How to see all UnresolvedLookupExpr node in Clang AST

Question

I am looking into various scenarios where UnresolvedLookupExpr node occurs. I notice that the output of -ast-dump and clang-query don't match.

Here is an example code in c++/9/bits/range_access.h.

template<typename _Container>
  inline constexpr auto
  cbegin(const _Container& __cont) noexcept(noexcept(std::begin(__cont)))
    -> decltype(std::begin(__cont))
  { return std::begin(__cont); }

The output of -ast-dump contains only one UnresolvedLookupExpr node.

| |-FunctionTemplateDecl 0xf4c0d8 <line:114:3, line:118:34> line:116:5 cbegin
| | |-TemplateTypeParmDecl 0xf4bbe0 <line:114:12, col:21> col:21 referenced typename depth 0 index 0 _Container
| | `-FunctionDecl 0xf4c030 <line:115:5, line:118:34> line:116:5 constexpr cbegin 'auto (const _Container &) noexcept(noexcept(std::begin(__cont))) -> decltype(std::begin(__cont))' inline
| |   |-ParmVarDecl 0xf4bcb0 <col:12, col:30> col:30 referenced __cont 'const _Container &'
| |   `-CompoundStmt 0xf4c2c8 <line:118:5, col:34>
| |     `-ReturnStmt 0xf4c2b8 <col:7, col:31>
| |       `-CallExpr 0xf4c290 <col:14, col:31> '<dependent type>'
| |         |-UnresolvedLookupExpr 0xf4c1e8 <col:14, col:19> '<overloaded function type>' lvalue (no ADL) = 'begin' 0xd8f4b0 0xf48bb8 0xf490f8 0xf4a130 0xf4aeb8 0xf4b308
| |         `-DeclRefExpr 0xf4c270 <col:25> 'const _Container' lvalue ParmVar 0xf4bcb0 '__cont' 'const _Container &'

The output of clang-query shows three.

clang-query> m unresolvedLookupExpr(hasAnyDeclaration(functionTemplateDecl(hasName("begin"))))

Match #1:
/usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/range_access.h:117:19: note: "root" binds here
      -> decltype(std::begin(__cont))
                  ^~~~~~~~~~
Match #2:
/usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/range_access.h:116:56: note: "root" binds here
    cbegin(const _Container& __cont) noexcept(noexcept(std::begin(__cont)))
                                                       ^~~~~~~~~~
Match #3:
/usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/range_access.h:118:14: note: "root" binds here
    { return std::begin(__cont); }
             ^~~~~~~~~~
3 matches.

It looks like the code in noexcept() and return type are not shown as AST in -ast-dump output.

Why is there such discrepancy?
Given that clang-query shows more occurrences, I assume -ast-dump doesn't show the full AST. Is there a way to easily get a more detailed AST?

How to see all UnresolvedLookupExpr node in Clang AST

0 Answers0