418458 - gcc-dehydra: temporary value destructors are not noted in process_function

Status: RESOLVED WONTFIX

(Developer Infrastructure :: Source Code Analysis, defect)

Description

[Benjamin Smedberg]

Attachment: dehydra-test-stack-temporaries.ii

Testcase attached: dehydra notes the call to the copy-constructor for the temporary object, but never notes the call to A::~A.

Comment 1

[(dormant account)]

Excellent testcase. 
I found the dehydra code that skips over cleanup expressions. Constructors for temporaries work fine as arguments. This is not the case for destructors.
There is no clean place to indicate temporary destructors.

Currently FunctionTakesA(a) expands into
FunctionTakesA(A(a))

Ideally I could try to inject the implied constructors/destructors as
tempa = A(A)
FunctionTakes
tempa.~A()

I'm not completely sure how this would interact with multiple sets of temporary constructors per function call and other similar situations.

Comment 2

[(dormant account)]

As discussed on IRC. Seems that Dave's CFG stuff is better suited for precise analyses.
Lets reopen the bug if it turns out to be a problem.