objective c - Xcode/LLDB: How to get information about an exception that was just thrown? -

-

ok, imagine breakpoint in objc_exception_throw has triggered. i'm sitting @ debugger prompt, , want more information exception object. find it?

the exception object passed in first argument objc_exception_throw. lldb provides $arg1..$argn variables refer arguments in correct calling convention, making simple print exception details:

(lldb) po $arg1 (lldb) po [$arg1 name] (lldb) po [$arg1 reason]

make sure select objc_exception_throw frame in call stack before executing these commands. see "advanced debugging , address sanitizer" in wwdc15 session videos see performed on stage.

outdated information

if you're on gdb, syntax refer first argument depends on calling conventions of architecture you're running on. if you're debugging on actual ios device, pointer object in register r0. print or send messages it, use following simple syntax:

(gdb) po $r0 (gdb) po [$r0 name] (gdb) po [$r0 reason]

on iphone simulator, function arguments passed on stack, syntax considerably more horrible. shortest expression construct gets *(id *)($ebp + 8). make things less painful, suggest using convenience variable:

(gdb) set $exception = *(id *)($ebp + 8) (gdb) po $exception (gdb) po [$exception name] (gdb) po [$exception reason]

you can set $exception automatically whenever breakpoint triggered adding command list objc_exception_throw breakpoint.

(note in cases tested, exception object present in eax , edx registers @ time breakpoint hit. i'm not sure that'll case, though.)

added comment below:

in lldb, select stack frame objc_exception_throw , enter command:

(lldb) po *(id *)($esp + 4)

Comments

Post a Comment

Popular posts from this blog

c++ - How do I get a multi line tooltip in MFC -

-
right now, have tool tip pops when hover on edit box. problem tool tip contains multiple error messages , in 1 long line. need have each error message on own line. error messages contained in cstring new line seperating them. my existing code below. bool ontooltiptext(uint, nmhdr* pnmhdr, lresult* presult) { assert(pnmhdr->code == ttn_needtexta || pnmhdr->code == ttn_needtextw); // need handle both ansi , unicode versions of message tooltiptexta* pttta = (tooltiptexta*)pnmhdr; tooltiptextw* ptttw = (tooltiptextw*)pnmhdr; // tchar szfulltext[256]; cstring strtiptext=_t(""); uint nid = pnmhdr->idfrom; if (pnmhdr->code == ttn_needtexta && (pttta->uflags & ttf_idishwnd) || pnmhdr->code == ttn_needtextw && (ptttw->uflags & ttf_idishwnd)) { // idfrom hwnd of tool nid = ::getdlgctrlid((hwnd)nid); } //m_errprojaccel[ch] contains 1 or more error messages each...
Read more

asp.net - In javascript how to find the height and width -

-
i having .aspx , masterpage page. in masterpage loading aspx page . in aspx page design using generating table structure using code-behind server in javascript how find height , width . regards, kumar if you're looking table height , width, should it var tbl = document.getelementbyid('tbldemo'); alert(tbl.offsetwidth + '\n' + tbl.offsetheight);
Read more

c# - DataTable to EnumerableRowCollection -

-
i have datatable according client requirement can contain invalid date "00/00/1999",null,empty string.(typed datset) when collect them enumerables wish convert of invalid forms empty string. (i.e) enumerablerowcollection<datarow> query = order in _table.asenumerable() select new { orderdate= string.isnullorempty(convert.tostring(order.field<datetime>("orderdate")) || (how check date invalid date) ? string.empty : order.field<datetime>("orderdate") } how check whether date valid date or not? datetime.tryparse...like given current code: datetime date; enumerablerowcollection<datarow> query = order in _table.asenumerable() select new { orderdate= string.isnullorempty(convert.tostring(order.field<datetime>("orderdate")) || !datetime.tryparse(convert.tostring(order.field<datetime...
Read more