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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* Based on LLVM/Clang.
*
* This file is distributed under the University of Illinois Open Source
* License. See LICENSE.TXT for details.
*
*/
#include "cascadingassignop.hxx"
/*
This is a compile check.
It checks for complex statements with conditional operators in conditional
operators, which are error prone, e.g.
Thing foo = IsBar() ? ( IsBaz() ? b1 : b2 ) : b3;
However, it finds 556 cases in sw/source alone, thus likely needs some more
restricting, e.g. by checking for multiline conditional operator statements or
a certain length in characters (but that needs the Context/SourceManager, which
I haven't played with yet).
*/
// the value is rather arbitrary, but code above this number of stmts begins to
// be smelly
static const int stmtlimit = 20;
namespace loplugin
{
struct WalkCounter
{
int stmtcount;
bool cascading;
bool conditionals;
};
// Ctor, nothing special, pass the argument(s).
CascadingAssignOp::CascadingAssignOp( const InstantiationData& data )
: FilteringPlugin( data )
{
}
// Perform the actual action.
void CascadingAssignOp::run()
{
// Traverse the whole AST of the translation unit (i.e. examine the whole source file).
// The Clang AST helper class will call VisitReturnStmt for every return statement.
TraverseDecl( compiler.getASTContext().getTranslationUnitDecl());
}
void CascadingAssignOp::Walk( const Stmt* stmt, WalkCounter& c )
{
for(Stmt::const_child_iterator it = stmt->child_begin(); it != stmt->child_end(); ++it)
{
++c.stmtcount;
const BinaryOperator* binop = dyn_cast< BinaryOperator >( *it );
if ( binop )
{
if ( (binop->isAssignmentOp() || binop->isCompoundAssignmentOp()))
c.cascading = true;
if ( dyn_cast< AbstractConditionalOperator >( binop ) || binop->isLogicalOp())
c.conditionals = true;
}
Walk(*it, c);
}
}
bool CascadingAssignOp::VisitStmt( const Stmt* stmt )
{
const BinaryOperator* binop = dyn_cast< BinaryOperator >( stmt );
if ( binop && (binop->isAssignmentOp() || binop->isCompoundAssignmentOp()))
{
WalkCounter c = { 0, false, false };
Walk(binop, c);
if(c.cascading && c.conditionals && c.stmtcount >= stmtlimit)
{
std::string msg("cascading assign operator mixing in conditionals, complexity: ");
msg.append(std::to_string(c.stmtcount));
report( DiagnosticsEngine::Warning, msg, binop->getLocStart());
}
}
return true;
}
// Register the plugin action with the LO plugin handling.
static Plugin::Registration< CascadingAssignOp > X( "cascadingassignop" );
} // namespace loplugin
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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