Commit Graph

710 Commits

Author SHA1 Message Date
Paul Fultz II 7841430793 Fix issue 9428: FP uninitvar for pointer passed to sscanf (#2344)
* Add indirect to library cfg files

* Check indirect for non null arguments

* Reenable subfunction analysis

* Use indirect 1 when using not-null

* Parse correct string name

* Update documentation

* Make attribute optional
2019-11-13 12:46:54 +01:00
Paul Fultz II c75bbbe253 Fix issue 9404: False positive: Either the condition 'if(x)' is redundant or there is possible null pointer dereference: a->x (#2322)
* Fix issue 9404: False positive: Either the condition 'if(x)' is redundant or there is possible null pointer dereference: a->x

* Use simpleMatch

* Add a test case for the FP

* Check if expression is changed

* Check for no return scope

* Use simpleMatch
2019-11-08 08:11:41 +01:00
Paul Fultz II 2e955d0f22 Fix issue 9453: False positive: danglingLifetime, address of array argument (#2335) 2019-11-07 09:33:17 +01:00
Paul Fultz II d1f225b8ee Fix issue 9201: FP: returnDanglingLifetime on pointer to variable of static struct (#2303)
* Fix issue 9201: FP: returnDanglingLifetime on pointer to variable of static struct

* Fix capture of non-local variables in lambdas
2019-11-05 07:10:32 +01:00
Paul Fultz II c38bbb75e4 Fix issue 9448: Check for temporaries from library function calls (#2312) 2019-11-03 22:02:10 +01:00
Daniel Marjamäki 6e9d496ab3 ValueFlow: handling of char literal size before ValueType has been set 2019-10-31 14:06:46 +01:00
Paul Fultz II 694d147097 Refactor ProgramMemory and PathAnalysis (#2311)
* Traverse conditions for container size

* Move program memory to seperate file

* Revert "Traverse conditions for container size"

This reverts commit 914783769f.

* Move pathanalysis to seperate files
2019-10-30 17:57:46 +01:00
Rikard Falkeborn f83eb127ae ValueFlow: sizeof string and char literals (#2285) 2019-10-20 21:02:28 +02:00
Daniel Marjamäki 78c02f0505 ValueFlow: Fixed false positives after escape scope 2019-10-20 20:57:16 +02:00
Daniel Marjamäki e50b9e2bef Fixed #8784 (False positive uninitialized variable) 2019-10-20 15:20:05 +02:00
Rikard Falkeborn 5c061c1c12 Set correct type and size of string and char literals (#2275)
* Set correct type and size of string and char literals

Use that string and char literal tokens store the prefix. This makes
it possible to distinghuish between different type of string literals
(i.e., utf8 encoded strings, utf16, wide strings, etc) which have
different type.

When the tokens holding the string and character values have the correct
type, it is possible to improve Token::getStrSize() to give the correct
result for all string types. Previously, it would return the number of
characters in the string, i.e., it would give the wrong size unless
the type of the string was char*.

Since strings now can have different size (in number of bytes) and
length (in number of elements), add a new helper function that returns
the number of characters. Checkers have been updated to use the correct
functions.

Having the size makes it possible to find more problems with prefixed
strings, and to reduce false positives, for example in the buffer
overflow checker.

Also, improve the stringLiteralWrite error message to also print the
prefix of the string (if there is one).

* Add comment and update string length
2019-10-20 07:11:57 +02:00
Daniel Marjamäki 9a2b71494f ValueFlow: Set value for :: 2019-10-19 21:08:59 +02:00
Daniel Marjamäki e0093c99ce Fixed #9276 (False positive: ValueFlow does not handle return in switch properly.) 2019-10-18 16:16:56 +02:00
Daniel Marjamäki 3a0a0fdefb Fixed #9424 (False positive: known condition after function call) 2019-10-18 08:21:07 +02:00
Daniel Marjamäki 15d7b9c83f Fixed #9347 (FP uninitvar for pointer passed to sscanf) 2019-10-17 17:41:54 +02:00
Ken-Patrick Lehrmann 24211cf8b9 Fix crashes in valueflow (#2236)
* Fix crashes in valueflow

http://cppcheck1.osuosl.org:8000/crash.html

For instance in http://cppcheck1.osuosl.org:8000/styx
```
==19651==ERROR: AddressSanitizer: SEGV on unknown address 0x00000000001c (pc 0x556f21abc3df bp 0x7ffc140d2720 sp 0x7ffc140d2710 T0)
==19651==The signal is caused by a READ memory access.
==19651==Hint: address points to the zero page.
    #0 0x556f21abc3de in Variable::isGlobal() const ../lib/symboldatabase.h:342
    #1 0x556f221f801a in valueFlowForwardVariable ../lib/valueflow.cpp:2471
    #2 0x556f22208130 in valueFlowForward ../lib/valueflow.cpp:3204
    #3 0x556f221e9e14 in valueFlowReverse ../lib/valueflow.cpp:1892
    #4 0x556f221f1a43 in valueFlowBeforeCondition ../lib/valueflow.cpp:2200
    #5 0x556f2223dbb5 in ValueFlow::setValues(TokenList*, SymbolDatabase*, ErrorLogger*, Settings const*) ../lib/valueflow.cpp:6521
    #6 0x556f220e5991 in Tokenizer::simplifyTokens1(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) ../lib/tokenize.cpp:2342
    #7 0x556f21d8d066 in CppCheck::checkFile(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::istream&) ../lib/cppcheck.cpp:508
    #8 0x556f21d84cd3 in CppCheck::check(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) ../lib/cppcheck.cpp:192
    #9 0x556f21a28796 in CppCheckExecutor::check_internal(CppCheck&, int, char const* const*) ../cli/cppcheckexecutor.cpp:884
    #10 0x556f21a24be8 in CppCheckExecutor::check(int, char const* const*) ../cli/cppcheckexecutor.cpp:198
    #11 0x556f22313063 in main ../cli/main.cpp:95
```

* Add test case for crash in valueflow
2019-10-16 20:54:07 +02:00
Paul Fultz II 19cf636a4a Move necessary code into valuetype (#2265)
* Fix parsing of smart pointers

* Improve deduction of return type

* Valuetype computation for decayed pointers
2019-10-12 11:40:02 +02:00
Paul Fultz II 4eb4762d95 Extend lifetime checking to temporaries (#2242)
* Use lifetimes to check for returning reference to temporaries

* Check for dangling temporaries

* Check for unknown types for returining by reference

* Remove old returnTemporary check

* Format

* Check for deref op

* Ternary operator return an lvalue reference

* Warn when returning temporaries from member functions

* Improve handling of pointer to function

* Extend lifetimes of const references
2019-10-08 09:28:39 +02:00
Daniel Marjamäki 954e98cc03 astyle formatting
[ci skip]
2019-10-05 16:32:43 +02:00
Paul Fultz II cf1c766292 Fix issue 9317: False positive returnDanglingLifetime when using reference to constant inside if statement (#2241) 2019-10-05 16:32:20 +02:00
Paul Fultz II 997803869d Forward values after assignment in valueFlowReverse (#2226)
* Forward values after assignment in valueFlowReverse

* Rename variables

* Format
2019-10-03 09:58:57 +02:00
orbitcowboy f05e21efa8 Formatted the code, there are no functional changes [ci skip]. 2019-10-01 08:39:08 +02:00
Paul Fultz II 166bd2bafc Fix issue 2153: valueFlowAfterCondition: struct member (#2228)
* Fix issue 2153: valueFlowAfterCondition: struct member

* Fix null pointer dereference

* Formatting

* Check for another null pointer

* Initialize variables

* Remove redundant condition

* Format

* Add missing initialization to copy constructor

* Format
2019-09-30 21:04:43 +02:00
Armin Müller b4af8bdc2e Typos found by running "codespell" (#2227) 2019-09-29 21:23:19 +02:00
Daniel Marjamäki 2dc477571c Fix gcc compiler warnings 2019-09-28 20:50:56 +02:00
Oliver Stöneberg 1fa4df419a avoid some unnecessary copies in emplace_back() calls (#2194) 2019-09-28 20:22:46 +02:00
Daniel Marjamäki b55c587ab2 astyle formatting
[ci skip]
2019-09-26 10:32:49 +02:00
Paul Fultz II 597d0fa35b Support expression in valueFlowAfterCondition (#2219)
* Add valueFlowForwardExpression function to forward values of an expression

* Use token for expression

* Fix name in bailout message

* Handle expressions

* Add more tests for more expressions

* Add more tests

* Solve the expression if possible

* Formatting
2019-09-26 10:32:25 +02:00
Paul Fultz II 0df4876059 Fix issue 9367: FP knownConditionTrueFalse (#2209) 2019-09-24 08:15:03 +02:00
Paul Fultz II 1616282f6b Use fixed number of iterations for valueflow loop (#2205) 2019-09-23 19:35:39 +02:00
Paul Fultz II a903aa7070 Fix issue 9351: false negative: (style) Condition '...' is always true (#2201) 2019-09-23 08:49:04 +02:00
Paul Fultz II c1961cec1c Fix issue 9362: FP: (style) Condition '(v&1)==0' is always false (#2200) 2019-09-21 19:53:54 +02:00
Paul Fultz II 40f1635c35 Fix issue 9361: false positive: (style) Condition 'isdigit(c)!=0' is always true (#2199) 2019-09-21 08:19:54 +02:00
Paul Fultz II ad8abdb0c3 Add impossible values to ValueFlow (#2186)
* Add impossible category

* Replace values

* Try to adjust known values

* Add ! for impossible values

* Add impossible with possible values

* Remove contradictions

* Add values when the branch is not dead

* Only copy possible values

* Dont bail on while loops

* Load std lib in valueflow

* Check for function calls

* Fix stl errors

* Fix incorrect impossible check

* Fix heap-after-use error

* Remove impossible values when they are lowered

* Show the bound and remove overlaps

* Infer conditions

* Dont push pointer values through dynamic_cast

* Add test for dynamic_cast issue

* Add shifttoomanybits test

* Add test for div by zero

* Add a test for issue 9315

* Dont make impossible value inconclusive

* Fix FP with shift operator

* Improve handleKnownValuesInLoop for impossible values

* Fix cppcheck warning

* Fix impossible values for ctu

* Bailout for streams

* Check equality conditions

* Fix overflows

* Add regression test for 9332

* Remove duplicate conditions

* Skip impossible values for invalid value

* Check for null

* Rename bound to range

* Formatting
2019-09-20 15:06:37 +02:00
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
warmsocks a56bc006b7 Fixed a typo in lib/checkother.cpp. Corrected spelling errors found by codespell. (#2170) 2019-09-11 19:21:38 +02:00
Daniel Marjamäki bee30b0ca2 astyle formatting
[ci skip]
2019-09-10 19:42:17 +02:00
Paul Fultz II dc0b3527ad Fix issue 9311: False positive duplicateCondition "same if condition" with pointer inside array of struct (#2166)
* Check for typeOf through an array

* Handle array constructors

* Format

* Fix compile error on gcc 4.8
2019-09-10 19:41:35 +02:00
Paul Fultz II ddb1f1b5ce Try to fix issue 9341: daca crash: isContainerSizeChangedByFunction (#2168) 2019-09-10 19:39:44 +02:00
Paul Fultz II 27ebff7ae4 Add deeper analysis of when a function changes a containers size (#2149)
* Add deeper analysis of when a function changes a containers size

* Fix issues

* Track addressOf
2019-09-06 21:18:45 +02:00
Paul Fultz II 9e140831eb Fix issue 9329: FP knownConditionTrueFalse - vector modified by function calls (#2145) 2019-09-05 16:42:26 +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 dc201d110d Fix issue 9274: false negative: (error) Buffer is accessed out of bounds (std::string, std::wstring) 2019-09-03 06:43:54 +02:00
Paul Fultz II cb509f1a8b Fix issue 4845: alias to vector element invalid after vector is changed (#2113)
* 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
2019-09-02 06:58:09 +02:00
Paul Fultz II 121093658d Fix issue 9202: False positive: std::array, size is a constant (#2132) 2019-09-01 09:44:34 +02:00
Daniel Marjamäki 1a25d3f9ec astyle formatting
[ci skip]
2019-08-30 18:34:14 +02:00
Paul Fultz II 0b9e823fc8 Fix issue 9305: False positive uninitvar - struct initialized via function (#2123) 2019-08-30 18:32:45 +02:00
Paul Fultz II 2942be53f7 Add more tests for valueFlowUninit (#2124) 2019-08-30 08:41:17 +02:00
Paul Fultz II 03fe6795bf Fix issue 9302: FP uninitvar - struct accessed via pointer (#2121) 2019-08-29 08:38:50 +02:00
Daniel Marjamäki a47633c4b9 Added TODO comment 2019-08-26 06:56:29 +02:00