<div dir="ltr"><div>Hi Artem,</div><div><br></div><div>It seems I was wrong, the situation is not so simple as I thought initially.</div><div><br></div><div>First of all, here the checkPreCall() call, it checks a call against CloseHandle and outputs result along with passed function information:</div><div><br></div><div>void HandleChecker::checkPreCall(</div><div><span style="white-space:pre"> </span>const CallEvent &Call,</div><div><span style="white-space:pre"> </span>CheckerContext &C) const</div><div>{</div><div><span style="white-space:pre"> </span>if (Call.isCalled(_closeHandleFn))</div><div><span style="white-space:pre"> </span>fprintf(stderr, "It's CloseHandle: ");</div><div><span style="white-space:pre"> </span>else</div><div><span style="white-space:pre"> </span>fprintf(stderr, "It's NOT CloseHandle: ");</div><div><span style="white-space:pre"> </span>Call.dump();</div><div>}</div><div><br></div><div>The first sample uses usual CloseHandle call, without function pointer:</div><div>CloseHandle(NULL);</div><div><br></div><div>So it works.</div><div><br></div><div>My original code that didn't work has used template class. The simplified code:</div><div><br></div><div>typedef BOOL (WINAPI *P_CloseHandle)(HANDLE);</div><div><br></div><div>template <P_CloseHandle pCloseHandle> struct AutoCloseHandle</div><div>{</div><div> AutoCloseHandle(HANDLE h) : _h(h) {}</div><div> ~AutoCloseHandle() { pCloseHandle(_h); };</div><div> HANDLE _h;</div><div>};</div><div><br></div><div>int main()</div><div>{</div><div> AutoCloseHandle<&CloseHandle> autoCloseHandle(NULL);</div><div> return 1;</div><div>}</div><div><br></div><div>The output:</div><div><br></div><div>It's NOT CloseHandle: &CloseHandle(this->_h)</div><div>It's NOT CloseHandle: 0</div><div>It's NOT CloseHandle: Call to ~AutoCloseHandle<&CloseHandle>() noexcept {</div><div> &CloseHandle(this->_h);</div><div>}</div><div>It's NOT CloseHandle: &CloseHandle(this->_h)</div><div><br></div><div>> Could you see if you can get Call.getOriginExpr()->dump() and/or Call.getDecl()->dump()? These should be more informative.</div><div><br></div><div>Sure, I've added it. Call.getDecl() is NULL for that call. Call.getOriginExpr() is the following:</div><div><br></div><div>CallExpr 0x64ecb10 'BOOL':'int'</div><div>|-SubstNonTypeTemplateParmExpr 0x64ecac0 'BOOL (*)(HANDLE) __attribute__((stdcall))'</div><div>| `-UnaryOperator 0x64ecaa8 'BOOL (*)(HANDLE) __attribute__((stdcall))' prefix '&' cannot overflow</div><div>| `-DeclRefExpr 0x64eca90 'BOOL (HANDLE) __attribute__((stdcall))':'BOOL (HANDLE) __attribute__((stdcall))' lvalue Function 0x57b8890 'CloseHandle' 'BOOL (HANDLE) __attribute__((stdcall))':'BOOL (HANDLE) __attribute__((stdcall))'</div><div>`-ImplicitCastExpr 0x64ecb30 'HANDLE':'void *' <LValueToRValue></div><div> `-MemberExpr 0x64ecae8 'HANDLE':'void *' lvalue ->_h 0x64dc710</div><div> `-CXXThisExpr 0x64ecad8 'struct AutoCloseHandle<&CloseHandle> *' this</div><div><br></div><div>Call.dump()'s result:</div><div><br></div><div>&CloseHandle(this->_h)</div><div><br></div><div>Thank you!</div></div><div class="gmail_extra"><br><div class="gmail_quote">2018-05-02 23:32 GMT+03:00 Artem Dergachev <span dir="ltr"><<a href="mailto:noqnoqneo@gmail.com" target="_blank">noqnoqneo@gmail.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF"><span class="">
On 5/2/18 3:58 AM, Artem Razin via cfe-dev wrote:<br>
</span><blockquote type="cite">
<div dir="ltr"><span class="">Hi All,
<div><br>
</div>
<div>I hope this is right place to ask such a newbie question
like the following.</div>
<div><br>
</div>
<div>I am trying to write a checker to catch potential handle
leaks (it's on Windows: a handle is closed by CloseHandle).</div>
<div><br>
</div>
<div>So I took SimpleStreamChecker as a base, now my
checkPreCall() checks if "CloseHandle" is called.
Call.isCalled() works great except one case when CloseHandle
is called by pointer. It happens because of using a template
class that took a pointer to closing function as template
parameter (useful to close different types of handles by
appropriate functions: FindClose, CloseHandle etc.).</div>
<div><br>
</div>
</span><div>Call.dump() prints "&CloseHandle(this->m_h)" in this
case, so it understands that this a pointer and that this is a
pointer of CloseHandle.But how to "extract" the the identifier
of CloseHandle?<br>
</div>
</div>
</blockquote>
<br>
I'm not quite understanding that dump, it looks a bit weird. What is
the actual code under analysis? Could you see if you can get
Call.getOriginExpr()->dump() and/or Call.getDecl()->dump()?
These should be more informative.<br>
<br>
In general the analyzer does indeed understand calls through
function pointers, as long as it can at all be tracked by looking at
the current execution path.<br>
<br>
And when it is tracked, CallEvent::isCalled() should "just work"
because it only looks at Call.getDecl() which should be the
path-specific decl.<br>
<br>
<blockquote type="cite"><span class="">
<div dir="ltr">
<div><br>
</div>
<div>Thank you in advance!</div>
<div>
<div><br>
</div>
-- <br>
<div class="m_1725759654421836021gmail_signature">Best regards, <br>
Artem A. Razin</div>
</div>
</div>
<br>
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</pre>
</blockquote>
<br>
</div>
</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature">Best regards, <br>Artem A. Razin</div>
</div>