Commit Graph

192 Commits

Author SHA1 Message Date
Paul Fultz II ba037837c9 Track lifetime across multiple returns
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.
2019-09-11 19:25:09 +02:00
Paul Fultz II 1afd56e964 Fix issue 8785: ValueFlow: Track pointer alias
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.
2019-09-03 17:16:15 +02:00
Paul Fultz II 4f76588f98 Fix issue 9275: False positive: Non-local object uses local variable (#2084) 2019-08-14 20:09:33 +02:00
Paul Fultz II b049fd9303 Improve propogation of lifetimes of function arguments
This will now warn for cases like this:

```cpp
int* f(int * x) {
    return x;
}
int * g(int x) {
    return f(&x);
}
````
2019-07-26 07:02:07 +02:00
Paul Fultz II 60b670babd Fix issue 9219: False positive, returnDanglingLifetime (#2026)
* Check for pointer deref for container methods

* Formatting
2019-07-23 21:59:05 +02:00
Paul Fultz II b0d10273ed Fix issue 3695: Handle class pointers
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;
};
```
2019-07-07 10:16:19 +02:00
Paul Fultz II e0ced1c415 Parse lambdas as functions (#1955)
* Parse lambdas as functions

* Fix issue with missing paren

* Fix error when parsing non-existent args

* Remove unused function variable
2019-07-05 12:30:42 +02:00
Paul Fultz II 66e0f06494 Fixx issue 9163: FP returnDanglingLifetime - returning std::string::find (#1912)
* Fixx issue 9163: FP returnDanglingLifetime - returning std::string::find

* Use simpleMatch
2019-06-24 18:52:17 +02:00
Paul Fultz II 8a1c0dd017 Fix FP with non-local variable referencing a non-local variable (#1864) 2019-06-02 10:21:26 +02:00
Paul Fultz II 6ae7be0f53 Fix FP with lifetime containers (#1865) 2019-06-02 10:14:48 +02:00
Daniel Marjamäki 57c6628732 Revert 'Cleaning up unsimplified templates'. This fix caused problems. 2019-05-16 21:11:04 +02:00
Daniel Marjamäki 2e7725dfa7 Fix test case, my change is reverted 2019-05-15 07:06:04 +02:00
Daniel Marjamäki d58d4273f9 Cleaning up unsimplified templates 2019-05-11 13:00:03 +02:00
Daniel Marjamäki 7efcb3cfe3 astyle formatting
[ci skip]
2019-05-05 11:41:29 +02:00
Paul Fultz II 8c03be3212 Fix issue 9077: False positive: Returning pointer to local variable (#1821)
* Avoid implicit conversion for lifetimes

* Fix issue 9077

* Add more tests

* Rename function

* Fix implicit conversion with containers

* Format

* Fix crash
2019-05-05 11:40:59 +02:00
Paul Fultz II 71bd7f68d4 Fix bug in lifetime constructors (#1816) 2019-05-01 07:52:52 +02:00
Frank Zingsheim 574b77cf1f Fixed: FP return reference to thread_local variable (#1758) 2019-03-27 12:22:53 +01:00
Paul Fultz II 774464eabb Fix issue 8996: False positive duplicateCondition
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.
2019-03-19 06:25:10 +01:00
Daniel Marjamäki 92485245ce Restore severity for 'autoVariables' 2019-03-15 15:13:11 +01:00
Daniel Marjamäki 3656f1ae4f Auto variables: Fix false negatives for normal tokens 2019-03-14 13:51:35 +01:00
Daniel Marjamäki 6eeee743d2 Auto variables: Minor cleanup 2019-03-14 06:41:11 +01:00
amai2012 7859d7d879 #3030 add another regression test 2019-02-22 21:10:05 +01:00
Paul Fultz II 507c7a4388 Improvement to lifetime tracking of addressof and derefencing
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);
}
```
2019-02-22 06:38:56 +01:00
Paul Fultz II 715714f4de Forward lifetimes in "for" loops (#1682)
* Forward lifetimes in for loops

* Format
2019-02-22 06:37:02 +01:00
Kamil Dudka 2908593cf6 checkautovariables: eliminate false positives on assignment of &ptr->item (#1667)
Even if `ptr` is a local variable, the object `ptr->item` might be not.
So taking address of `ptr->item` is definitely not unsafe in general.

This commit fixes false positives triggered by commit
1.85-249-gf42648fe2 on the following code of sssd:

https://github.com/SSSD/sssd/blob/d409df33/src/sbus/request/sbus_request.c#L359
2019-02-18 09:35:07 +01:00
Daniel Marjamäki bd7790fd8c Update copyright year 2019-02-09 07:24:06 +01:00
Paul Fultz II c176775afb Avoid infinite recursion in getLifetimeVariable (#1634)
* Fix direct recursion

* Limit depth of getLifetimeVariable
2019-01-31 10:34:41 +01:00
Paul Fultz II 165a22ed0f Lifetime: Support analysis with functions that do not return a reference (#1632)
* Initial support for function return

* Add test case

* Add support for reference parameters

* Format
2019-01-29 09:47:52 +01:00
Paul Fultz II d6aaf401df Lifetime: Follow functions that return references
This will now warn for cases like this:

```cpp
int& f(int& a) {
    return a;
}
int& hello() {
    int x = 0;
    return f(x);
}
```
2019-01-26 11:03:57 +01:00
Paul Fultz II 3975913637 Extend lifetime checking for references
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;
}
```
2019-01-23 07:29:16 +01:00
Daniel Marjamäki 8dd641b8be Use OVERRIDE in test 2019-01-12 15:45:25 +01:00
Paul Fultz II 921f6e4313 Fix issue 8883: False positive: returnDanglingLifetime with local struct or class (#1585) 2019-01-11 09:51:02 +01:00
practicalswift 0a1b3a9d6f Fix typos (#1568) 2019-01-06 17:15:57 +01:00
Paul Fultz II e4677ae640 Fix issue 8910: Regression: ValueFlow: wrong conditional tokvalue
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.
2018-12-29 09:31:21 +01:00
Paul Fultz II 45dcfad9f9 Fix issue 8899: False positive returnDanglingLifetime when returning by value
This fixes the FP from:

```cpp
#include <string>

class MyString
{
        public:
        MyString(char* source)
        {
                length = strlen( source );
                buffer = new char[length+1];
                if( buffer )
                {
                        strcpy( buffer, source );
                }
        }

        char* buffer;
        int length;
};

MyString Foo()
{
        char arr[20];
        sprintf(arr, "hello world");

        return arr;
}

void main()
{
        MyString str = Foo();

        printf(str.buffer);
}
```
2018-12-15 17:58:45 +01:00
Paul Fultz II 3e1b34dd8f Fix FPs and crashes with byDerefCopy (#1503)
* Fix FP when inserting a range into a container

* Formatting

* Fix crash
2018-12-02 14:31:31 +01:00
Daniel Marjamäki ccbaad32f9 Fix merge conflicts 2018-12-01 19:14:43 +01:00
Paul Fultz II b841b818d2 Fix 8872: Crash in LifetimeStore when there is no scope for variable
This fixes crash in:

```cpp
struct edit_line_paste_over {
    void operator()(agi::Context *c) override {
        paste_lines(c, true, [&](AssDialogue *new_line) -> AssDialogue * {
            AssDialogue *ret = paste_over(c->parent, pasteOverOptions, new_line, static_cast<AssDialogue*>(&*pos));
            return ret;
          });
    }
};
```
2018-12-01 19:11:26 +01:00
Paul Fultz II 67dd822910 Fix FP in lifetime anlaysis: Dont decay std array
This will fix FP with:

```cpp
std::array<char, 1> f() {
    std::array<char, 1> x;
    return x;
}
```
2018-12-01 19:09:19 +01:00
Paul Fultz II 229c45e7f8 Fix issue 8865: FP with dangling lifetime
This fixes:

```cpp
void f(uint32_t event, unsigned long op, const xen_ulong_t *args)
{
    struct __packed {
        uint32_t op;
        uint32_t args[6];
    } d;
    uint32_t *a = d.args;
}
```
2018-12-01 19:07:46 +01:00
Daniel Marjamäki f42648fe22 Fixed #8114 (false positive: Address of local auto-variable assigned to a function parameter.) 2018-12-01 10:11:02 +01:00
Paul Fultz II f16d9d7d90 Issue 6175: Check lifetime of a variables stored in containers and member variables
Cppcheck will now warn for all cases here:

```cpp
#include <vector>
class CCluster {};
class MyClass
{ public:
    std::vector<CCluster*> m_cluster;
    void createCluster()
    {
        CCluster cl;
        CCluster* pcl=&cl;
        m_cluster.push_back(pcl);
    }
    void createCluster2()
    {
        CCluster cl;
        m_cluster.push_back(&cl);
    }
    CCluster* Cluster()
    {
        CCluster cl;
        CCluster* pcl=&cl;
        return pcl;
    }
    CCluster* Cluster2()
    {
        CCluster cl;
        return &cl;
    }
};

```
2018-11-21 08:43:57 +01:00
Paul Fultz II 7ef119cbfc Fix FPs in lifetime checker
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;
}
```
2018-11-17 09:41:59 +01:00
Paul Fultz II d376e9f245 Track variable lifetime through function calls (#1481) 2018-11-16 06:12:28 +01:00
Paul Fultz II 54453c5802 Fix FP when copying pointer to string (#1479) 2018-11-14 06:59:25 +01:00
Paul Fultz II 0e11bb07c8 Extend lifetime analysis to pointer usage (#1477)
* 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
2018-11-12 10:08:17 +01:00
Paul Fultz II 68d6b96878 Diagnose invalid lifetimes (#1475)
* Add check for invalid lifetimes

* Fix FP with member variables

* Dont forward lifetime values in subfunction

* Update message to use out of scope
2018-11-11 16:43:54 +01:00
Daniel Marjamäki ee2dfb6604 Fixed #8058 (False positive returnAddressOfAutoVariable within lambda) 2018-11-11 07:52:38 +01:00
Paul Fultz II 1ffcc6b730 Add initial lifetime checker (#1448)
* Inital valueflow lifetime checker

* Forward values

* Add initial tests

* Fix deplicate messages

* Fix traversing nested lambdas

* Turn test case into a todo

* Skip if returning a container

* Fix FP when using references

* Add missing header

* Fix FP from broken scopes

* Fix FP with static variable

* Add test for more FPs

* Parse lambda functions

* Check for capture by value

* Add tests for using a container and lambda together

* Fix cppcheck errors

* Add test for nextAfterAstRightmostLeaf

* Add valueflow tests

* Update error message

* Check for correct lambda token

* Improve error path reporting

* Fix hang when parsing arrays that look almlost like lambdas
2018-11-10 16:40:40 +01:00
Daniel Marjamäki 66ca03fa0c Fixed #8826 (false negative: Invalid memory address freed) 2018-11-03 18:55:20 +01:00