ba037837c9
This will now warn when doing something like this:
```cpp
template <class T, class K, class V>
const V& get_default(const T& t, const K& k, const V& v) {
auto it = t.find(k);
if (it == t.end()) return v;
return it->second;
}
const int& bar(const std::unordered_map<int, int>& m, int k) {
auto x = 0;
return get_default(m, k, x);
}
```
The lifetime warning is considered inconclusive in this case.
I also updated valueflow to no tinject inconclusive values unless `--inconclusive` flag is passed. This creates some false negatives because library functions are not configured to not modify their input parameters, and there are some checks that do not check if the value is inconclusive or not.
321 lines
11 KiB
C++
321 lines
11 KiB
C++
/*
|
|
* Cppcheck - A tool for static C/C++ code analysis
|
|
* Copyright (C) 2007-2019 Cppcheck team.
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
|
|
//---------------------------------------------------------------------------
|
|
#ifndef astutilsH
|
|
#define astutilsH
|
|
//---------------------------------------------------------------------------
|
|
|
|
#include <functional>
|
|
#include <string>
|
|
#include <vector>
|
|
|
|
#include "errorlogger.h"
|
|
#include "utils.h"
|
|
|
|
class Library;
|
|
class Settings;
|
|
class Scope;
|
|
class Token;
|
|
class Variable;
|
|
|
|
enum class ChildrenToVisit {
|
|
none,
|
|
op1,
|
|
op2,
|
|
op1_and_op2,
|
|
done // found what we looked for, don't visit any more children
|
|
};
|
|
|
|
/**
|
|
* Visit AST nodes recursively. The order is not "well defined"
|
|
*/
|
|
void visitAstNodes(const Token *ast, std::function<ChildrenToVisit(const Token *)> visitor);
|
|
|
|
std::vector<const Token*> astFlatten(const Token* tok, const char* op);
|
|
|
|
bool astHasToken(const Token* root, const Token * tok);
|
|
|
|
bool astHasVar(const Token * tok, nonneg int varid);
|
|
|
|
/** Is expression a 'signed char' if no promotion is used */
|
|
bool astIsSignedChar(const Token *tok);
|
|
/** Is expression a 'char' if no promotion is used? */
|
|
bool astIsUnknownSignChar(const Token *tok);
|
|
/** Is expression of integral type? */
|
|
bool astIsIntegral(const Token *tok, bool unknown);
|
|
/** Is expression of floating point type? */
|
|
bool astIsFloat(const Token *tok, bool unknown);
|
|
/** Is expression of boolean type? */
|
|
bool astIsBool(const Token *tok);
|
|
|
|
bool astIsPointer(const Token *tok);
|
|
|
|
bool astIsIterator(const Token *tok);
|
|
|
|
bool astIsContainer(const Token *tok);
|
|
|
|
/**
|
|
* Get canonical type of expression. const/static/etc are not included and neither *&.
|
|
* For example:
|
|
* Expression type Return
|
|
* std::string std::string
|
|
* int * int
|
|
* static const int int
|
|
* std::vector<T> std::vector
|
|
*/
|
|
std::string astCanonicalType(const Token *expr);
|
|
|
|
/** Is given syntax tree a variable comparison against value */
|
|
const Token * astIsVariableComparison(const Token *tok, const std::string &comp, const std::string &rhs, const Token **vartok=nullptr);
|
|
|
|
const Token * nextAfterAstRightmostLeaf(const Token * tok);
|
|
|
|
Token* astParentSkipParens(Token* tok);
|
|
const Token* astParentSkipParens(const Token* tok);
|
|
|
|
bool precedes(const Token * tok1, const Token * tok2);
|
|
|
|
bool isSameExpression(bool cpp, bool macro, const Token *tok1, const Token *tok2, const Library& library, bool pure, bool followVar, ErrorPath* errors=nullptr);
|
|
|
|
bool isEqualKnownValue(const Token * const tok1, const Token * const tok2);
|
|
|
|
bool isDifferentKnownValues(const Token * const tok1, const Token * const tok2);
|
|
|
|
/**
|
|
* Are two conditions opposite
|
|
* @param isNot do you want to know if cond1 is !cond2 or if cond1 and cond2 are non-overlapping. true: cond1==!cond2 false: cond1==true => cond2==false
|
|
* @param cpp c++ file
|
|
* @param cond1 condition1
|
|
* @param cond2 condition2
|
|
* @param library files data
|
|
* @param pure boolean
|
|
*/
|
|
bool isOppositeCond(bool isNot, bool cpp, const Token * const cond1, const Token * const cond2, const Library& library, bool pure, bool followVar, ErrorPath* errors=nullptr);
|
|
|
|
bool isOppositeExpression(bool cpp, const Token * const tok1, const Token * const tok2, const Library& library, bool pure, bool followVar, ErrorPath* errors=nullptr);
|
|
|
|
bool isConstExpression(const Token *tok, const Library& library, bool pure, bool cpp);
|
|
|
|
bool isWithoutSideEffects(bool cpp, const Token* tok);
|
|
|
|
bool isUniqueExpression(const Token* tok);
|
|
|
|
/** Is scope a return scope (scope will unconditionally return) */
|
|
bool isReturnScope(const Token *endToken, const Settings * settings = nullptr, bool functionScope=false);
|
|
|
|
/// Return the token to the function and the argument number
|
|
const Token * getTokenArgumentFunction(const Token * tok, int& argn);
|
|
|
|
/** Is variable changed by function call?
|
|
* In case the answer of the question is inconclusive, e.g. because the function declaration is not known
|
|
* the return value is false and the output parameter inconclusive is set to true
|
|
*
|
|
* @param tok ast tree
|
|
* @param varid Variable Id
|
|
* @param settings program settings
|
|
* @param inconclusive pointer to output variable which indicates that the answer of the question is inconclusive
|
|
*/
|
|
bool isVariableChangedByFunctionCall(const Token *tok, int indirect, nonneg int varid, const Settings *settings, bool *inconclusive);
|
|
|
|
/** Is variable changed by function call?
|
|
* In case the answer of the question is inconclusive, e.g. because the function declaration is not known
|
|
* the return value is false and the output parameter inconclusive is set to true
|
|
*
|
|
* @param tok token of variable in function call
|
|
* @param settings program settings
|
|
* @param inconclusive pointer to output variable which indicates that the answer of the question is inconclusive
|
|
*/
|
|
bool isVariableChangedByFunctionCall(const Token *tok, int indirect, const Settings *settings, bool *inconclusive);
|
|
|
|
/** Is variable changed in block of code? */
|
|
bool isVariableChanged(const Token *start, const Token *end, const nonneg int varid, bool globalvar, const Settings *settings, bool cpp, int depth = 20);
|
|
|
|
bool isVariableChanged(const Token *tok, int indirect, const Settings *settings, bool cpp, int depth = 20);
|
|
|
|
bool isVariableChanged(const Variable * var, const Settings *settings, bool cpp, int depth = 20);
|
|
|
|
const Token* findVariableChanged(const Token *start, const Token *end, int indirect, const nonneg int varid, bool globalvar, const Settings *settings, bool cpp, int depth = 20);
|
|
Token* findVariableChanged(Token *start, const Token *end, int indirect, const nonneg int varid, bool globalvar, const Settings *settings, bool cpp, int depth = 20);
|
|
|
|
/// If token is an alias if another variable
|
|
bool isAliasOf(const Token *tok, nonneg int varid);
|
|
|
|
bool isAliased(const Variable *var);
|
|
|
|
/** Determines the number of arguments - if token is a function call or macro
|
|
* @param start token which is supposed to be the function/macro name.
|
|
* \return Number of arguments
|
|
*/
|
|
int numberOfArguments(const Token *start);
|
|
|
|
/**
|
|
* Get arguments (AST)
|
|
*/
|
|
std::vector<const Token *> getArguments(const Token *ftok);
|
|
|
|
const Token *findLambdaStartToken(const Token *last);
|
|
|
|
/**
|
|
* find lambda function end token
|
|
* \param first The [ token
|
|
* \return nullptr or the }
|
|
*/
|
|
const Token *findLambdaEndToken(const Token *first);
|
|
|
|
bool isLikelyStream(bool cpp, const Token *stream);
|
|
|
|
/**
|
|
* do we see a likely write of rhs through overloaded operator
|
|
* s >> x;
|
|
* a & x;
|
|
*/
|
|
bool isLikelyStreamRead(bool cpp, const Token *op);
|
|
|
|
bool isCPPCast(const Token* tok);
|
|
|
|
bool isConstVarExpression(const Token *tok);
|
|
|
|
const Variable *getLHSVariable(const Token *tok);
|
|
|
|
bool isScopeBracket(const Token* tok);
|
|
|
|
struct PathAnalysis {
|
|
enum class Progress {
|
|
Continue,
|
|
Break
|
|
};
|
|
PathAnalysis(const Token* start, const Library& library)
|
|
: start(start), library(&library)
|
|
{}
|
|
const Token * start;
|
|
const Library * library;
|
|
|
|
struct Info {
|
|
const Token* tok;
|
|
ErrorPath errorPath;
|
|
bool known;
|
|
};
|
|
|
|
void forward(const std::function<Progress(const Info&)>& f) const;
|
|
template<class F>
|
|
void forwardAll(F f) {
|
|
forward([&](const Info& info) {
|
|
f(info);
|
|
return Progress::Continue;
|
|
});
|
|
}
|
|
template<class Predicate>
|
|
Info forwardFind(Predicate pred) {
|
|
Info result{};
|
|
forward([&](const Info& info) {
|
|
if (pred(info)) {
|
|
result = info;
|
|
return Progress::Break;
|
|
}
|
|
return Progress::Continue;
|
|
});
|
|
return result;
|
|
}
|
|
private:
|
|
|
|
Progress forwardRecursive(const Token* tok, Info info, const std::function<PathAnalysis::Progress(const Info&)>& f) const;
|
|
Progress forwardRange(const Token* startToken, const Token* endToken, Info info, const std::function<Progress(const Info&)>& f) const;
|
|
|
|
static const Scope* findOuterScope(const Scope * scope);
|
|
|
|
static std::pair<bool, bool> checkCond(const Token * tok, bool& known);
|
|
};
|
|
|
|
/**
|
|
* @brief Returns true if there is a path between the two tokens
|
|
*
|
|
* @param start Starting point of the path
|
|
* @param dest The path destination
|
|
* @param errorPath Adds the path traversal to the errorPath
|
|
*/
|
|
bool reaches(const Token * start, const Token * dest, const Library& library, ErrorPath* errorPath);
|
|
|
|
/**
|
|
* Forward data flow analysis for checks
|
|
* - unused value
|
|
* - redundant assignment
|
|
* - valueflow analysis
|
|
*/
|
|
class FwdAnalysis {
|
|
public:
|
|
FwdAnalysis(bool cpp, const Library &library) : mCpp(cpp), mLibrary(library), mWhat(What::Reassign), mValueFlowKnown(true) {}
|
|
|
|
bool hasOperand(const Token *tok, const Token *lhs) const;
|
|
|
|
/**
|
|
* Check if "expr" is reassigned. The "expr" can be a tree (x.y[12]).
|
|
* @param expr Symbolic expression to perform forward analysis for
|
|
* @param startToken First token in forward analysis
|
|
* @param endToken Last token in forward analysis
|
|
* @return Token where expr is reassigned. If it's not reassigned then nullptr is returned.
|
|
*/
|
|
const Token *reassign(const Token *expr, const Token *startToken, const Token *endToken);
|
|
|
|
/**
|
|
* Check if "expr" is used. The "expr" can be a tree (x.y[12]).
|
|
* @param expr Symbolic expression to perform forward analysis for
|
|
* @param startToken First token in forward analysis
|
|
* @param endToken Last token in forward analysis
|
|
* @return true if expr is used.
|
|
*/
|
|
bool unusedValue(const Token *expr, const Token *startToken, const Token *endToken);
|
|
|
|
struct KnownAndToken {
|
|
bool known;
|
|
const Token *token;
|
|
};
|
|
|
|
std::vector<KnownAndToken> valueFlow(const Token *expr, const Token *startToken, const Token *endToken);
|
|
|
|
/** Is there some possible alias for given expression */
|
|
bool possiblyAliased(const Token *expr, const Token *startToken) const;
|
|
|
|
static bool isNullOperand(const Token *expr);
|
|
private:
|
|
static bool isEscapedAlias(const Token* expr);
|
|
|
|
/** Result of forward analysis */
|
|
struct Result {
|
|
enum class Type { NONE, READ, WRITE, BREAK, RETURN, BAILOUT } type;
|
|
explicit Result(Type type) : type(type), token(nullptr) {}
|
|
Result(Type type, const Token *token) : type(type), token(token) {}
|
|
const Token *token;
|
|
};
|
|
|
|
struct Result check(const Token *expr, const Token *startToken, const Token *endToken);
|
|
struct Result checkRecursive(const Token *expr, const Token *startToken, const Token *endToken, const std::set<int> &exprVarIds, bool local, bool inInnerClass);
|
|
|
|
// Is expression a l-value global data?
|
|
bool isGlobalData(const Token *expr) const;
|
|
|
|
const bool mCpp;
|
|
const Library &mLibrary;
|
|
enum class What { Reassign, UnusedValue, ValueFlow } mWhat;
|
|
std::vector<KnownAndToken> mValueFlow;
|
|
bool mValueFlowKnown;
|
|
};
|
|
|
|
#endif // astutilsH
|