cppcheck/CheckOther.cpp

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//---------------------------------------------------------------------------
#include "CheckOther.h"
#include "tokenize.h"
#include "CommonCheck.h"
#include <list>
#include <sstream>
#include <stdlib.h> // <- atoi
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Warning on C-Style casts.. p = (kalle *)foo;
//---------------------------------------------------------------------------
void WarningOldStylePointerCast()
{
for (TOKEN *tok = tokens; tok; tok = tok->next)
{
// Old style pointer casting..
if (!match(tok, "( type * ) var"))
continue;
// Is "type" a class?
const char *pattern[] = {"class","",NULL};
pattern[1] = getstr(tok, 1);
if (!findtoken(tokens, pattern))
continue;
std::ostringstream ostr;
ostr << FileLine(tok) << ": C-style pointer casting";
ReportErr(ostr.str());
}
}
//---------------------------------------------------------------------------
// Use standard function "isdigit" instead
//---------------------------------------------------------------------------
void WarningIsDigit()
{
for (TOKEN *tok = tokens; tok; tok = tok->next)
{
bool err = false;
err |= match(tok, "var >= '0' && var <= '9'");
err |= match(tok, "* var >= '0' && * var <= '9'");
err |= match(tok, "( var >= '0' ) && ( var <= '9' )");
err |= match(tok, "( * var >= '0' ) && ( * var <= '9' )");
if (err)
{
std::ostringstream ostr;
ostr << FileLine(tok) << ": The condition can be simplified; use 'isdigit'";
ReportErr(ostr.str());
}
}
}
//---------------------------------------------------------------------------
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//---------------------------------------------------------------------------
// Use standard function "isalpha" instead
//---------------------------------------------------------------------------
void WarningIsAlpha()
{
for (TOKEN *tok = tokens; tok; tok = tok->next)
{
bool err = false;
if ( tok->str[0] != '(' )
continue;
err |= match(tok, "( var >= 'A' && var <= 'Z' ) || ( var >= 'a' && var <= 'z' )");
err |= match(tok, "( var >= 'a' && var <= 'z' ) || ( var >= 'A' && var <= 'Z' )");
err |= match(tok, "( * var >= 'A' && * var <= 'Z' ) || ( * var >= 'a' && * var <= 'z' )");
err |= match(tok, "( * var >= 'a' && * var <= 'z' ) || ( * var >= 'A' && * var <= 'Z' )");
err |= match(tok, "( ( var >= 'A' ) && ( var <= 'Z' ) ) || ( ( var >= 'a' ) && ( var <= 'z' ) )");
err |= match(tok, "( ( var >= 'a' ) && ( var <= 'z' ) ) || ( ( var >= 'A' ) && ( var <= 'Z' ) )");
err |= match(tok, "( ( * var >= 'A' ) && ( * var <= 'Z' ) ) || ( ( * var >= 'a' ) && ( * var <= 'z' ) )");
err |= match(tok, "( ( * var >= 'a' ) && ( * var <= 'z' ) ) || ( ( * var >= 'A' ) && ( * var <= 'Z' ) )");
if (err)
{
std::ostringstream ostr;
ostr << FileLine(tok) << ": The condition can be simplified; use 'isalpha'";
ReportErr(ostr.str());
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Redundant code..
//---------------------------------------------------------------------------
void WarningRedundantCode()
{
// if (p) delete p
for (TOKEN *tok = tokens; tok; tok = tok->next)
{
if (strcmp(tok->str,"if"))
continue;
const char *varname1 = NULL;
TOKEN *tok2 = NULL;
if (match(tok,"if ( var )"))
{
varname1 = getstr(tok, 2);
tok2 = gettok(tok, 4);
}
else if (match(tok,"if ( var != NULL )"))
{
varname1 = getstr(tok, 2);
tok2 = gettok(tok, 6);
}
if (varname1==NULL || tok2==NULL)
continue;
bool err = false;
if (match(tok2,"delete var ;"))
err = (strcmp(getstr(tok2,1),varname1)==0);
else if (match(tok2,"{ delete var ; }"))
err = (strcmp(getstr(tok2,2),varname1)==0);
else if (match(tok2,"delete [ ] var ;"))
err = (strcmp(getstr(tok2,1),varname1)==0);
else if (match(tok2,"{ delete [ ] var ; }"))
err = (strcmp(getstr(tok2,2),varname1)==0);
else if (match(tok2,"free ( var )"))
err = (strcmp(getstr(tok2,2),varname1)==0);
else if (match(tok2,"{ free ( var ) ; }"))
err = (strcmp(getstr(tok2,3),varname1)==0);
if (err)
{
std::ostringstream ostr;
ostr << FileLine(tok) << ": Redundant condition. It is safe to deallocate a NULL pointer";
ReportErr(ostr.str());
}
}
// TODO
// if (haystack.find(needle) != haystack.end())
// haystack.remove(needle);
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
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// if (condition) ....
//---------------------------------------------------------------------------
void WarningIf()
{
// Search for 'if (condition);'
for (TOKEN *tok = tokens; tok; tok = tok->next)
{
if (strcmp(tok->str,"if")==0)
{
int parlevel = 0;
for (TOKEN *tok2 = tok->next; tok2; tok2 = tok2->next)
{
if (tok2->str[0]=='(')
parlevel++;
else if (tok2->str[0]==')')
{
parlevel--;
if (parlevel<=0)
{
if (strcmp(getstr(tok2,1), ";") == 0 &&
strcmp(getstr(tok2,2), "else") != 0)
{
std::ostringstream ostr;
ostr << FileLine(tok) << ": Found \"if (condition);\"";
ReportErr(ostr.str());
}
break;
}
}
}
}
}
// Search for 'a=b; if (a==b)'
for (TOKEN *tok = tokens; tok; tok = tok->next)
{
// Begin statement?
if ( ! strchr(";{}", tok->str[0]) )
continue;
tok = tok->next;
if ( ! tok )
break;
if (!match(tok,"var = var ; if ( var"))
continue;
if ( strcmp(getstr(tok, 9), ")") != 0 )
continue;
// var1 = var2 ; if ( var3 cond var4 )
const char *var1 = tok->str;
const char *var2 = getstr(tok, 2);
const char *var3 = getstr(tok, 6);
const char *cond = getstr(tok, 7);
const char *var4 = getstr(tok, 8);
// Check that var3 is equal with either var1 or var2
if (strcmp(var1,var3) && strcmp(var2,var3))
continue;
// Check that var4 is equal with either var1 or var2
if (strcmp(var1,var4) && strcmp(var2,var4))
continue;
// Check that there is a condition..
const char *p[6] = {"==","<=",">=","!=","<",">"};
bool iscond = false;
for (int i = 0; i < 6; i++)
iscond |= (strcmp(cond, p[i]) == 0);
if (!iscond)
break;
// we found the error. Report.
std::ostringstream ostr;
ostr << FileLine(gettok(tok,4)) << ": The condition is always ";
for (int i = 0; i < 6; i++)
{
if (strcmp(cond, p[i]) == 0)
ostr << (i < 3 ? "True" : "False");
}
ReportErr(ostr.str());
}
// Search for 'if (condition) flag = true;'
bool newstatement = false;
for (TOKEN *tok = tokens; tok; tok = tok->next)
{
if (!newstatement || strcmp(tok->str,"if"))
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{
newstatement = (strchr("{};",tok->str[0]));
continue;
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}
int parlevel = 0;
for (TOKEN *tok2 = tok->next; tok2; tok2 = tok2->next)
{
if (tok2->str[0]=='(')
parlevel++;
else if (tok2->str[0]==')')
{
parlevel--;
if (parlevel<=0)
{
if ( strcmp(getstr(tok2,5), "else") == 0 )
{
if ( match(tok2->next, "var = true ; else var = false ;") )
{
std::ostringstream ostr;
ostr << FileLine(tok) << ": Found \"if (condition) var=true; else var=false;\", it can be rewritten as \"var = (condition);\"";
ReportErr(ostr.str());
}
}
else if ( match(tok2->next, "var = true ;") )
{
std::ostringstream ostr;
ostr << FileLine(tok) << ": Found \"if (condition) var = true;\", it can be rewritten as \"var |= (condition);\"";
ReportErr(ostr.str());
}
else if ( match(tok2->next, "var = false ;") )
{
std::ostringstream ostr;
ostr << FileLine(tok) << ": Found \"if (condition) var = false;\", it can be rewritten as \"var &= (!condition);\"";
ReportErr(ostr.str());
}
break;
}
}
}
newstatement = (strchr("{};",tok->str[0]));
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// strtol(str, 0, radix) <- radix must be 0 or 2-36
//---------------------------------------------------------------------------
void InvalidFunctionUsage()
{
for ( TOKEN *tok = tokens; tok; tok = tok->next )
{
if ( strcmp(tok->str, "strtol") && strcmp(tok->str, "strtoul") )
continue;
// Locate the third parameter of the function call..
int parlevel = 0;
int param = 1;
for ( TOKEN *tok2 = tok->next; tok2; tok2 = tok2->next )
{
if ( tok2->str[0] == '(' )
parlevel++;
else if (tok2->str[0] == ')')
parlevel--;
else if (parlevel == 1 && tok2->str[0] == ',')
{
param++;
if (param==3)
{
if ( match(tok2, ", num )") )
{
int radix = atoi(tok2->next->str);
if (!(radix==0 || (radix>=2 && radix<=36)))
{
std::ostringstream ostr;
ostr << FileLine(tok2) << ": Invalid radix in call to strtol or strtoul. Must be 0 or 2-36";
ReportErr(ostr.str());
}
}
break;
}
}
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Dangerous usage of 'strtok'
//---------------------------------------------------------------------------
static TOKEN *GetFunction( TOKEN *content )
{
TOKEN *func = NULL;
int indentlevel = 0;
for (TOKEN *tok = tokens; tok; tok = tok->next)
{
if ( tok->str[0] == '{' )
indentlevel++;
else if ( tok->str[0] == '}' )
{
indentlevel--;
if (indentlevel == 0)
func = NULL;
}
else if (indentlevel == 0)
{
if (tok->str[0] == ';')
func = NULL;
else if ( match(tok, "var :: var (") )
func = tok->next->next;
else if ( match(tok, "type var (") )
func = tok->next;
}
else if (indentlevel>0 && func)
{
if ( tok == content )
return func;
}
}
return NULL;
}
void WarningStrTok()
{
std::list<TOKEN *> funclist;
// Which functions contain the 'strtok'?
for (TOKEN *tok = tokens; tok; tok = tok->next)
{
if (strcmp(tok->str,"strtok")!=0)
continue;
TOKEN *func = GetFunction(tok);
if (!func)
continue;
funclist.push_back( func );
}
// No functions in list => No errors
if ( funclist.empty() )
return;
// Take closer look at the strtok usage.
std::list<TOKEN *>::const_iterator it1;
for (it1 = funclist.begin(); it1 != funclist.end(); it1++)
{
// Search this function to check that it doesn't call any other of
// the functions in the funclist.
int indentlevel = 0;
for ( TOKEN *tok = *it1; tok; tok = tok->next )
{
if ( tok->str[0] == '{' )
indentlevel++;
else if ( tok->str[0] == '}' )
{
if ( indentlevel <= 1 )
break;
indentlevel--;
}
else if ( indentlevel >= 1 )
{
// Only interested in function calls..
if (!(IsName(tok->str) && strcmp(getstr(tok,1), "(") == 0))
continue;
// Check if function name is in funclist..
std::list<TOKEN *>::const_iterator it2;
for (it2 = funclist.begin(); it2 != funclist.end(); it2++)
{
if ( strcmp( tok->str, (*it2)->str ) )
continue;
std::ostringstream ostr;
ostr << FileLine(tok) << ": Possible bug. Both '" << (*it1)->str << "' and '" << (*it2)->str << "' uses strtok.";
ReportErr(ostr.str());
break;
}
}
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Assignment in condition
//---------------------------------------------------------------------------
void CheckIfAssignment()
{
for (TOKEN *tok = tokens; tok; tok = tok->next)
{
if (match(tok,"if ( a = b )"))
{
std::ostringstream ostr;
ostr << FileLine(tok) << ": Possible bug. Should it be '==' instead of '='?";
ReportErr(ostr.str());
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Check for case without break
//---------------------------------------------------------------------------
void CheckCaseWithoutBreak()
{
for ( TOKEN *tok = tokens; tok; tok = tok->next )
{
if ( strcmp(tok->str,"case")!=0 )
continue;
// Found a case, check that there's a break..
int indentlevel = 0;
for (TOKEN *tok2 = tok->next; tok2; tok2 = tok2->next)
{
if (tok2->str[0] == '{')
indentlevel++;
else if (tok2->str[0] == '}')
{
indentlevel--;
if (indentlevel < 0)
{
std::ostringstream ostr;
ostr << FileLine(tok) << ": 'case' without 'break'.";
ReportErr(ostr.str());
}
}
if (indentlevel==0)
{
if (strcmp(tok2->str,"break")==0)
break;
if (strcmp(tok2->str,"return")==0)
break;
if (strcmp(tok2->str,"case")==0)
{
std::ostringstream ostr;
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ostr << FileLine(tok) << ": Found 'case' without 'break'.";
ReportErr(ostr.str());
break;
}
}
}
}
}