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Refactorization: Use SymbolDatabase scope information in ValueFlow

This commit is contained in:
PKEuS 2015-02-01 12:10:20 +01:00
parent 54b6b8e571
commit a4cc4c3e3f
3 changed files with 368 additions and 360 deletions
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4
lib/tokenize.cpp
View File

@ -1638,7 +1638,7 @@ bool Tokenizer::tokenize(std::istream &code,
} }
list.createAst(); list.createAst();
ValueFlow::setValues(&list, _errorLogger, _settings); ValueFlow::setValues(&list, _symbolDatabase, _errorLogger, _settings);
} }
return true; return true;
@ -3854,7 +3854,7 @@ bool Tokenizer::simplifyTokenList2()
list.createAst(); list.createAst();
ValueFlow::setValues(&list, _errorLogger, _settings); ValueFlow::setValues(&list, _symbolDatabase, _errorLogger, _settings);
if (_settings->terminated()) if (_settings->terminated())
return false; return false;

721
lib/valueflow.cpp
View File

@ -421,231 +421,235 @@ static void valueFlowBitAnd(TokenList *tokenlist)
} }
} }
static void valueFlowBeforeCondition(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings) static void valueFlowBeforeCondition(TokenList *tokenlist, SymbolDatabase *symboldatabase, ErrorLogger *errorLogger, const Settings *settings)
{ {
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) { const std::size_t functions = symboldatabase->functionScopes.size();
unsigned int varid=0; for (std::size_t i = 0; i < functions; ++i) {
MathLib::bigint num=0; const Scope * scope = symboldatabase->functionScopes[i];
const Variable *var=0; for (Token* tok = const_cast<Token*>(scope->classStart); tok != scope->classEnd; tok = tok->next()) {
if (tok->isComparisonOp() && tok->astOperand1() && tok->astOperand2()) { unsigned int varid=0;
if (tok->astOperand1()->isName() && tok->astOperand2()->isNumber()) { MathLib::bigint num=0;
const Variable *var=0;
if (tok->isComparisonOp() && tok->astOperand1() && tok->astOperand2()) {
if (tok->astOperand1()->isName() && tok->astOperand2()->isNumber()) {
varid = tok->astOperand1()->varId();
var = tok->astOperand1()->variable();
num = MathLib::toLongNumber(tok->astOperand2()->str());
} else if (tok->astOperand1()->isNumber() && tok->astOperand2()->isName()) {
varid = tok->astOperand2()->varId();
var = tok->astOperand2()->variable();
num = MathLib::toLongNumber(tok->astOperand1()->str());
} else {
continue;
}
} else if (Token::Match(tok->previous(), "if|while ( %name% %oror%|&&|)") ||
Token::Match(tok, "%oror%|&& %name% %oror%|&&|)")) {
varid = tok->next()->varId();
var = tok->next()->variable();
num = 0;
} else if (tok->str() == "!" && tok->astOperand1() && tok->astOperand1()->isName()) {
varid = tok->astOperand1()->varId(); varid = tok->astOperand1()->varId();
var = tok->astOperand1()->variable(); var = tok->astOperand1()->variable();
num = MathLib::toLongNumber(tok->astOperand2()->str()); num = 0;
} else if (tok->astOperand1()->isNumber() && tok->astOperand2()->isName()) {
varid = tok->astOperand2()->varId();
var = tok->astOperand2()->variable();
num = MathLib::toLongNumber(tok->astOperand1()->str());
} else { } else {
continue; continue;
} }
} else if (Token::Match(tok->previous(), "if|while ( %name% %oror%|&&|)") ||
Token::Match(tok, "%oror%|&& %name% %oror%|&&|)")) {
varid = tok->next()->varId();
var = tok->next()->variable();
num = 0;
} else if (tok->str() == "!" && tok->astOperand1() && tok->astOperand1()->isName()) {
varid = tok->astOperand1()->varId();
var = tok->astOperand1()->variable();
num = 0;
} else {
continue;
}
if (varid == 0U || !var) if (varid == 0U || !var)
continue;
// bailout: global non-const variables
if (!(var->isLocal() || var->isArgument()) && !var->isConst()) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok, "global variable " + var->name());
continue;
}
// bailout: for/while-condition, variable is changed in while loop
for (const Token *tok2 = tok; tok2; tok2 = tok2->astParent()) {
if (tok2->astParent() || tok2->str() != "(" || !Token::simpleMatch(tok2->link(), ") {"))
continue; continue;
// Variable changed in 3rd for-expression // bailout: global non-const variables
if (Token::simpleMatch(tok2->previous(), "for (")) { if (!(var->isLocal() || var->isArgument()) && !var->isConst()) {
if (isVariableChanged(tok2->astOperand2()->astOperand2(), tok2->link(), varid)) {
varid = 0U;
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok, "variable " + var->name() + " used in loop");
}
}
// Variable changed in loop code
if (Token::Match(tok2->previous(), "for|while (")) {
const Token * const start = tok2->link()->next();
const Token * const end = start->link();
if (isVariableChanged(start,end,varid)) {
varid = 0U;
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok, "variable " + var->name() + " used in loop");
}
}
// if,macro => bailout
else if (Token::simpleMatch(tok2->previous(), "if (") && tok2->previous()->isExpandedMacro()) {
varid = 0U;
if (settings->debugwarnings) if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok, "variable " + var->name() + ", condition is defined in macro"); bailout(tokenlist, errorLogger, tok, "global variable " + var->name());
}
}
if (varid == 0U)
continue;
// extra logic for unsigned variables 'i>=1' => possible value can also be 0
ValueFlow::Value val(tok, num);
val.varId = varid;
if (Token::Match(tok, "<|>")) {
if (num != 0)
continue; continue;
if (!var->typeStartToken()->isUnsigned())
continue;
}
ValueFlow::Value val2;
if (num==1U && Token::Match(tok,"<=|>=")) {
if (var->typeStartToken()->isUnsigned()) {
val2 = ValueFlow::Value(tok,0);
val2.varId = varid;
}
}
for (Token *tok2 = tok->previous(); ; tok2 = tok2->previous()) {
if (!tok2) {
if (settings->debugwarnings) {
std::list<ErrorLogger::ErrorMessage::FileLocation> callstack;
callstack.push_back(ErrorLogger::ErrorMessage::FileLocation(tok,tokenlist));
ErrorLogger::ErrorMessage errmsg(callstack, Severity::debug, "iterated too far", "debugValueFlowBeforeCondition", false);
errorLogger->reportErr(errmsg);
}
break;
} }
if (tok2->varId() == varid) { // bailout: for/while-condition, variable is changed in while loop
// bailout: assignment for (const Token *tok2 = tok; tok2; tok2 = tok2->astParent()) {
if (Token::Match(tok2->previous(), "!!* %name% =")) { if (tok2->astParent() || tok2->str() != "(" || !Token::simpleMatch(tok2->link(), ") {"))
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "assignment of " + tok2->str());
break;
}
// increment/decrement
if (Token::Match(tok2->previous(), "[;{}] %name% ++|-- ;"))
val.intvalue += (tok2->strAt(1)=="++") ? -1 : 1;
else if (Token::Match(tok2->tokAt(-2), "[;{}] ++|-- %name% ;"))
val.intvalue += (tok2->strAt(-1)=="++") ? -1 : 1;
else if (Token::Match(tok2->previous(), "++|-- %name%") || Token::Match(tok2, "%name% ++|--")) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "increment/decrement of " + tok2->str());
break;
}
// bailout: variable is used in rhs in assignment to itself
if (bailoutSelfAssignment(tok2)) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "variable " + tok2->str() + " is used in rhs in assignment to itself");
break;
}
if (Token::Match(tok2->previous(), "sizeof|.")) {
const Token *prev = tok2->previous();
while (Token::Match(prev,"%name%|.") && prev->str() != "sizeof")
prev = prev->previous();
if (prev && prev->str() == "sizeof")
continue;
}
// assigned by subfunction?
bool inconclusive = false;
if (bailoutFunctionPar(tok2,val2.condition ? val2 : val, settings, &inconclusive)) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "possible assignment of " + tok2->str() + " by subfunction");
break;
}
val.inconclusive |= inconclusive;
val2.inconclusive |= inconclusive;
// skip if variable is conditionally used in ?: expression
if (const Token *parent = skipValueInConditionalExpression(tok2)) {
if (settings->debugwarnings)
bailout(tokenlist,
errorLogger,
tok2,
"no simplification of " + tok2->str() + " within " + (Token::Match(parent,"[?:]") ? "?:" : parent->str()) + " expression");
continue; continue;
}
setTokenValue(tok2, val); // Variable changed in 3rd for-expression
if (val2.condition) if (Token::simpleMatch(tok2->previous(), "for (")) {
setTokenValue(tok2,val2); if (isVariableChanged(tok2->astOperand2()->astOperand2(), tok2->link(), varid)) {
if (var && tok2 == var->nameToken()) varid = 0U;
break;
}
// skip sizeof..
if (tok2->str() == ")" && Token::Match(tok2->link()->previous(), "typeof|sizeof ("))
tok2 = tok2->link();
// goto label
if (Token::Match(tok2, "[;{}] %name% :")) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2->next(), "variable " + var->name() + " stopping on goto label");
break;
}
if (tok2->str() == "}") {
const Token *vartok = Token::findmatch(tok2->link(), "%varid%", tok2, varid);
while (Token::Match(vartok, "%name% = %num% ;") && !vartok->tokAt(2)->getValue(num))
vartok = Token::findmatch(vartok->next(), "%varid%", tok2, varid);
if (vartok) {
if (settings->debugwarnings) {
std::string errmsg = "variable ";
if (var)
errmsg += var->name() + " ";
errmsg += "stopping on }";
bailout(tokenlist, errorLogger, tok2, errmsg);
}
break;
} else {
tok2 = tok2->link();
}
} else if (tok2->str() == "{") {
// if variable is assigned in loop don't look before the loop
if (tok2->previous() &&
(Token::simpleMatch(tok2->previous(), "do") ||
(tok2->strAt(-1) == ")" && Token::Match(tok2->linkAt(-1)->previous(), "for|while (")))) {
const Token *start = tok2;
const Token *end = start->link();
if (isVariableChanged(start,end,varid)) {
if (settings->debugwarnings) if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + " is assigned in loop. so valueflow analysis bailout when start of loop is reached."); bailout(tokenlist, errorLogger, tok, "variable " + var->name() + " used in loop");
break;
} }
} }
// Global variable : stop when leaving the function scope // Variable changed in loop code
if (!var->isLocal()) { if (Token::Match(tok2->previous(), "for|while (")) {
if (!Token::Match(tok2->previous(), ")|else|do {")) const Token * const start = tok2->link()->next();
const Token * const end = start->link();
if (isVariableChanged(start,end,varid)) {
varid = 0U;
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok, "variable " + var->name() + " used in loop");
}
}
// if,macro => bailout
else if (Token::simpleMatch(tok2->previous(), "if (") && tok2->previous()->isExpandedMacro()) {
varid = 0U;
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok, "variable " + var->name() + ", condition is defined in macro");
}
}
if (varid == 0U)
continue;
// extra logic for unsigned variables 'i>=1' => possible value can also be 0
ValueFlow::Value val(tok, num);
val.varId = varid;
if (Token::Match(tok, "<|>")) {
if (num != 0)
continue;
if (!var->typeStartToken()->isUnsigned())
continue;
}
ValueFlow::Value val2;
if (num==1U && Token::Match(tok,"<=|>=")) {
if (var->typeStartToken()->isUnsigned()) {
val2 = ValueFlow::Value(tok,0);
val2.varId = varid;
}
}
for (Token *tok2 = tok->previous(); ; tok2 = tok2->previous()) {
if (!tok2 || tok2->next() == scope->classStart) {
if (settings->debugwarnings) {
std::list<ErrorLogger::ErrorMessage::FileLocation> callstack;
callstack.push_back(ErrorLogger::ErrorMessage::FileLocation(tok,tokenlist));
ErrorLogger::ErrorMessage errmsg(callstack, Severity::debug, "iterated too far", "debugValueFlowBeforeCondition", false);
errorLogger->reportErr(errmsg);
}
break;
}
if (tok2->varId() == varid) {
// bailout: assignment
if (Token::Match(tok2->previous(), "!!* %name% =")) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "assignment of " + tok2->str());
break; break;
if (Token::simpleMatch(tok2->previous(), ") {") && }
!Token::Match(tok2->linkAt(-1)->previous(), "if|for|while ("))
// increment/decrement
if (Token::Match(tok2->previous(), "[;{}] %name% ++|-- ;"))
val.intvalue += (tok2->strAt(1)=="++") ? -1 : 1;
else if (Token::Match(tok2->tokAt(-2), "[;{}] ++|-- %name% ;"))
val.intvalue += (tok2->strAt(-1)=="++") ? -1 : 1;
else if (Token::Match(tok2->previous(), "++|-- %name%") || Token::Match(tok2, "%name% ++|--")) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "increment/decrement of " + tok2->str());
break;
}
// bailout: variable is used in rhs in assignment to itself
if (bailoutSelfAssignment(tok2)) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "variable " + tok2->str() + " is used in rhs in assignment to itself");
break;
}
if (Token::Match(tok2->previous(), "sizeof|.")) {
const Token *prev = tok2->previous();
while (Token::Match(prev,"%name%|.") && prev->str() != "sizeof")
prev = prev->previous();
if (prev && prev->str() == "sizeof")
continue;
}
// assigned by subfunction?
bool inconclusive = false;
if (bailoutFunctionPar(tok2,val2.condition ? val2 : val, settings, &inconclusive)) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "possible assignment of " + tok2->str() + " by subfunction");
break;
}
val.inconclusive |= inconclusive;
val2.inconclusive |= inconclusive;
// skip if variable is conditionally used in ?: expression
if (const Token *parent = skipValueInConditionalExpression(tok2)) {
if (settings->debugwarnings)
bailout(tokenlist,
errorLogger,
tok2,
"no simplification of " + tok2->str() + " within " + (Token::Match(parent,"[?:]") ? "?:" : parent->str()) + " expression");
continue;
}
setTokenValue(tok2, val);
if (val2.condition)
setTokenValue(tok2,val2);
if (var && tok2 == var->nameToken())
break; break;
} }
} else if (tok2->str() == ";") {
const Token *parent = tok2->previous(); // skip sizeof..
while (parent && !Token::Match(parent, "return|break|continue|goto")) if (tok2->str() == ")" && Token::Match(tok2->link()->previous(), "typeof|sizeof ("))
parent = parent->astParent(); tok2 = tok2->link();
// reaching a break/continue/return
if (parent) { // goto label
if (Token::Match(tok2, "[;{}] %name% :")) {
if (settings->debugwarnings) if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + " stopping on " + parent->str()); bailout(tokenlist, errorLogger, tok2->next(), "variable " + var->name() + " stopping on goto label");
break; break;
} }
if (tok2->str() == "}") {
const Token *vartok = Token::findmatch(tok2->link(), "%varid%", tok2, varid);
while (Token::Match(vartok, "%name% = %num% ;") && !vartok->tokAt(2)->getValue(num))
vartok = Token::findmatch(vartok->next(), "%varid%", tok2, varid);
if (vartok) {
if (settings->debugwarnings) {
std::string errmsg = "variable ";
if (var)
errmsg += var->name() + " ";
errmsg += "stopping on }";
bailout(tokenlist, errorLogger, tok2, errmsg);
}
break;
} else {
tok2 = tok2->link();
}
} else if (tok2->str() == "{") {
// if variable is assigned in loop don't look before the loop
if (tok2->previous() &&
(Token::simpleMatch(tok2->previous(), "do") ||
(tok2->strAt(-1) == ")" && Token::Match(tok2->linkAt(-1)->previous(), "for|while (")))) {
const Token *start = tok2;
const Token *end = start->link();
if (isVariableChanged(start,end,varid)) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + " is assigned in loop. so valueflow analysis bailout when start of loop is reached.");
break;
}
}
// Global variable : stop when leaving the function scope
if (!var->isLocal()) {
if (!Token::Match(tok2->previous(), ")|else|do {"))
break;
if (Token::simpleMatch(tok2->previous(), ") {") &&
!Token::Match(tok2->linkAt(-1)->previous(), "if|for|while ("))
break;
}
} else if (tok2->str() == ";") {
const Token *parent = tok2->previous();
while (parent && !Token::Match(parent, "return|break|continue|goto"))
parent = parent->astParent();
// reaching a break/continue/return
if (parent) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + " stopping on " + parent->str());
break;
}
}
} }
} }
} }
@ -1010,179 +1014,185 @@ static bool valueFlowForward(Token * const startToken,
return true; return true;
} }
static void valueFlowAfterAssign(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings) static void valueFlowAfterAssign(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger *errorLogger, const Settings *settings)
{ {
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) { const std::size_t functions = symboldatabase->functionScopes.size();
// Assignment for (std::size_t i = 0; i < functions; ++i) {
if ((tok->str() != "=") || (tok->astParent())) const Scope * scope = symboldatabase->functionScopes[i];
continue; for (Token* tok = const_cast<Token*>(scope->classStart); tok != scope->classEnd; tok = tok->next()) {
// Assignment
if ((tok->str() != "=") || (tok->astParent()))
continue;
// Lhs should be a variable // Lhs should be a variable
if (!tok->astOperand1() || !tok->astOperand1()->isName()) if (!tok->astOperand1() || !tok->astOperand1()->varId())
continue; continue;
const unsigned int varid = tok->astOperand1()->varId(); const unsigned int varid = tok->astOperand1()->varId();
if (varid == 0U) const Variable *var = tok->astOperand1()->variable();
continue; if (!var || (!var->isLocal() && !var->isArgument()))
const Variable *var = tok->astOperand1()->variable(); continue;
if (!var || !var->isLocal())
continue;
const Token * const endOfVarScope = var->typeStartToken()->scope()->classEnd; const Token * const endOfVarScope = var->typeStartToken()->scope()->classEnd;
// Rhs values.. // Rhs values..
if (!tok->astOperand2() || tok->astOperand2()->values.empty()) if (!tok->astOperand2() || tok->astOperand2()->values.empty())
continue; continue;
const std::list<ValueFlow::Value>& values = tok->astOperand2()->values; const std::list<ValueFlow::Value>& values = tok->astOperand2()->values;
const bool constValue = tok->astOperand2()->isNumber(); const bool constValue = tok->astOperand2()->isNumber();
valueFlowForward(tok, endOfVarScope, var, varid, values, constValue, tokenlist, errorLogger, settings); valueFlowForward(tok, endOfVarScope, var, varid, values, constValue, tokenlist, errorLogger, settings);
}
} }
} }
static void valueFlowAfterCondition(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings) static void valueFlowAfterCondition(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger *errorLogger, const Settings *settings)
{ {
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) { const std::size_t functions = symboldatabase->functionScopes.size();
const Token *vartok, *numtok; for (std::size_t i = 0; i < functions; ++i) {
const Scope * scope = symboldatabase->functionScopes[i];
for (Token* tok = const_cast<Token*>(scope->classStart); tok != scope->classEnd; tok = tok->next()) {
const Token *vartok, *numtok;
// Comparison // Comparison
if (Token::Match(tok,"==|!=|>=|<=")) { if (Token::Match(tok, "==|!=|>=|<=")) {
if (!tok->astOperand1() || !tok->astOperand2()) if (!tok->astOperand1() || !tok->astOperand2())
continue; continue;
if (tok->astOperand1()->isNumber()) { if (tok->astOperand1()->isNumber()) {
numtok = tok->astOperand1(); numtok = tok->astOperand1();
vartok = tok->astOperand2(); vartok = tok->astOperand2();
} else { } else {
numtok = tok->astOperand2(); numtok = tok->astOperand2();
vartok = tok->astOperand1();
}
if (vartok->str() == "=" && vartok->astOperand1() && vartok->astOperand2())
vartok = vartok->astOperand1();
if (!vartok->isName() || !numtok->isNumber() || !MathLib::isInt(numtok->str()))
continue;
} else if (tok->str() == "!") {
vartok = tok->astOperand1(); vartok = tok->astOperand1();
numtok = nullptr;
if (!vartok || !vartok->isName())
continue;
} else if (tok->isName() &&
(Token::Match(tok->astParent(), "%oror%|&&") ||
Token::Match(tok->tokAt(-2), "if|while ( %var% [)=]"))) {
vartok = tok;
numtok = nullptr;
} else {
continue;
} }
if (vartok->str() == "=" && vartok->astOperand1() && vartok->astOperand2())
vartok = vartok->astOperand1(); const unsigned int varid = vartok->varId();
if (!vartok->isName() || !numtok->isNumber() || !MathLib::isInt(numtok->str())) if (varid == 0U)
continue; continue;
} else if (tok->str() == "!") { const Variable *var = vartok->variable();
vartok = tok->astOperand1(); if (!var || !(var->isLocal() || var->isArgument()))
numtok = nullptr;
if (!vartok || !vartok->isName())
continue; continue;
std::list<ValueFlow::Value> values;
values.push_back(ValueFlow::Value(tok, numtok ? MathLib::toLongNumber(numtok->str()) : 0LL));
} else if (tok->isName() && if (Token::Match(tok->astParent(), "%oror%|&&")) {
(Token::Match(tok->astParent(), "%oror%|&&") || Token *parent = const_cast<Token*>(tok->astParent());
Token::Match(tok->tokAt(-2), "if|while ( %var% [)=]"))) { const std::string &op(parent->str());
vartok = tok;
numtok = nullptr;
} else { if (parent->astOperand1() == tok &&
continue; ((op == "&&" && Token::Match(tok, "==|>=|<=|!")) ||
} (op == "||" && Token::Match(tok, "%name%|!=")))) {
bool assign = false;
const unsigned int varid = vartok->varId(); for (; !assign && parent && parent->str() == op; parent = const_cast<Token*>(parent->astParent())) {
if (varid == 0U) std::stack<Token *> tokens;
continue; tokens.push(const_cast<Token*>(parent->astOperand2()));
const Variable *var = vartok->variable(); while (!tokens.empty()) {
if (!var || !(var->isLocal() || var->isArgument())) Token *rhstok = tokens.top();
continue; tokens.pop();
std::list<ValueFlow::Value> values; if (!rhstok)
values.push_back(ValueFlow::Value(tok, numtok ? MathLib::toLongNumber(numtok->str()) : 0LL)); continue;
tokens.push(const_cast<Token*>(rhstok->astOperand1()));
if (Token::Match(tok->astParent(), "%oror%|&&")) { tokens.push(const_cast<Token*>(rhstok->astOperand2()));
Token *parent = const_cast<Token*>(tok->astParent()); if (rhstok->varId() == varid)
const std::string &op(parent->str()); setTokenValue(rhstok, values.front());
if (Token::Match(rhstok, "++|--|=") && Token::Match(rhstok->astOperand1(), "%varid%", varid)) {
if (parent->astOperand1() == tok && assign = true;
((op == "&&" && Token::Match(tok, "==|>=|<=|!")) || break;
(op == "||" && Token::Match(tok, "%name%|!=")))) { }
bool assign = false;
for (; !assign && parent && parent->str() == op; parent = const_cast<Token*>(parent->astParent())) {
std::stack<Token *> tokens;
tokens.push(const_cast<Token*>(parent->astOperand2()));
while (!tokens.empty()) {
Token *rhstok = tokens.top();
tokens.pop();
if (!rhstok)
continue;
tokens.push(const_cast<Token*>(rhstok->astOperand1()));
tokens.push(const_cast<Token*>(rhstok->astOperand2()));
if (rhstok->varId() == varid)
setTokenValue(rhstok, values.front());
if (Token::Match(rhstok, "++|--|=") && Token::Match(rhstok->astOperand1(),"%varid%",varid)) {
assign = true;
break;
} }
while (parent->astParent() && parent == parent->astParent()->astOperand2())
parent = const_cast<Token*>(parent->astParent());
} }
while (parent->astParent() && parent == parent->astParent()->astOperand2())
parent = const_cast<Token*>(parent->astParent());
} }
} }
}
const Token *top = tok->astTop(); const Token *top = tok->astTop();
if (top && Token::Match(top->previous(), "if|while (") && !top->previous()->isExpandedMacro()) { if (top && Token::Match(top->previous(), "if|while (") && !top->previous()->isExpandedMacro()) {
// does condition reassign variable? // does condition reassign variable?
if (tok != top->astOperand2() && if (tok != top->astOperand2() &&
Token::Match(top->astOperand2(), "%oror%|&&") && Token::Match(top->astOperand2(), "%oror%|&&") &&
isVariableChanged(top,top->link(),varid)) { isVariableChanged(top, top->link(), varid)) {
if (settings->debugwarnings) if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok, "assignment in condition"); bailout(tokenlist, errorLogger, tok, "assignment in condition");
continue;
}
// start token of conditional code
Token *startToken = nullptr;
// based on the comparison, should we check the if or while?
int codeblock = 0;
if (Token::Match(tok, "==|>=|<=|!"))
codeblock = 1;
else if (Token::Match(tok, "%name%|!="))
codeblock = 2;
// determine startToken based on codeblock
if (codeblock > 0) {
// if astParent is "!" we need to invert codeblock
const Token *parent = tok->astParent();
while (parent && parent->str() == "&&")
parent = parent->astParent();
if (parent && parent->str() == "!")
codeblock = (codeblock == 1) ? 2 : 1;
// convert codeblock to a startToken
if (codeblock == 1 && Token::simpleMatch(top->link(), ") {"))
startToken = top->link()->next();
else if (Token::simpleMatch(top->link()->linkAt(1), "} else {"))
startToken = top->link()->linkAt(1)->tokAt(2);
}
bool ok = true;
if (startToken)
ok = valueFlowForward(startToken->next(), startToken->link(), var, varid, values, true, tokenlist, errorLogger, settings);
// After conditional code..
if (ok && Token::simpleMatch(top->link(), ") {")) {
Token *after = top->link()->linkAt(1);
std::string unknownFunction;
if (settings->library.isScopeNoReturn(after,&unknownFunction)) {
if (settings->debugwarnings && !unknownFunction.empty())
bailout(tokenlist, errorLogger, after, "possible noreturn scope");
continue; continue;
} }
bool isreturn = (codeblock == 1 && isReturn(after)); // start token of conditional code
Token *startToken = nullptr;
if (Token::simpleMatch(after, "} else {")) { // based on the comparison, should we check the if or while?
after = after->linkAt(2); int codeblock = 0;
if (Token::simpleMatch(after->tokAt(-2), ") ; }")) { if (Token::Match(tok, "==|>=|<=|!"))
if (settings->debugwarnings) codeblock = 1;
else if (Token::Match(tok, "%name%|!="))
codeblock = 2;
// determine startToken based on codeblock
if (codeblock > 0) {
// if astParent is "!" we need to invert codeblock
const Token *parent = tok->astParent();
while (parent && parent->str() == "&&")
parent = parent->astParent();
if (parent && parent->str() == "!")
codeblock = (codeblock == 1) ? 2 : 1;
// convert codeblock to a startToken
if (codeblock == 1 && Token::simpleMatch(top->link(), ") {"))
startToken = top->link()->next();
else if (Token::simpleMatch(top->link()->linkAt(1), "} else {"))
startToken = top->link()->linkAt(1)->tokAt(2);
}
bool ok = true;
if (startToken)
ok = valueFlowForward(startToken->next(), startToken->link(), var, varid, values, true, tokenlist, errorLogger, settings);
// After conditional code..
if (ok && Token::simpleMatch(top->link(), ") {")) {
Token *after = top->link()->linkAt(1);
std::string unknownFunction;
if (settings->library.isScopeNoReturn(after, &unknownFunction)) {
if (settings->debugwarnings && !unknownFunction.empty())
bailout(tokenlist, errorLogger, after, "possible noreturn scope"); bailout(tokenlist, errorLogger, after, "possible noreturn scope");
continue; continue;
} }
isreturn |= (codeblock == 2 && isReturn(after));
}
if (!isreturn) { bool isreturn = (codeblock == 1 && isReturn(after));
// TODO: constValue could be true if there are no assignments in the conditional blocks and
// perhaps if there are no && and no || in the condition if (Token::simpleMatch(after, "} else {")) {
bool constValue = false; after = after->linkAt(2);
valueFlowForward(after->next(), top->scope()->classEnd, var, varid, values, constValue, tokenlist, errorLogger, settings); if (Token::simpleMatch(after->tokAt(-2), ") ; }")) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, after, "possible noreturn scope");
continue;
}
isreturn |= (codeblock == 2 && isReturn(after));
}
if (!isreturn) {
// TODO: constValue could be true if there are no assignments in the conditional blocks and
// perhaps if there are no && and no || in the condition
bool constValue = false;
valueFlowForward(after->next(), top->scope()->classEnd, var, varid, values, constValue, tokenlist, errorLogger, settings);
}
} }
} }
} }
@ -1512,17 +1522,14 @@ static void valueFlowForLoopSimplifyAfter(Token *fortok, unsigned int varid, con
settings); settings);
} }
static void valueFlowForLoop(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings) static void valueFlowForLoop(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger *errorLogger, const Settings *settings)
{ {
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) { for (std::list<Scope>::const_iterator scope = symboldatabase->scopeList.begin(); scope != symboldatabase->scopeList.end(); ++scope) {
if (!Token::simpleMatch(tok, "for (") || if (scope->type != Scope::eFor)
!Token::simpleMatch(tok->next()->astOperand2(), ";") ||
!Token::simpleMatch(tok->next()->astOperand2()->astOperand2(), ";"))
continue; continue;
Token * const bodyStart = tok->linkAt(1)->next(); Token* tok = const_cast<Token*>(scope->classDef);
if (!bodyStart || !bodyStart->link() || bodyStart->str() != "{") Token* const bodyStart = const_cast<Token*>(scope->classStart);
continue;
unsigned int varid(0); unsigned int varid(0);
MathLib::bigint num1(0), num2(0), numAfter(0); MathLib::bigint num1(0), num2(0), numAfter(0);
@ -1678,7 +1685,7 @@ static void valueFlowFunctionReturn(TokenList *tokenlist, ErrorLogger *errorLogg
} }
} }
void ValueFlow::setValues(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings) void ValueFlow::setValues(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger *errorLogger, const Settings *settings)
{ {
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) for (Token *tok = tokenlist->front(); tok; tok = tok->next())
tok->values.clear(); tok->values.clear();
@ -1688,9 +1695,9 @@ void ValueFlow::setValues(TokenList *tokenlist, ErrorLogger *errorLogger, const
valueFlowPointerAlias(tokenlist); valueFlowPointerAlias(tokenlist);
valueFlowFunctionReturn(tokenlist, errorLogger, settings); valueFlowFunctionReturn(tokenlist, errorLogger, settings);
valueFlowBitAnd(tokenlist); valueFlowBitAnd(tokenlist);
valueFlowForLoop(tokenlist, errorLogger, settings); valueFlowForLoop(tokenlist, symboldatabase, errorLogger, settings);
valueFlowBeforeCondition(tokenlist, errorLogger, settings); valueFlowBeforeCondition(tokenlist, symboldatabase, errorLogger, settings);
valueFlowAfterAssign(tokenlist, errorLogger, settings); valueFlowAfterAssign(tokenlist, symboldatabase, errorLogger, settings);
valueFlowAfterCondition(tokenlist, errorLogger, settings); valueFlowAfterCondition(tokenlist, symboldatabase, errorLogger, settings);
valueFlowSubFunction(tokenlist, errorLogger, settings); valueFlowSubFunction(tokenlist, errorLogger, settings);
} }

3
lib/valueflow.h
View File

@ -23,6 +23,7 @@
class Token; class Token;
class TokenList; class TokenList;
class SymbolDatabase;
class ErrorLogger; class ErrorLogger;
class Settings; class Settings;
@ -54,7 +55,7 @@ namespace ValueFlow {
bool inconclusive; bool inconclusive;
}; };
void setValues(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings); void setValues(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger *errorLogger, const Settings *settings);
} }
#endif // valueflowH #endif // valueflowH