compilerplugins/clang/rtlconstasciimacro.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * Based on LLVM/Clang.
   6  *
   7  * This file is distributed under the University of Illinois Open Source
   8  * License. See LICENSE.TXT for details.
   9  *
  10  */
  11
  12 /*
  13 This is a rewriter.
  14
  15 Remove uses of the macro RTL_CONSTASCII_USTRINGPARAM. One run is for one
  16 specific use (see below), modify source to remove other uses.
  17 */
  18
  19 #include "plugin.hxx"
  20
  21 #include <clang/Lex/Preprocessor.h>
  22
  23 namespace loplugin
  24 {
  25
  26 class RtlConstAsciiMacro
  27     : public RecursiveASTVisitor< RtlConstAsciiMacro >
  28     , public PPCallbacks
  29     , public RewritePlugin
  30     {
  31     public:
  32         explicit RtlConstAsciiMacro( CompilerInstance& compiler, Rewriter& rewriter );
  33         virtual void run() override;
  34         bool VisitCXXConstructExpr( CXXConstructExpr* expr );
  35         bool VisitCXXTemporaryObjectExpr( CXXTemporaryObjectExpr* expr );
  36         bool VisitStringLiteral( const StringLiteral* literal );
  37 #if __clang_major__ < 3 || __clang_major__ == 3 && __clang_minor__ < 3
  38         virtual void MacroExpands( const Token& macro, const MacroInfo* info, SourceRange range ) override;
  39 #else
  40         virtual void MacroExpands( const Token& macro, const MacroDirective* directive,
  41             SourceRange range, const MacroArgs* args ) override;
  42 #endif
  43         enum { isPPCallback = true };
  44     private:
  45         map< SourceLocation, SourceLocation > expansions; // start location -> end location
  46         bool searchingForString;
  47         bool suitableString;
  48     };
  49
  50 RtlConstAsciiMacro::RtlConstAsciiMacro( CompilerInstance& compiler, Rewriter& rewriter )
  51     : RewritePlugin( compiler, rewriter )
  52     , searchingForString( false )
  53     {
  54     compiler.getPreprocessor().addPPCallbacks( this );
  55     }
  56
  57 void RtlConstAsciiMacro::run()
  58     {
  59     TraverseDecl( compiler.getASTContext().getTranslationUnitDecl());
  60     }
  61
  62
  63 #if __clang_major__ < 3 || __clang_major__ == 3 && __clang_minor__ < 3
  64 void RtlConstAsciiMacro::MacroExpands( const Token& macro, const MacroInfo*, SourceRange range )
  65 #else
  66 void RtlConstAsciiMacro::MacroExpands( const Token& macro, const MacroDirective*,
  67     SourceRange range, const MacroArgs* )
  68 #endif
  69     {
  70     if( macro.getIdentifierInfo()->getName() != "RTL_CONSTASCII_USTRINGPARAM" )
  71         return;
  72     expansions[ range.getBegin() ] = range.getEnd();
  73     }
  74
  75 /* Remove use with the following ctor:
  76     OUString( const sal_Char * value, sal_Int32 length,
  77               rtl_TextEncoding encoding,
  78               sal_uInt32 convertFlags = OSTRING_TO_OUSTRING_CVTFLAGS )
  79    This means searching for CXXConstructExpr.
  80    For removal when used with functions it should check e.g. for CallExpr.
  81 */
  82 bool RtlConstAsciiMacro::VisitCXXConstructExpr( CXXConstructExpr* expr )
  83     {
  84     if( ignoreLocation( expr ))
  85         return true;
  86     if( expr->getNumArgs() != 4 )
  87         return true;
  88     // The last argument should be the default one when the macro is used.
  89     if( dyn_cast< CXXDefaultArgExpr >( expr->getArg( 3 )) == NULL )
  90         return true;
  91     if( expr->getConstructor()->getQualifiedNameAsString() != "rtl::OUString::OUString" )
  92         return true;
  93     const SourceManager& src = compiler.getSourceManager();
  94     SourceLocation start = src.getExpansionLoc( expr->getArg( 0 )->getLocStart());
  95     // Macro fills in the first 3 arguments, so they must all come from the same expansion.
  96     if( start != src.getExpansionLoc( expr->getArg( 2 )->getLocEnd()))
  97         return true;
  98     if( expansions.find( start ) == expansions.end())
  99         return true;
 100     SourceLocation end = expansions[ start ];
 101     // Remove the location, since sometimes the same code may be processed more than once
 102     // (e.g. non-trivial default arguments).
 103     expansions.erase( start );
 104     // Check if the string argument to the macro is suitable.
 105     searchingForString = true;
 106     suitableString = false;
 107     TraverseStmt( expr->getArg( 0 ));
 108     searchingForString = false;
 109     if( !suitableString )
 110         return true;
 111     // Seach for '(' (don't just remove a given length to handle possible whitespace).
 112     const char* text = compiler.getSourceManager().getCharacterData( start );
 113     const char* pos = text;
 114     while( *pos != '(' )
 115         ++pos;
 116     ++pos;
 117     if( text[ -1 ] == ' ' && *pos == ' ' )
 118         ++pos; // do not leave two spaces
 119     removeText( start, pos - text, RemoveLineIfEmpty );
 120     const char* textend = compiler.getSourceManager().getCharacterData( end );
 121     if( textend[ -1 ] == ' ' && textend[ 1 ] == ' ' )
 122         removeText( end, 2, RemoveLineIfEmpty ); // Remove ') '.
 123     else
 124         removeText( end, 1, RemoveLineIfEmpty ); // Remove ')'.
 125     return true;
 126     }
 127
 128 bool RtlConstAsciiMacro::VisitCXXTemporaryObjectExpr( CXXTemporaryObjectExpr* expr )
 129     {
 130     return VisitCXXConstructExpr( expr );
 131     }
 132
 133 bool RtlConstAsciiMacro::VisitStringLiteral( const StringLiteral* literal )
 134     {
 135     if( !searchingForString )
 136         return true;
 137     if( suitableString ) // two string literals?
 138         {
 139         report( DiagnosticsEngine::Warning, "cannot analyze RTL_CONSTASCII_USTRINGPARAM (plugin needs fixing)" )
 140             << literal->getSourceRange();
 141         return true;
 142         }
 143     if( !literal->isAscii()) // ignore
 144         return true;
 145     if( !literal->containsNonAsciiOrNull())
 146         suitableString = true;
 147     return true;
 148     }
 149
 150 static Plugin::Registration< RtlConstAsciiMacro > X( "rtlconstasciimacro" );
 151
 152 } // namespace
 153
 154 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */