AST dump - nodes are missing

Clang Frontend
1

Hello.

This is what I'm doing.

clang++ -cc1 -I/home/kevg/Desktop/llvm_playground/llvm/include -ast-dump llvm_playground/llvm/lib/Support/SmallVector.cpp

And this is how SmallVector::grow_pod looks like.

`-CXXMethodDecl 0x2e3ddc8 parent 0x2e15fc0 <line:19:1, line:41:1> line:19:23 invalid grow_pod 'void (void *, int, int)'
  >-ParmVarDecl 0x2e3dc50 <col:32, col:38> col:38 used FirstEl 'void *'
  >-ParmVarDecl 0x2e3dcc0 <col:47, col:54> col:54 invalid MinSizeInBytes 'int'
  >-ParmVarDecl 0x2e3dd30 <line:20:32, col:39> col:39 invalid TSize 'int'
  >-CompoundStmt 0x2e502c8 <col:46, line:41:1>
  > >-DeclStmt 0x2e3df58 <line:21:3, col:40>
  > > `-VarDecl 0x2e3dee0 <col:3, col:10> col:10 invalid CurSizeBytes 'int'
  > >-DeclStmt 0x2e3e018 <line:22:3, col:62>
  > > `-VarDecl 0x2e3df80 <col:3, col:10> col:10 invalid NewCapacityInBytes 'int'
  > >-DeclStmt 0x2e3e0a0 <line:26:3, col:16>
  > > `-VarDecl 0x2e3e040 <col:3, col:9> col:9 used NewElts 'void *'
  > >-IfStmt 0x2e4fe70 <line:27:3, line:35:3>
  > > >-<<<NULL>>>
  > > >-<<<NULL>>>
  > > >-BinaryOperator 0x2e3e160 <line:27:7, col:17> '_Bool' '=='
  > > > >-ImplicitCastExpr 0x2e3e130 <col:7> 'void *' <LValueToRValue>
  > > > > `-MemberExpr 0x2e3e0d0 <col:7> 'void *' lvalue ->BeginX 0x2e161b0
  > > > > `-CXXThisExpr 0x2e3e0b8 <col:7> 'class llvm::SmallVectorBase *' this
  > > > `-ImplicitCastExpr 0x2e3e148 <col:17> 'void *' <LValueToRValue>
  > > > `-DeclRefExpr 0x2e3e108 <col:17> 'void *' lvalue ParmVar 0x2e3dc50 'FirstEl' 'void *'
  > > >-CompoundStmt 0x2e4fd78 <col:26, line:32:3>
  > > `-CompoundStmt 0x2e4fe58 <col:10, line:35:3>
  > `-BinaryOperator 0x2e501b0 <line:39:3, col:18> 'void *' lvalue '='
  > >-MemberExpr 0x2e50138 <col:3, col:9> 'void *' lvalue ->BeginX 0x2e161b0
  > > `-CXXThisExpr 0x2e50120 <col:3> 'class llvm::SmallVectorBase *' this
  > `-ImplicitCastExpr 0x2e50198 <col:18> 'void *' <LValueToRValue>
  > `-DeclRefExpr 0x2e50170 <col:18> 'void *' lvalue Var 0x2e3e040 'NewElts' 'void *'
  `-FullComment 0x2e62600 <line:17:4, line:18:72>
    `-ParagraphComment 0x2e625d0 <line:17:4, line:18:72>
      >-TextComment 0x2e62580 <line:17:4, col:78> Text=" grow_pod - This is an implementation of the grow() method which only works"
      `-TextComment 0x2e625a0 <line:18:4, col:72> Text=" on POD-like datatypes and is out of line to reduce code duplication."

Source code llvm/SmallVector.cpp at master · llvm-mirror/llvm · GitHub

There is no first 'if' at all, last line is absent too.

Some nodes disappeared.

I'm writing a clang-based tool and when I try to use RecursiveASTVisitor on that declaration it can't find those absent nodes too.

Is this a bug or some kind of strange behaviour?

$ clang++ --version
clang version 4.0.0-svn278304-1~exp1 (trunk)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

2

Matching IfStmt AST node on that line using clang-query works fine for me. Thus, clang isn’t a problem.

- Kirill

3

Are you sure you don’t get any compiler errors?
It is usually the case when you get partial ast.

4

Hello Eugene,

Many AST nodes in your dump are marked as invalid. Are you sure your compilation command is correct? Maybe you need some additional includes or defines?

17.08.2016 21:03, Eugene Kosov via cfe-dev пишет:

5

Sure I did have errors. Thanks for your help!

6

No problem.

btw I think we should make FAQ for clang-tools-extra to include issues like this (actually Eugene wasn’t using clang-check to dump, but I think it is one of the common things.

If you have any other issues that you thing should be mentioned please write it here:
https://docs.google.com/document/d/1_1G-Ib6bdi-Y0zvznJ2ZGLVUHpqMYJ4I7luOLKNj2Bg/edit?usp=sharing