[cfe-dev] AST bug parsing tags.cpp file?

[Billy Araujo via cfe-dev]

Hi,

Also something else happens if you move
ColorTag::~ColorTag() {}

down to be at line 261 (without changing scope) is now a CXXDestructorDecl
but the line numbers are all screwed up.

CXXDestructorDecl 0x269fdc0 <line:307:3, col:13> col:3 ~ColorTag 'void ()
noexcept'

Regards,

Billy.




On Thu, Jul 30, 2020 at 11:54 AM Billy Araujo <billyaraujo at gmail.com> wrote:

> Hi Dave,
>
> Thanks for your reply. I don't think it is a cxxMemberCallExpr().
> I think it is parsing issue because this is what happens:
>
> class ColorTag()
> {
> public:
>    ColorTag():
>    ~ColorTag();
> }
>
> ColorTag()::ColorTag() {
>   //...
> }
>
> ColorTag::~ColorTag() {}
>
> It is interpreted as: CXXMemberCallExpr() as if ColorTag::~ColorTag() was
> called inside the constructor. You can see below in the AST output
> cxxMemberCallExpr parent is CXXConstructorDecl.
>
> `-CXXConstructorDecl 0x2e76988 parent 0x2e60608 prev 0x2e61578
> <line:238:1, line:434:2> line:238:11 ColorTag 'void (const ColorTag &)'
>   |-ParmVarDecl 0x2e768f8 <col:20, col:36> col:36 used tag 'const ColorTag
> &'
>   |-CXXCtorInitializer 'PliObjectTag'
>   | `-CXXConstructExpr 0x2e76b10 <line:239:7, col:39> 'PliObjectTag' 'void
> (const PliTag::Type)'
>   |   `-DeclRefExpr 0x2e76ab0 <col:20, col:28> 'PliTag::Type' EnumConstant
> 0x2e579e8 'COLOR_NGOBJ' 'PliTag::Type'
>   |-CXXCtorInitializer Field 0x2e60e88 'm_style' 'ColorTag::styleType'
>   | `-ImplicitCastExpr 0x2e76bd8 <line:240:15, col:19>
> 'ColorTag::styleType' <LValueToRValue>
>   |   `-MemberExpr 0x2e76b88 <col:15, col:19> 'const ColorTag::styleType'
> lvalue .m_style 0x2e60e88
>   |     `-DeclRefExpr 0x2e76b68 <col:15> 'const ColorTag' lvalue ParmVar
> 0x2e768f8 'tag' 'const ColorTag &'
>   |-CXXCtorInitializer Field 0x2e60ee8 'm_attribute'
> 'ColorTag::attributeType'
>   | `-ImplicitCastExpr 0x2e76c88 <line:241:19, col:23>
> 'ColorTag::attributeType' <LValueToRValue>
>   |   `-MemberExpr 0x2e76c38 <col:19, col:23> 'const
> ColorTag::attributeType' lvalue .m_attribute 0x2e60ee8
>   |     `-DeclRefExpr 0x2e76c18 <col:19> 'const ColorTag' lvalue ParmVar
> 0x2e768f8 'tag' 'const ColorTag &'
>   `-CompoundStmt 0x2e76fb0 <line:242:36, line:434:2>
>     |-IfStmt 0x2e76d98 <line:243:3, line:249:1>
>     | |-OpaqueValueExpr 0x2e76d80 <<invalid sloc>> 'bool'
>     | `-CompoundStmt 0x2e76d70 <line:243:28, line:249:1>
>     |-CXXMemberCallExpr 0x2e76e68 <line:251:1, col:21> 'void'
>     | `-MemberExpr 0x2e76e20 <col:1, col:12> '<bound member function
> type>' ->~ColorTag 0x2e61670
>     |   `-CXXThisExpr 0x2e76e10 <col:11> 'ColorTag *' implicit this
>
> So this:
>
> class ColorTag()
> {
> public:
>    ColorTag():
>    ~ColorTag();
> }
>
> ColorTag()::ColorTag() {
>   //...
> }
>
> ColorTag::~ColorTag() {}
>
> Is interpreted like this:
>
> class ColorTag()
> {
> public:
>    ColorTag():
>    ~ColorTag();
> }
>
> ColorTag()::ColorTag() {
>   //...
>  ColorTag::~ColorTag() {}
> }
>
> Regards,
>
> Billy.
>
>
>
>
> On Thu, Jul 30, 2020 at 1:27 AM David Rector <davrecthreads at gmail.com>
> wrote:
>
>> I think you are not distinguishing properly between the declaration of
>> the destructor and its usage (via a CXXMemberCallExpr) within the
>> implementation/"body" of some other method declaration (this body should be
>> enclosed in a "CompoundStmt").
>>
>> For example, the dump of
>>
>> ```
>> struct ColorTag {
>>   ~ColorTag() {}
>>   void destroy() {
>>     ColorTag::~ColorTag();
>>   }
>> };
>> ```
>>
>> looks like this:
>>
>> ```
>> TranslationUnitDecl
>> `-CXXRecordDecl <line:1:1, line:5:1> line:1:8 struct ColorTag definition
>>   ...(Definition data, implicitly-generated declarations)...
>>   |-CXXDestructorDecl <line:2:5, col:18> col:5 used ~ColorTag 'void ()
>> noexcept'
>>   |-CXXMethodDecl <line:2:5, line:4:5> line:2:10 destroy 'void ()'
>>   | `-CompoundStmt <col:20, line:4:5>
>>   |   `-CXXMemberCallExpr <line:3:9, col:29> 'void'
>>   |     `-MemberExpr <col:9, col:20> '<bound member function
>> type>' ->~ColorTag 0x55790cbbaa40
>>   |       `-CXXThisExpr <col:19> 'ColorTag *' implicit this
>>   ...
>> ```
>>
>> Hope that helps, good luck,
>>
>> Dave
>>
>> On Jul 29, 2020, at 10:40 AM, Billy Araujo via cfe-dev <
>> cfe-dev at lists.llvm.org> wrote:
>>
>> Hi,
>>
>> On project opentoonz there is a file called:
>> opentoonz/toonz/sources/image/pli/tags.cp
>>
>> If I run clang-check, the AST it builds seems wrong.
>>
>> clang-check -ast-dump /home/opentoonz/toonz/sources/image/pli/tags.cpp |
>> grep -B 1 -A 1 "~ColorTag"
>>
>>     |-CXXMemberCallExpr 0x22893e8 <line:253:1, col:21> 'void'
>>     | `-MemberExpr 0x22893a0 <col:1, col:12> '<bound member function
>> type>' ->~ColorTag 0x2274c00
>>     |   `-CXXThisExpr 0x2289390 <col:11> 'ColorTag *' implicit this
>>
>> Line 253 appears as a CXXMemberCallExpr instead of a CXXDestructorDecl.
>>
>> So the AST thinks it is calling an explicit destructor method call
>> although it is a destructor implementation.
>>
>> clang-check --version
>> LLVM (http://llvm.org/):
>>   LLVM version 10.0.0
>>
>>   Optimized build.
>>   Default target: x86_64-pc-linux-gnu
>>   Host CPU: nehalem
>>
>> Is this a bug or am I missing something?
>>
>> Regards,
>>
>> Billy.
>>
>> _______________________________________________
>> cfe-dev mailing list
>> cfe-dev at lists.llvm.org
>> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>>
>>
>>
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