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Refactorized CheckUnusedVar

This commit is contained in:
PKEuS 2011-12-18 20:15:41 +01:00 committed by Daniel Marjamäki
parent b6b97fa43d
commit 6dc2a6e7ab
4 changed files with 369 additions and 672 deletions
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2
lib/checkother.cpp
View File

@ -1398,7 +1398,7 @@ void CheckOther::checkWrongPrintfScanfArguments()
case 'G': case 'G':
if (varTypeTok && varTypeTok->str() == "const") if (varTypeTok && varTypeTok->str() == "const")
varTypeTok = varTypeTok->next(); varTypeTok = varTypeTok->next();
if (varTypeTok && (isKnownType(variableInfo, varTypeTok) && !Token::Match(varTypeTok, "float|double") || variableInfo->isPointer() || variableInfo->isArray())) if (varTypeTok && ((isKnownType(variableInfo, varTypeTok) && !Token::Match(varTypeTok, "float|double")) || variableInfo->isPointer() || variableInfo->isArray()))
invalidPrintfArgTypeError_float(tok, numFormat, *i); invalidPrintfArgTypeError_float(tok, numFormat, *i);
else if (Token::Match(argListTok, "%str%")) else if (Token::Match(argListTok, "%str%"))
invalidPrintfArgTypeError_float(tok, numFormat, *i); invalidPrintfArgTypeError_float(tok, numFormat, *i);

614
lib/checkunusedvar.cpp
View File

@ -28,70 +28,19 @@ namespace {
CheckUnusedVar instance; CheckUnusedVar instance;
} }
/**
* @brief This class is used to capture the control flow within a function.
*/
class ScopeInfo {
public:
ScopeInfo() : _token(NULL), _parent(NULL) { }
ScopeInfo(const Token *token, ScopeInfo *parent_) : _token(token), _parent(parent_) { }
~ScopeInfo();
ScopeInfo *parent() {
return _parent;
}
ScopeInfo *addChild(const Token *token);
void remove(ScopeInfo *scope);
private:
const Token *_token;
ScopeInfo *_parent;
std::list<ScopeInfo *> _children;
};
ScopeInfo::~ScopeInfo()
{
while (!_children.empty()) {
delete *_children.begin();
_children.pop_front();
}
}
ScopeInfo *ScopeInfo::addChild(const Token *token)
{
ScopeInfo *temp = new ScopeInfo(token, this);
_children.push_back(temp);
return temp;
}
void ScopeInfo::remove(ScopeInfo *scope)
{
std::list<ScopeInfo *>::iterator it;
for (it = _children.begin(); it != _children.end(); ++it) {
if (*it == scope) {
delete *it;
_children.erase(it);
break;
}
}
}
/** /**
* @brief This class is used create a list of variables within a function. * @brief This class is used create a list of variables within a function.
*/ */
class Variables { class Variables {
public: public:
enum VariableType { standard, array, pointer, reference, pointerArray, referenceArray, pointerPointer }; enum VariableType { standard, array, pointer, reference, pointerArray, referenceArray, pointerPointer, none };
/** Store information about variable usage */ /** Store information about variable usage */
class VariableUsage { class VariableUsage {
public: public:
VariableUsage(const Token *name = 0, VariableUsage(const Token *name = 0,
VariableType type = standard, VariableType type = standard,
ScopeInfo *scope = NULL, const Scope *scope = NULL,
bool read = false, bool read = false,
bool write = false, bool write = false,
bool modified = false, bool modified = false,
@ -118,13 +67,13 @@ public:
const Token *_name; const Token *_name;
VariableType _type; VariableType _type;
ScopeInfo *_scope; const Scope *_scope;
bool _read; bool _read;
bool _write; bool _write;
bool _modified; // read/modify/write bool _modified; // read/modify/write
bool _allocateMemory; bool _allocateMemory;
std::set<unsigned int> _aliases; std::set<unsigned int> _aliases;
std::set<ScopeInfo *> _assignments; std::set<const Scope*> _assignments;
}; };
typedef std::map<unsigned int, VariableUsage> VariableMap; typedef std::map<unsigned int, VariableUsage> VariableMap;
@ -132,10 +81,10 @@ public:
void clear() { void clear() {
_varUsage.clear(); _varUsage.clear();
} }
VariableMap &varUsage() { const VariableMap &varUsage() {
return _varUsage; return _varUsage;
} }
void addVar(const Token *name, VariableType type, ScopeInfo *scope, bool write_); void addVar(const Token *name, VariableType type, const Scope *scope, bool write_);
void allocateMemory(unsigned int varid); void allocateMemory(unsigned int varid);
void read(unsigned int varid); void read(unsigned int varid);
void readAliases(unsigned int varid); void readAliases(unsigned int varid);
@ -158,6 +107,7 @@ private:
VariableMap _varUsage; VariableMap _varUsage;
}; };
/** /**
* Alias the 2 given variables. Either replace the existing aliases if * Alias the 2 given variables. Either replace the existing aliases if
* they exist or merge them. You would replace an existing alias when this * they exist or merge them. You would replace an existing alias when this
@ -177,11 +127,9 @@ void Variables::alias(unsigned int varid1, unsigned int varid2, bool replace)
return; return;
} }
std::set<unsigned int>::iterator i;
if (replace) { if (replace) {
// remove var1 from all aliases // remove var1 from all aliases
for (i = var1->_aliases.begin(); i != var1->_aliases.end(); ++i) { for (std::set<unsigned int>::iterator i = var1->_aliases.begin(); i != var1->_aliases.end(); ++i) {
VariableUsage *temp = find(*i); VariableUsage *temp = find(*i);
if (temp) if (temp)
@ -193,7 +141,7 @@ void Variables::alias(unsigned int varid1, unsigned int varid2, bool replace)
} }
// var1 gets all var2s aliases // var1 gets all var2s aliases
for (i = var2->_aliases.begin(); i != var2->_aliases.end(); ++i) { for (std::set<unsigned int>::iterator i = var2->_aliases.begin(); i != var2->_aliases.end(); ++i) {
if (*i != varid1) if (*i != varid1)
var1->_aliases.insert(*i); var1->_aliases.insert(*i);
} }
@ -246,7 +194,7 @@ void Variables::eraseAll(unsigned int varid)
void Variables::addVar(const Token *name, void Variables::addVar(const Token *name,
VariableType type, VariableType type,
ScopeInfo *scope, const Scope *scope,
bool write_) bool write_)
{ {
if (name->varId() > 0) if (name->varId() > 0)
@ -391,15 +339,15 @@ Variables::VariableUsage *Variables::find(unsigned int varid)
return 0; return 0;
} }
static int doAssignment(Variables &variables, const Token *tok, bool dereference, ScopeInfo *scope) static int doAssignment(Variables &variables, const Token *tok, bool dereference, const Scope *scope)
{ {
int next = 0;
// a = a + b; // a = a + b;
if (Token::Match(tok, "%var% = %var% !!;") && tok->str() == tok->strAt(2)) { if (Token::Match(tok, "%var% = %var% !!;") && tok->str() == tok->strAt(2)) {
return 2; return 2;
} }
int next = 0;
// check for aliased variable // check for aliased variable
const unsigned int varid1 = tok->varId(); const unsigned int varid1 = tok->varId();
Variables::VariableUsage *var1 = variables.find(varid1); Variables::VariableUsage *var1 = variables.find(varid1);
@ -504,13 +452,8 @@ static int doAssignment(Variables &variables, const Token *tok, bool dereference
// not in same scope as declaration // not in same scope as declaration
else { else {
std::set<ScopeInfo *>::iterator assignment;
// check for an assignment in this scope
assignment = var1->_assignments.find(scope);
// no other assignment in this scope // no other assignment in this scope
if (assignment == var1->_assignments.end()) { if (var1->_assignments.find(scope) == var1->_assignments.end()) {
// nothing to replace // nothing to replace
if (var1->_assignments.empty()) if (var1->_assignments.empty())
replace = false; replace = false;
@ -559,13 +502,8 @@ static int doAssignment(Variables &variables, const Token *tok, bool dereference
if (var1->_scope == scope) if (var1->_scope == scope)
variables.clearAliases(varid1); variables.clearAliases(varid1);
else { else {
std::set<ScopeInfo *>::iterator assignment;
// check for an assignment in this scope
assignment = var1->_assignments.find(scope);
// no other assignment in this scope // no other assignment in this scope
if (assignment == var1->_assignments.end()) { if (var1->_assignments.find(scope) == var1->_assignments.end()) {
/** /**
* @todo determine if existing aliases should be discarded * @todo determine if existing aliases should be discarded
*/ */
@ -605,408 +543,133 @@ static int doAssignment(Variables &variables, const Token *tok, bool dereference
return next; return next;
} }
static bool nextIsStandardType(const Token *tok) static bool isRecordTypeWithoutSideEffects(const Variable& var)
{ {
tok = tok->next();
if (tok->str() == "static")
tok = tok->next();
return tok->isStandardType();
}
static bool nextIsStandardTypeOrVoid(const Token *tok)
{
tok = tok->next();
if (tok->str() == "static")
tok = tok->next();
if (tok->str() == "const")
tok = tok->next();
return tok->isStandardType() || tok->str() == "void";
}
bool CheckUnusedVar::isRecordTypeWithoutSideEffects(const Token *tok)
{
const Variable * var = _tokenizer->getSymbolDatabase()->getVariableFromVarId(tok->varId());
// a type that has no side effects (no constructors and no members with constructors) // a type that has no side effects (no constructors and no members with constructors)
/** @todo false negative: check base class for side effects */ /** @todo false negative: check base class for side effects */
/** @todo false negative: check constructors for side effects */ /** @todo false negative: check constructors for side effects */
if (var && var->type() && var->type()->numConstructors == 0 && if (var.type() && var.type()->numConstructors == 0 &&
(var->type()->varlist.empty() || var->type()->needInitialization == Scope::True) && (var.type()->varlist.empty() || var.type()->needInitialization == Scope::True) &&
var->type()->derivedFrom.empty()) var.type()->derivedFrom.empty())
return true; return true;
return false; return false;
} }
static bool isPartOfClassStructUnion(const Token* tok)
{
for (; tok; tok = tok->previous()) {
if (tok->str() == "}" || tok->str() == ")")
tok = tok->link();
else if (tok->str() == "(")
return(false);
else if (tok->str() == "{") {
return(tok->strAt(-1) == "struct" || tok->strAt(-2) == "struct" || tok->strAt(-1) == "class" || tok->strAt(-2) == "class" || tok->strAt(-1) == "union" || tok->strAt(-2) == "union");
}
}
return false;
}
//--------------------------------------------------------------------------- //---------------------------------------------------------------------------
// Usage of function variables // Usage of function variables
//--------------------------------------------------------------------------- //---------------------------------------------------------------------------
void CheckUnusedVar::checkFunctionVariableUsage() void CheckUnusedVar::checkFunctionVariableUsage_iterateScopes(const Scope* const scope, Variables& variables)
{ {
if (!_settings->isEnabled("style")) if (scope->type == Scope::eClass || scope->type == Scope::eUnion || scope->type == Scope::eStruct)
return; return;
// Parse all executing scopes.. // Find declarations
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase(); for (std::list<Variable>::const_iterator i = scope->varlist.begin(); i != scope->varlist.end(); ++i) {
Variables::VariableType type = Variables::none;
std::list<Scope>::const_iterator scope; if (i->isArray() && (i->nameToken()->previous()->str() == "*" || i->nameToken()->strAt(-2) == "*"))
type = Variables::pointerArray;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) { else if (i->isArray() && i->nameToken()->previous()->str() == "&")
// only check functions type = Variables::referenceArray;
if (scope->type != Scope::eFunction) else if (i->isArray())
type = Variables::array;
else if (i->nameToken()->previous()->str() == "&")
type = Variables::reference;
else if (i->nameToken()->previous()->str() == "*" && i->nameToken()->strAt(-2) == "*")
type = Variables::pointerPointer;
else if (i->nameToken()->previous()->str() == "*" || i->nameToken()->strAt(-2) == "*")
type = Variables::pointer;
else if (i->typeEndToken()->isStandardType() || isRecordTypeWithoutSideEffects(*i) || Token::simpleMatch(i->nameToken()->tokAt(-3), "std :: string"))
type = Variables::standard;
if (type == Variables::none || isPartOfClassStructUnion(i->typeStartToken()))
continue; continue;
const Token* defValTok = i->nameToken()->next();
// First token for the current scope.. for (; defValTok; defValTok = defValTok->next()) {
const Token *const tok1 = scope->classStart; if (defValTok->str() == "[")
defValTok = defValTok->link();
// varId, usage {read, write, modified} else if (defValTok->str() == "(" || defValTok->str() == "=") {
Variables variables; variables.addVar(i->nameToken(), type, scope, true);
// scopes
ScopeInfo scopes;
ScopeInfo *info = &scopes;
unsigned int indentlevel = 0;
for (const Token *tok = tok1; tok; tok = tok->next()) {
if (tok->str() == "{") {
// replace the head node when found
if (indentlevel == 0)
scopes = ScopeInfo(tok, NULL);
// add the new scope
else
info = info->addChild(tok);
++indentlevel;
} else if (tok->str() == "}") {
--indentlevel;
info = info->parent();
if (indentlevel == 0)
break; break;
} else if (Token::Match(tok, "struct|union|class {") || } else if (defValTok->str() == ";" || defValTok->str() == "," || defValTok->str() == ")") {
Token::Match(tok, "struct|union|class %type% {|:")) { variables.addVar(i->nameToken(), type, scope, i->isStatic());
while (tok->str() != "{") break;
tok = tok->next(); }
}
if (i->isArray() && Token::Match(i->nameToken(), "%var% [ %var% ]")) // Array index variable read.
variables.read(i->nameToken()->tokAt(2)->varId());
if (Token::simpleMatch(defValTok, "= {")) {
for (const Token* tok = defValTok; tok && tok != defValTok->linkAt(1); tok = tok->next())
if (Token::Match(tok, "%var%")) // Variables used to initialize the array read.
variables.read(tok->varId());
} else if (Token::Match(defValTok, "( %var% )")) // Variables used to initialize the variable read.
variables.readAll(defValTok->next()->varId()); // ReadAll?
else if (defValTok->str() == "=") {
doAssignment(variables, i->nameToken(), false, scope);
}
}
// Check variable usage
for (const Token *tok = scope->classDef->next(); tok && tok != scope->classEnd; tok = tok->next()) {
if (tok->str() == "for" || tok->str() == "catch") {
for (std::list<Scope*>::const_iterator i = scope->nestedList.begin(); i != scope->nestedList.end(); ++i) {
if ((*i)->classDef == tok) { // Find associated scope
checkFunctionVariableUsage_iterateScopes(*i, variables); // Scan child scope
tok = (*i)->classStart->link();
break;
}
}
if (!tok)
break;
}
if (tok->str() == "{") {
for (std::list<Scope*>::const_iterator i = scope->nestedList.begin(); i != scope->nestedList.end(); ++i) {
if ((*i)->classStart == tok) { // Find associated scope
checkFunctionVariableUsage_iterateScopes(*i, variables); // Scan child scope
tok = tok->link(); tok = tok->link();
if (! tok) break;
}
}
if (!tok)
break; break;
} }
if (Token::Match(tok, "[;{}] asm ( %str% )")) { if (Token::Match(tok, "asm ( %str% )")) {
variables.clear(); variables.clear();
break; break;
} }
// standard type declaration with possible initialization if (Token::Match(tok, "%type% const| *|&| const| *| const| %var% ;|[|,|)|=|(") && tok->str() != "return" && tok->str() != "throw") { // Declaration: Skip
// int i; int j = 0; static int k; const Token* old = tok;
if (Token::Match(tok, "[;{}] static| %type% %var% ;|=") &&
!Token::Match(tok->next(), "return|throw")) {
tok = tok->next(); tok = tok->next();
while (Token::Match(tok, "const|*|&"))
const bool isStatic = tok->str() == "static";
if (isStatic)
tok = tok->next(); tok = tok->next();
tok = Token::findmatch(tok, "[,;)=(]");
if (tok->isStandardType() || isRecordTypeWithoutSideEffects(tok->next())) { if (tok && Token::Match(tok, "( %var% )")) // Simple initialization through copy ctor
variables.addVar(tok->next(), Variables::standard, info, tok = tok->next();
tok->strAt(2) == "=" || isStatic); else if (tok && Token::Match(tok, "= %var% ;")) // Simple initialization
tok = tok->next();
if (!tok)
break;
if (tok->str() == ")" && tok->link() && Token::Match(tok->link()->previous(), "if|for|while"))
tok = old;
} }
tok = tok->next();
}
// standard const type declaration
// const int i = x;
else if (Token::Match(tok, "[;{}] const %type% %var% =")) {
tok = tok->tokAt(2);
if (tok->isStandardType() || isRecordTypeWithoutSideEffects(tok->next()))
variables.addVar(tok->next(), Variables::standard, info, true);
tok = tok->next();
}
// std::string declaration with possible initialization
// std::string s; std::string s = "string";
else if (Token::Match(tok, "[;{}] static| std :: string %var% ;|=")) {
tok = tok->next();
const bool isStatic = tok->str() == "static";
if (isStatic)
tok = tok->next();
tok = tok->tokAt(3);
variables.addVar(tok, Variables::standard, info,
tok->next()->str() == "=" || isStatic);
}
// standard struct type declaration with possible initialization
// struct S s; struct S s = { 0 }; static struct S s;
else if (Token::Match(tok, "[;{}] static| struct %type% %var% ;|=") &&
(isRecordTypeWithoutSideEffects(tok->strAt(1) == "static" ? tok->tokAt(4) : tok->tokAt(3)))) {
tok = tok->next();
bool isStatic = tok->str() == "static";
if (isStatic)
tok = tok->next();
tok = tok->next();
variables.addVar(tok->next(), Variables::standard, info,
tok->strAt(2) == "=" || isStatic);
tok = tok->next();
}
// standard type declaration and initialization using constructor
// int i(0); static int j(0);
else if (Token::Match(tok, "[;{}] static| %type% %var% ( %any% ) ;") &&
nextIsStandardType(tok)) {
tok = tok->next();
if (tok->str() == "static")
tok = tok->next();
variables.addVar(tok->next(), Variables::standard, info, true);
// check if a local variable is used to initialize this variable
if (tok->tokAt(3)->varId() > 0)
variables.readAll(tok->tokAt(3)->varId());
tok = tok->tokAt(4);
}
// standard type declaration of array of with possible initialization
// int i[10]; int j[2] = { 0, 1 }; static int k[2] = { 2, 3 };
else if (Token::Match(tok, "[;{}] static| const| %type% *| %var% [ %any% ] ;|=") &&
nextIsStandardType(tok)) {
tok = tok->next();
const bool isStatic = tok->str() == "static";
if (isStatic)
tok = tok->next();
if (tok->str() == "const")
tok = tok->next();
if (tok->str() != "return" && tok->str() != "throw") {
bool isPointer = bool(tok->strAt(1) == "*");
const Token * const nametok = tok->tokAt(isPointer ? 2 : 1);
variables.addVar(nametok, isPointer ? Variables::pointerArray : Variables::array, info,
nametok->strAt(4) == "=" || isStatic);
// check for reading array size from local variable
if (nametok->tokAt(2)->varId() != 0)
variables.read(nametok->tokAt(2)->varId());
// look at initializers
if (Token::simpleMatch(nametok->tokAt(4), "= {")) {
tok = nametok->tokAt(6);
while (tok->str() != "}") {
if (Token::Match(tok, "%var%"))
variables.read(tok->varId());
tok = tok->next();
}
} else
tok = nametok->tokAt(3);
}
}
// pointer or reference declaration with possible initialization
// int * i; int * j = 0; static int * k = 0;
else if (Token::Match(tok, "[;{}] static| const| %type% *|& %var% ;|=")) {
tok = tok->next();
const bool isStatic = tok->str() == "static";
if (isStatic)
tok = tok->next();
if (tok->str() == "const")
tok = tok->next();
if (tok->strAt(1) == "::")
tok = tok->tokAt(2);
if (tok->str() != "return" && tok->str() != "throw") {
Variables::VariableType type;
if (tok->next()->str() == "*")
type = Variables::pointer;
else
type = Variables::reference;
bool written = tok->strAt(3) == "=";
variables.addVar(tok->tokAt(2), type, info, written || isStatic);
int offset = 0;
// check for assignment
if (written)
offset = doAssignment(variables, tok->tokAt(2), false, info);
tok = tok->tokAt(2 + offset);
}
}
// pointer to pointer declaration with possible initialization
// int ** i; int ** j = 0; static int ** k = 0;
else if (Token::Match(tok, "[;{}] static| const| %type% * * %var% ;|=")) {
tok = tok->next();
const bool isStatic = tok->str() == "static";
if (isStatic)
tok = tok->next();
if (tok->str() == "const")
tok = tok->next();
if (tok->str() != "return") {
bool written = tok->strAt(4) == "=";
variables.addVar(tok->tokAt(3), Variables::pointerPointer, info, written || isStatic);
int offset = 0;
// check for assignment
if (written)
offset = doAssignment(variables, tok->tokAt(3), false, info);
tok = tok->tokAt(3 + offset);
}
}
// pointer or reference of struct or union declaration with possible initialization
// struct s * i; struct s * j = 0; static struct s * k = 0;
else if (Token::Match(tok, "[;{}] static| const| struct|union %type% *|& %var% ;|=")) {
Variables::VariableType type;
tok = tok->next();
const bool isStatic = tok->str() == "static";
if (isStatic)
tok = tok->next();
if (tok->str() == "const")
tok = tok->next();
if (tok->strAt(2) == "*")
type = Variables::pointer;
else
type = Variables::reference;
const bool written = tok->strAt(4) == "=";
variables.addVar(tok->tokAt(3), type, info, written || isStatic);
int offset = 0;
// check for assignment
if (written)
offset = doAssignment(variables, tok->tokAt(3), false, info);
tok = tok->tokAt(3 + offset);
}
// pointer or reference declaration with initialization using constructor
// int * i(j); int * k(i); static int * l(i);
else if (Token::Match(tok, "[;{}] static| const| %type% &|* %var% ( %any% ) ;") &&
nextIsStandardTypeOrVoid(tok)) {
Variables::VariableType type;
tok = tok->next();
if (tok->str() == "static")
tok = tok->next();
if (tok->str() == "const")
tok = tok->next();
if (tok->next()->str() == "*")
type = Variables::pointer;
else
type = Variables::reference;
unsigned int varid = 0;
// check for aliased variable
if (Token::Match(tok->tokAt(4), "%var%"))
varid = tok->tokAt(4)->varId();
variables.addVar(tok->tokAt(2), type, info, true);
// check if a local variable is used to initialize this variable
if (varid > 0) {
Variables::VariableUsage *var = variables.find(varid);
if (type == Variables::pointer) {
variables.use(tok->tokAt(4)->varId());
if (var && (var->_type == Variables::array ||
var->_type == Variables::pointer))
var->_aliases.insert(tok->varId());
} else {
variables.readAll(tok->tokAt(4)->varId());
if (var)
var->_aliases.insert(tok->varId());
}
}
tok = tok->tokAt(5);
}
// array of pointer or reference declaration with possible initialization
// int * p[10]; int * q[10] = { 0 }; static int * * r[10] = { 0 };
else if (Token::Match(tok, "[;{}] static| const| %type% *|& %var% [ %any% ] ;|=")) {
tok = tok->next();
const bool isStatic = tok->str() == "static";
if (isStatic)
tok = tok->next();
if (tok->str() == "const")
tok = tok->next();
if (tok->str() != "return") {
variables.addVar(tok->tokAt(2),
tok->next()->str() == "*" ? Variables::pointerArray : Variables::referenceArray, info,
tok->strAt(6) == "=" || isStatic);
// check for reading array size from local variable
if (tok->tokAt(4)->varId() != 0)
variables.read(tok->tokAt(4)->varId());
tok = tok->tokAt(5);
}
}
// array of pointer or reference of struct or union declaration with possible initialization
// struct S * p[10]; struct T * q[10] = { 0 }; static struct S * r[10] = { 0 };
else if (Token::Match(tok, "[;{}] static| const| struct|union %type% *|& %var% [ %any% ] ;|=")) {
tok = tok->next();
const bool isStatic = tok->str() == "static";
if (isStatic)
tok = tok->next();
if (tok->str() == "const")
tok = tok->next();
variables.addVar(tok->tokAt(3),
tok->strAt(2) == "*" ? Variables::pointerArray : Variables::referenceArray, info,
tok->strAt(7) == "=" || isStatic);
// check for reading array size from local variable
if (tok->tokAt(5)->varId() != 0)
variables.read(tok->tokAt(5)->varId());
tok = tok->tokAt(6);
}
// Freeing memory (not considered "using" the pointer if it was also allocated in this function) // Freeing memory (not considered "using" the pointer if it was also allocated in this function)
else if (Token::Match(tok, "free|g_free|kfree|vfree ( %var% )") || if (Token::Match(tok, "free|g_free|kfree|vfree ( %var% )") ||
Token::Match(tok, "delete %var% ;") || Token::Match(tok, "delete %var% ;") ||
Token::Match(tok, "delete [ ] %var% ;")) { Token::Match(tok, "delete [ ] %var% ;")) {
unsigned int varid = 0; unsigned int varid = 0;
@ -1015,10 +678,10 @@ void CheckUnusedVar::checkFunctionVariableUsage()
tok = tok->tokAt(3); tok = tok->tokAt(3);
} else if (tok->strAt(1) == "[") { } else if (tok->strAt(1) == "[") {
varid = tok->tokAt(3)->varId(); varid = tok->tokAt(3)->varId();
tok = tok->tokAt(4); tok = tok->tokAt(3);
} else { } else {
varid = tok->next()->varId(); varid = tok->next()->varId();
tok = tok->tokAt(2); tok = tok->next();
} }
Variables::VariableUsage *var = variables.find(varid); Variables::VariableUsage *var = variables.find(varid);
@ -1060,7 +723,7 @@ void CheckUnusedVar::checkFunctionVariableUsage()
const unsigned int varid1 = tok->varId(); const unsigned int varid1 = tok->varId();
const Token *start = tok; const Token *start = tok;
tok = tok->tokAt(doAssignment(variables, tok, dereference, info)); tok = tok->tokAt(doAssignment(variables, tok, dereference, scope));
if (pre || post) if (pre || post)
variables.use(varid1); variables.use(varid1);
@ -1092,7 +755,8 @@ void CheckUnusedVar::checkFunctionVariableUsage()
// is it a user defined type? // is it a user defined type?
if (!type->isStandardType()) { if (!type->isStandardType()) {
if (!isRecordTypeWithoutSideEffects(start)) const Variable* variable = _tokenizer->getSymbolDatabase()->getVariableFromVarId(start->varId());
if (!variable || !isRecordTypeWithoutSideEffects(*variable))
allocate = false; allocate = false;
} }
} }
@ -1157,15 +821,15 @@ void CheckUnusedVar::checkFunctionVariableUsage()
else if (Token::Match(tok, ">>|& %var%")) else if (Token::Match(tok, ">>|& %var%"))
variables.use(tok->next()->varId()); // use = read + write variables.use(tok->next()->varId()); // use = read + write
else if (Token::Match(tok, "[;{}] %var% >>")) else if (Token::Match(tok, "%var% >>|&") && Token::Match(tok->previous(), "[{};:]"))
variables.use(tok->next()->varId()); // use = read + write variables.read(tok->varId());
// function parameter // function parameter
else if (Token::Match(tok, "[(,] %var% [")) else if (Token::Match(tok, "[(,] %var% ["))
variables.use(tok->next()->varId()); // use = read + write variables.use(tok->next()->varId()); // use = read + write
else if (Token::Match(tok, "[(,] %var% [,)]") && tok->previous()->str() != "*") else if (Token::Match(tok, "[(,] %var% [,)]") && tok->previous()->str() != "*") {
variables.use(tok->next()->varId()); // use = read + write variables.use(tok->next()->varId()); // use = read + write
else if (Token::Match(tok, "[(,] (") && } else if (Token::Match(tok, "[(,] (") &&
Token::Match(tok->next()->link(), ") %var% [,)]")) Token::Match(tok->next()->link(), ") %var% [,)]"))
variables.use(tok->next()->link()->next()->varId()); // use = read + write variables.use(tok->next()->link()->next()->varId()); // use = read + write
@ -1183,24 +847,24 @@ void CheckUnusedVar::checkFunctionVariableUsage()
variables.use(tok->varId()); // use = read + write variables.use(tok->varId()); // use = read + write
else if ((Token::Match(tok, "[(=&!]") || tok->isExtendedOp()) && else if ((Token::Match(tok, "[(=&!]") || tok->isExtendedOp()) &&
(Token::Match(tok->next(), "%var%") && !Token::Match(tok->next(), "true|false|new"))) (Token::Match(tok->next(), "%var%") && !Token::Match(tok->next(), "true|false|new")) && tok->strAt(2) != "=")
variables.readAll(tok->next()->varId()); variables.readAll(tok->next()->varId());
else if (Token::Match(tok, "%var%") && (tok->next()->str() == ")" || tok->next()->isExtendedOp())) else if (Token::Match(tok, "%var%") && (tok->next()->str() == ")" || tok->next()->isExtendedOp()))
variables.readAll(tok->varId()); variables.readAll(tok->varId());
else if (Token::Match(tok, "; %var% ;")) else if (Token::Match(tok, "%var% ;") && Token::Match(tok->previous(), "[;{}:]"))
variables.readAll(tok->next()->varId()); variables.readAll(tok->varId());
else if (Token::Match(tok, "++|-- %var%")) { else if (Token::Match(tok, "++|-- %var%")) {
if (tok->strAt(-1) != ";") if (!Token::Match(tok->previous(), "[;{}:]"))
variables.use(tok->next()->varId()); variables.use(tok->next()->varId());
else else
variables.modified(tok->next()->varId()); variables.modified(tok->next()->varId());
} }
else if (Token::Match(tok, "%var% ++|--")) { else if (Token::Match(tok, "%var% ++|--")) {
if (tok->strAt(-1) != ";") if (!Token::Match(tok->previous(), "[;{}:]"))
variables.use(tok->varId()); variables.use(tok->varId());
else else
variables.modified(tok->varId()); variables.modified(tok->varId());
@ -1216,10 +880,29 @@ void CheckUnusedVar::checkFunctionVariableUsage()
} }
} }
} }
}
void CheckUnusedVar::checkFunctionVariableUsage()
{
if (!_settings->isEnabled("style"))
return;
// Parse all executing scopes..
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
for (std::list<Scope>::const_iterator scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
// only check functions
if (scope->type != Scope::eFunction)
continue;
// varId, usage {read, write, modified}
Variables variables;
checkFunctionVariableUsage_iterateScopes(&*scope, variables);
// Check usage of all variables in the current scope.. // Check usage of all variables in the current scope..
Variables::VariableMap::const_iterator it; for (Variables::VariableMap::const_iterator it = variables.varUsage().begin(); it != variables.varUsage().end(); ++it) {
for (it = variables.varUsage().begin(); it != variables.varUsage().end(); ++it) {
const Variables::VariableUsage &usage = it->second; const Variables::VariableUsage &usage = it->second;
const std::string &varname = usage._name->str(); const std::string &varname = usage._name->str();
@ -1369,4 +1052,3 @@ void CheckUnusedVar::unusedStructMemberError(const Token *tok, const std::string
{ {
reportError(tok, Severity::style, "unusedStructMember", "struct or union member '" + structname + "::" + varname + "' is never used"); reportError(tok, Severity::style, "unusedStructMember", "struct or union member '" + structname + "::" + varname + "' is never used");
} }

8
lib/checkunusedvar.h
View File

@ -26,6 +26,8 @@
#include "settings.h" #include "settings.h"
class Token; class Token;
class Scope;
class Variables;
/// @addtogroup Checks /// @addtogroup Checks
/// @{ /// @{
@ -59,6 +61,8 @@ public:
} }
/** @brief %Check for unused function variables */ /** @brief %Check for unused function variables */
void checkFunctionVariableUsage_iterateScopes(const Scope* const scope, Variables& variables);
void checkVariableUsage(const Scope* const scope, const Token* start, Variables& variables);
void checkFunctionVariableUsage(); void checkFunctionVariableUsage();
/** @brief %Check that all struct members are used */ /** @brief %Check that all struct members are used */
@ -96,10 +100,6 @@ public:
"* unassigned variable\n" "* unassigned variable\n"
"* unused struct member\n"; "* unused struct member\n";
} }
private:
/** @brief check if token is a record type without side effects */
bool isRecordTypeWithoutSideEffects(const Token *tok);
}; };
/// @} /// @}
//--------------------------------------------------------------------------- //---------------------------------------------------------------------------

21
test/testunusedvar.cpp
View File

@ -83,6 +83,7 @@ private:
TEST_CASE(localvar35); // ticket #2535 TEST_CASE(localvar35); // ticket #2535
TEST_CASE(localvar36); // ticket #2805 TEST_CASE(localvar36); // ticket #2805
TEST_CASE(localvar37); // ticket #3078 TEST_CASE(localvar37); // ticket #3078
TEST_CASE(localvar38);
TEST_CASE(localvaralias1); TEST_CASE(localvaralias1);
TEST_CASE(localvaralias2); // ticket #1637 TEST_CASE(localvaralias2); // ticket #1637
TEST_CASE(localvaralias3); // ticket #1639 TEST_CASE(localvaralias3); // ticket #1639
@ -1359,6 +1360,16 @@ private:
ASSERT_EQUALS("", errout.str()); ASSERT_EQUALS("", errout.str());
} }
void localvar38() {
functionVariableUsage("std::string f() {\n"
" const char code[] = \"foo\";\n"
" const std::string s1(sizeof_(code));\n"
" const std::string s2 = sizeof_(code);\n"
" return(s1+s2);\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
void localvaralias1() { void localvaralias1() {
functionVariableUsage("void foo()\n" functionVariableUsage("void foo()\n"
"{\n" "{\n"
@ -2287,9 +2298,7 @@ private:
" } while(a--);\n" " } while(a--);\n"
"}\n"); "}\n");
TODO_ASSERT_EQUALS("[test.cpp:4]: (style) Unused variable: x\n" TODO_ASSERT_EQUALS("[test.cpp:4]: (style) Unused variable: x\n"
"[test.cpp:4]: (style) Unused variable: z\n", "[test.cpp:4]: (style) Unused variable: z\n", "", errout.str());
"", errout.str());
} }
void localvarStruct4() { void localvarStruct4() {
@ -2477,6 +2486,12 @@ private:
" for (;a;);\n" " for (;a;);\n"
"}\n"); "}\n");
ASSERT_EQUALS("", errout.str()); ASSERT_EQUALS("", errout.str());
functionVariableUsage("void foo() {\n"
" for (int i = 0; (pci = cdi_list_get(pciDevices, i)); i++)\n"
" {}\n"
"}");
ASSERT_EQUALS("", errout.str());
} }
void localvarShift1() { void localvarShift1() {