[cfe-dev] Find Type by name
Roman Popov via cfe-dev
cfe-dev at lists.llvm.org
Wed Feb 28 20:02:14 PST 2018
Ok, simply adding suffixes based on BuiltinType Kind solves the problem
for me. I will update to Clang trunk tomorrow and check if it will work
there.
2018-02-28 18:54 GMT-08:00 Roman Popov <ripopov at gmail.com>:
> Well, from what I'm seeing non-type argument printer is actually untyped.
> It uses APInt, which looks like "generic" arbitrary precision integer,
> that knows nothing about C++ type system.
>
> So solution is to print APInt value without type postfix, and then
> generate type postfix based on template parameter type.
>
> I'm not really familiar with Clang yet, so it will take a time to fix
> this. But I will try.
>
> Another option would be using mangled type names in AST Matcher. This way
> it will be even better: you wan't need to demangle names from LLVM IR.
>
>
>
> 2018-02-28 18:07 GMT-08:00 Roman Popov <ripopov at gmail.com>:
>
>> Ok, let me run the code in debugger to understand how it makes decision
>> when to print U.
>>
>> 2018-02-28 18:05 GMT-08:00 Artem Dergachev <noqnoqneo at gmail.com>:
>>
>>> Huh, nice one. It means that the problem is somewhere in
>>> QualType::getQualifiedNameAsString(). No, it doesn't seem to be fixed
>>> in trunk. This might be an easy and welcomed patch.
>>>
>>> On 28/02/2018 5:56 PM, Roman Popov wrote:
>>>
>>>> Btw, I'm using Clang 5.0, probably it is already fixed in trunk?
>>>>
>>>> 2018-02-28 17:54 GMT-08:00 Roman Popov <ripopov at gmail.com <mailto:
>>>> ripopov at gmail.com>>:
>>>>
>>>> Yes, it matches indeed vs my_nm::my_type<int, 10>.
>>>>
>>>> I think this is a bug in*asString() *matcher: Here is reproducer:
>>>>
>>>> *namespace my_nm {*
>>>> *template<typename T, unsigned U>*
>>>> *struct my_type { };*
>>>> *}*
>>>> *
>>>> *
>>>> *my_nm::my_type<int, 10> m1;*
>>>> *my_nm::my_type<int, 11u> m2;*
>>>>
>>>> LLVM IR generator correctly generates both types with unsigned
>>>> second parameter. But AST Matcher thinks that m1 has signed
>>>> parameter, and m2 has unsigned:
>>>>
>>>> m1 matches vs *my_nm::my_type<int, 10>*
>>>> m2 matches vs *my_nm::my_type<int, 11U> *(notice capital U)
>>>>
>>>> In LLVM IR types are *my_nm::my_type<int, 10u> and
>>>> *my_nm::my_type<int, 11u> **
>>>>
>>>>
>>>> Thanks, Roman
>>>>
>>>>
>>>>
>>>> 2018-02-28 17:37 GMT-08:00 Artem Dergachev <noqnoqneo at gmail.com
>>>> <mailto:noqnoqneo at gmail.com>>:
>>>>
>>>>
>>>> Sorry i don't have a quick way of trying this at the moment;
>>>> Does it work with "struct my_nm::my_type<int, 10>"? - because
>>>> that's what i see in clang's -ast-dump. Does
>>>> varDecl(hasType(asString(...))) work? If you match qualType()
>>>> and dump .getAsString() on all results, what do you see?
>>>>
>>>> Cause i think it should ultimately work.
>>>>
>>>> On 28/02/2018 2:12 PM, Roman Popov wrote:
>>>>
>>>> Thanks Artem. This is what I've tried before writing
>>>> original mail. However it does not work, I got zero matches.
>>>>
>>>> Here is reproducer:
>>>>
>>>> *namespace my_nm {*
>>>> *template<typename T, unsigned U>*
>>>> *struct my_type { };*
>>>> *}*
>>>> *
>>>> *
>>>> *my_nm::my_type<int, 10> m;
>>>> *
>>>>
>>>>
>>>> I got types from LLVM IR analysis, and then want to find
>>>> them in Clang AST.
>>>>
>>>> From LLVM I got mangled name:
>>>> *N5my_nm7my_typeIiLj10EEE*
>>>>
>>>> Demangled to:
>>>> *my_nm::my_type<int, 10u>*
>>>>
>>>> However I can't find it by any matcher:
>>>>
>>>> auto matches =
>>>> match(qualType(asString("*my_nm::my_type<int,
>>>> 10u>*")).bind("types"), astCtx); // Zero matches
>>>>
>>>> auto matches =
>>>> match(qualType(asString("*N5my
>>>> _nm7my_typeIiLj10EEE*")).bind("types"),
>>>> astCtx); // Zero matches
>>>>
>>>> Probably there is some other way to go back from LLVM IR
>>>> to Clang AST?
>>>>
>>>>
>>>> Thanks,
>>>> Roman
>>>>
>>>>
>>>> 2018-02-28 12:36 GMT-08:00 Artem Dergachev
>>>> <noqnoqneo at gmail.com <mailto:noqnoqneo at gmail.com>
>>>> <mailto:noqnoqneo at gmail.com <mailto:noqnoqneo at gmail.com>>>:
>>>>
>>>> I don't think it's possible via straightforward lookup
>>>> - you might
>>>> need to scan the AST to do this.
>>>>
>>>> Eg. using ASTMatchers:
>>>>
>>>> qualType(asString("my_nm::my_type<int, 10u>"))
>>>>
>>>> Or, if you're not using ASTMatchers (likely), you can
>>>> do the same
>>>> with a RecursiveASTVisitor. Or manually.
>>>>
>>>>
>>>> On 27/02/2018 10:56 AM, Roman Popov via cfe-dev wrote:
>>>>
>>>> Hello,
>>>>
>>>> Is it possible to find type in AST by it's
>>>> qualified type?
>>>>
>>>> For example I have string "my_nm::my_type<int,
>>>> 10u>", how can
>>>> I get clang::QualType if type is present in
>>>> translation unit?
>>>>
>>>> Thanks,
>>>> Roman
>>>>
>>>>
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>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>
>
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