//===--- Pragma.cpp - Pragma registration and handling --------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements the PragmaHandler/PragmaTable interfaces and implements // pragma related methods of the Preprocessor class. // //===----------------------------------------------------------------------===// #include "clang/Lex/Pragma.h" #include "clang/Lex/HeaderSearch.h" #include "clang/Lex/Preprocessor.h" #include "clang/Basic/Diagnostic.h" #include "clang/Basic/FileManager.h" #include "clang/Basic/SourceManager.h" using namespace clang; // Out-of-line destructor to provide a home for the class. PragmaHandler::~PragmaHandler() { } //===----------------------------------------------------------------------===// // PragmaNamespace Implementation. //===----------------------------------------------------------------------===// PragmaNamespace::~PragmaNamespace() { for (unsigned i = 0, e = Handlers.size(); i != e; ++i) delete Handlers[i]; } /// FindHandler - Check to see if there is already a handler for the /// specified name. If not, return the handler for the null identifier if it /// exists, otherwise return null. If IgnoreNull is true (the default) then /// the null handler isn't returned on failure to match. PragmaHandler *PragmaNamespace::FindHandler(const IdentifierInfo *Name, bool IgnoreNull) const { PragmaHandler *NullHandler = 0; for (unsigned i = 0, e = Handlers.size(); i != e; ++i) { if (Handlers[i]->getName() == Name) return Handlers[i]; if (Handlers[i]->getName() == 0) NullHandler = Handlers[i]; } return IgnoreNull ? 0 : NullHandler; } void PragmaNamespace::RemovePragmaHandler(PragmaHandler *Handler) { for (unsigned i = 0, e = Handlers.size(); i != e; ++i) { if (Handlers[i] == Handler) { Handlers[i] = Handlers.back(); Handlers.pop_back(); return; } } assert(0 && "Handler not registered in this namespace"); } void PragmaNamespace::HandlePragma(Preprocessor &PP, Token &Tok) { // Read the 'namespace' that the directive is in, e.g. STDC. Do not macro // expand it, the user can have a STDC #define, that should not affect this. PP.LexUnexpandedToken(Tok); // Get the handler for this token. If there is no handler, ignore the pragma. PragmaHandler *Handler = FindHandler(Tok.getIdentifierInfo(), false); if (Handler == 0) return; // Otherwise, pass it down. Handler->HandlePragma(PP, Tok); } //===----------------------------------------------------------------------===// // Preprocessor Pragma Directive Handling. //===----------------------------------------------------------------------===// /// HandlePragmaDirective - The "#pragma" directive has been parsed. Lex the /// rest of the pragma, passing it to the registered pragma handlers. void Preprocessor::HandlePragmaDirective() { ++NumPragma; // Invoke the first level of pragma handlers which reads the namespace id. Token Tok; PragmaHandlers->HandlePragma(*this, Tok); // If the pragma handler didn't read the rest of the line, consume it now. if (CurPPLexer->ParsingPreprocessorDirective) DiscardUntilEndOfDirective(); } /// Handle_Pragma - Read a _Pragma directive, slice it up, process it, then /// return the first token after the directive. The _Pragma token has just /// been read into 'Tok'. void Preprocessor::Handle_Pragma(Token &Tok) { // Remember the pragma token location. SourceLocation PragmaLoc = Tok.getLocation(); // Read the '('. Lex(Tok); if (Tok.isNot(tok::l_paren)) { Diag(PragmaLoc, diag::err__Pragma_malformed); return; } // Read the '"..."'. Lex(Tok); if (Tok.isNot(tok::string_literal) && Tok.isNot(tok::wide_string_literal)) { Diag(PragmaLoc, diag::err__Pragma_malformed); return; } // Remember the string. std::string StrVal = getSpelling(Tok); SourceLocation StrLoc = Tok.getLocation(); // Read the ')'. Lex(Tok); if (Tok.isNot(tok::r_paren)) { Diag(PragmaLoc, diag::err__Pragma_malformed); return; } // The _Pragma is lexically sound. Destringize according to C99 6.10.9.1. if (StrVal[0] == 'L') // Remove L prefix. StrVal.erase(StrVal.begin()); assert(StrVal[0] == '"' && StrVal[StrVal.size()-1] == '"' && "Invalid string token!"); // Remove the front quote, replacing it with a space, so that the pragma // contents appear to have a space before them. StrVal[0] = ' '; // Replace the terminating quote with a \n\0. StrVal[StrVal.size()-1] = '\n'; StrVal += '\0'; // Remove escaped quotes and escapes. for (unsigned i = 0, e = StrVal.size(); i != e-1; ++i) { if (StrVal[i] == '\\' && (StrVal[i+1] == '\\' || StrVal[i+1] == '"')) { // \\ -> '\' and \" -> '"'. StrVal.erase(StrVal.begin()+i); --e; } } // Plop the string (including the newline and trailing null) into a buffer // where we can lex it. SourceLocation TokLoc = CreateString(&StrVal[0], StrVal.size(), StrLoc); const char *StrData = SourceMgr.getCharacterData(TokLoc); // Make and enter a lexer object so that we lex and expand the tokens just // like any others. Lexer *TL = new Lexer(TokLoc, *this, StrData, StrData+StrVal.size()-1 /* no null */); // Ensure that the lexer thinks it is inside a directive, so that end \n will // return an EOM token. TL->ParsingPreprocessorDirective = true; // This lexer really is for _Pragma. TL->Is_PragmaLexer = true; EnterSourceFileWithLexer(TL, 0); // With everything set up, lex this as a #pragma directive. HandlePragmaDirective(); // Finally, return whatever came after the pragma directive. return Lex(Tok); } /// HandlePragmaOnce - Handle #pragma once. OnceTok is the 'once'. /// void Preprocessor::HandlePragmaOnce(Token &OnceTok) { if (isInPrimaryFile()) { Diag(OnceTok, diag::pp_pragma_once_in_main_file); return; } // Get the current file lexer we're looking at. Ignore _Pragma 'files' etc. unsigned FileID = getCurrentFileLexer()->getFileID(); // Mark the file as a once-only file now. HeaderInfo.MarkFileIncludeOnce(SourceMgr.getFileEntryForID(FileID)); } void Preprocessor::HandlePragmaMark() { assert(CurPPLexer && "No current lexer?"); if (CurLexer) CurLexer->ReadToEndOfLine(); else CurPTHLexer->DiscardToEndOfLine(); } /// HandlePragmaPoison - Handle #pragma GCC poison. PoisonTok is the 'poison'. /// void Preprocessor::HandlePragmaPoison(Token &PoisonTok) { Token Tok; while (1) { // Read the next token to poison. While doing this, pretend that we are // skipping while reading the identifier to poison. // This avoids errors on code like: // #pragma GCC poison X // #pragma GCC poison X if (CurPPLexer) CurPPLexer->LexingRawMode = true; LexUnexpandedToken(Tok); if (CurPPLexer) CurPPLexer->LexingRawMode = false; // If we reached the end of line, we're done. if (Tok.is(tok::eom)) return; // Can only poison identifiers. if (Tok.isNot(tok::identifier)) { Diag(Tok, diag::err_pp_invalid_poison); return; } // Look up the identifier info for the token. We disabled identifier lookup // by saying we're skipping contents, so we need to do this manually. IdentifierInfo *II = LookUpIdentifierInfo(Tok); // Already poisoned. if (II->isPoisoned()) continue; // If this is a macro identifier, emit a warning. if (II->hasMacroDefinition()) Diag(Tok, diag::pp_poisoning_existing_macro); // Finally, poison it! II->setIsPoisoned(); } } /// HandlePragmaSystemHeader - Implement #pragma GCC system_header. We know /// that the whole directive has been parsed. void Preprocessor::HandlePragmaSystemHeader(Token &SysHeaderTok) { if (isInPrimaryFile()) { Diag(SysHeaderTok, diag::pp_pragma_sysheader_in_main_file); return; } // Get the current file lexer we're looking at. Ignore _Pragma 'files' etc. PreprocessorLexer *TheLexer = getCurrentFileLexer(); // Mark the file as a system header. const FileEntry *File = SourceMgr.getFileEntryForID(TheLexer->getFileID()); HeaderInfo.MarkFileSystemHeader(File); // Notify the client, if desired, that we are in a new source file. if (Callbacks) Callbacks->FileChanged(SysHeaderTok.getLocation(), PPCallbacks::SystemHeaderPragma, SrcMgr::C_System); } /// HandlePragmaDependency - Handle #pragma GCC dependency "foo" blah. /// void Preprocessor::HandlePragmaDependency(Token &DependencyTok) { Token FilenameTok; CurPPLexer->LexIncludeFilename(FilenameTok); // If the token kind is EOM, the error has already been diagnosed. if (FilenameTok.is(tok::eom)) return; // Reserve a buffer to get the spelling. llvm::SmallVector FilenameBuffer; FilenameBuffer.resize(FilenameTok.getLength()); const char *FilenameStart = &FilenameBuffer[0]; unsigned Len = getSpelling(FilenameTok, FilenameStart); const char *FilenameEnd = FilenameStart+Len; bool isAngled = GetIncludeFilenameSpelling(FilenameTok.getLocation(), FilenameStart, FilenameEnd); // If GetIncludeFilenameSpelling set the start ptr to null, there was an // error. if (FilenameStart == 0) return; // Search include directories for this file. const DirectoryLookup *CurDir; const FileEntry *File = LookupFile(FilenameStart, FilenameEnd, isAngled, 0, CurDir); if (File == 0) { Diag(FilenameTok, diag::err_pp_file_not_found) << std::string(FilenameStart, FilenameEnd); return; } unsigned FileID = getCurrentFileLexer()->getFileID(); const FileEntry *CurFile = SourceMgr.getFileEntryForID(FileID); // If this file is older than the file it depends on, emit a diagnostic. if (CurFile && CurFile->getModificationTime() < File->getModificationTime()) { // Lex tokens at the end of the message and include them in the message. std::string Message; Lex(DependencyTok); while (DependencyTok.isNot(tok::eom)) { Message += getSpelling(DependencyTok) + " "; Lex(DependencyTok); } Message.erase(Message.end()-1); Diag(FilenameTok, diag::pp_out_of_date_dependency) << Message; } } /// AddPragmaHandler - Add the specified pragma handler to the preprocessor. /// If 'Namespace' is non-null, then it is a token required to exist on the /// pragma line before the pragma string starts, e.g. "STDC" or "GCC". void Preprocessor::AddPragmaHandler(const char *Namespace, PragmaHandler *Handler) { PragmaNamespace *InsertNS = PragmaHandlers; // If this is specified to be in a namespace, step down into it. if (Namespace) { IdentifierInfo *NSID = getIdentifierInfo(Namespace); // If there is already a pragma handler with the name of this namespace, // we either have an error (directive with the same name as a namespace) or // we already have the namespace to insert into. if (PragmaHandler *Existing = PragmaHandlers->FindHandler(NSID)) { InsertNS = Existing->getIfNamespace(); assert(InsertNS != 0 && "Cannot have a pragma namespace and pragma" " handler with the same name!"); } else { // Otherwise, this namespace doesn't exist yet, create and insert the // handler for it. InsertNS = new PragmaNamespace(NSID); PragmaHandlers->AddPragma(InsertNS); } } // Check to make sure we don't already have a pragma for this identifier. assert(!InsertNS->FindHandler(Handler->getName()) && "Pragma handler already exists for this identifier!"); InsertNS->AddPragma(Handler); } /// RemovePragmaHandler - Remove the specific pragma handler from the /// preprocessor. If \arg Namespace is non-null, then it should be the /// namespace that \arg Handler was added to. It is an error to remove /// a handler that has not been registered. void Preprocessor::RemovePragmaHandler(const char *Namespace, PragmaHandler *Handler) { PragmaNamespace *NS = PragmaHandlers; // If this is specified to be in a namespace, step down into it. if (Namespace) { IdentifierInfo *NSID = getIdentifierInfo(Namespace); PragmaHandler *Existing = PragmaHandlers->FindHandler(NSID); assert(Existing && "Namespace containing handler does not exist!"); NS = Existing->getIfNamespace(); assert(NS && "Invalid namespace, registered as a regular pragma handler!"); } NS->RemovePragmaHandler(Handler); // If this is a non-default namespace and it is now empty, remove // it. if (NS != PragmaHandlers && NS->IsEmpty()) PragmaHandlers->RemovePragmaHandler(NS); } namespace { /// PragmaOnceHandler - "#pragma once" marks the file as atomically included. struct PragmaOnceHandler : public PragmaHandler { PragmaOnceHandler(const IdentifierInfo *OnceID) : PragmaHandler(OnceID) {} virtual void HandlePragma(Preprocessor &PP, Token &OnceTok) { PP.CheckEndOfDirective("#pragma once"); PP.HandlePragmaOnce(OnceTok); } }; /// PragmaMarkHandler - "#pragma mark ..." is ignored by the compiler, and the /// rest of the line is not lexed. struct PragmaMarkHandler : public PragmaHandler { PragmaMarkHandler(const IdentifierInfo *MarkID) : PragmaHandler(MarkID) {} virtual void HandlePragma(Preprocessor &PP, Token &MarkTok) { PP.HandlePragmaMark(); } }; /// PragmaPoisonHandler - "#pragma poison x" marks x as not usable. struct PragmaPoisonHandler : public PragmaHandler { PragmaPoisonHandler(const IdentifierInfo *ID) : PragmaHandler(ID) {} virtual void HandlePragma(Preprocessor &PP, Token &PoisonTok) { PP.HandlePragmaPoison(PoisonTok); } }; /// PragmaSystemHeaderHandler - "#pragma system_header" marks the current file /// as a system header, which silences warnings in it. struct PragmaSystemHeaderHandler : public PragmaHandler { PragmaSystemHeaderHandler(const IdentifierInfo *ID) : PragmaHandler(ID) {} virtual void HandlePragma(Preprocessor &PP, Token &SHToken) { PP.HandlePragmaSystemHeader(SHToken); PP.CheckEndOfDirective("#pragma"); } }; struct PragmaDependencyHandler : public PragmaHandler { PragmaDependencyHandler(const IdentifierInfo *ID) : PragmaHandler(ID) {} virtual void HandlePragma(Preprocessor &PP, Token &DepToken) { PP.HandlePragmaDependency(DepToken); } }; } // end anonymous namespace /// RegisterBuiltinPragmas - Install the standard preprocessor pragmas: /// #pragma GCC poison/system_header/dependency and #pragma once. void Preprocessor::RegisterBuiltinPragmas() { AddPragmaHandler(0, new PragmaOnceHandler(getIdentifierInfo("once"))); AddPragmaHandler(0, new PragmaMarkHandler(getIdentifierInfo("mark"))); AddPragmaHandler("GCC", new PragmaPoisonHandler(getIdentifierInfo("poison"))); AddPragmaHandler("GCC", new PragmaSystemHeaderHandler( getIdentifierInfo("system_header"))); AddPragmaHandler("GCC", new PragmaDependencyHandler( getIdentifierInfo("dependency"))); }