lib/CodeGen/CodeGenAction.cpp

   1 //===--- CodeGenAction.cpp - LLVM Code Generation Frontend Action ---------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "clang/CodeGen/CodeGenAction.h"
  11 #include "clang/Basic/SourceManager.h"
  12 #include "clang/Basic/TargetInfo.h"
  13 #include "clang/AST/ASTConsumer.h"
  14 #include "clang/AST/ASTContext.h"
  15 #include "clang/AST/DeclGroup.h"
  16 #include "clang/CodeGen/BackendUtil.h"
  17 #include "clang/CodeGen/ModuleBuilder.h"
  18 #include "clang/Frontend/CompilerInstance.h"
  19 #include "clang/Frontend/FrontendDiagnostic.h"
  20 #include "llvm/LLVMContext.h"
  21 #include "llvm/Module.h"
  22 #include "llvm/Pass.h"
  23 #include "llvm/ADT/OwningPtr.h"
  24 #include "llvm/Support/IRReader.h"
  25 #include "llvm/Support/MemoryBuffer.h"
  26 #include "llvm/Support/SourceMgr.h"
  27 #include "llvm/Support/Timer.h"
  28 using namespace clang;
  29 using namespace llvm;
  30
  31 namespace clang {
  32   class BackendConsumer : public ASTConsumer {
  33     Diagnostic &Diags;
  34     BackendAction Action;
  35     const CodeGenOptions &CodeGenOpts;
  36     const TargetOptions &TargetOpts;
  37     llvm::raw_ostream *AsmOutStream;
  38     ASTContext *Context;
  39
  40     Timer LLVMIRGeneration;
  41
  42     llvm::OwningPtr<CodeGenerator> Gen;
  43
  44     llvm::OwningPtr<llvm::Module> TheModule;
  45
  46   public:
  47     BackendConsumer(BackendAction action, Diagnostic &_Diags,
  48                     const CodeGenOptions &compopts,
  49                     const TargetOptions &targetopts, bool TimePasses,
  50                     const std::string &infile, llvm::raw_ostream *OS,
  51                     LLVMContext &C) :
  52       Diags(_Diags),
  53       Action(action),
  54       CodeGenOpts(compopts),
  55       TargetOpts(targetopts),
  56       AsmOutStream(OS),
  57       LLVMIRGeneration("LLVM IR Generation Time"),
  58       Gen(CreateLLVMCodeGen(Diags, infile, compopts, C)) {
  59       llvm::TimePassesIsEnabled = TimePasses;
  60     }
  61
  62     llvm::Module *takeModule() { return TheModule.take(); }
  63
  64     virtual void Initialize(ASTContext &Ctx) {
  65       Context = &Ctx;
  66
  67       if (llvm::TimePassesIsEnabled)
  68         LLVMIRGeneration.startTimer();
  69
  70       Gen->Initialize(Ctx);
  71
  72       TheModule.reset(Gen->GetModule());
  73
  74       if (llvm::TimePassesIsEnabled)
  75         LLVMIRGeneration.stopTimer();
  76     }
  77
  78     virtual void HandleTopLevelDecl(DeclGroupRef D) {
  79       PrettyStackTraceDecl CrashInfo(*D.begin(), SourceLocation(),
  80                                      Context->getSourceManager(),
  81                                      "LLVM IR generation of declaration");
  82
  83       if (llvm::TimePassesIsEnabled)
  84         LLVMIRGeneration.startTimer();
  85
  86       Gen->HandleTopLevelDecl(D);
  87
  88       if (llvm::TimePassesIsEnabled)
  89         LLVMIRGeneration.stopTimer();
  90     }
  91
  92     virtual void HandleTranslationUnit(ASTContext &C) {
  93       {
  94         PrettyStackTraceString CrashInfo("Per-file LLVM IR generation");
  95         if (llvm::TimePassesIsEnabled)
  96           LLVMIRGeneration.startTimer();
  97
  98         Gen->HandleTranslationUnit(C);
  99
 100         if (llvm::TimePassesIsEnabled)
 101           LLVMIRGeneration.stopTimer();
 102       }
 103
 104       // Silently ignore if we weren't initialized for some reason.
 105       if (!TheModule)
 106         return;
 107
 108       // Make sure IR generation is happy with the module. This is released by
 109       // the module provider.
 110       Module *M = Gen->ReleaseModule();
 111       if (!M) {
 112         // The module has been released by IR gen on failures, do not double
 113         // free.
 114         TheModule.take();
 115         return;
 116       }
 117
 118       assert(TheModule.get() == M &&
 119              "Unexpected module change during IR generation");
 120
 121       // Install an inline asm handler so that diagnostics get printed through
 122       // our diagnostics hooks.
 123       LLVMContext &Ctx = TheModule->getContext();
 124       LLVMContext::InlineAsmDiagHandlerTy OldHandler =
 125         Ctx.getInlineAsmDiagnosticHandler();
 126       void *OldContext = Ctx.getInlineAsmDiagnosticContext();
 127       Ctx.setInlineAsmDiagnosticHandler(InlineAsmDiagHandler, this);
 128
 129       EmitBackendOutput(Diags, CodeGenOpts, TargetOpts,
 130                         TheModule.get(), Action, AsmOutStream);
 131
 132       Ctx.setInlineAsmDiagnosticHandler(OldHandler, OldContext);
 133     }
 134
 135     virtual void HandleTagDeclDefinition(TagDecl *D) {
 136       PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
 137                                      Context->getSourceManager(),
 138                                      "LLVM IR generation of declaration");
 139       Gen->HandleTagDeclDefinition(D);
 140     }
 141
 142     virtual void CompleteTentativeDefinition(VarDecl *D) {
 143       Gen->CompleteTentativeDefinition(D);
 144     }
 145
 146     virtual void HandleVTable(CXXRecordDecl *RD, bool DefinitionRequired) {
 147       Gen->HandleVTable(RD, DefinitionRequired);
 148     }
 149
 150     static void InlineAsmDiagHandler(const llvm::SMDiagnostic &SM,void *Context,
 151                                      unsigned LocCookie) {
 152       SourceLocation Loc = SourceLocation::getFromRawEncoding(LocCookie);
 153       ((BackendConsumer*)Context)->InlineAsmDiagHandler2(SM, Loc);
 154     }
 155
 156     void InlineAsmDiagHandler2(const llvm::SMDiagnostic &,
 157                                SourceLocation LocCookie);
 158   };
 159 }
 160
 161 /// ConvertBackendLocation - Convert a location in a temporary llvm::SourceMgr
 162 /// buffer to be a valid FullSourceLoc.
 163 static FullSourceLoc ConvertBackendLocation(const llvm::SMDiagnostic &D,
 164                                             SourceManager &CSM) {
 165   // Get both the clang and llvm source managers.  The location is relative to
 166   // a memory buffer that the LLVM Source Manager is handling, we need to add
 167   // a copy to the Clang source manager.
 168   const llvm::SourceMgr &LSM = *D.getSourceMgr();
 169
 170   // We need to copy the underlying LLVM memory buffer because llvm::SourceMgr
 171   // already owns its one and clang::SourceManager wants to own its one.
 172   const MemoryBuffer *LBuf =
 173   LSM.getMemoryBuffer(LSM.FindBufferContainingLoc(D.getLoc()));
 174
 175   // Create the copy and transfer ownership to clang::SourceManager.
 176   llvm::MemoryBuffer *CBuf =
 177   llvm::MemoryBuffer::getMemBufferCopy(LBuf->getBuffer(),
 178                                        LBuf->getBufferIdentifier());
 179   FileID FID = CSM.createFileIDForMemBuffer(CBuf);
 180
 181   // Translate the offset into the file.
 182   unsigned Offset = D.getLoc().getPointer()  - LBuf->getBufferStart();
 183   SourceLocation NewLoc =
 184   CSM.getLocForStartOfFile(FID).getFileLocWithOffset(Offset);
 185   return FullSourceLoc(NewLoc, CSM);
 186 }
 187
 188
 189 /// InlineAsmDiagHandler2 - This function is invoked when the backend hits an
 190 /// error parsing inline asm.  The SMDiagnostic indicates the error relative to
 191 /// the temporary memory buffer that the inline asm parser has set up.
 192 void BackendConsumer::InlineAsmDiagHandler2(const llvm::SMDiagnostic &D,
 193                                             SourceLocation LocCookie) {
 194   // There are a couple of different kinds of errors we could get here.  First,
 195   // we re-format the SMDiagnostic in terms of a clang diagnostic.
 196
 197   // Strip "error: " off the start of the message string.
 198   llvm::StringRef Message = D.getMessage();
 199   if (Message.startswith("error: "))
 200     Message = Message.substr(7);
 201
 202   // If the SMDiagnostic has an inline asm source location, translate it.
 203   FullSourceLoc Loc;
 204   if (D.getLoc() != SMLoc())
 205     Loc = ConvertBackendLocation(D, Context->getSourceManager());
 206
 207
 208   // If this problem has clang-level source location information, report the
 209   // issue as being an error in the source with a note showing the instantiated
 210   // code.
 211   if (LocCookie.isValid()) {
 212     Diags.Report(LocCookie, diag::err_fe_inline_asm).AddString(Message);
 213
 214     if (D.getLoc().isValid())
 215       Diags.Report(Loc, diag::note_fe_inline_asm_here);
 216     return;
 217   }
 218
 219   // Otherwise, report the backend error as occuring in the generated .s file.
 220   // If Loc is invalid, we still need to report the error, it just gets no
 221   // location info.
 222   Diags.Report(Loc, diag::err_fe_inline_asm).AddString(Message);
 223 }
 224
 225 //
 226
 227 CodeGenAction::CodeGenAction(unsigned _Act, LLVMContext *_VMContext)
 228   : Act(_Act), VMContext(_VMContext ? _VMContext : new LLVMContext),
 229     OwnsVMContext(!_VMContext) {}
 230
 231 CodeGenAction::~CodeGenAction() {
 232   TheModule.reset();
 233   if (OwnsVMContext)
 234     delete VMContext;
 235 }
 236
 237 bool CodeGenAction::hasIRSupport() const { return true; }
 238
 239 void CodeGenAction::EndSourceFileAction() {
 240   // If the consumer creation failed, do nothing.
 241   if (!getCompilerInstance().hasASTConsumer())
 242     return;
 243
 244   // Steal the module from the consumer.
 245   TheModule.reset(BEConsumer->takeModule());
 246 }
 247
 248 llvm::Module *CodeGenAction::takeModule() {
 249   return TheModule.take();
 250 }
 251
 252 llvm::LLVMContext *CodeGenAction::takeLLVMContext() {
 253   OwnsVMContext = false;
 254   return VMContext;
 255 }
 256
 257 static raw_ostream *GetOutputStream(CompilerInstance &CI,
 258                                     llvm::StringRef InFile,
 259                                     BackendAction Action) {
 260   switch (Action) {
 261   case Backend_EmitAssembly:
 262     return CI.createDefaultOutputFile(false, InFile, "s");
 263   case Backend_EmitLL:
 264     return CI.createDefaultOutputFile(false, InFile, "ll");
 265   case Backend_EmitBC:
 266     return CI.createDefaultOutputFile(true, InFile, "bc");
 267   case Backend_EmitNothing:
 268     return 0;
 269   case Backend_EmitMCNull:
 270   case Backend_EmitObj:
 271     return CI.createDefaultOutputFile(true, InFile, "o");
 272   }
 273
 274   assert(0 && "Invalid action!");
 275   return 0;
 276 }
 277
 278 ASTConsumer *CodeGenAction::CreateASTConsumer(CompilerInstance &CI,
 279                                               llvm::StringRef InFile) {
 280   BackendAction BA = static_cast<BackendAction>(Act);
 281   llvm::OwningPtr<llvm::raw_ostream> OS(GetOutputStream(CI, InFile, BA));
 282   if (BA != Backend_EmitNothing && !OS)
 283     return 0;
 284
 285   BEConsumer =
 286       new BackendConsumer(BA, CI.getDiagnostics(),
 287                           CI.getCodeGenOpts(), CI.getTargetOpts(),
 288                           CI.getFrontendOpts().ShowTimers, InFile, OS.take(),
 289                           *VMContext);
 290   return BEConsumer;
 291 }
 292
 293 void CodeGenAction::ExecuteAction() {
 294   // If this is an IR file, we have to treat it specially.
 295   if (getCurrentFileKind() == IK_LLVM_IR) {
 296     BackendAction BA = static_cast<BackendAction>(Act);
 297     CompilerInstance &CI = getCompilerInstance();
 298     raw_ostream *OS = GetOutputStream(CI, getCurrentFile(), BA);
 299     if (BA != Backend_EmitNothing && !OS)
 300       return;
 301
 302     bool Invalid;
 303     SourceManager &SM = CI.getSourceManager();
 304     const llvm::MemoryBuffer *MainFile = SM.getBuffer(SM.getMainFileID(),
 305                                                       &Invalid);
 306     if (Invalid)
 307       return;
 308
 309     // FIXME: This is stupid, IRReader shouldn't take ownership.
 310     llvm::MemoryBuffer *MainFileCopy =
 311       llvm::MemoryBuffer::getMemBufferCopy(MainFile->getBuffer(),
 312                                            getCurrentFile().c_str());
 313
 314     llvm::SMDiagnostic Err;
 315     TheModule.reset(ParseIR(MainFileCopy, Err, *VMContext));
 316     if (!TheModule) {
 317       // Translate from the diagnostic info to the SourceManager location.
 318       SourceLocation Loc = SM.getLocation(
 319         SM.getFileEntryForID(SM.getMainFileID()), Err.getLineNo(),
 320         Err.getColumnNo() + 1);
 321
 322       // Get a custom diagnostic for the error. We strip off a leading
 323       // diagnostic code if there is one.
 324       llvm::StringRef Msg = Err.getMessage();
 325       if (Msg.startswith("error: "))
 326         Msg = Msg.substr(7);
 327       unsigned DiagID = CI.getDiagnostics().getCustomDiagID(Diagnostic::Error,
 328                                                             Msg);
 329
 330       CI.getDiagnostics().Report(Loc, DiagID);
 331       return;
 332     }
 333
 334     EmitBackendOutput(CI.getDiagnostics(), CI.getCodeGenOpts(),
 335                       CI.getTargetOpts(), TheModule.get(),
 336                       BA, OS);
 337     return;
 338   }
 339
 340   // Otherwise follow the normal AST path.
 341   this->ASTFrontendAction::ExecuteAction();
 342 }
 343
 344 //
 345
 346 EmitAssemblyAction::EmitAssemblyAction(llvm::LLVMContext *_VMContext)
 347   : CodeGenAction(Backend_EmitAssembly, _VMContext) {}
 348
 349 EmitBCAction::EmitBCAction(llvm::LLVMContext *_VMContext)
 350   : CodeGenAction(Backend_EmitBC, _VMContext) {}
 351
 352 EmitLLVMAction::EmitLLVMAction(llvm::LLVMContext *_VMContext)
 353   : CodeGenAction(Backend_EmitLL, _VMContext) {}
 354
 355 EmitLLVMOnlyAction::EmitLLVMOnlyAction(llvm::LLVMContext *_VMContext)
 356   : CodeGenAction(Backend_EmitNothing, _VMContext) {}
 357
 358 EmitCodeGenOnlyAction::EmitCodeGenOnlyAction(llvm::LLVMContext *_VMContext)
 359   : CodeGenAction(Backend_EmitMCNull, _VMContext) {}
 360
 361 EmitObjAction::EmitObjAction(llvm::LLVMContext *_VMContext)
 362   : CodeGenAction(Backend_EmitObj, _VMContext) {}