bba6dfb8b2
Fix issue 4744: ValueFlow: known integer result
...
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
}
```
2019-01-03 07:05:31 +01:00
2b63997c2c
Fixed #8928 (false positive: (style) Variable 'x' is assigned a value that is never used.)
2019-01-02 20:23:02 +01:00
39ceb53578
Comment out code in valueFlowArray. There was too many false positives.
2019-01-02 19:57:11 +01:00
39a96a5a16
ValueFlow: Temporarily comment out valueFlowTerminatingCondition
2019-01-02 19:42:08 +01:00
7a40b85531
Fixed #8906 (Encoding error in XML message: info attribute)
2019-01-02 18:22:12 +01:00
236c88151f
Fixed #8926 (false positive: (style) Condition 's.x<=y' is always true)
2019-01-02 18:05:55 +01:00
3b9828a132
template simplifier: fix crash on daca c++-annotations project ( #1556 )
...
Fix scope info bug on derived template class which caused a use after
free crash when deleting a template forward declaration in a different
scope.
2019-01-02 07:15:45 +01:00
19514331fb
Fixed #8907 (unknown macro not detected)
2019-01-01 19:30:13 +01:00
115be7dfc8
ValueFlow: better FwdAnalysis for complex expressions
2019-01-01 18:23:47 +01:00
be7afac875
ValueFlow: remove handling of == for complex expressions it did not work properly
2019-01-01 17:23:46 +01:00
13ffefc8b8
Valueflow: Fix right shift with more than 31 bits ( #1553 )
...
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?)
2019-01-01 14:15:50 +01:00
a73e989d1a
isConstVarExpression: Fix FPs when there is C++ cast
2019-01-01 11:34:44 +01:00
04d3672bde
Fixed #7203 (Better syntax error, handle array declaration with @)
2019-01-01 09:45:41 +01:00
c37b807613
template simplifier: also check if instantiated template is not specialized ( #1551 )
2018-12-31 21:29:53 +01:00
ac357a96f7
Fixed #7384 (confuses syntax with variable name / "variable '(' is less than zero")
2018-12-31 18:36:06 +01:00
4918a18bfb
ValueFlow: Value of expression after condition
2018-12-31 17:37:38 +01:00
9dc8faa3b6
template simplifier: fix location of forward declaration for explicit specializations ( #1550 )
2018-12-31 17:19:34 +01:00
141ce7cd63
ValueFlow: Use FwdAnalysisAllPaths in ValueFlow to track complex expressions
2018-12-31 17:05:46 +01:00
aa4f61acdf
CTU: Avoid FP in else block
2018-12-31 08:24:39 +01:00
fb6a291370
CTU: Avoid FP in code protected by &&,||,?
2018-12-31 08:16:21 +01:00
6b49a784c5
Fixed #8911 (Regression: False positive: Unassigned variable (alias))
2018-12-30 20:20:20 +01:00
91a580cbd7
CTU: more warnings
2018-12-30 18:31:37 +01:00
c8901e9bab
CTU: Find paths better
2018-12-30 16:23:25 +01:00
da91ce2016
Fixed #6183 (TemplateSimplifier: Does not handle methods) ( #1546 )
...
* Fixed #6183 (TemplateSimplifier: Does not handle methods)
* Fix function lookup.
2018-12-29 11:19:53 +01:00
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
d18f5d8709
CTU: Reuse CheckNullPointer::isPointerDeRef in the nullpointer isUnsafeUsage
2018-12-29 09:26:57 +01:00
03ed4afc70
Export interfaces from cppcheck-core.dll used from testrunner. In turn remove ctu sources from testrunner which are obsolete now.
2018-12-28 23:09:44 +01:00
128ad96b59
Add ctu sources to VS projects
2018-12-27 22:11:40 +01:00
a40fe3c67f
Fixed #7872 (ValueFlow: static_cast)
2018-12-27 21:33:01 +01:00
6fef02498c
Fixed #7263 (False negative: redundant assignment using +=)
2018-12-27 17:27:53 +01:00
271763e680
CTU: Refactoring
2018-12-25 21:11:23 +01:00
a1dca6acd5
Fix CTU nullpointer check
2018-12-25 12:04:01 +01:00
162576146e
Revert "Fixed #6183 (TemplateSimplifier: Does not handle methods) ( #1540 )"
...
This reverts commit 7875555b03
2018-12-24 20:10:00 +01:00
7875555b03
Fixed #6183 (TemplateSimplifier: Does not handle methods) ( #1540 )
2018-12-24 07:25:11 +01:00
611eb81302
Fixed checkcfg: test/cfg/std.cpp:2904:error:uninitvar:Uninitialized variable: s
2018-12-23 18:09:55 +01:00
b79619832e
Clarify warning
2018-12-23 12:42:18 +01:00
e6e3987935
snprintf/g_snprintf: do not allow uninitialized target buffer
2018-12-22 20:40:47 +01:00
48c960f56c
template simplifier: better detection of template functions ( #1539 )
...
* template simplifier: better detection of template functions
* fix comment
2018-12-22 10:05:10 +01:00
204ce795ba
Print test case name in assert
...
I sometimes find myself wondering which test cases I have broken when I fiddle with some check (since I then can try running these specific tests in the debugger, or make a small change and see if the tests pass). This PR adds the testclass and the test case names to the file and line number. I took special care to cover the case where an assert would be placed directly in the ```run()```-function, i.e., not inside a test case (from what I could see, no such case exists). If there is no need to handle this case, the code can be simplified (there wouldn't be need for the ```teardownTest()```-function for example).
The exact format for how to print the test name is very much up for discussion.
2018-12-21 13:55:24 +01:00
d528934139
template simplifier: also remove forward declarations when removing expanded templates ( #1536 )
2018-12-20 20:55:27 +01:00
19e979315f
Correct detection of Microsoft extensions in MathLib::isValidIntegerSuffix. Remove public overloaded implementation which was not used outside mathlib.cpp. ( #1531 )
2018-12-20 12:20:31 +01:00
0f4eac657d
Make script less verbose
2018-12-19 22:18:24 +01:00
c31331d085
template simplifier: fix explicit instantiation with types starting with const and ending in * and &. ( #1530 )
2018-12-19 21:59:59 +01:00
e2c433a0f8
Fixed #8914 (False positive with unary_function argument)
2018-12-19 19:43:05 +01:00
378ffed37e
Address compiler warning
2018-12-19 14:39:04 +01:00
bc34f0239d
Disable the subfunction value flow analysis. It does not work well and needs to be rewritten. There are false positives.
2018-12-18 14:36:49 +01:00
34330b51d1
Fix issue 8905: Condition 'a==0' is always false
...
This fixes the FP in:
```cpp
void f(const int a[]){ if (a == 0){} }
```
2018-12-18 08:16:43 +01:00
1cba78090c
Fix const anonymous struct. ( #1527 )
2018-12-18 08:15:12 +01:00
0f63874c62
Take back the whole program analysis for null pointers and uninitialized variables
2018-12-18 07:56:33 +01:00
643ddd4caa
Code cleanup
2018-12-17 18:54:32 +01:00
3b328f9187
CheckMemoryLeak: Cleanup the old memory leaks check
2018-12-17 18:12:50 +01:00
fe38e256cc
Fixed #7907 (FN: redundant assignment inside switchcase, overwritten by assignment outside of switch)
2018-12-17 16:10:47 +01:00
bf4e850e11
Fixed #4475 (New check: struct member is assigned a value that is not read)
2018-12-17 15:40:15 +01:00
858d9a18a7
Fixed #3857 (false negative: (style) Variable 'var' is assigned a value that is never used)
2018-12-17 15:16:47 +01:00
025881cf35
Fix issue 8829: Condition '...' is always true (int buf[42]; if(buf != NULL){})
...
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
}
```
2018-12-17 06:07:34 +01:00
9b973e652c
Issue 8830: New check: Function argument evaluates to constant value
...
Add a check for function arguments that can be constant:
```cpp
extern void bar(int);
void f(int x) {
bar((x & 0x01) >> 7); // function 'bar' is always called with a '0'-argument
}
```
2018-12-17 06:04:24 +01:00
2090866cd0
template simplifier: remove explicit instantiations after instantiation ( #1523 )
...
* template simplifier: remove explicit instantiations after instantiation
* Fix use after free crash in clang test suite.
2018-12-17 05:58:48 +01:00
357e2fbfb3
Add testcase for #8807 (False negative: Redundant variable assignments (loop))
2018-12-16 21:45:26 +01:00
c8d688607a
Fixed #8901 (Unused value: const variable initialization)
2018-12-16 19:01:05 +01:00
21eb1c5e22
FwdAnalysis: Fix false negatives for struct members
2018-12-16 18:32:34 +01:00
46a0172480
FwdAnalysis: fix FP in loop
2018-12-16 16:43:04 +01:00
3af0d73f82
Unused value: Fixed false negatives for loops
2018-12-16 11:18:37 +01:00
3262a3bebe
Add isSameExpression to valueflow analysis
...
Check for same expressions in valueflow analysis.
2018-12-16 07:35:27 +01:00
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
1bfe98447a
FwdAnalysis: Tweak possiblyAliased
2018-12-15 11:54:00 +01:00
f26549e5ab
Fixed #8896 (Tokenizer: Anonymous struct)
2018-12-15 08:42:35 +01:00
a1c275436f
Fix #8902 (Crash in TemplateSimplifier) ( #1521 )
2018-12-15 07:52:47 +01:00
37416010ef
Unused value: Fix false positive (ast, {})
2018-12-14 18:56:09 +01:00
be6782d386
Fix FP 8891: Incorrect return scope when using uniform initialization
...
This fixes the FP in:
```cpp
std::string f(const std::string& data)
{
if (data.empty())
return {};
data[0];
}
```
2018-12-14 18:31:10 +01:00
9742c1e2ae
make checkcfg: Try to fix inline suppressions
2018-12-14 13:51:03 +01:00
8464085535
UnusedVariables: Fix FP for unknown variable
2018-12-13 21:37:21 +01:00
092d434f91
UnusedVar: Fix FP for array arguments
2018-12-13 21:08:18 +01:00
1f27cd56c0
FwdAnalysis; Code cleanup, isNullOperand
2018-12-13 21:01:33 +01:00
0b4e08cac9
Use FwdAnalysis in UnusedVar. This is still work-in-progress. Merging to master branch so it can be tested.
2018-12-13 18:52:56 +01:00
0f83aff3b8
Improve trailing return type support. ( #1520 )
...
* Improve trailing return type support.
* Partial fix for #8889 (varid on function when using trailing return type)
* Handle operators in templates.
2018-12-13 06:34:10 +01:00
e0b64ec7a9
Fixed #8884 (AST: handle xs... template argument)
2018-12-12 19:00:14 +01:00
6924522475
Refactor methods for identification of numeric literals. ( #1514 )
2018-12-10 12:10:26 +01:00
a16f694254
Revert "Fix issue 8884: Regression: False positive: Variable 'f' is reassigned a value before the old one has been used ( #1513 )"
...
This reverts commit 6953dddfa6
2018-12-08 08:25:20 +01:00
6953dddfa6
Fix issue 8884: Regression: False positive: Variable 'f' is reassigned a value before the old one has been used ( #1513 )
2018-12-08 07:33:51 +01:00
a68086c959
Implement hexadecimal float conversion in MathLib::toDoubleNumber ind… ( #1506 )
...
* Implement hexadecimal float conversion in MathLib::toDoubleNumber independent of C99/C++17
* Refactor MathLib::isFloatHex and cure some false results
2018-12-06 22:16:16 +01:00
a90c56ad76
Fixed #8880 (Regression: syntax error for valid C++ template code) ( #1509 )
2018-12-06 21:47:48 +01:00
01d0199ecf
Fix testrunner
2018-12-04 19:56:22 +01:00
bd0a935d8a
Tokenizer: Improved handling of compiler extensions that use @ (see https://sourceforge.net/p/cppcheck/discussion/general/thread/8f618cb0a3 )
2018-12-04 19:33:39 +01:00
88c61e8d1e
ValueFlow: Avoid FP when lambda is used
2018-12-04 18:54:26 +01:00
f5a94ed300
ValueFlow: Fix FP when lambda is called
2018-12-04 18:46:00 +01:00
7c47283e6d
Fix testrunner
2018-12-04 17:17:07 +01:00
49413b7d4c
Tokenizer: Add simplifyAt to handle some nonstandard code with @
2018-12-04 16:52:41 +01:00
61878c5e11
Add null pointer check to fix SEGFAULT ( #1499 )
...
* Add null pointer check to fix segfault
* Add first test case to reproduce problem
2018-12-02 14:36:01 +01:00
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
ba564076db
Fixed #7907 (FN: redundant assignment inside switchcase, overwritten by assignment outside of switch)
2018-12-02 14:04:59 +01:00
8087cfed5d
Fixed #8627 (Tokenizer::setVarIdPass2: constructor parameter)
2018-12-02 09:28:05 +01:00
ccbaad32f9
Fix merge conflicts
2018-12-01 19:14:43 +01:00
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
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
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
2c803a1ead
Revert " #6514 Try to support hexadecimal floating numbers in MathLib::toDoubleNumber"
...
This reverts commit a73decf7e4
2018-12-01 19:01:51 +01:00
501f99ac5a
Revert "astyle formatting"
...
This reverts commit 9289c9a283
2018-12-01 19:01:40 +01:00
96929c53c0
Fixed #8873 (Add syntaxError when there is no RHS for +-)
2018-12-01 17:29:41 +01:00
9289c9a283
astyle formatting
2018-12-01 13:17:16 +01:00
f42648fe22
Fixed #8114 (false positive: Address of local auto-variable assigned to a function parameter.)
2018-12-01 10:11:02 +01:00
a73decf7e4
#6514 Try to support hexadecimal floating numbers in MathLib::toDoubleNumber
2018-12-01 00:50:26 +01:00
cad4e4ab20
Fix handling of `sizeof &var` ( #1498 )
...
Fixes https://trac.cppcheck.net/ticket/8870
2018-11-30 13:53:58 +01:00
3d024f3f6d
template simplifier: fix function forward declaration bug for constructor with initializer list. ( #1497 )
2018-11-29 06:24:28 +01:00
dd94bfede9
CheckStl: Improving checking of container access out of bounds
2018-11-28 19:27:28 +01:00
6493db6ca2
Try to clarify message for container access out of bounds a little more.
2018-11-28 13:58:01 +01:00
0f2f807798
Improve the container out of bounds messages. They are still not perfect.
2018-11-28 07:03:56 +01:00
13c6489571
Redundant variable assignment: Fix FN for struct members
2018-11-27 18:22:22 +01:00
5a6f9ac82a
Fix FP with strcmp and terminating conditions
2018-11-27 06:39:29 +01:00
f2660ed203
template simplifier: fix instantiated template names in forward declarations ( #1495 )
...
This now handles the revised example code in #8603 .
2018-11-27 06:17:04 +01:00
2887ee10c0
Fixed #8800 (Possible variable assignment ignored in boolean expression)
2018-11-26 14:00:03 +01:00
affd03f1d6
Minor tweak for redundantVariableAssignment
2018-11-26 11:16:50 +01:00
e20079a5d9
template simplifier: fix 3 function forward declaration bugs ( #1493 )
...
* fix support for multi token types
* fix support for const member functions
* fix duplicate template parameters sometimes being inserted
2018-11-26 06:23:12 +01:00
86f9fb778b
Fixed #8864 (compile commands: handle define with string value)
2018-11-25 15:09:23 +01:00
0160f80ffe
redundantVarAssignment: avoid FPs when loops are used
2018-11-25 10:32:30 +01:00
22f736eae2
redundant variable assignments: avoid FPs for initializations
2018-11-25 08:49:09 +01:00
2f66b31d43
redundantAssignmentInSwitch: fix false positive when there is goto
2018-11-24 21:39:01 +01:00
b7ca9bdc8d
Travis: redundantCopy is not detected at the moment
2018-11-24 12:01:10 +01:00
ec89c7b1b8
Travis: redundantCopy is not detected at the moment
2018-11-24 11:27:27 +01:00
a3921ea861
Refactor valueFlowAfterCondition
...
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.
2018-11-24 10:07:12 +01:00
866688c70a
Rewriting redundantAssignment checker
2018-11-24 10:03:54 +01:00
358f0c473d
Modify template simplifier to add forward declarations of some templa… ( #1489 )
...
* Modify template simplifier to add forward declarations of some template functions so symbol database can make sense of the expanded templates.
* Fix travis.
2018-11-23 11:36:09 +01:00
ef05be2600
wxwidgets.cfg: Fixed FP due to overlaoded function wxSizer::Add().
2018-11-23 09:49:08 +01:00
c181d28b1a
astyle formatting
...
[ci skip]
2018-11-23 06:47:27 +01:00
428d0147bc
wxwidgets.cfg: Added support for wxSizer::Add().
2018-11-22 14:04:22 +01:00
d6c85118a7
wxwidgets.cfg: Improved support for some wxStaticText member functions.
2018-11-22 13:47:17 +01:00
2b9bdc52d7
wxwidgets.cfg: Added support for wxWindow::Close() and derived classes.
2018-11-22 13:31:09 +01:00
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
081bd7660e
Fix Travis
2018-11-21 08:39:21 +01:00
b4aa04db41
std.cfg: Added returnValue calculation for isless(), islessgreater() etc.
2018-11-20 16:58:33 +01:00
58b3d75b62
std.cfg: Added invalidFunctionArg cfg for strchr().
2018-11-20 08:32:54 +01:00
a8cbbe0e16
Fixed #8816 (FP shadowLocal - variable shadows a template function?)
2018-11-19 07:00:15 +01:00
9ef3c79bc6
Fixed #8851 (Crash in valueFlowContainerForward (daca@home: pbbam))
2018-11-18 20:18:55 +01:00
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
d376e9f245
Track variable lifetime through function calls ( #1481 )
2018-11-16 06:12:28 +01:00
d880d64a9c
test: avoid a mutable comparator for test ( #1482 )
2018-11-15 16:21:12 +01:00
5d086d60ad
Fixed #8844 (snd: Wrong varid and ast)
2018-11-14 21:05:09 +01:00
69f2e0938a
VarId: Improved varids for struct members ( #8844 )
2018-11-14 19:11:35 +01:00
69f6100d83
Fixed #8339 (false positive: unread variable despite delete is used on it)
2018-11-14 17:04:21 +01:00
54453c5802
Fix FP when copying pointer to string ( #1479 )
2018-11-14 06:59:25 +01:00
f0c86b9d14
Fix issue 8842: Crash in valueFlowTerminatingCondition on incomplete code ( #1480 )
2018-11-14 06:23:45 +01:00
e6a5e0f752
Warn when there is a unknown macro
2018-11-13 16:49:15 +01:00
69e7392ce2
Fixed #8449 (False positive 'constStatement' when initializing std::unordered_map)
2018-11-12 18:10:34 +01:00
3d629944da
Fixed #8100 (False positive when method/function defines lambda with pointer return value)
2018-11-12 11:28:38 +01:00
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
58882b1f14
Fixed #8261 (False positive "Statements following return, break, continue, goto or throw will never be executed.")
2018-11-12 06:31:17 +01:00
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
3f55707b30
Fixed #8064 (Taking the address of a moved variable is not accessing it)
2018-11-11 12:47:27 +01:00
e46691597e
Fix issue 8841: FP knownConditionTrueFalse - Dont treat unknown function as noreturn ( #1474 )
...
* Fix issue 8841: Dont treat unknown function as noreturn
* Add a parameter to set default value when the function is unknown
2018-11-11 08:04:01 +01:00
ee2dfb6604
Fixed #8058 (False positive returnAddressOfAutoVariable within lambda)
2018-11-11 07:52:38 +01:00
93cde415a7
Fixed #7988 (variable in condition gets wrong varid)
2018-11-11 07:50:25 +01:00
Paul Fultz II
Daniel Marjamäki
IOBYTE
rikardfalkeborn
amai2012
orbitcowboy
amai2012
Igor
Colomban Wendling
Carlo Marcelo Arenas Belon