Add debug support for X86/ELF targets (Linux). This allows llvm-gcc4
[oota-llvm.git] / lib / Target / X86 / X86AsmPrinter.cpp
index 36f4249e223a58da644036ddbbfe33412a0d9e4d..60316517a829e5edd6302b73ea3f5dd2f28463f5 100644 (file)
 //
 //===----------------------------------------------------------------------===//
 
+#include "X86AsmPrinter.h"
 #include "X86ATTAsmPrinter.h"
 #include "X86IntelAsmPrinter.h"
-#include "X86.h"
+#include "X86MachineFunctionInfo.h"
+#include "X86Subtarget.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/CallingConv.h"
+#include "llvm/Constants.h"
 #include "llvm/Module.h"
 #include "llvm/Type.h"
 #include "llvm/Assembly/Writer.h"
 #include "llvm/Support/Mangler.h"
-#include "llvm/Support/CommandLine.h"
+#include "llvm/Target/TargetAsmInfo.h"
+
 using namespace llvm;
-using namespace x86;
 
-Statistic<> llvm::x86::EmittedInsts("asm-printer",
-                                    "Number of machine instrs printed");
+Statistic<> llvm::EmittedInsts("asm-printer",
+                               "Number of machine instrs printed");
+
+static X86FunctionInfo calculateFunctionInfo(const Function *F,
+                                             const TargetData *TD) {
+  X86FunctionInfo Info;
+  uint64_t Size = 0;
+  
+  switch (F->getCallingConv()) {
+  case CallingConv::X86_StdCall:
+    Info.setDecorationStyle(StdCall);
+    break;
+  case CallingConv::X86_FastCall:
+    Info.setDecorationStyle(FastCall);
+    break;
+  default:
+    return Info;
+  }
+
+  for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
+       AI != AE; ++AI)
+    Size += TD->getTypeSize(AI->getType());
+
+  // Size should be aligned to DWORD boundary
+  Size = ((Size + 3)/4)*4;
+  
+  // We're not supporting tooooo huge arguments :)
+  Info.setBytesToPopOnReturn((unsigned int)Size);
+  return Info;
+}
+
+
+/// decorateName - Query FunctionInfoMap and use this information for various
+/// name decoration.
+void X86SharedAsmPrinter::decorateName(std::string &Name,
+                                       const GlobalValue *GV) {
+  const Function *F = dyn_cast<Function>(GV);
+  if (!F) return;
+
+  // We don't want to decorate non-stdcall or non-fastcall functions right now
+  unsigned CC = F->getCallingConv();
+  if (CC != CallingConv::X86_StdCall && CC != CallingConv::X86_FastCall)
+    return;
+    
+  FMFInfoMap::const_iterator info_item = FunctionInfoMap.find(F);
+
+  const X86FunctionInfo *Info;
+  if (info_item == FunctionInfoMap.end()) {
+    // Calculate apropriate function info and populate map
+    FunctionInfoMap[F] = calculateFunctionInfo(F, TM.getTargetData());
+    Info = &FunctionInfoMap[F];
+  } else {
+    Info = &info_item->second;
+  }
+        
+  switch (Info->getDecorationStyle()) {
+  case None:
+    break;
+  case StdCall:
+    if (!F->isVarArg()) // Variadic functions do not receive @0 suffix.
+      Name += '@' + utostr_32(Info->getBytesToPopOnReturn());
+    break;
+  case FastCall:
+    if (!F->isVarArg()) // Variadic functions do not receive @0 suffix.
+      Name += '@' + utostr_32(Info->getBytesToPopOnReturn());
 
-enum AsmWriterFlavorTy { att, intel };
-cl::opt<AsmWriterFlavorTy>
-AsmWriterFlavor("x86-asm-syntax",
-                cl::desc("Choose style of code to emit from X86 backend:"),
-                cl::values(
-                           clEnumVal(att,   "  Emit AT&T-style assembly"),
-                           clEnumVal(intel, "  Emit Intel-style assembly"),
-                           clEnumValEnd),
-                cl::init(att));
+    if (Name[0] == '_') {
+      Name[0] = '@';
+    } else {
+      Name = '@' + Name;
+    }    
+    break;
+  default:
+    assert(0 && "Unsupported DecorationStyle");
+  }
+}
 
 /// doInitialization
-bool X86SharedAsmPrinter::doInitialization(Module& M) {
-  forCygwin = false;
-  forDarwin = false;
-  bool forWin32 = false;
-  const std::string& TT = M.getTargetTriple();
-  if (TT.length() > 5) {
-    forCygwin = TT.find("cygwin") != std::string::npos ||
-                TT.find("mingw")  != std::string::npos;
-    forDarwin = TT.find("darwin") != std::string::npos;
-  } else if (TT.empty()) {
-#if defined(__CYGWIN__) || defined(__MINGW32__)
-    forCygwin = true;
-#elif defined(__APPLE__)
-    forDarwin = true;
-#elif defined(_WIN32)
-    forWin32 = true;
-#endif
+bool X86SharedAsmPrinter::doInitialization(Module &M) {
+  if (Subtarget->isTargetDarwin()) {
+    const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
+    if (!Subtarget->is64Bit())
+      X86PICStyle = PICStyle::Stub;
+
+    // Emit initial debug information.
+    DW.BeginModule(&M);
+  } else if (Subtarget->isTargetELF()) {
+    // Emit initial debug information.
+    DW.BeginModule(&M);
   }
 
-  if (forDarwin) {
-    AlignmentIsInBytes = false;
-    GlobalPrefix = "_";
-    Data64bitsDirective = 0;       // we can't emit a 64-bit unit
-    ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
-    PrivateGlobalPrefix = "L";     // Marker for constant pool idxs
-    ConstantPoolSection = "\t.const\n";
-    LCOMMDirective = "\t.lcomm\t";
-    COMMDirectiveTakesAlignment = false;
-  } else if (forCygwin) {
-    GlobalPrefix = "_";
-    COMMDirectiveTakesAlignment = false;
-  } else if (forWin32) {
-    GlobalPrefix = "_";
-  }  
-  
   return AsmPrinter::doInitialization(M);
 }
 
 bool X86SharedAsmPrinter::doFinalization(Module &M) {
-  const TargetData &TD = TM.getTargetData();
+  // Note: this code is not shared by the Intel printer as it is too different
+  // from how MASM does things.  When making changes here don't forget to look
+  // at X86IntelAsmPrinter::doFinalization().
+  const TargetData *TD = TM.getTargetData();
 
   // Print out module-level global variables here.
-  for (Module::const_global_iterator I = M.global_begin(),
-         E = M.global_end(); I != E; ++I)
-    if (I->hasInitializer()) {   // External global require no code
-      O << "\n\n";
-      std::string name = Mang->getValueName(I);
-      Constant *C = I->getInitializer();
-      unsigned Size = TD.getTypeSize(C->getType());
-      unsigned Align = TD.getTypeAlignmentShift(C->getType());
+  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
+       I != E; ++I) {
+    if (!I->hasInitializer()) continue;   // External global require no code
+    
+    // Check to see if this is a special global used by LLVM, if so, emit it.
+    if (EmitSpecialLLVMGlobal(I))
+      continue;
+    
+    std::string name = Mang->getValueName(I);
+    Constant *C = I->getInitializer();
+    unsigned Size = TD->getTypeSize(C->getType());
+    unsigned Align = TD->getPreferredAlignmentLog(I);
 
+    if (C->isNullValue() && /* FIXME: Verify correct */
+        (I->hasInternalLinkage() || I->hasWeakLinkage() ||
+         I->hasLinkOnceLinkage() ||
+         (Subtarget->isTargetDarwin() && 
+          I->hasExternalLinkage() && !I->hasSection()))) {
+      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
+      if (I->hasExternalLinkage()) {
+          O << "\t.globl\t" << name << "\n";
+          O << "\t.zerofill __DATA__, __common, " << name << ", "
+            << Size << ", " << Align;
+      } else {
+        SwitchToDataSection(TAI->getDataSection(), I);
+        if (TAI->getLCOMMDirective() != NULL) {
+          if (I->hasInternalLinkage()) {
+            O << TAI->getLCOMMDirective() << name << "," << Size;
+            if (Subtarget->isTargetDarwin())
+              O << "," << (TAI->getAlignmentIsInBytes() ? (1 << Align) : Align);
+          } else
+            O << TAI->getCOMMDirective()  << name << "," << Size;
+        } else {
+          if (!Subtarget->isTargetCygwin()) {
+            if (I->hasInternalLinkage())
+              O << "\t.local\t" << name << "\n";
+          }
+          O << TAI->getCOMMDirective()  << name << "," << Size;
+          if (TAI->getCOMMDirectiveTakesAlignment())
+            O << "," << (TAI->getAlignmentIsInBytes() ? (1 << Align) : Align);
+        }
+      }
+      O << "\t\t" << TAI->getCommentString() << " " << I->getName() << "\n";
+    } else {
       switch (I->getLinkage()) {
-      default: assert(0 && "Unknown linkage type!");
       case GlobalValue::LinkOnceLinkage:
-      case GlobalValue::WeakLinkage:   // FIXME: Verify correct for weak.
-        if (C->isNullValue()) {
-          O << COMMDirective << name << "," << Size;
-          if (COMMDirectiveTakesAlignment)
-            O << "," << (1 << Align);
-          O << "\t\t# ";
-          WriteAsOperand(O, I, true, true, &M);
-          O << "\n";
-          continue;
+      case GlobalValue::WeakLinkage:
+        if (Subtarget->isTargetDarwin()) {
+          O << "\t.globl " << name << "\n"
+            << "\t.weak_definition " << name << "\n";
+          SwitchToDataSection(".section __DATA,__const_coal,coalesced", I);
+        } else if (Subtarget->isTargetCygwin()) {
+          std::string SectionName(".section\t.data$linkonce." +
+                                  name +
+                                  ",\"aw\"\n");
+          SwitchToDataSection(SectionName.c_str(), I);
+          O << "\t.globl " << name << "\n"
+            << "\t.linkonce same_size\n";
+        } else {
+          std::string SectionName("\t.section\t.llvm.linkonce.d." +
+                                  name +
+                                  ",\"aw\",@progbits\n");
+          SwitchToDataSection(SectionName.c_str(), I);
+          O << "\t.weak " << name << "\n";
         }
-        
-        // Nonnull linkonce -> weak
-        O << "\t.weak " << name << "\n";
-        O << "\t.section\t.llvm.linkonce.d." << name << ",\"aw\",@progbits\n";
-        SwitchSection("", I);
-        break;
-      case GlobalValue::InternalLinkage:
-        if (C->isNullValue()) {
-          if (LCOMMDirective) {
-            O << LCOMMDirective << name << "," << Size << "," << Align;
-            continue;
-          } else {
-            SwitchSection(".bss", I);
-            O << "\t.local " << name << "\n";
-            O << COMMDirective << name << "," << Size;
-            if (COMMDirectiveTakesAlignment)
-              O << "," << (1 << Align);
-            O << "\t\t# ";
-            WriteAsOperand(O, I, true, true, &M);
-            O << "\n";
-            continue;
-          }
-        }
-        SwitchSection(C->isNullValue() ? ".bss" : ".data", I);
         break;
       case GlobalValue::AppendingLinkage:
         // FIXME: appending linkage variables should go into a section of
         // their name or something.  For now, just emit them as external.
+      case GlobalValue::DLLExportLinkage:
+        DLLExportedGVs.insert(Mang->makeNameProper(I->getName(),""));
+        // FALL THROUGH
       case GlobalValue::ExternalLinkage:
-        SwitchSection(C->isNullValue() ? ".bss" : ".data", I);
         // If external or appending, declare as a global symbol
         O << "\t.globl " << name << "\n";
+        // FALL THROUGH
+      case GlobalValue::InternalLinkage: {
+        if (I->isConstant()) {
+          const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
+          if (TAI->getCStringSection() && CVA && CVA->isCString()) {
+            SwitchToDataSection(TAI->getCStringSection(), I);
+            break;
+          }
+        }
+        SwitchToDataSection(TAI->getDataSection(), I);
         break;
       }
-
-      EmitAlignment(Align);
-      if (!forCygwin && !forDarwin) {
-        O << "\t.type " << name << ",@object\n";
-        O << "\t.size " << name << "," << Size << "\n";
+      default:
+        assert(0 && "Unknown linkage type!");
       }
-      O << name << ":\t\t\t\t# ";
-      WriteAsOperand(O, I, true, true, &M);
-      O << " = ";
-      WriteAsOperand(O, C, false, false, &M);
-      O << "\n";
+
+      EmitAlignment(Align, I);
+      O << name << ":\t\t\t\t" << TAI->getCommentString() << " " << I->getName()
+        << "\n";
+      if (TAI->hasDotTypeDotSizeDirective())
+        O << "\t.size " << name << ", " << Size << "\n";
+
       EmitGlobalConstant(C);
+      O << '\n';
     }
+  }
+  
+  // Output linker support code for dllexported globals
+  if (DLLExportedGVs.begin() != DLLExportedGVs.end()) {
+    SwitchToDataSection(".section .drectve", 0);    
+  }
 
-  if (forDarwin) {
-    SwitchSection("", 0);
-    // Output stubs for external global variables
-    if (GVStubs.begin() != GVStubs.end())
-      O << "\t.non_lazy_symbol_pointer\n";
-    for (std::set<std::string>::iterator i = GVStubs.begin(), e = GVStubs.end();
+  for (std::set<std::string>::iterator i = DLLExportedGVs.begin(),
+         e = DLLExportedGVs.end();
          i != e; ++i) {
-      O << "L" << *i << "$non_lazy_ptr:\n";
-      O << "\t.indirect_symbol " << *i << "\n";
-      O << "\t.long\t0\n";
-    }
+    O << "\t.ascii \" -export:" << *i << ",data\"\n";
+  }    
+
+  if (DLLExportedFns.begin() != DLLExportedFns.end()) {
+    SwitchToDataSection(".section .drectve", 0);    
+  }
+
+  for (std::set<std::string>::iterator i = DLLExportedFns.begin(),
+         e = DLLExportedFns.end();
+         i != e; ++i) {
+    O << "\t.ascii \" -export:" << *i << "\"\n";
+  }    
+  if (Subtarget->isTargetDarwin()) {
+    SwitchToDataSection("", 0);
 
     // Output stubs for dynamically-linked functions
     unsigned j = 1;
     for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
          i != e; ++i, ++j) {
-      O << "\t.symbol_stub\n";
+      SwitchToDataSection(".section __IMPORT,__jump_table,symbol_stubs,"
+                          "self_modifying_code+pure_instructions,5", 0);
       O << "L" << *i << "$stub:\n";
       O << "\t.indirect_symbol " << *i << "\n";
-      O << "\tjmp\t*L" << j << "$lz\n";
-      O << "L" << *i << "$stub_binder:\n";
-      O << "\tpushl\t$L" << j << "$lz\n";
-      O << "\tjmp\tdyld_stub_binding_helper\n";
-      O << "\t.section __DATA, __la_sym_ptr3,lazy_symbol_pointers\n";
-      O << "L" << j << "$lz:\n";
-      O << "\t.indirect_symbol " << *i << "\n";
-      O << "\t.long\tL" << *i << "$stub_binder\n";
+      O << "\thlt ; hlt ; hlt ; hlt ; hlt\n";
     }
 
     O << "\n";
 
-    // Output stubs for link-once variables
-    if (LinkOnceStubs.begin() != LinkOnceStubs.end())
-      O << ".data\n.align 2\n";
-    for (std::set<std::string>::iterator i = LinkOnceStubs.begin(),
-         e = LinkOnceStubs.end(); i != e; ++i) {
-      O << "L" << *i << "$non_lazy_ptr:\n"
-        << "\t.long\t" << *i << '\n';
+    // Output stubs for external and common global variables.
+    if (GVStubs.begin() != GVStubs.end())
+      SwitchToDataSection(
+                    ".section __IMPORT,__pointers,non_lazy_symbol_pointers", 0);
+    for (std::set<std::string>::iterator i = GVStubs.begin(), e = GVStubs.end();
+         i != e; ++i) {
+      O << "L" << *i << "$non_lazy_ptr:\n";
+      O << "\t.indirect_symbol " << *i << "\n";
+      O << "\t.long\t0\n";
     }
+
+    // Emit final debug information.
+    DW.EndModule();
+
+    // Funny Darwin hack: This flag tells the linker that no global symbols
+    // contain code that falls through to other global symbols (e.g. the obvious
+    // implementation of multiple entry points).  If this doesn't occur, the
+    // linker can safely perform dead code stripping.  Since LLVM never
+    // generates code that does this, it is always safe to set.
+    O << "\t.subsections_via_symbols\n";
+  } else if (Subtarget->isTargetELF()) {
+    // Emit final debug information.
+    DW.EndModule();
   }
 
   AsmPrinter::doFinalization(M);
@@ -200,13 +303,13 @@ bool X86SharedAsmPrinter::doFinalization(Module &M) {
 /// for a MachineFunction to the given output stream, using the given target
 /// machine description.
 ///
-FunctionPass *llvm::createX86CodePrinterPass(std::ostream &o,TargetMachine &tm){
-  switch (AsmWriterFlavor) {
-  default:
-    assert(0 && "Unknown asm flavor!");
-  case intel:
-    return new X86IntelAsmPrinter(o, tm);
-  case att:
-    return new X86ATTAsmPrinter(o, tm);
+FunctionPass *llvm::createX86CodePrinterPass(std::ostream &o,
+                                             X86TargetMachine &tm) {
+  const X86Subtarget *Subtarget = &tm.getSubtarget<X86Subtarget>();
+
+  if (Subtarget->isFlavorIntel()) {
+    return new X86IntelAsmPrinter(o, tm, tm.getTargetAsmInfo());
+  } else {
+    return new X86ATTAsmPrinter(o, tm, tm.getTargetAsmInfo());
   }
 }