compilerplugins/clang/rtlconstasciimacro.cxx

   1 /*
   2  * This file is part of the LibreOffice project.
   3  *
   4  * Based on LLVM/Clang.
   5  *
   6  * This file is distributed under the University of Illinois Open Source
   7  * License. See LICENSE.TXT for details.
   8  *
   9  */
  10
  11 /*
  12 This is a rewriter.
  13
  14 Remove uses of the macro RTL_CONSTASCII_USTRINGPARAM. One run is for one
  15 specific use (see below), modify source to remove other uses.
  16 */
  17
  18 #include "plugin.hxx"
  19
  20 #include <clang/Lex/Preprocessor.h>
  21
  22 namespace loplugin
  23 {
  24
  25 class RtlConstAsciiMacro
  26     : public RecursiveASTVisitor< RtlConstAsciiMacro >
  27     , public PPCallbacks
  28     , public RewritePlugin
  29     {
  30     public:
  31         explicit RtlConstAsciiMacro( CompilerInstance& compiler, Rewriter& rewriter );
  32         virtual void run() override;
  33         bool VisitCXXConstructExpr( CXXConstructExpr* expr );
  34         bool VisitCXXTemporaryObjectExpr( CXXTemporaryObjectExpr* expr );
  35         bool VisitStringLiteral( const StringLiteral* literal );
  36 #if __clang_major__ < 3 || __clang_major__ == 3 && __clang_minor__ < 3
  37         virtual void MacroExpands( const Token& macro, const MacroInfo* info, SourceRange range ) override;
  38 #else
  39         virtual void MacroExpands( const Token& macro, const MacroDirective* directive,
  40             SourceRange range, const MacroArgs* args ) override;
  41 #endif
  42     private:
  43         map< SourceLocation, SourceLocation > expansions; // start location -> end location
  44         bool searchingForString;
  45         bool suitableString;
  46     };
  47
  48 RtlConstAsciiMacro::RtlConstAsciiMacro( CompilerInstance& compiler, Rewriter& rewriter )
  49     : RewritePlugin( compiler, rewriter )
  50     , searchingForString( false )
  51     {
  52     compiler.getPreprocessor().addPPCallbacks( this );
  53     }
  54
  55 void RtlConstAsciiMacro::run()
  56     {
  57     TraverseDecl( compiler.getASTContext().getTranslationUnitDecl());
  58     }
  59
  60
  61 #if __clang_major__ < 3 || __clang_major__ == 3 && __clang_minor__ < 3
  62 void RtlConstAsciiMacro::MacroExpands( const Token& macro, const MacroInfo*, SourceRange range )
  63 #else
  64 void RtlConstAsciiMacro::MacroExpands( const Token& macro, const MacroDirective*,
  65     SourceRange range, const MacroArgs* )
  66 #endif
  67     {
  68     if( macro.getIdentifierInfo()->getName() != "RTL_CONSTASCII_USTRINGPARAM" )
  69         return;
  70     expansions[ range.getBegin() ] = range.getEnd();
  71     }
  72
  73 /* Remove use with the following ctor:
  74     OUString( const sal_Char * value, sal_Int32 length,
  75               rtl_TextEncoding encoding,
  76               sal_uInt32 convertFlags = OSTRING_TO_OUSTRING_CVTFLAGS )
  77    This means searching for CXXConstructExpr.
  78    For removal when used with functions it should check e.g. for CallExpr.
  79 */
  80 bool RtlConstAsciiMacro::VisitCXXConstructExpr( CXXConstructExpr* expr )
  81     {
  82     if( ignoreLocation( expr ))
  83         return true;
  84     if( expr->getNumArgs() != 4 )
  85         return true;
  86     // The last argument should be the default one when the macro is used.
  87     if( dyn_cast< CXXDefaultArgExpr >( expr->getArg( 3 )) == NULL )
  88         return true;
  89     if( expr->getConstructor()->getQualifiedNameAsString() != "rtl::OUString::OUString" )
  90         return true;
  91     const SourceManager& src = compiler.getSourceManager();
  92     SourceLocation start = src.getExpansionLoc( expr->getArg( 0 )->getLocStart());
  93     // Macro fills in the first 3 arguments, so they must all come from the same expansion.
  94     if( start != src.getExpansionLoc( expr->getArg( 2 )->getLocEnd()))
  95         return true;
  96     if( expansions.find( start ) == expansions.end())
  97         return true;
  98     SourceLocation end = expansions[ start ];
  99     // Remove the location, since sometimes the same code may be processed more than once
 100     // (e.g. non-trivial default arguments).
 101     expansions.erase( start );
 102     // Check if the string argument to the macro is suitable.
 103     searchingForString = true;
 104     suitableString = false;
 105     TraverseStmt( expr->getArg( 0 ));
 106     searchingForString = false;
 107     if( !suitableString )
 108         return true;
 109     // Seach for '(' (don't just remove a given length to handle possible whitespace).
 110     const char* text = compiler.getSourceManager().getCharacterData( start );
 111     const char* pos = text;
 112     while( *pos != '(' )
 113         ++pos;
 114     ++pos;
 115     if( text[ -1 ] == ' ' && *pos == ' ' )
 116         ++pos; // do not leave two spaces
 117     removeText( start, pos - text, RemoveLineIfEmpty );
 118     const char* textend = compiler.getSourceManager().getCharacterData( end );
 119     if( textend[ -1 ] == ' ' && textend[ 1 ] == ' ' )
 120         removeText( end, 2, RemoveLineIfEmpty ); // Remove ') '.
 121     else
 122         removeText( end, 1, RemoveLineIfEmpty ); // Remove ')'.
 123     return true;
 124     }
 125
 126 bool RtlConstAsciiMacro::VisitCXXTemporaryObjectExpr( CXXTemporaryObjectExpr* expr )
 127     {
 128     return VisitCXXConstructExpr( expr );
 129     }
 130
 131 bool RtlConstAsciiMacro::VisitStringLiteral( const StringLiteral* literal )
 132     {
 133     if( !searchingForString )
 134         return true;
 135     if( suitableString ) // two string literals?
 136         {
 137         report( DiagnosticsEngine::Warning, "cannot analyze RTL_CONSTASCII_USTRINGPARAM (plugin needs fixing)" )
 138             << literal->getSourceRange();
 139         return true;
 140         }
 141     if( !literal->isAscii()) // ignore
 142         return true;
 143     if( !literal->containsNonAsciiOrNull())
 144         suitableString = true;
 145     return true;
 146     }
 147
 148 static Plugin::Registration< RtlConstAsciiMacro > X( "rtlconstasciimacro" );
 149
 150 } // namespace