This fixes the issue by making `ProgramMemory` keep track of values based on the conditions.
It also removes the `deadpointer` check since it duplicates the `invalidLifetime` check.
* Try harder to track ref lifetimes
* Dont add lifetimes for references
* Use correct token
* Check for front and back as well
* Improve handling of addresses
* Formatting
* Fix FP
This fixes the FP in cases like this:
```cpp
void f() {
bool b;
bool * x = &b;
if (x != nullptr)
x = 1;
}
```
It tracks the indirection of the uninit value in valueflow.
This will diagnose more issues such as:
```cpp
void f(std::vector<int> &v) {
auto v0 = v.begin();
v.push_back(123);
std::cout << *v0 << std::endl;
}
```
This switches to use lifetime analysis to check for assigning to non-local variables:
```cpp
class test
{
public:
void f()
{
int x;
this->ptr = &x;
}
protected:
int *ptr;
};
```
* Allow to configure realloc like functions
* memleakonrealloc: Bring back tests.
The old memleak checker was removed, and the tests for it was removed in
commit 9765a2dfab. This also removed the
tests for memleakOnRealloc. Bring back those tests, somewhat modified
since the checker no longer checks for memory leaks.
* Add realloc to mem leak check
* Add tests of realloc buffer size
* Configure realloc functions
* Add test of freopen
* Allow to configure which element is realloc argument
* Fix wrong close in test
cppcheck now warns for this
* Update manual
* Update docs
* Rename alloc/dalloc/realloc functions
Naming the member function realloc caused problems on appveyor. Rename
the alloc and dealloc functions as well for consistency.
* Change comparisson order
* Remove variable and use function call directly
* Create temporary variable to simplify
* Throw mismatchError on mismatching allocation/reallocation
* Refactor to separate function
* Fix potential nullptr dereference
As pointed out by cppcheck.
* Update symbol database such that the override keyword implies that the function is also virtual
* Add test case for implicit override
* change isVirtual to hasVirtualSpecifier
* fix method documentation for getVirtualFunctionCalls and getFirstVirtualFunctionCallStack
* Fix isImplicitlyVirtual to consider the override keyword and document logic
* Fix getFirstVirtualFunctionCallStack and getVirtualFunctionCalls to use isImplicitlyVirtual instead of isVirtual so new test case passes
Building with enhanced clang warnings indicated a large number of
instances with the warning:
`warning: zero as null pointer constant`
Recommended practice in C++11 is to use `nullptr` as value for
a NULL or empty pointer value. All instances where this warning
was encountered were corrected in this commit.
Where warning was encountered in dependency code (i.e. external library)
no chnages were made. Patching will be offered upstream.
strdup() allocates the string length plus one for a terminating null
character. Add one to compensate for this.
Fixes false positive buffer out of bounds on code like this:
void f() {
const char *a = "abcd";
char * b = strdup(a);
printf("%c", b[4]); // prints the terminating null character
free(b);
}
Also, add a testcase for valueFlowDynamicBufferSize() and add tests for
strdup(), malloc() and calloc().
* Add non const version of some methods of Token
The aim is to reduce the (ab)use of const_cast.
* Cleanup some more const_cast in valueflow
* Remove useless const_cast
* Remove some const_cast from templatesimplifier
* Remove some const_cast from valueflow
With the following code
int f(int x, int y) {
if (!!(x != 0)) {
return y/x;
}
cppcheck would wrongly warn that there might be a division by zero in
"return y/x;".
* build: remove -Wabi and add -Wundef
gcc >= 8 throws a warning about -Wabi (without a specific ABI version)
being ignored, while -Wundef seems more useful (as shown by the change
in config.h, which was probably an unfortunate typo)
travis.yaml should probably be updated soon, but was left out from this
change as the current images don't yet need it
* lib: unused function in valueflow
refactored out since 8c03be3212
lib/valueflow.cpp:3124:21: warning: unused function 'endTemplateArgument' [-Wunused-function]
* readme: include picojson
* make: also clean exe
This will warn for cases where searching in an associative container happens before insertion, like this:
```cpp
void f1(std::set<unsigned>& s, unsigned x) {
if (s.find(x) == s.end()) {
s.insert(x);
}
}
void f2(std::map<unsigned, unsigned>& m, unsigned x) {
if (m.find(x) == m.end()) {
m.emplace(x, 1);
} else {
m[x] = 1;
}
}
```
In the case of the map it could be written as `m[x] = 1` as it will create the key if it doesnt exist, so the extra search is not necessary.
I have this marked as `performance` as it is mostly concerning performance, but there could be a copy-paste error possibly, although I dont think thats common.
This fixes issue 8996 by improving the alias checking by using lifetime analysis. It also extends the lifetime checker to handle constructors and initializer lists for containers and arrays.
This uses the lifetime analysis to check when comparing pointer that point to different objects:
```cpp
int main(void)
{
int foo[10];
int bar[10];
int diff;
if(foo > bar) // Undefined Behavior
{
diff = 1;
}
return 0;
}
```
This will now warn for cases like this:
```cpp
auto& f() {
std::vector<int> x;
return x[0];
}
```
It also improves the handling of address of operator, so it can now warn across some function calls, like this:
```cpp
int& f(int& a) {
return a;
}
int* hello() {
int x = 0;
return &f(x);
}
```
This will use the lifetime checker for dangling references. It will find these cases for indirectly assigned reference:
```cpp
int &foo()
{
int s = 0;
int& x = s;
return x;
}
```
This will also fix issue 510 as well:
```cpp
int &f( int k )
{
static int &r = k;
return r;
}
```
This fixes valueflow to have a value for `||` operator here:
```cpp
bool f()
{
bool a = (4 == 3); // <-- 0
bool b = (3 == 3); // <-- 1
return a || b; // <-- 1
}
```
When comparing if the shift is large enough to make the result zero, use
an unsigned long long to make sure the result fits. Also, a check that
avoids setting the value if the shift is equal to or larger than the
number of bits in the operand (this is undefined behaviour). Finally,
add a check to make sure the calculated value is not too large to store.
Add test cases to cover this.
This was detected by an MSVC warning.
valueflow.cpp(1350): warning C4334: '<<' : result of 32-bit shift implicitly
converted to 64 bits (was 64-bit shift intended?)
* valueflow: remove unused variable known
since e4677ae640 will trigger :
lib/valueflow.cpp:506:20: warning: unused variable 'known' [-Wunused-variable]
const bool known = (parent->astOperand1()->hasKnownValue() ||
* templatesimplifier: cleanup
since 48c960f56c showing:
lib/templatesimplifier.h:279:16: warning: private field 'mTokenizer' is not used
[-Wunused-private-field]
Tokenizer *mTokenizer;
This fixes issue in:
```cpp
void f()
{
char stack[512];
RGNDATA *data;
if (data_size > sizeof (stack))
data = malloc (data_size);
else
data = (RGNDATA *)stack;
if ((char *)data != stack)
free (data); // <- data is not stack
}
```
It seems the `ProgramMemory` can't handle two known values(such as int and tok) together. So instead `ValueFlowAfterAssign` runs `ValueFlowForward` with tok values and then runs it with the other values.
This makes arrays non-null in valueflow, so it can catch comparisons against null that is always true:
```cpp
void f(void) {
int buf[42];
if( buf != 0) {;} // << always true
}
```
So this unifies the `valueFlowAfterCondition` so it re-uses more code between checking for integers and container sizes. This should make valueFlowContainer more robust.
It also extends valueflow to support container comparisons such as `if (v.size() < 3)` or `if (v.size() > 3)` using the same mechanism that is used for integers.
This fixes several FPs in the lifetime checker. It also fixes issue [8846](https://trac.cppcheck.net/ticket/8846):
```cpp
int * f(int a[])
{
return a;
}
```
* Use lifetime analysis for pointers as well
* Fix issue 1143: Pointer to local array
* Update message when using pointers
* Avoid infinite loop in tracing lifetimes