tree-sitter / tree-sitter/tree-sitter-cpp

bug: Consecutive conditions using less-than "<" operator parsed as an ERROR

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bug
Dominant language
JavaScript
Stars
453
Forks
185
PR merge metrics
No merged PRs in 30d

Description

Did you check existing issues?
  • I have read all the tree-sitter docs if it relates to using the parser
  • I have searched the existing issues of tree-sitter-cpp
Tree-Sitter CLI Version, if relevant (output of tree-sitter --version)

tree-sitter 0.22.6

Describe the bug

Consecutive conditions using operator < will produce ERROR. Using only one condition using operator < parsed without any ERROR.

Steps To Reproduce/Bad Parse Tree

Debug graph included below.

(ERROR [0, 0] - [11, 0]
  (struct_specifier [0, 0] - [3, 1]
    name: (type_identifier [0, 7] - [0, 8])
    body: (field_declaration_list [0, 9] - [3, 1]
      (field_declaration [1, 1] - [1, 12]
        type: (primitive_type [1, 1] - [1, 4])
        declarator: (field_identifier [1, 5] - [1, 11]))
      (field_declaration [2, 1] - [2, 12]
        type: (primitive_type [2, 1] - [2, 4])
        declarator: (field_identifier [2, 5] - [2, 11]))))
  type: (primitive_type [5, 0] - [5, 3])
  (function_declarator [5, 4] - [5, 21]
    declarator: (identifier [5, 4] - [5, 9])
    parameters: (parameter_list [5, 9] - [5, 21]
      (parameter_declaration [5, 10] - [5, 20]
        (type_qualifier [5, 10] - [5, 15])
        type: (type_identifier [5, 16] - [5, 17])
        declarator: (reference_declarator [5, 17] - [5, 20]
          (identifier [5, 19] - [5, 20])))))
  (identifier [7, 4] - [7, 5])
  (identifier [7, 6] - [7, 12])
  (number_literal [7, 15] - [7, 16])
  (identifier [7, 20] - [7, 21])
  (identifier [7, 22] - [7, 28])
  (ERROR [7, 31] - [8, 8]
    (number_literal [7, 31] - [7, 32]))
  (number_literal [8, 9] - [8, 11]))

Debug graph: log.zip

Expected Behavior/Parse Tree

Operator < should not produce any ERROR node.

Repro
struct X {
  int field0;
  int field1;
};

int func(const X& a)
{
  if(a.field0 < 0 || a.field1 < 0)
    return -1;
  return 0;
}

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the provided C++ reproduction and inspect its parse output using the tree-sitter CLI and the supplied debug graph. Compare the consecutive less-than conditions with a single condition; done means the reproduced input parses without any ERROR node.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
compilers
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

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