[cdt-dev] RecursionResolvingBinding

["Sergey Prigogin" <eclipse.sprigogin@xxxxxxxxx>]

I've noticed that RecursionResolvingBinding gets created large number of times during indexing. Here is a code fragment extracted from stdio.h that triggers one of the cases:

  typedef struct _IO_FILE FILE;

  struct _IO_FILE {
    struct _IO_FILE *_chain;
  };

  int fclose(FILE *__stream);

Here's the stack with recursion:
Thread [Worker-1] (Suspended (breakpoint at line 48 in CPPASTName$RecursionResolvingBinding))    
    CPPASTName$RecursionResolvingBinding.<init>(IASTName) line: 48    
    CPPASTName.resolveBinding() line: 74    
    CPPASTElaboratedTypeSpecifier.getRoleForName(IASTName) line: 95    
    CPPASTName.isReference() line: 235    
    CPPSemantics.resolveAmbiguities(LookupData, IASTName) line: 1653    
    CPPSemantics.resolveAmbiguities(IASTName, Object[]) line: 1530    
    CPPNamespaceScope(CPPScope).getBindingInAST(IASTName, boolean) line: 212    
    CPPNamespaceScope(CPPScope).getBinding(IASTName, boolean, IIndexFileSet) line: 136    
    CPPSemantics.lookup(LookupData, Object) line: 679    
    CPPSemantics.resolveBinding(IASTName) line: 172    
    CPPVisitor.createBinding(ICPPASTElaboratedTypeSpecifier) line: 343    
    CPPVisitor.createBinding(IASTName) line: 237    
    CPPASTName.resolveBinding() line: 77    
    CPPASTElaboratedTypeSpecifier.getRoleForName(IASTName) line: 95    
    CPPASTName.isReference() line: 235    
    CPPSemantics.resolveAmbiguities(LookupData, IASTName) line: 1653    
    CPPSemantics.resolveAmbiguities(IASTName, Object[]) line: 1530    
    CPPNamespaceScope(CPPScope).getBindingInAST(IASTName, boolean) line: 212    
    CPPNamespaceScope(CPPScope).getBinding(IASTName, boolean, IIndexFileSet) line: 136    
    CPPSemantics.lookup(LookupData, Object) line: 679    
    CPPSemantics.resolveBinding(IASTName) line: 172    
    CPPVisitor.createBinding(ICPPASTElaboratedTypeSpecifier) line: 343    
    CPPVisitor.createBinding(IASTName) line: 237    
    CPPASTName.resolveBinding() line: 77    
    CPPASTElaboratedTypeSpecifier.getRoleForName(IASTName) line: 95    
    CPPASTName.isReference() line: 235    
    CPPSemantics.resolveAmbiguities(LookupData, IASTName) line: 1653    
    CPPSemantics.resolveAmbiguities(IASTName, Object[]) line: 1530    
    CPPNamespaceScope(CPPScope).getBindingInAST(IASTName, boolean) line: 212    
    CPPNamespaceScope(CPPScope).getBinding(IASTName, boolean, IIndexFileSet) line: 136    
    CPPSemantics.lookup(LookupData, Object) line: 679    
    CPPSemantics.resolveBinding(IASTName) line: 172    
    CPPVisitor.createBinding(ICPPASTElaboratedTypeSpecifier) line: 343    
    CPPVisitor.createBinding(IASTName) line: 237    
    CPPASTName.resolveBinding() line: 77    
    CPPASTElaboratedTypeSpecifier.getRoleForName(IASTName) line: 95    
    CPPASTName.isReference() line: 235    
    CPPSemantics.resolveAmbiguities(LookupData, IASTName) line: 1653    
    CPPSemantics.resolveAmbiguities(IASTName, Object[]) line: 1530    
    CPPNamespaceScope(CPPScope).getBindingInAST(IASTName, boolean) line: 212    
    CPPNamespaceScope(CPPScope).getBinding(IASTName, boolean, IIndexFileSet) line: 136    
    CPPSemantics.lookup(LookupData, Object) line: 679    
    CPPSemantics.resolveBinding(IASTName) line: 172    
    CPPVisitor.createBinding(ICPPASTElaboratedTypeSpecifier) line: 343    
    CPPVisitor.createBinding(IASTName) line: 237    
    CPPASTName.resolveBinding() line: 77    
    CPPASTElaboratedTypeSpecifier.getRoleForName(IASTName) line: 95    
    CPPASTName.isReference() line: 235    
    CPPSemantics.resolveAmbiguities(LookupData, IASTName) line: 1653    
    CPPSemantics.resolveAmbiguities(IASTName, Object[]) line: 1530    
    CPPNamespaceScope(CPPScope).getBindingInAST(IASTName, boolean) line: 212    
    CPPNamespaceScope(CPPScope).getBinding(IASTName, boolean, IIndexFileSet) line: 136    
    CPPSemantics.lookup(LookupData, Object) line: 679    
    CPPSemantics.resolveBinding(IASTName) line: 172    
    CPPVisitor.createBinding(ICPPASTElaboratedTypeSpecifier) line: 343    
    CPPVisitor.createBinding(IASTName) line: 237    
    CPPASTName.resolveBinding() line: 77    
    PDOMFastIndexerTask(PDOMWriter).resolveNames(Map<IIndexFileLocation,Symbols>, IIndexFileLocation[], ArrayList<IStatus>, IProgressMonitor) line: 236    
    PDOMFastIndexerTask(PDOMWriter).addSymbols(IASTTranslationUnit, IIndexFileLocation[], IWritableIndex, int, boolean, int, ITodoTaskUpdater, IProgressMonitor) line: 150    
    PDOMFastIndexerTask(AbstractIndexerTask).writeToIndex(int, IASTTranslationUnit, int, IProgressMonitor) line: 634    
    PDOMFastIndexerTask(AbstractIndexerTask).parseFile(Object, int, IIndexFileLocation, IScannerInfo, IProgressMonitor) line: 599    
    PDOMFastIndexerTask(AbstractIndexerTask).parseLinkage(int, Map<Integer,List<Object>>, IProgressMonitor) line: 485    
    PDOMFastIndexerTask(AbstractIndexerTask).runTask(IProgressMonitor) line: 235    
    PDOMFastIndexerTask(PDOMIndexerTask).run(IProgressMonitor) line: 109    
    PDOMIndexerJob.run(IProgressMonitor) line: 94    
    Worker.run() line: 55    

The name being resolved is _IO_FILE inside the typedef.

It's interesting that the resulting AST doesn't contain any problem bindings. Still, creation of  an intermediate RecursionResolvingBinding doesn't look right. I suspect that 5 recursive calls leading to creation of a RecursionResolvingBinding cause significant overhead and should better be avoided. It looks like on real code base some RecursionResolvingBindings do remain in AST and become user-visible problems, but I'm not sure if they have similar causes or not.

I tried to reproduce creation of RecursionResolvingBinding in a test, but surprisingly the same code inside a test doesn't trigger a RecursionResolvingBinding.

Please let me know if routine creation of RecursionResolvingBinding is expected or not.

-sergey