[lldb-dev] Symtab for PECOFF

[Zachary Turner via lldb-dev]

That would be my thought, yea
On Fri, Aug 31, 2018 at 1:21 AM Aleksandr Urakov <
aleksandr.urakov at jetbrains.com> wrote:

> Thanks for the reply!
>
> Yes, the function search is implemented in the way similar to what you
> have described (and even the search in a symbol file is done before the
> search in a symtab). But for Module::FindSymbolsWithNameAndType function I
> can't find any relevant function in the SymbolFile. Do you mean that we
> need to extend the SymbolFile interface with such a function (which will
> search all public symbols by the name and the type), and then implement it
> in derived classes?
>
> On Thu, Aug 30, 2018 at 6:03 PM Zachary Turner <zturner at google.com> wrote:
>
>> It seems reasonable to me to say that if the symbol is not found in the
>> executables symtab, it will fall back to searching in the symbol file..
>> this logic doesn’t even need to be specific to PDB
>> On Thu, Aug 30, 2018 at 7:00 AM Aleksandr Urakov via lldb-dev <
>> lldb-dev at lists.llvm.org> wrote:
>>
>>> Hello!
>>>
>>> I'm working on an expressions evaluation on Windows, and currently I'm
>>> trying to make a JIT evaluation working.
>>>
>>> When I'm trying to evaluate the next expression:
>>>
>>> print S::x
>>>
>>>
>>> on the next code:
>>>
>>> struct S {
>>>   static int x;
>>>   void foo() { }
>>> };
>>> int S::x = 5;
>>>
>>> int main() {
>>>   S().foo(); // here
>>>   return 0;
>>> }
>>>
>>>
>>> the evaluation requires JIT (but printing of global variables requires
>>> not, and I can't figure out what is the key difference between a class
>>> static variable and a global variable in the case?).
>>>
>>> During symbols resolving IRExecutionUnit::FindInSymbols is used, and it
>>> searches a symbol among functions (which is not our case), and then calls
>>> Module::FindSymbolsWithNameAndType for each module in the list. This
>>> function looks symbols up in a Symtab, which is retrieved through a
>>> SymbolVendor, and it retrieves one from an ObjectFile. ELF files
>>> contain symbols for such a variables in their symbol tables, but the
>>> problem is that PE files usually contain info about exported (and imported)
>>> symbols only, so the lookup in Symtab fails.
>>>
>>> I think that we need somehow to retrieve a symbols info from a symbol
>>> file. I thought that we can emit a Symtab from a SymbolFile just like
>>> from an ObjectFile (and for now implement it for SymbolFilePDB only),
>>> but I'm not sure if this solution is good. How can we solve the problem
>>> else?
>>>
>>> --
>>> Aleksandr Urakov
>>> Software Developer
>>> JetBrains
>>> http://www.jetbrains.com
>>> The Drive to Develop
>>> _______________________________________________
>>> lldb-dev mailing list
>>> lldb-dev at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
>>>
>>
>
> --
> Aleksandr Urakov
> Software Developer
> JetBrains
> http://www.jetbrains.com
> The Drive to Develop
>
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