hohn/codeql
1
0
Fork 0
mirror of https://github.com/github/codeql.git synced 2026-04-30 19:26:02 +02:00
Code Issues Packages Projects Releases Wiki Activity

[CPP-340] Create QL query for function call argument count mismatches.

Browse Source 
Update QHELP file, test and test results.
This commit is contained in:
Ziemowit Laski
2019-03-18 16:10:35 -07:00
parent 241994d1f8
commit 0c350dc504
4 changed files with 32 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
cpp/ql/src/Likely Bugs/Likely Typos/FutileParams.qhelp
View File

@@ -5,18 +5,25 @@
<overview>
<p>A function is called with arguments despite having an empty parameter list. This may indicate
that the incorrect function is being called, or that the author misunderstood the function.</p>
<p>A function is called with arguments despite having been <i>declared</i> with an empty parameter list.
In addition, we were either unable to find a <i>definition</i> of the function, or found one with
an incompatible number of parameters.</p>
<p>This may indicate that an incorrect function is being called, or that the signature (parameter list)
of the called function is not known to the author.</p>
<p>In C, a function declared with an empty parameter list <code>()</code> is considered to have an unknown
parameter list, and therefore can be called with any set of arguments. To declare a function
which takes no arguments, you must use <code>(void)</code> as the parameter list in any forward declarations.
In C++, either style of declaration indicates that the function accepts no arguments.</p>
In C++, <code>()</code> means the same as <code>(void)</code>, i.e., indicates that the function accepts no
arguments.</p>
</overview>
<recommendation>
<p>Call the function without arguments, or call a different function that expects the arguments
being passed.</p>
being passed. If possible, change the forward declaration of the <code>()</code>-function to reflect the
arguments being passed, or change the <code>()</code> to <code>(void)</code> to indicate that no arguments
shall be passed.</p>
</recommendation>
<example><sample src="FutileParams.c" />

19
cpp/ql/src/Likely Bugs/Likely Typos/FutileParams.ql
View File

@@ -12,11 +12,14 @@
import cpp
from Function f, FunctionCall fc
where fc.getTarget() = f
and f.getNumberOfParameters() = 0
and not f.isVarargs()
and fc.getNumberOfArguments() != 0
and not f instanceof BuiltInFunction
and exists(FunctionDeclarationEntry fde | fde = f.getADeclarationEntry() | not fde.isImplicit())
select fc, "This call has arguments, but $@ is not declared with any parameters.", f, f.toString()
from FunctionCall fc, Function f
where f = fc.getTarget() and not f.isVarargs()
/* There must be a mismatch between number of call arguments and number of parameters in some
* non-implicit declaration of Function f
*/
and exists ( FunctionDeclarationEntry fde | fde = f.getADeclarationEntry() | not fde.isImplicit() and fde.getNumberOfParameters() != fc.getNumberOfArguments())
/* There must be no _definition_ of Function f whose number of parameters matches number of call arguments */
and not exists ( FunctionDeclarationEntry fde | fde = f.getADeclarationEntry() | fde.isDefinition() and fde.getNumberOfParameters() = fc.getNumberOfArguments())
select fc