compilerplugins/clang/store/bodynotinblock.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 #include "bodynotinblock.hxx"
  13
  14 namespace loplugin
  15 {
  16
  17 /*
  18 This is a compile check.
  19
  20 Check for two statements that are both indented to look like a body of if/while/for
  21 but are not inside a compound statement and thus the second one is unrelated.
  22
  23 For example:
  24
  25     if( a != 0 )
  26         b = 2;
  27         c = 3;
  28
  29 Here either both statements should be inside {} or the second statement in indented wrong.
  30 */
  31
  32 BodyNotInBlock::BodyNotInBlock( const InstantiationData& data )
  33     : Plugin( data )
  34     {
  35     }
  36
  37 void BodyNotInBlock::run()
  38     {
  39     TraverseDecl( compiler.getASTContext().getTranslationUnitDecl());
  40     }
  41
  42 bool BodyNotInBlock::VisitIfStmt( const IfStmt* stmt )
  43     {
  44     if( ignoreLocation( stmt ))
  45         return true;
  46     checkBody( stmt->getThen(), stmt->getIfLoc(), 0, stmt->getElse() != NULL );
  47     checkBody( stmt->getElse(), stmt->getElseLoc(), 0 );
  48     return true;
  49     }
  50
  51 bool BodyNotInBlock::VisitWhileStmt( const WhileStmt* stmt )
  52     {
  53     if( ignoreLocation( stmt ))
  54         return true;
  55     checkBody( stmt->getBody(), stmt->getWhileLoc(), 1 );
  56     return true;
  57     }
  58
  59 bool BodyNotInBlock::VisitForStmt( const ForStmt* stmt )
  60     {
  61     if( ignoreLocation( stmt ))
  62         return true;
  63     checkBody( stmt->getBody(), stmt->getForLoc(), 2 );
  64     return true;
  65     }
  66
  67 bool BodyNotInBlock::VisitCXXForRangeStmt( const CXXForRangeStmt* stmt )
  68     {
  69     if( ignoreLocation( stmt ))
  70         return true;
  71     checkBody( stmt->getBody(), stmt->getForLoc(), 2 );
  72     return true;
  73     }
  74
  75 void BodyNotInBlock::checkBody( const Stmt* body, SourceLocation stmtLocation, int stmtType, bool dontGoUp )
  76     {
  77     if( body == NULL )
  78         return;
  79     // TODO: If the if/else/while/for comes from a macro expansion, ignore it completely for
  80     // now. The code below could assume everything is in the same place (and thus also column)
  81     // and give a false warning. Moreover some macros are rather loosely written and would
  82     // result in poor formatting. To be evaluated later, maybe this could be handled
  83     // including macro expansion.
  84     if( stmtLocation.isMacroID())
  85         return;
  86     if( dyn_cast< CompoundStmt >( body ))
  87         return; // if body is a compound statement, then it is in {}
  88     const Stmt* previousParent = parentStmt( body ); // Here the statement itself.
  89     // Find the next statement (in source position) after 'body'.
  90     for(;;)
  91         {
  92         const Stmt* parent = parentStmt( previousParent );
  93         if( parent == NULL )
  94             break;
  95         for( ConstStmtIterator it = parent->child_begin();
  96              it != parent->child_end();
  97              )
  98             {
  99             if( *it == previousParent ) // found grand(grand...)parent
 100                 {
 101                 // get next statement after our (grand...)parent
 102                 ++it;
 103                 while( it != parent->child_end() && *it == NULL )
 104                     ++it; // skip empty ones (missing 'else' bodies for example)
 105                 if( it != parent->child_end())
 106                     {
 107                     bool invalid1, invalid2;
 108                     unsigned bodyColumn = compiler.getSourceManager()
 109                         .getPresumedColumnNumber( body->getLocStart(), &invalid1 );
 110                     unsigned nextStatementColumn = compiler.getSourceManager()
 111                         .getPresumedColumnNumber( (*it)->getLocStart(), &invalid2 );
 112                     if( invalid1 || invalid2 )
 113                         return;
 114                     if( bodyColumn == nextStatementColumn )
 115                         {
 116                         report( DiagnosticsEngine::Warning,
 117                             "statement aligned as second statement in %select{if|while|for}0 body but not in a statement block",
 118                             (*it)->getLocStart()) << stmtType;
 119                         report( DiagnosticsEngine::Note,
 120                             "%select{if|while|for}0 body statement is here",
 121                             body->getLocStart()) << stmtType;
 122                         }
 123                     return;
 124                     }
 125                 // else we need to go higher to find the next statement
 126                 }
 127             else
 128                 ++it;
 129             }
 130         // If going up would mean leaving a {} block, stop, because the } should
 131         // make it visible the two statements are not in the same body.
 132         if( dyn_cast< CompoundStmt >( parent ))
 133             return;
 134         // If the body to be checked is a body of an if statement that has also
 135         // an else part, don't go up, the else is after the body and should make
 136         // it clear the body does not continue there.
 137         if( dontGoUp )
 138             return;
 139         previousParent = parent;
 140         }
 141     }
 142
 143 static Plugin::Registration< BodyNotInBlock > X( "bodynotinblock" );
 144
 145 } // namespace
 146
 147 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */