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Difference between revisions of "CDT/Archive/designs/StaticAnalysis/CheckerIdeas"
< CDT | Archive | designs | StaticAnalysis
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Line 5: | Line 5: | ||
;Unused #include | ;Unused #include | ||
− | + | #include <stdio.h> | |
int main() { return 1; } | int main() { return 1; } | ||
Line 18: | Line 18: | ||
;Result of comparison is constant | ;Result of comparison is constant | ||
− | + | (x==x) | |
(!x && x) | (!x && x) | ||
;Redundant comparison operations | ;Redundant comparison operations | ||
− | + | (!(!x)) | |
(x!=0 || 0!=x) | (x!=0 || 0!=x) | ||
;Comparison is used on "boolean" values | ;Comparison is used on "boolean" values | ||
− | + | 0<x<3 | |
!x>5 | !x>5 | ||
;Consequent re-assignment without usage (sub-case of Value is never used after assignment) | ;Consequent re-assignment without usage (sub-case of Value is never used after assignment) | ||
− | + | x=1; | |
x=2; | x=2; | ||
;Value is never used after assignment | ;Value is never used after assignment | ||
− | + | int x; | |
x=23; | x=23; | ||
return; | return; | ||
Line 47: | Line 47: | ||
:This is compiler error - catch early and have a quick fix so Ctrl-1 work like in java, I so like java quick fixes and code generation! | :This is compiler error - catch early and have a quick fix so Ctrl-1 work like in java, I so like java quick fixes and code generation! | ||
− | + | { x = 5; } | |
:Quick fix | :Quick fix | ||
− | + | { int x = 5; } | |
;Buffer over flow | ;Buffer over flow | ||
Line 115: | Line 115: | ||
:Spotting erroneous use of . where -> was intended. | :Spotting erroneous use of . where -> was intended. | ||
− | ; | + | ;Static callback functions |
:Functions whose pointer is passed around must be declared static. | :Functions whose pointer is passed around must be declared static. | ||
Revision as of 08:37, 25 November 2010
This page is collection of ideas for checker that can be implemented for C/C++ Static Analysis in CDT (Codan). Feel free to add your own ideas or links.
Checkers
- Unused #include
#include <stdio.h> int main() { return 1; }
- Malloc called without sizeof consideration
int * arr = (int *)malloc(20); // should be malloc(20*sizeof(int))
- Assigned to itself
x = x;
- Result of comparison is constant
(x==x) (!x && x)
- Redundant comparison operations
(!(!x)) (x!=0 || 0!=x)
- Comparison is used on "boolean" values
0<x<3 !x>5
- Consequent re-assignment without usage (sub-case of Value is never used after assignment)
x=1; x=2;
- Value is never used after assignment
int x; x=23; return;
- Unused local variable
- local variable is not used in function
- Undeclared variable
- This is compiler error - catch early and have a quick fix so Ctrl-1 work like in java, I so like java quick fixes and code generation!
{ x = 5; }
- Quick fix
{ int x = 5; }
- Buffer over flow
- This code is unsafe
char x[10]; char y[15]; memcpy(x,y,20);
- Also this code
char x[10]; x[11] = 'a'; b = x[11];
- Invalid value assignment to enum
enum ee { a, b }; ee dd; dd = 7;
- Reduce scope
- When a variable or a function has a greater scope than where it is used, that scope may be reduced.
- For example: a variable with file scope that is only used in one function, can be declared static with function scope.
- Or, a function that is only used in one file, may be declared with the static keyword, and its declaration removed from header files included by other files.
- Variable with same name in higher scope
int a; void foo( void ) { int a; }
- Missing "break" in "switch"
- finding missing "break" when one "case" ends and another starts, or the "switch" ends. Unless /* no break */
switch { case 1: // <- here (before next "case") case 2: /* no break */ // <- This is OK case 3: // <- here (end of "switch") }
- Missing "default" in "switch"
switch { case 1: case 2: case 3: // <- here (no default) }
- Condition always TRUE / FALSE
if( 1 > 2 ) // Always FALSE if( 1 < 2 ) // Always TRUE
- -> or .
- Spotting erroneous use of -> where . was intended.
- Spotting erroneous use of . where -> was intended.
- Static callback functions
- Functions whose pointer is passed around must be declared static.