Commit bce360b7 authored by Diogo Sampaio's avatar Diogo Sampaio
Browse files

Detect source location overflow due includes 

Summary:
As discussed in http://lists.llvm.org/pipermail/cfe-dev/2019-October/063459.html
the overflow of the souce locations (limited to 2^31 chars) can generate all sorts of
weird things (bogus warnings, hangs, crashes, miscompilation and correct compilation).
In debug mode this assert would fail. So it might be a good start, as in PR42301,
to detect the failure and exit with a proper error message.

Reviewers: rsmith, thakis, miyuki

Reviewed By: miyuki

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70183
parent ec62bf2f

clang/include/clang/Basic/DiagnosticCommonKinds.td

+3 −0
Original line number Diff line number Diff line
@@ -282,6 +282,9 @@ def err_file_modified : Error< 
  "file '%0' modified since it was first processed">, DefaultFatal;

def err_file_too_large : Error<

  "sorry, unsupported: file '%0' is too large for Clang to process">;

def err_include_too_large : Error<

  "sorry, this include generates a translation unit too large for"

  " Clang to process.">, DefaultFatal;

def err_unsupported_bom : Error<"%0 byte order mark detected in '%1', but "

  "encoding is not supported">, DefaultFatal;

def err_unable_to_rename_temp : Error<

clang/include/clang/Lex/Preprocessor.h

+3 −1
Original line number Diff line number Diff line
@@ -2203,12 +2203,14 @@ private: 
      ModuleBegin,

      ModuleImport,

      SkippedModuleImport,

      Failure,

    } Kind;

    Module *ModuleForHeader = nullptr;



    ImportAction(ActionKind AK, Module *Mod = nullptr)

        : Kind(AK), ModuleForHeader(Mod) {

      assert((AK == None || Mod) && "no module for module action");

      assert((AK == None || Mod || AK == Failure) &&

             "no module for module action");

    }

  };

clang/lib/Basic/SourceManager.cpp

+6 −4
Original line number Diff line number Diff line
@@ -577,13 +577,15 @@ FileID SourceManager::createFileID(const ContentCache *File, StringRef Filename, 
    SLocEntryLoaded[Index] = true;

    return FileID::get(LoadedID);

  }

  unsigned FileSize = File->getSize();

  if (!(NextLocalOffset + FileSize + 1 > NextLocalOffset &&

        NextLocalOffset + FileSize + 1 <= CurrentLoadedOffset)) {

    Diag.Report(IncludePos, diag::err_include_too_large);

    return FileID();

  }

  LocalSLocEntryTable.push_back(

      SLocEntry::get(NextLocalOffset,

                     FileInfo::get(IncludePos, File, FileCharacter, Filename)));

  unsigned FileSize = File->getSize();

  assert(NextLocalOffset + FileSize + 1 > NextLocalOffset &&

         NextLocalOffset + FileSize + 1 <= CurrentLoadedOffset &&

         "Ran out of source locations!");

  // We do a +1 here because we want a SourceLocation that means "the end of the

  // file", e.g. for the "no newline at the end of the file" diagnostic.

  NextLocalOffset += FileSize + 1;

clang/lib/Lex/PPDirectives.cpp

+11 −1
Original line number Diff line number Diff line
@@ -1708,6 +1708,13 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc, 
    EnterAnnotationToken(SourceRange(HashLoc, EndLoc),

                         tok::annot_module_include, Action.ModuleForHeader);

    break;

  case ImportAction::Failure:

    assert(TheModuleLoader.HadFatalFailure &&

           "This should be an early exit only to a fatal error");

    TheModuleLoader.HadFatalFailure = true;

    IncludeTok.setKind(tok::eof);

    CurLexer->cutOffLexing();

    return;

  }

}
@@ -2165,7 +2172,10 @@ Preprocessor::ImportAction Preprocessor::HandleHeaderIncludeOrImport( 
  if (IncludePos.isMacroID())

    IncludePos = SourceMgr.getExpansionRange(IncludePos).getEnd();

  FileID FID = SourceMgr.createFileID(*File, IncludePos, FileCharacter);

  assert(FID.isValid() && "Expected valid file ID");

  if (!FID.isValid()) {

    TheModuleLoader.HadFatalFailure = true;

    return ImportAction::Failure;

  }



  // If all is good, enter the new file!

  if (EnterSourceFile(FID, CurDir, FilenameTok.getLocation()))

clang/lib/Lex/Preprocessor.cpp

+10 −0
Original line number Diff line number Diff line
@@ -906,6 +906,9 @@ void Preprocessor::Lex(Token &Result) { 
    }

  } while (!ReturnedToken);



  if (Result.is(tok::unknown) && TheModuleLoader.HadFatalFailure)

    return;



  if (Result.is(tok::code_completion) && Result.getIdentifierInfo()) {

    // Remember the identifier before code completion token.

    setCodeCompletionIdentifierInfo(Result.getIdentifierInfo());
@@ -1200,6 +1203,13 @@ bool Preprocessor::LexAfterModuleImport(Token &Result) { 
      Suffix[0].setAnnotationValue(Action.ModuleForHeader);

      // FIXME: Call the moduleImport callback?

      break;

    case ImportAction::Failure:

      assert(TheModuleLoader.HadFatalFailure &&

             "This should be an early exit only to a fatal error");

      Result.setKind(tok::eof);

      CurLexer->cutOffLexing();

      EnterTokens(Suffix);

      return true;

    }



    EnterTokens(Suffix);