Rem: Out << " % "; break;
510 case Instruction::SetEQ: Out << " == "; break;
511 case Instruction::SetNE: Out << " != "; break;
512 case Instruction::SetLT: Out << " < "; break;
513 case Instruction::SetLE: Out << " <= "; break;
514 case Instruction::SetGT: Out << " > "; break;
515 case Instruction::SetGE: Out << " >= "; break;
516 case Instruction::Shl: Out << " << "; break;
517 case Instruction::Shr: Out << " >> "; break;
518 default: assert(0 && "Illegal opcode here!");
520 printConstant(CE->getOperand(1));
525 std::cerr << "CWriter Error: Unhandled constant expression: "
529 } else if (isa<UndefValue>(CPV) && CPV->getType()->isFirstClassType()) {
531 printType(Out, CPV->getType());
532 Out << ")/*UNDEF*/0)";
536 switch (CPV->getType()->getTypeID()) {
538 Out << (CPV == ConstantBool::False ? "0" : "1"); break;
539 case Type::SByteTyID:
540 case Type::ShortTyID:
541 Out << cast<ConstantSInt>(CPV)->getValue(); break;
543 if ((int)cast<ConstantSInt>(CPV)->getValue() == (int)0x80000000)
544 Out << "((int)0x80000000U)"; // Handle MININT specially to avoid warning
546 Out << cast<ConstantSInt>(CPV)->getValue();
550 if (cast<ConstantSInt>(CPV)->isMinValue())
551 Out << "(/*INT64_MIN*/(-9223372036854775807LL)-1)";
553 Out << cast<ConstantSInt>(CPV)->getValue() << "ll"; break;
555 case Type::UByteTyID:
556 case Type::UShortTyID:
557 Out << cast<ConstantUInt>(CPV)->getValue(); break;
559 Out << cast<ConstantUInt>(CPV)->getValue() << "u"; break;
560 case Type::ULongTyID:
561 Out << cast<ConstantUInt>(CPV)->getValue() << "ull"; break;
563 case Type::FloatTyID:
564 case Type::DoubleTyID: {
565 ConstantFP *FPC = cast<ConstantFP>(CPV);
566 std::map<const ConstantFP*, unsigned>::iterator I = FPConstantMap.find(FPC);
567 if (I != FPConstantMap.end()) {
568 // Because of FP precision problems we must load from a stack allocated
569 // value that holds the value in hex.
570 Out << "(*(" << (FPC->getType() == Type::FloatTy ? "float" : "double")
571 << "*)&FPConstant" << I->second << ")";
573 if (IsNAN(FPC->getValue())) {
576 // The prefix for a quiet NaN is 0x7FF8. For a signalling NaN,
578 const unsigned long QuietNaN = 0x7ff8UL;
579 const unsigned long SignalNaN = 0x7ff4UL;
581 // We need to grab the first part of the FP #
588 DHex.d = FPC->getValue();
589 sprintf(Buffer, "0x%llx", (unsigned long long)DHex.ll);
591 std::string Num(&Buffer[0], &Buffer[6]);
592 unsigned long Val = strtoul(Num.c_str(), 0, 16);
594 if (FPC->getType() == Type::FloatTy)
595 Out << "LLVM_NAN" << (Val == QuietNaN ? "" : "S") << "F(\""
596 << Buffer << "\") /*nan*/ ";
598 Out << "LLVM_NAN" << (Val == QuietNaN ? "" : "S") << "(\""
599 << Buffer << "\") /*nan*/ ";
600 } else if (IsInf(FPC->getValue())) {
602 if (FPC->getValue() < 0) Out << "-";
603 Out << "LLVM_INF" << (FPC->getType() == Type::FloatTy ? "F" : "")
608 // Print out the constant as a floating point number.
610 sprintf(Buffer, "%a", FPC->getValue());
613 Num = ftostr(FPC->getValue());
621 case Type::ArrayTyID:
622 if (isa<ConstantAggregateZero>(CPV) || isa<UndefValue>(CPV)) {
623 const ArrayType *AT = cast<ArrayType>(CPV->getType());
625 if (AT->getNumElements()) {
627 Constant *CZ = Constant::getNullValue(AT->getElementType());
629 for (unsigned i = 1, e = AT->getNumElements(); i != e; ++i) {
636 printConstantArray(cast<ConstantArray>(CPV));
640 case Type::StructTyID:
641 if (isa<ConstantAggregateZero>(CPV) || isa<UndefValue>(CPV)) {
642 const StructType *ST = cast<StructType>(CPV->getType());
644 if (ST->getNumElements()) {
646 printConstant(Constant::getNullValue(ST->getElementType(0)));
647 for (unsigned i = 1, e = ST->getNumElements(); i != e; ++i) {
649 printConstant(Constant::getNullValue(ST->getElementType(i)));
655 if (CPV->getNumOperands()) {
657 printConstant(cast<Constant>(CPV->getOperand(0)));
658 for (unsigned i = 1, e = CPV->getNumOperands(); i != e; ++i) {
660 printConstant(cast<Constant>(CPV->getOperand(i)));
667 case Type::PointerTyID:
668 if (isa<ConstantPointerNull>(CPV)) {
670 printType(Out, CPV->getType());
671 Out << ")/*NULL*/0)";
673 } else if (GlobalValue *GV = dyn_cast<GlobalValue>(CPV)) {
679 std::cerr << "Unknown constant type: " << *CPV << "\n";
684 void CWriter::writeOperandInternal(Value *Operand) {
685 if (Instruction *I = dyn_cast<Instruction>(Operand))
686 if (isInlinableInst(*I) && !isDirectAlloca(I)) {
687 // Should we inline this instruction to build a tree?
694 Constant* CPV = dyn_cast<Constant>(Operand);
695 if (CPV && !isa<GlobalValue>(CPV)) {
698 Out << Mang->getValueName(Operand);
702 void CWriter::writeOperand(Value *Operand) {
703 if (isa<GlobalVariable>(Operand) || isDirectAlloca(Operand))
704 Out << "(&"; // Global variables are references as their addresses by llvm
706 writeOperandInternal(Operand);
708 if (isa<GlobalVariable>(Operand) || isDirectAlloca(Operand))
712 // generateCompilerSpecificCode - This is where we add conditional compilation
713 // directives to cater to specific compilers as need be.
715 static void generateCompilerSpecificCode(std::ostream& Out) {
716 // Alloca is hard to get, and we don't want to include stdlib.h here...
717 Out << "/* get a declaration for alloca */\n"
718 << "#if defined(__CYGWIN__) || defined(__APPLE__)\n"
719 << "extern void *__builtin_alloca(unsigned long);\n"
720 << "#define alloca(x) __builtin_alloca(x)\n"
721 << "#elif defined(__sun__)\n"
722 << "#if defined(__sparcv9)\n"
723 << "extern void *__builtin_alloca(unsigned long);\n"
725 << "extern void *__builtin_alloca(unsigned int);\n"
727 << "#define alloca(x) __builtin_alloca(x)\n"
728 << "#elif defined(__FreeBSD__)\n"
729 << "#define alloca(x) __builtin_alloca(x)\n"
731 << "#include <alloca.h>\n"
734 // We output GCC specific attributes to preserve 'linkonce'ness on globals.
735 // If we aren't being compiled with GCC, just drop these attributes.
736 Out << "#ifndef __GNUC__ /* Can only support \"linkonce\" vars with GCC */\n"
737 << "#define __attribute__(X)\n"
741 // At some point, we should support "external weak" vs. "weak" linkages.
742 // On Mac OS X, "external weak" is spelled "__attribute__((weak_import))".
743 Out << "#if defined(__GNUC__) && defined(__APPLE_CC__)\n"
744 << "#define __EXTERNAL_WEAK__ __attribute__((weak_import))\n"
745 << "#elif defined(__GNUC__)\n"
746 << "#define __EXTERNAL_WEAK__ __attribute__((weak))\n"
748 << "#define __EXTERNAL_WEAK__\n"
752 // For now, turn off the weak linkage attribute on Mac OS X. (See above.)
753 Out << "#if defined(__GNUC__) && defined(__APPLE_CC__)\n"
754 << "#define __ATTRIBUTE_WEAK__\n"
755 << "#elif defined(__GNUC__)\n"
756 << "#define __ATTRIBUTE_WEAK__ __attribute__((weak))\n"
758 << "#define __ATTRIBUTE_WEAK__\n"
761 // Define NaN and Inf as GCC builtins if using GCC, as 0 otherwise
762 // From the GCC documentation:
764 // double __builtin_nan (const char *str)
766 // This is an implementation of the ISO C99 function nan.
768 // Since ISO C99 defines this function in terms of strtod, which we do
769 // not implement, a description of the parsing is in order. The string is
770 // parsed as by strtol; that is, the base is recognized by leading 0 or
771 // 0x prefixes. The number parsed is placed in the significand such that
772 // the least significant bit of the number is at the least significant
773 // bit of the significand. The number is truncated to fit the significand
774 // field provided. The significand is forced to be a quiet NaN.
776 // This function, if given a string literal, is evaluated early enough
777 // that it is considered a compile-time constant.
779 // float __builtin_nanf (const char *str)
781 // Similar to __builtin_nan, except the return type is float.
783 // double __builtin_inf (void)
785 // Similar to __builtin_huge_val, except a warning is generated if the
786 // target floating-point format does not support infinities. This
787 // function is suitable for implementing the ISO C99 macro INFINITY.
789 // float __builtin_inff (void)
791 // Similar to __builtin_inf, except the return type is float.
792 Out << "#ifdef __GNUC__\n"
793 << "#define LLVM_NAN(NanStr) __builtin_nan(NanStr) /* Double */\n"
794 << "#define LLVM_NANF(NanStr) __builtin_nanf(NanStr) /* Float */\n"
795 << "#define LLVM_NANS(NanStr) __builtin_nans(NanStr) /* Double */\n"
796 << "#define LLVM_NANSF(NanStr) __builtin_nansf(NanStr) /* Float */\n"
797 << "#define LLVM_INF __builtin_inf() /* Double */\n"
798 << "#define LLVM_INFF __builtin_inff() /* Float */\n"
800 << "#define LLVM_NAN(NanStr) ((double)0.0) /* Double */\n"
801 << "#define LLVM_NANF(NanStr) 0.0F /* Float */\n"
802 << "#define LLVM_NANS(NanStr) ((double)0.0) /* Double */\n"
803 << "#define LLVM_NANSF(NanStr) 0.0F /* Float */\n"
804 << "#define LLVM_INF ((double)0.0) /* Double */\n"
805 << "#define LLVM_INFF 0.0F /* Float */\n"
809 bool CWriter::doInitialization(Module &M) {
815 // Ensure that all structure types have names...
816 Mang = new Mangler(M);
818 // get declaration for alloca
819 Out << "/* Provide Declarations */\n";
820 Out << "#include <stdarg.h>\n"; // Varargs support
821 Out << "#include <setjmp.h>\n"; // Unwind support
822 generateCompilerSpecificCode(Out);
824 // Provide a definition for `bool' if not compiling with a C++ compiler.
826 << "#ifndef __cplusplus\ntypedef unsigned char bool;\n#endif\n"
828 << "\n\n/* Support for floating point constants */\n"
829 << "typedef unsigned long long ConstantDoubleTy;\n"
830 << "typedef unsigned int ConstantFloatTy;\n"
832 << "\n\n/* Global Declarations */\n";
834 // First output all the declarations for the program, because C requires
835 // Functions & globals to be declared before they are used.
838 // Loop over the symbol table, emitting all named constants...
839 printModuleTypes(M.getSymbolTable());
841 // Global variable declarations...
843 Out << "\n/* External Global Variable Declarations */\n";
844 for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I) {
845 if (I->hasExternalLinkage()) {
847 printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
853 // Function declarations
855 Out << "\n/* Function Declarations */\n";
856 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
857 // Don't print declarations for intrinsic functions.
858 if (!I->getIntrinsicID() &&
859 I->getName() != "setjmp" && I->getName() != "longjmp") {
860 printFunctionSignature(I, true);
861 if (I->hasWeakLinkage()) Out << " __ATTRIBUTE_WEAK__";
862 if (I->hasLinkOnceLinkage()) Out << " __ATTRIBUTE_WEAK__";
868 // Output the global variable declarations
870 Out << "\n\n/* Global Variable Declarations */\n";
871 for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
872 if (!I->isExternal()) {
873 if (I->hasInternalLinkage())
877 printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
879 if (I->hasLinkOnceLinkage())
880 Out << " __attribute__((common))";
881 else if (I->hasWeakLinkage())
882 Out << " __ATTRIBUTE_WEAK__";
887 // Output the global variable definitions and contents...
889 Out << "\n\n/* Global Variable Definitions and Initialization */\n";
890 for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
891 if (!I->isExternal()) {
892 if (I->hasInternalLinkage())
894 printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
895 if (I->hasLinkOnceLinkage())
896 Out << " __attribute__((common))";
897 else if (I->hasWeakLinkage())
898 Out << " __ATTRIBUTE_WEAK__";
900 // If the initializer is not null, emit the initializer. If it is null,
901 // we try to avoid emitting large amounts of zeros. The problem with
902 // this, however, occurs when the variable has weak linkage. In this
903 // case, the assembler will complain about the variable being both weak
904 // and common, so we disable this optimization.
905 if (!I->getInitializer()->isNullValue()) {
907 writeOperand(I->getInitializer());
908 } else if (I->hasWeakLinkage()) {
909 // We have to specify an initializer, but it doesn't have to be
910 // complete. If the value is an aggregate, print out { 0 }, and let
911 // the compiler figure out the rest of the zeros.
913 if (isa<StructType>(I->getInitializer()->getType()) ||
914 isa<ArrayType>(I->getInitializer()->getType())) {
917 // Just print it out normally.
918 writeOperand(I->getInitializer());
926 Out << "\n\n/* Function Bodies */\n";
931 /// Output all floating point constants that cannot be printed accurately...
932 void CWriter::printFloatingPointConstants(Function &F) {
943 // Scan the module for floating point constants. If any FP constant is used
944 // in the function, we want to redirect it here so that we do not depend on
945 // the precision of the printed form, unless the printed form preserves
948 static unsigned FPCounter = 0;
949 for (constant_iterator I = constant_begin(&F), E = constant_end(&F);
951 if (const ConstantFP *FPC = dyn_cast<ConstantFP>(*I))
952 if (!isFPCSafeToPrint(FPC) && // Do not put in FPConstantMap if safe.
953 !FPConstantMap.count(FPC)) {
954 double Val = FPC->getValue();
956 FPConstantMap[FPC] = FPCounter; // Number the FP constants
958 if (FPC->getType() == Type::DoubleTy) {
960 Out << "static const ConstantDoubleTy FPConstant" << FPCounter++
961 << " = 0x" << std::hex << DBLUnion.U << std::dec
962 << "ULL; /* " << Val << " */\n";
963 } else if (FPC->getType() == Type::FloatTy) {
965 Out << "static const ConstantFloatTy FPConstant" << FPCounter++
966 << " = 0x" << std::hex << FLTUnion.U << std::dec
967 << "U; /* " << Val << " */\n";
969 assert(0 && "Unknown float type!");
976 /// printSymbolTable - Run through symbol table looking for type names. If a
977 /// type name is found, emit it's declaration...
979 void CWriter::printModuleTypes(const SymbolTable &ST) {
980 // If there are no type names, exit early.
981 if ( ! ST.hasTypes() )
984 // We are only interested in the type plane of the symbol table...
985 SymbolTable::type_const_iterator I = ST.type_begin();
986 SymbolTable::type_const_iterator End = ST.type_end();
988 // Print out forward declarations for structure types before anything else!
989 Out << "/* Structure forward decls */\n";
990 for (; I != End; ++I)
991 if (const Type *STy = dyn_cast<StructType>(I->second)) {
992 std::string Name = "struct l_" + Mangler::makeNameProper(I->first);
993 Out << Name << ";\n";
994 TypeNames.insert(std::make_pair(STy, Name));
999 // Now we can print out typedefs...
1000 Out << "/* Typedefs */\n";
1001 for (I = ST.type_begin(); I != End; ++I) {
1002 const Type *Ty = cast<Type>(I->second);
1003 std::string Name = "l_" + Mangler::makeNameProper(I->first);
1005 printType(Out, Ty, Name);
1011 // Keep track of which structures have been printed so far...
1012 std::set<const StructType *> StructPrinted;
1014 // Loop over all structures then push them into the stack so they are
1015 // printed in the correct order.
1017 Out << "/* Structure contents */\n";
1018 for (I = ST.type_begin(); I != End; ++I)
1019 if (const StructType *STy = dyn_cast<StructType>(I->second))
1020 // Only print out used types!
1021 printContainedStructs(STy, StructPrinted);
1024 // Push the struct onto the stack and recursively push all structs
1025 // this one depends on.
1026 void CWriter::printContainedStructs(const Type *Ty,
1027 std::set<const StructType*> &StructPrinted){
1028 if (const StructType *STy = dyn_cast<StructType>(Ty)) {
1029 //Check to see if we have already printed this struct
1030 if (StructPrinted.count(STy) == 0) {
1031 // Print all contained types first...
1032 for (StructType::element_iterator I = STy->element_begin(),
1033 E = STy->element_end(); I != E; ++I) {
1034 const Type *Ty1 = I->get();
1035 if (isa<StructType>(Ty1) || isa<ArrayType>(Ty1))
1036 printContainedStructs(*I, StructPrinted);
1039 //Print structure type out..
1040 StructPrinted.insert(STy);
1041 std::string Name = TypeNames[STy];
1042 printType(Out, STy, Name, true);
1046 // If it is an array, check contained types and continue
1047 } else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)){
1048 const Type *Ty1 = ATy->getElementType();
1049 if (isa<StructType>(Ty1) || isa<ArrayType>(Ty1))
1050 printContainedStructs(Ty1, StructPrinted);
1055 void CWriter::printFunctionSignature(const Function *F, bool Prototype) {
1056 if (F->hasInternalLinkage()) Out << "static ";
1058 // Loop over the arguments, printing them...
1059 const FunctionType *FT = cast<FunctionType>(F->getFunctionType());
1061 std::stringstream FunctionInnards;
1063 // Print out the name...
1064 FunctionInnards << Mang->getValueName(F) << "(";
1066 if (!F->isExternal()) {
1068 std::string ArgName;
1069 if (F->abegin()->hasName() || !Prototype)
1070 ArgName = Mang->getValueName(F->abegin());
1071 printType(FunctionInnards, F->afront().getType(), ArgName);
1072 for (Function::const_aiterator I = ++F->abegin(), E = F->aend();
1074 FunctionInnards << ", ";
1075 if (I->hasName() || !Prototype)
1076 ArgName = Mang->getValueName(I);
1079 printType(FunctionInnards, I->getType(), ArgName);
1083 // Loop over the arguments, printing them...
1084 for (FunctionType::param_iterator I = FT->param_begin(),
1085 E = FT->param_end(); I != E; ++I) {
1086 if (I != FT->param_begin()) FunctionInnards << ", ";
1087 printType(FunctionInnards, *I);
1091 // Finish printing arguments... if this is a vararg function, print the ...,
1092 // unless there are no known types, in which case, we just emit ().
1094 if (FT->isVarArg() && FT->getNumParams()) {
1095 if (FT->getNumParams()) FunctionInnards << ", ";
1096 FunctionInnards << "..."; // Output varargs portion of signature!
1097 } else if (!FT->isVarArg() && FT->getNumParams() == 0) {
1098 FunctionInnards << "void"; // ret() -> ret(void) in C.
1100 FunctionInnards << ")";
1101 // Print out the return type and the entire signature for that matter
1102 printType(Out, F->getReturnType(), FunctionInnards.str());
1105 void CWriter::printFunction(Function &F) {
1106 printFunctionSignature(&F, false);
1109 // print local variable information for the function
1110 for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E; ++I)
1111 if (const AllocaInst *AI = isDirectAlloca(&*I)) {
1113 printType(Out, AI->getAllocatedType(), Mang->getValueName(AI));
1114 Out << "; /* Address exposed local */\n";
1115 } else if (I->getType() != Type::VoidTy && !isInlinableInst(*I)) {
1117 printType(Out, I->getType(), Mang->getValueName(&*I));
1120 if (isa<PHINode>(*I)) { // Print out PHI node temporaries as well...
1122 printType(Out, I->getType(),
1123 Mang->getValueName(&*I)+"__PHI_TEMPORARY");
1130 // print the basic blocks
1131 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
1132 if (Loop *L = LI->getLoopFor(BB)) {
1133 if (L->getHeader() == BB && L->getParentLoop() == 0)
1136 printBasicBlock(BB);
1143 void CWriter::printLoop(Loop *L) {
1144 Out << " do { /* Syntactic loop '" << L->getHeader()->getName()
1145 << "' to make GCC happy */\n";
1146 for (unsigned i = 0, e = L->getBlocks().size(); i != e; ++i) {
1147 BasicBlock *BB = L->getBlocks()[i];
1148 Loop *BBLoop = LI->getLoopFor(BB);
1150 printBasicBlock(BB);
1151 else if (BB == BBLoop->getHeader() && BBLoop->getParentLoop() == L)
1154 Out << " } while (1); /* end of syntactic loop '"
1155 << L->getHeader()->getName() << "' */\n";
1158 void CWriter::printBasicBlock(BasicBlock *BB) {
1160 // Don't print the label for the basic block if there are no uses, or if
1161 // the only terminator use is the predecessor basic block's terminator.
1162 // We have to scan the use list because PHI nodes use basic blocks too but
1163 // do not require a label to be generated.
1165 bool NeedsLabel = false;
1166 for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
1167 if (isGotoCodeNecessary(*PI, BB)) {
1172 if (NeedsLabel) Out << Mang->getValueName(BB) << ":\n";
1174 // Output all of the instructions in the basic block...
1175 for (BasicBlock::iterator II = BB->begin(), E = --BB->end(); II != E;
1177 if (!isInlinableInst(*II) && !isDirectAlloca(II)) {
1178 if (II->getType() != Type::VoidTy)
1187 // Don't emit prefix or suffix for the terminator...
1188 visit(*BB->getTerminator());
1192 // Specific Instruction type classes... note that all of the casts are
1193 // necessary because we use the instruction classes as opaque types...
1195 void CWriter::visitReturnInst(ReturnInst &I) {
1196 // Don't output a void return if this is the last basic block in the function
1197 if (I.getNumOperands() == 0 &&
1198 &*--I.getParent()->getParent()->end() == I.getParent() &&
1199 !I.getParent()->size() == 1) {
1204 if (I.getNumOperands()) {
1206 writeOperand(I.getOperand(0));
1211 void CWriter::visitSwitchInst(SwitchInst &SI) {
1214 writeOperand(SI.getOperand(0));
1215 Out << ") {\n default:\n";
1216 printPHICopiesForSuccessor (SI.getParent(), SI.getDefaultDest(), 2);
1217 printBranchToBlock(SI.getParent(), SI.getDefaultDest(), 2);
1219 for (unsigned i = 2, e = SI.getNumOperands(); i != e; i += 2) {
1221 writeOperand(SI.getOperand(i));
1223 BasicBlock *Succ = cast<BasicBlock>(SI.getOperand(i+1));
1224 printPHICopiesForSuccessor (SI.getParent(), Succ, 2);
1225 printBranchToBlock(SI.getParent(), Succ, 2);
1226 if (Succ == SI.getParent()->getNext())
1232 void CWriter::visitUnreachableInst(UnreachableInst &I) {
1233 Out << " /*UNREACHABLE*/;\n";
1236 bool CWriter::isGotoCodeNecessary(BasicBlock *From, BasicBlock *To) {
1237 /// FIXME: This should be reenabled, but loop reordering safe!!
1240 if (From->getNext() != To) // Not the direct successor, we need a goto
1243 //isa<SwitchInst>(From->getTerminator())
1246 if (LI->getLoopFor(From) != LI->getLoopFor(To))
1251 void CWriter::printPHICopiesForSuccessor (BasicBlock *CurBlock,
1252 BasicBlock *Successor,
1254 for (BasicBlock::iterator I = Successor->begin(); isa<PHINode>(I); ++I) {
1255 PHINode *PN = cast<PHINode>(I);
1256 // Now we have to do the printing.
1257 Value *IV = PN->getIncomingValueForBlock(CurBlock);
1258 if (!isa<UndefValue>(IV)) {
1259 Out << std::string(Indent, ' ');
1260 Out << " " << Mang->getValueName(I) << "__PHI_TEMPORARY = ";
1262 Out << "; /* for PHI node */\n";
1267 void CWriter::printBranchToBlock(BasicBlock *CurBB, BasicBlock *Succ,
1269 if (isGotoCodeNecessary(CurBB, Succ)) {
1270 Out << std::string(Indent, ' ') << " goto ";
1276 // Branch instruction printing - Avoid printing out a branch to a basic block
1277 // that immediately succeeds the current one.
1279 void CWriter::visitBranchInst(BranchInst &I) {
1281 if (I.isConditional()) {
1282 if (isGotoCodeNecessary(I.getParent(), I.getSuccessor(0))) {
1284 writeOperand(I.getCondition());
1287 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(0), 2);
1288 printBranchToBlock(I.getParent(), I.getSuccessor(0), 2);
1290 if (isGotoCodeNecessary(I.getParent(), I.getSuccessor(1))) {
1291 Out << " } else {\n";
1292 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(1), 2);
1293 printBranchToBlock(I.getParent(), I.getSuccessor(1), 2);
1296 // First goto not necessary, assume second one is...
1298 writeOperand(I.getCondition());
1301 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(1), 2);
1302 printBranchToBlock(I.getParent(), I.getSuccessor(1), 2);
1307 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(0), 0);
1308 printBranchToBlock(I.getParent(), I.getSuccessor(0), 0);
1313 // PHI nodes get copied into temporary values at the end of predecessor basic
1314 // blocks. We now need to copy these temporary values into the REAL value for
1316 void CWriter::visitPHINode(PHINode &I) {
1318 Out << "__PHI_TEMPORARY";
1322 void CWriter::visitBinaryOperator(Instruction &I) {
1323 // binary instructions, shift instructions, setCond instructions.
1324 assert(!isa<PointerType>(I.getType()));
1326 // We must cast the results of binary operations which might be promoted.
1327 bool needsCast = false;
1328 if ((I.getType() == Type::UByteTy) || (I.getType() == Type::SByteTy)
1329 || (I.getType() == Type::UShortTy) || (I.getType() == Type::ShortTy)
1330 || (I.getType() == Type::FloatTy)) {
1333 printType(Out, I.getType());
1337 writeOperand(I.getOperand(0));
1339 switch (I.getOpcode()) {
1340 case Instruction::Add: Out << " + "; break;
1341 case Instruction::Sub: Out << " - "; break;
1342 case Instruction::Mul: Out << "*"; break;
1343 case Instruction::Div: Out << "/"; break;
1344 case Instruction::Rem: Out << "%"; break;
1345 case Instruction::And: Out << " & "; break;
1346 case Instruction::Or: Out << " | "; break;
1347 case Instruction::Xor: Out << " ^ "; break;
1348 case Instruction::SetEQ: Out << " == "; break;
1349 case Instruction::SetNE: Out << " != "; break;
1350 case Instruction::SetLE: Out << " <= "; break;
1351 case Instruction::SetGE: Out << " >= "; break;
1352 case Instruction::SetLT: Out << " < "; break;
1353 case Instruction::SetGT: Out << " > "; break;
1354 case Instruction::Shl : Out << " << "; break;
1355 case Instruction::Shr : Out << " >> "; break;
1356 default: std::cerr << "Invalid operator type!" << I; abort();
1359 writeOperand(I.getOperand(1));
1366 void CWriter::visitCastInst(CastInst &I) {
1367 if (I.getType() == Type::BoolTy) {
1369 writeOperand(I.getOperand(0));
1374 printType(Out, I.getType());
1376 if (isa<PointerType>(I.getType())&&I.getOperand(0)->getType()->isIntegral() ||
1377 isa<PointerType>(I.getOperand(0)->getType())&&I.getType()->isIntegral()) {
1378 // Avoid "cast to pointer from integer of different size" warnings
1382 writeOperand(I.getOperand(0));
1385 void CWriter::visitSelectInst(SelectInst &I) {
1387 writeOperand(I.getCondition());
1389 writeOperand(I.getTrueValue());
1391 writeOperand(I.getFalseValue());
1396 void CWriter::lowerIntrinsics(Function &F) {
1397 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1398 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; )
1399 if (CallInst *CI = dyn_cast<CallInst>(I++))
1400 if (Function *F = CI->getCalledFunction())
1401 switch (F->getIntrinsicID()) {
1402 case Intrinsic::not_intrinsic:
1403 case Intrinsic::vastart:
1404 case Intrinsic::vacopy:
1405 case Intrinsic::vaend:
1406 case Intrinsic::returnaddress:
1407 case Intrinsic::frameaddress:
1408 case Intrinsic::setjmp:
1409 case Intrinsic::longjmp:
1410 // We directly implement these intrinsics
1413 // All other intrinsic calls we must lower.
1414 Instruction *Before = CI->getPrev();
1415 IL.LowerIntrinsicCall(CI);
1416 if (Before) { // Move iterator to instruction after call
1426 void CWriter::visitCallInst(CallInst &I) {
1427 // Handle intrinsic function calls first...
1428 if (Function *F = I.getCalledFunction())
1429 if (Intrinsic::ID ID = (Intrinsic::ID)F->getIntrinsicID()) {
1431 default: assert(0 && "Unknown LLVM intrinsic!");
1432 case Intrinsic::vastart:
1435 Out << "va_start(*(va_list*)&" << Mang->getValueName(&I) << ", ";
1436 // Output the last argument to the enclosing function...
1437 if (I.getParent()->getParent()->aempty()) {
1438 std::cerr << "The C backend does not currently support zero "
1439 << "argument varargs functions, such as '"
1440 << I.getParent()->getParent()->getName() << "'!\n";
1443 writeOperand(&I.getParent()->getParent()->aback());
1446 case Intrinsic::vaend:
1447 if (!isa<ConstantPointerNull>(I.getOperand(1))) {
1448 Out << "va_end(*(va_list*)&";
1449 writeOperand(I.getOperand(1));
1452 Out << "va_end(*(va_list*)0)";
1455 case Intrinsic::vacopy:
1457 Out << "va_copy(*(va_list*)&" << Mang->getValueName(&I) << ", ";
1458 Out << "*(va_list*)&";
1459 writeOperand(I.getOperand(1));
1462 case Intrinsic::returnaddress:
1463 Out << "__builtin_return_address(";
1464 writeOperand(I.getOperand(1));
1467 case Intrinsic::frameaddress:
1468 Out << "__builtin_frame_address(";
1469 writeOperand(I.getOperand(1));
1472 case Intrinsic::setjmp:
1473 Out << "setjmp(*(jmp_buf*)";
1474 writeOperand(I.getOperand(1));
1477 case Intrinsic::longjmp:
1478 Out << "longjmp(*(jmp_buf*)";
1479 writeOperand(I.getOperand(1));
1481 writeOperand(I.getOperand(2));
1487 Value *Callee = I.getCalledValue();
1489 // GCC is really a PITA. It does not permit codegening casts of functions to
1490 // function pointers if they are in a call (it generates a trap instruction
1491 // instead!). We work around this by inserting a cast to void* in between the
1492 // function and the function pointer cast. Unfortunately, we can't just form
1493 // the constant expression here, because the folder will immediately nuke it.
1495 // Note finally, that this is completely unsafe. ANSI C does not guarantee
1496 // that void* and function pointers have the same size. :( To deal with this
1497 // in the common case, we handle casts where the number of arguments passed
1500 bool WroteCallee = false;
1501 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Callee))
1502 if (CE->getOpcode() == Instruction::Cast)
1503 if (Function *RF = dyn_cast<Function>(CE->getOperand(0))) {
1504 const FunctionType *RFTy = RF->getFunctionType();
1505 if (RFTy->getNumParams() == I.getNumOperands()-1) {
1506 // If the call site expects a value, and the actual callee doesn't
1507 // provide one, return 0.
1508 if (I.getType() != Type::VoidTy &&
1509 RFTy->getReturnType() == Type::VoidTy)
1510 Out << "0 /*actual callee doesn't return value*/; ";
1513 // Ok, just cast the pointer type.
1515 printType(Out, CE->getType());
1523 const PointerType *PTy = cast<PointerType>(Callee->getType());
1524 const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1525 const Type *RetTy = FTy->getReturnType();
1527 if (!WroteCallee) writeOperand(Callee);
1530 unsigned NumDeclaredParams = FTy->getNumParams();
1532 if (I.getNumOperands() != 1) {
1533 CallSite::arg_iterator AI = I.op_begin()+1, AE = I.op_end();
1534 if (NumDeclaredParams && (*AI)->getType() != FTy->getParamType(0)) {
1536 printType(Out, FTy->getParamType(0));
1543 for (ArgNo = 1, ++AI; AI != AE; ++AI, ++ArgNo) {
1545 if (ArgNo < NumDeclaredParams &&
1546 (*AI)->getType() != FTy->getParamType(ArgNo)) {
1548 printType(Out, FTy->getParamType(ArgNo));
1557 void CWriter::visitMallocInst(MallocInst &I) {
1558 assert(0 && "lowerallocations pass didn't work!");
1561 void CWriter::visitAllocaInst(AllocaInst &I) {
1563 printType(Out, I.getType());
1564 Out << ") alloca(sizeof(";
1565 printType(Out, I.getType()->getElementType());
1567 if (I.isArrayAllocation()) {
1569 writeOperand(I.getOperand(0));
1574 void CWriter::visitFreeInst(FreeInst &I) {
1575 assert(0 && "lowerallocations pass didn't work!");
1578 void CWriter::printIndexingExpression(Value *Ptr, gep_type_iterator I,
1579 gep_type_iterator E) {
1580 bool HasImplicitAddress = false;
1581 // If accessing a global value with no indexing, avoid *(&GV) syndrome
1582 if (GlobalValue *V = dyn_cast<GlobalValue>(Ptr)) {
1583 HasImplicitAddress = true;
1584 } else if (isDirectAlloca(Ptr)) {
1585 HasImplicitAddress = true;
1589 if (!HasImplicitAddress)
1590 Out << "*"; // Implicit zero first argument: '*x' is equivalent to 'x[0]'
1592 writeOperandInternal(Ptr);
1596 const Constant *CI = dyn_cast<Constant>(I.getOperand());
1597 if (HasImplicitAddress && (!CI || !CI->isNullValue()))
1600 writeOperandInternal(Ptr);
1602 if (HasImplicitAddress && (!CI || !CI->isNullValue())) {
1604 HasImplicitAddress = false; // HIA is only true if we haven't addressed yet
1607 assert(!HasImplicitAddress || (CI && CI->isNullValue()) &&
1608 "Can only have implicit address with direct accessing");
1610 if (HasImplicitAddress) {
1612 } else if (CI && CI->isNullValue()) {
1613 gep_type_iterator TmpI = I; ++TmpI;
1615 // Print out the -> operator if possible...
1616 if (TmpI != E && isa<StructType>(*TmpI)) {
1617 Out << (HasImplicitAddress ? "." : "->");
1618 Out << "field" << cast<ConstantUInt>(TmpI.getOperand())->getValue();
1624 if (isa<StructType>(*I)) {
1625 Out << ".field" << cast<ConstantUInt>(I.getOperand())->getValue();
1628 writeOperand(I.getOperand());
1633 void CWriter::visitLoadInst(LoadInst &I) {
1635 writeOperand(I.getOperand(0));
1638 void CWriter::visitStoreInst(StoreInst &I) {
1640 writeOperand(I.getPointerOperand());
1642 writeOperand(I.getOperand(0));
1645 void CWriter::visitGetElementPtrInst(GetElementPtrInst &I) {
1647 printIndexingExpression(I.getPointerOperand(), gep_type_begin(I),
1651 void CWriter::visitVANextInst(VANextInst &I) {
1652 Out << Mang->getValueName(I.getOperand(0));
1653 Out << "; va_arg(*(va_list*)&" << Mang->getValueName(&I) << ", ";
1654 printType(Out, I.getArgType());
1658 void CWriter::visitVAArgInst(VAArgInst &I) {
1660 Out << "{ va_list Tmp; va_copy(Tmp, *(va_list*)&";
1661 writeOperand(I.getOperand(0));
1662 Out << ");\n " << Mang->getValueName(&I) << " = va_arg(Tmp, ";
1663 printType(Out, I.getType());
1664 Out << ");\n va_end(Tmp); }";
1667 //===----------------------------------------------------------------------===//
1668 // External Interface declaration
1669 //===----------------------------------------------------------------------===//
1671 bool CTargetMachine::addPassesToEmitAssembly(PassManager &PM, std::ostream &o) {
1672 PM.add(createLowerGCPass());
1673 PM.add(createLowerAllocationsPass());
1674 PM.add(createLowerInvokePass());
1675 PM.add(new CBackendNameAllUsedStructs());
1676 PM.add(new CWriter(o, getIntrinsicLowering()));