[cfe-dev] Wrong order of AST traversal?

[Ilya Biryukov via cfe-dev]

Hi Max,

You can get the attributes with Decl::attrs() method (also available for
FunctionDecl).

On Thu, Jul 18, 2019 at 9:28 AM Max Sagebaum via cfe-dev <
cfe-dev at lists.llvm.org> wrote:

> Hello @ all,
>
> I want to annotate some function and generate some additional properties
> for the annotated functions in an xml document. My problem is, that the AST
> traversal seems to traverse the attributes of the function after the
> traversal of the function has been finished. I could not find any valuable
> resources on this topic by searching via google. So I am addressing my
> question here.
>
> (Since I do not know if file attachments are allowed I provide the files
> as comments.)
>
> My test files is: (attributeTest.cpp)
>
> void func1()
> __attribute((annotate(R"(Test)"))) {
>   int a = 1 + 1;
> }
>
>
> clang-check gives me the correct hierarchy: clang-check --ast-dump
> attributeTest.cpp
>
> TranslationUnitDecl 0x559b4c7dc598 <<invalid sloc>> <invalid sloc>
> |-TypedefDecl 0x559b4c7dce70 <<invalid sloc>> <invalid sloc> implicit
> __int128_t '__int128'
> | `-BuiltinType 0x559b4c7dcb30 '__int128'
> |-TypedefDecl 0x559b4c7dced8 <<invalid sloc>> <invalid sloc> implicit
> __uint128_t 'unsigned __int128'
> | `-BuiltinType 0x559b4c7dcb50 'unsigned __int128'
> |-TypedefDecl 0x559b4c7dd208 <<invalid sloc>> <invalid sloc> implicit
> __NSConstantString '__NSConstantString_tag'
> | `-RecordType 0x559b4c7dcfb0 '__NSConstantString_tag'
> |   `-CXXRecord 0x559b4c7dcf28 '__NSConstantString_tag'
> |-TypedefDecl 0x559b4c7dd2a0 <<invalid sloc>> <invalid sloc> implicit
> __builtin_ms_va_list 'char *'
> | `-PointerType 0x559b4c7dd260 'char *'
> |   `-BuiltinType 0x559b4c7dc630 'char'
> |-TypedefDecl 0x559b4c818958 <<invalid sloc>> <invalid sloc> implicit
> __builtin_va_list '__va_list_tag [1]'
> | `-ConstantArrayType 0x559b4c818900 '__va_list_tag [1]' 1
> |   `-RecordType 0x559b4c7dd380 '__va_list_tag'
> |     `-CXXRecord 0x559b4c7dd2f0 '__va_list_tag'
> `-FunctionDecl 0x559b4c818a98
> </home/msagebaum/Kaiserslautern/Programms/adDSLParser/temp/attributeTest.cpp:1:1,
> line:4:1> line:1:6 func1 'void ()'
>   |-CompoundStmt 0x559b4c818cb0 <line:2:36, line:4:1>
>   | `-DeclStmt 0x559b4c818c98 <line:3:3, col:16>
>   |   `-VarDecl 0x559b4c818bd8 <col:3, col:15> col:7 a 'int' cinit
>   |     `-BinaryOperator 0x559b4c818c78 <col:11, col:15> 'int' '+'
>   |       |-IntegerLiteral 0x559b4c818c38 <col:11> 'int' 1
>   |       `-IntegerLiteral 0x559b4c818c58 <col:15> 'int' 1
>   `-AnnotateAttr 0x559b4c818b30 <line:2:14, col:32> "Test"
>
>
> If I now run the file through my AST Visitor: (parserTest.cpp)
>
> #include <iostream>
>
> #include "clang/AST/ASTConsumer.h"
> #include "clang/AST/QualTypeNames.h"
> #include "clang/AST/RecursiveASTVisitor.h"
> #include "clang/Frontend/CompilerInstance.h"
> #include "clang/Frontend/FrontendAction.h"
> #include "clang/Tooling/CommonOptionsParser.h"
> #include "clang/Tooling/Tooling.h"
>
> #include <llvm/Support/CommandLine.h>
>
> using namespace llvm;
> using namespace clang;
> using namespace clang::tooling;
>
> class XMLGenerator : public RecursiveASTVisitor<XMLGenerator> {
> public:
>
>   bool TraverseFunctionDecl(FunctionDecl *declaration) {
>
>     std::cout << "Function start" << std::endl;
>
>     RecursiveASTVisitor<XMLGenerator>::TraverseFunctionDecl(declaration);
>
>     std::cout << "Function end" << std::endl;
>     return true;
>   }
>
>   bool TraverseAnnotateAttr(AnnotateAttr *a) {
>     std::cout << "Annotation start" << std::endl;
>
>     RecursiveASTVisitor<XMLGenerator>::TraverseAnnotateAttr(a);
>
>     std::cout << "Annotation end" << std::endl;
>     return true;
>   }
> };
>
> class XMLGeneratorClassConsumer : public clang::ASTConsumer {
> public:
>   explicit XMLGeneratorClassConsumer()
>     : Visitor() {}
>
>   virtual void HandleTranslationUnit(clang::ASTContext &Context) {
>     Visitor.TraverseDecl(Context.getTranslationUnitDecl());
>   }
> private:
>   XMLGenerator Visitor;
> };
>
> class XMLGeneratorClassAction : public clang::ASTFrontendAction {
> public:
>   virtual std::unique_ptr<clang::ASTConsumer> CreateASTConsumer(
>     clang::CompilerInstance &Compiler, llvm::StringRef InFile) {
>     return std::unique_ptr<clang::ASTConsumer>(
>         new XMLGeneratorClassConsumer());
>   }
> };
>
> static llvm::cl::OptionCategory MyToolCategory("my-tool options");
>
> int main(int argc, const char **argv) {
>   CommonOptionsParser OptionsParser(argc, argv, MyToolCategory);
>   ClangTool Tool(OptionsParser.getCompilations(),
>                  OptionsParser.getSourcePathList());
>
>   return
> Tool.run(newFrontendActionFactory<XMLGeneratorClassAction>().get());
> }
>
>
> Compilation: (compile.sh)
>
> g++ -g -O0 -Wall -pedantic -std=c++11 -fno-rtti -c parserTest.cpp -o
> parserTest.o -I/usr/include
> g++ -g -O0 -Wall -pedantic -std=c++11 -fno-rtti -o parserTest.exe
> parserTest.o -L/usr/lib64  -Wl,--start-group -lclangAnalysis -lclangParse
> -lclangEdit -lclangSema -lclangTooling -lclangDriver -lclangSerialization
> -lclangFrontend -lclangBasic -lclangASTMatchers -lclangAST -lclangLex
> -lLLVM-8 -Wl,--end-group -lpthread -lz
>
>
> The result is:
>
> Function start
> Function end
> Annotation start
> Annotation end
>
>
> What I would expect is:
>
> Function start
> Annotation start
> Annotation end
> Function end
>
>
> My questions are now:
> Is the order provided by my implementation the correct one or is the
> expected order the correct one?
> Is there a way to change the visitor order such that attributes are
> visited inside of the function?
> If not: Is there a way to get a list of attributes from 'FunctionDecl'?
> (Could not find any methods in the api
> https://clang.llvm.org/doxygen/classclang_1_1FunctionDecl.html)
>
> Thanks in advance for any help.
>
> Cheers
>
> Max
> _______________________________________________
> cfe-dev mailing list
> cfe-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>


-- 
Regards,
Ilya Biryukov
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