[cfe-dev] Wrong order of AST traversal?
Ilya Biryukov via cfe-dev
cfe-dev at lists.llvm.org
Thu Jul 18 02:40:22 PDT 2019
We already have a DEF_TRAVERSE_DECL macro that contains the boilerplate
common to all Decl traversals, moving it there seems to give the desired
behavior.
I've sent https://reviews.llvm.org/D64907 for review, let's see whether
Richard thinks it's a good idea.
On Thu, Jul 18, 2019 at 11:01 AM Kim Gräsman <kim.grasman at gmail.com> wrote:
> I looked quickly at RecursiveASTVisitor.h, and it looks like the
> challenge is that attributes can be attached to other decls as well.
>
> Attrs are traversed generically for all Decl after any dynamic-type
> traversal:
>
> https://github.com/llvm/llvm-project/blob/master/clang/include/clang/AST/RecursiveASTVisitor.h#L707
>
> So I think in order to change this, attribute traversal would need to
> be custom-implemented for every kind of Decl.
>
> - Kim
>
> On Thu, Jul 18, 2019 at 10:54 AM Ilya Biryukov via cfe-dev
> <cfe-dev at lists.llvm.org> wrote:
> >
> > I would agree the traversal order is wrong, attributes are logically
> attached to a function, i.e. they are "child nodes".
> > Therefore, they should be traversed alongside others child nodes
> (function body, type, etc).
> >
> >
> > On Thu, Jul 18, 2019 at 10:35 AM Max Sagebaum <
> max.sagebaum at scicomp.uni-kl.de> wrote:
> >>
> >> Hello Ilya,
> >>
> >> thank you for the fast reply. I do not know why I missed that.
> >>
> >> Nevertheless, is the traversal order correct?
> >>
> >> Cheers
> >>
> >> Max
> >>
> >> On Thu, 2019-07-18 at 09:40 +0200, Ilya Biryukov wrote:
> >>
> >> 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
> >>
> >>
> >>
> >> --
> >>
> >> Dr. Max Sagebaum
> >>
> >> Chair for Scientific Computing,
> >> TU Kaiserslautern,
> >> Bldg/Geb 34, Paul-Ehrlich-Strasse,
> >> 67663 Kaiserslautern, Germany
> >>
> >> Phone: +49 (0)631 205 5638
> >> Fax: +49 (0)631 205 3056
> >> Email: max.sagebaum at scicomp.uni-kl.de
> >> URL: www.scicomp.uni-kl.de
> >>
> >>
> >>
> >>
> >>
> >>
> >
> >
> > --
> > Regards,
> > Ilya Biryukov
> > _______________________________________________
> > 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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