libreoffice/compilerplugins/clang/store/cascadingcondop.cxx
Bjoern Michaelsen 395d6a96aa cascading conditional operators, give a hint on complexity
Change-Id: Ie9d0b07a32cc17705db735ea18f70f28d57badd4
Reviewed-on: https://gerrit.libreoffice.org/12990
Reviewed-by: Björn Michaelsen <bjoern.michaelsen@canonical.com>
Tested-by: Björn Michaelsen <bjoern.michaelsen@canonical.com>
2014-11-20 18:16:02 +00:00

87 lines
2.4 KiB
C++

/* -*- 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 "cascadingcondop.hxx"
/*
This is a compile check.
It checks for complex statements with conditional operators in conditional
operators, which are errorprone, 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 havent played with yet).
*/
// the value is rather arbitrary, but code above this number of stmts begins to
// be smelly
static const int stmtlimit = 50;
namespace loplugin
{
struct WalkCounter
{
int stmtcount;
bool cascading;
};
// Ctor, nothing special, pass the argument(s).
CascadingCondOp::CascadingCondOp( const InstantiationData& data )
: Plugin( data )
{
}
// Perform the actual action.
void CascadingCondOp::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 CascadingCondOp::Walk( const Stmt* stmt, WalkCounter& c )
{
for(Stmt::const_child_iterator it = stmt->child_begin(); it != stmt->child_end(); ++it)
{
++c.stmtcount;
if ( dyn_cast< ConditionalOperator >( *it ))
c.cascading = true;
Walk(*it, c);
}
}
bool CascadingCondOp::VisitStmt( const Stmt* stmt )
{
if ( const ConditionalOperator* condop = dyn_cast< ConditionalOperator >( stmt ))
{
WalkCounter c = { 0, false };
Walk(condop, c);
if(c.cascading && c.stmtcount >= stmtlimit)
{
std::string msg("cascading conditional operator, complexity: ");
msg.append(std::to_string(c.stmtcount));
report( DiagnosticsEngine::Warning, msg, condop->getLocStart());
}
}
return true;
}
// Register the plugin action with the LO plugin handling.
static Plugin::Registration< CascadingCondOp > X( "cascadingcondop" );
} // namespace loplugin
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */