Stage two of getting CFE top correct.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@39734 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 369 insertions, 0 deletions

diff --git a/Lex/Pragma.cpp b/Lex/Pragma.cpp
new file mode 100644
index 0000000000..de59934b4d
--- /dev/null
+++ b/Lex/Pragma.cpp
@@ -0,0 +1,369 @@
+//===--- Pragma.cpp - Pragma registration and handling --------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and 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/PPCallbacks.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"
+#include "llvm/ADT/SmallVector.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::HandlePragma(Preprocessor &PP, LexerToken &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.
+  LexerToken Tok;
+  PragmaHandlers->HandlePragma(*this, Tok);
+  
+  // If the pragma handler didn't read the rest of the line, consume it now.
+  if (CurLexer->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(LexerToken &Tok) {
+  // Remember the pragma token location.
+  SourceLocation PragmaLoc = Tok.getLocation();
+  
+  // Read the '('.
+  Lex(Tok);
+  if (Tok.getKind() != tok::l_paren)
+    return Diag(PragmaLoc, diag::err__Pragma_malformed);
+
+  // Read the '"..."'.
+  Lex(Tok);
+  if (Tok.getKind() != tok::string_literal &&
+      Tok.getKind() != tok::wide_string_literal)
+    return Diag(PragmaLoc, diag::err__Pragma_malformed);
+  
+  // Remember the string.
+  std::string StrVal = getSpelling(Tok);
+  SourceLocation StrLoc = Tok.getLocation();
+
+  // Read the ')'.
+  Lex(Tok);
+  if (Tok.getKind() != tok::r_paren)
+    return Diag(PragmaLoc, diag::err__Pragma_malformed);
+  
+  // 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);
+
+  unsigned FileID = TokLoc.getFileID();
+  assert(FileID && "Could not get FileID for _Pragma?");
+
+  // Make and enter a lexer object so that we lex and expand the tokens just
+  // like any others.
+  Lexer *TL = new Lexer(SourceMgr.getBuffer(FileID), FileID, *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(LexerToken &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()->getCurFileID();
+  
+  // Mark the file as a once-only file now.
+  HeaderInfo.MarkFileIncludeOnce(SourceMgr.getFileEntryForFileID(FileID));
+}
+
+/// HandlePragmaPoison - Handle #pragma GCC poison.  PoisonTok is the 'poison'.
+///
+void Preprocessor::HandlePragmaPoison(LexerToken &PoisonTok) {
+  LexerToken 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 (CurLexer) CurLexer->LexingRawMode = true;
+    LexUnexpandedToken(Tok);
+    if (CurLexer) CurLexer->LexingRawMode = false;
+    
+    // If we reached the end of line, we're done.
+    if (Tok.getKind() == tok::eom) return;
+    
+    // Can only poison identifiers.
+    if (Tok.getKind() != 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->getMacroInfo())
+      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(LexerToken &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.
+  Lexer *TheLexer = getCurrentFileLexer();
+  
+  // Mark the file as a system header.
+  const FileEntry *File = 
+    SourceMgr.getFileEntryForFileID(TheLexer->getCurFileID());
+  HeaderInfo.MarkFileSystemHeader(File);
+  
+  // Notify the client, if desired, that we are in a new source file.
+  if (Callbacks)
+    Callbacks->FileChanged(TheLexer->getSourceLocation(TheLexer->BufferPtr),
+                           PPCallbacks::SystemHeaderPragma,
+                           DirectoryLookup::SystemHeaderDir);
+}
+
+/// HandlePragmaDependency - Handle #pragma GCC dependency "foo" blah.
+///
+void Preprocessor::HandlePragmaDependency(LexerToken &DependencyTok) {
+  LexerToken FilenameTok;
+  CurLexer->LexIncludeFilename(FilenameTok);
+
+  // If the token kind is EOM, the error has already been diagnosed.
+  if (FilenameTok.getKind() == tok::eom)
+    return;
+  
+  // Reserve a buffer to get the spelling.
+  llvm::SmallVector<char, 128> FilenameBuffer;
+  FilenameBuffer.resize(FilenameTok.getLength());
+  
+  const char *FilenameStart = &FilenameBuffer[0], *FilenameEnd;
+  bool isAngled = GetIncludeFilenameSpelling(FilenameTok,
+                                             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)
+    return Diag(FilenameTok, diag::err_pp_file_not_found,
+                std::string(FilenameStart, FilenameEnd));
+  
+  unsigned FileID = getCurrentFileLexer()->getCurFileID();
+  const FileEntry *CurFile = SourceMgr.getFileEntryForFileID(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.getKind() != 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);
+}
+
+namespace {
+struct PragmaOnceHandler : public PragmaHandler {
+  PragmaOnceHandler(const IdentifierInfo *OnceID) : PragmaHandler(OnceID) {}
+  virtual void HandlePragma(Preprocessor &PP, LexerToken &OnceTok) {
+    PP.CheckEndOfDirective("#pragma once");
+    PP.HandlePragmaOnce(OnceTok);
+  }
+};
+
+struct PragmaPoisonHandler : public PragmaHandler {
+  PragmaPoisonHandler(const IdentifierInfo *ID) : PragmaHandler(ID) {}
+  virtual void HandlePragma(Preprocessor &PP, LexerToken &PoisonTok) {
+    PP.HandlePragmaPoison(PoisonTok);
+  }
+};
+
+struct PragmaSystemHeaderHandler : public PragmaHandler {
+  PragmaSystemHeaderHandler(const IdentifierInfo *ID) : PragmaHandler(ID) {}
+  virtual void HandlePragma(Preprocessor &PP, LexerToken &SHToken) {
+    PP.HandlePragmaSystemHeader(SHToken);
+    PP.CheckEndOfDirective("#pragma");
+  }
+};
+struct PragmaDependencyHandler : public PragmaHandler {
+  PragmaDependencyHandler(const IdentifierInfo *ID) : PragmaHandler(ID) {}
+  virtual void HandlePragma(Preprocessor &PP, LexerToken &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("GCC", new PragmaPoisonHandler(getIdentifierInfo("poison")));
+  AddPragmaHandler("GCC", new PragmaSystemHeaderHandler(
+                                          getIdentifierInfo("system_header")));
+  AddPragmaHandler("GCC", new PragmaDependencyHandler(
+                                          getIdentifierInfo("dependency")));
+}