[cfe-dev] RecursiveASTVisitor Behavior

[Deep Majumder via cfe-dev]

Hi Michael,
Although your return type is bool, since you have no return statement at
the end of the method in the Visitor, that method returns false implicitly.
Please add a "return true;" at the end of the visitor methods.
Warm regards,
Deep

On Thu, 18 Mar, 2021, 9:32 pm Michael Chiu via cfe-dev, <
cfe-dev at lists.llvm.org> wrote:

> Hi David,
>
> Thanks for the prompt reply. I should’ve been more clear but I am
> returning bool in all of the visitor method functions, but clang::VarDecl
> is still not visited which is why I’m so perplexed.
>
> On Thu, Mar 18, 2021 at 8:58 AM David Rector <davrecthreads at gmail.com>
> wrote:
>
>>
>>
>> On Mar 18, 2021, at 11:42 AM, Michael Chiu via cfe-dev <
>> cfe-dev at lists.llvm.org> wrote:
>>
>> Hi All,
>>
>> I have c code, below, that I'm trying to visit the AST of by using
>> RecursiveASTVisitor. I'm trying to get the RecursiveASTVisitor to visit
>> variable declarations (clang::VarDecl) by implementing bool
>> VistVarDecl(clang::VarDecl *vardecl). However, the clang::VarDecl nodes
>> are never visited even though I've managed to visit all the other nodes in
>> the AST though. Moreover, using clang-query on test1.c I *can* match
>> varDecl.
>>
>> Does anyone know the clang::VarDecl nodes are the only nodes that aren't
>> visited by the RecursiveASTVisitor but are matched by clang-query?
>>
>> Thanks in advaince!
>>
>> ```
>> double multiply(double x, double y) {
>>
>>     return x * y * y;
>> }
>> int main(int argc, char const *argv[]){
>>     double a;
>>
>>     int b;
>>
>>     float d;
>>
>>     double x = 3.0;
>>     double y = 5.0;
>>
>>     double z = multiply(x,y);
>>
>>     return 0;
>> }
>> ```
>>
>> My RecursiveASTVisitor is as follows:
>> ```
>> struct MyASTVisitor : public clang::RecursiveASTVistor<MyASTVisitor> {
>>
>>   bool VistVarDecl(clang::VarDecl *vardecl) {
>>      llvm::outs() << "Found a VarDecl";
>>
>> Add `return true;’ here and in the others.  (Traversal halts after the
>> first false return, and all these are returning false by default.)
>>
>>   };
>>
>>   bool VisitFunctionDecl(clang::FunctionDecl *decl) {
>>      llvm::outs() << "Found a FunctionDecl";
>>   };
>>
>>   // other functions implemented similarly just to see if it visits properly
>>   bool VisitParmVarmDecl(clang::ParmVarDecl *paramvardecl);
>>   bool VisitCallExpr(clang::CallExpr *callexpr);
>>   bool VisitImplicitCastExpr(clang::ImplicitCastExpr *castexpr);
>>   bool VisitBinaryOperator(clang::BinaryOperator *bo);
>>   bool VisitDeclStmt(clang::DeclStmt *declstmt);
>>   bool VisitDeclRefExpr(clang::DeclRefExpr *declrefexpr);
>>   bool VisitFloatingLiteral(clang::FloatingLiteral *floatliteral);
>> };
>> struct MyASTConsumer : public clang::ASTConsumer {
>>
>>   bool HandleTopLevelDecl(clang::DeclGroupRef DR) override {
>>     for (clang::DeclGroupRef::iterator b = DR.begin(), e = DR.end(); b != e; ++b) {
>>         Visitor.TraverseDecl(*b);
>>      }
>>      return true;
>>   }private:
>>   MyASTVisitor Visitor;
>> };
>> ```
>>
>>
>> --
>> Michael.
>> _______________________________________________
>> cfe-dev mailing list
>> cfe-dev at lists.llvm.org
>> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>>
>>
>> --
> M.
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