Hello, >> But then, after lowering on the eh pass (gcc/tree-eh.c:1161), the "finally" >> location is set up to the `gimple_location (tf->try_finally_expr)' which >> actually expands to "testcase.cxx:4", a place where the "try" block starts. >> >> The dump testcase.cxx.009t.ehopt shows no location info for destructor: >> std::unique_ptr<char>::~unique_ptr (&lang); >> >> And next testcase.cxx.010t.eh dump shows equal location for constructor and >> destructor: >> [testcase.cxx:4:38] std::unique_ptr<char>::unique_ptr ([testcase.cxx:4:38] >> &lang, D.42272); [testcase.cxx:4:38] std::unique_ptr<char>::~unique_ptr >> (&lang); >> >> I performed several experiments trying to get information about gimple_block >> around the try_finally_expr statement right in `lower_try_finally_onedest', >> but unsuccessfully. And also, as far as I understand, this issue should be >> fixed in all the lowering functions, not only this one. >> >> Where should I dig in order to fix the issue? > > We have been using this patchlet locally for some time: > > Index: tree-eh.c > =================================================================== > --- tree-eh.c (revision 248944) > +++ tree-eh.c (working copy) > @@ -1413,11 +1413,12 @@ lower_try_finally_switch (struct leh_sta > x = gimple_build_assign (finally_tmp, > build_int_cst (integer_type_node, > fallthru_index)); > + gimple_set_location (x, finally_loc); > gimple_seq_add_stmt (&tf->top_p_seq, x); > > tmp = build_int_cst (integer_type_node, fallthru_index); > last_case = build_case_label (tmp, NULL, > - create_artificial_label (tf_loc)); > + create_artificial_label (finally_loc)); > case_label_vec.quick_push (last_case); > last_case_index++; > > @@ -1426,7 +1427,7 @@ lower_try_finally_switch (struct leh_sta > > tmp = lower_try_finally_fallthru_label (tf); > x = gimple_build_goto (tmp); > - gimple_set_location (x, tf_loc); > + gimple_set_location (x, finally_loc); > gimple_seq_add_stmt (&switch_body, x); > }
I tried the patch, but it has no effect since `lower_try_finally_switch' is not used in automatically generated destructors (at least for `unique_ptr'), the `lower_try_finally_onedest' is used and it seems that the is no straightforward way to generate `finally_loc' in like of the one you use in the patch. It seems that the best solution here will be to find the end of scope where the object is created but I still can't implement the method to extract this info. gimple_block() does not provide this info, and accordingly to GCC online docs it shouldn't: > the C++ front end uses pseudo-scopes to handle cleanups for objects with > destructors, these don’t translate into the GIMPLE form The best thing I could achieve is to set `finally' source location equal to the previous statement. Now my report shows to the last line in function, which is much better than blaming constructor, but still not the result I wanted to get; this might be confusing when last line is some kind of resource freeing function call. Best Regards, Vyacheslav Barinov
