Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

Error on conditional compilation preprocessor directive

See original GitHub issue

var a = new ArrayList()
{
    #if DEBUG
        Capacity = 3
    #else
        Capacity = 4
    #endif
};

Actual:

(compilation_unit [0, 8] - [7, 10]
  (global_statement [0, 8] - [7, 10]
    (local_declaration_statement [0, 8] - [7, 10]
      (variable_declaration [0, 8] - [7, 9]
        type: (implicit_type [0, 8] - [0, 11])
        (variable_declarator [0, 12] - [7, 9]
          (identifier [0, 12] - [0, 13])
          (equals_value_clause [0, 14] - [7, 9]
            (object_creation_expression [0, 16] - [7, 9]
              type: (identifier [0, 20] - [0, 29])
              arguments: (argument_list [0, 29] - [0, 31])
              initializer: (initializer_expression [1, 8] - [7, 9]
                (preprocessor_call [2, 12] - [2, 21]
                  (preprocessor_directive [2, 12] - [2, 15])
                  (identifier [2, 16] - [2, 21]))
                (assignment_expression [3, 16] - [5, 28]
                  left: (identifier [3, 16] - [3, 24])
                  (assignment_operator [3, 25] - [3, 26])
                  right: (assignment_expression [3, 27] - [5, 28]
                    left: (integer_literal [3, 27] - [3, 28])
                    (preprocessor_call [4, 12] - [4, 17]
                      (preprocessor_directive [4, 12] - [4, 17]))
                    (ERROR [5, 16] - [5, 24])
                    (assignment_operator [5, 25] - [5, 26])
                    right: (integer_literal [5, 27] - [5, 28])))
                (preprocessor_call [6, 12] - [6, 18]
                  (preprocessor_directive [6, 12] - [6, 18]))))))))))
foo.cs	0 ms	(ERROR [5, 16] - [5, 24])

Expected:

(compilation_unit [0, 8] - [8, 0]
  (global_statement [0, 8] - [7, 10]
    (local_declaration_statement [0, 8] - [7, 10]
      (variable_declaration [0, 8] - [7, 9]
        type: (implicit_type [0, 8] - [0, 11])
        (variable_declarator [0, 12] - [7, 9]
          (identifier [0, 12] - [0, 13])
          (equals_value_clause [0, 14] - [7, 9]
            (object_creation_expression [0, 16] - [7, 9]
              type: (identifier [0, 20] - [0, 29])
              arguments: (argument_list [0, 29] - [0, 31])
              initializer: (initializer_expression [1, 8] - [7, 9]
                (preprocessor_call [2, 12] - [2, 21]
                  (preprocessor_directive [2, 12] - [2, 15])
                  (identifier [2, 16] - [2, 21]))
                (assignment_expression [3, 16] - [3, 28]
                  left: (identifier [3, 16] - [3, 24])
                  (assignment_operator [3, 25] - [3, 26])
                  right: (integer_literal [3, 27] - [3, 28]))
                (preprocessor_call [4, 12] - [4, 17]
                  (preprocessor_directive [4, 12] - [4, 17]))
                (assignment_expression [5, 16] - [5, 28]
                  left: (identifier [5, 16] - [5, 24])
                  (assignment_operator [5, 25] - [5, 26])
                  right: (integer_literal [5, 27] - [5, 28]))
                (preprocessor_call [6, 12] - [6, 18]
                  (preprocessor_directive [6, 12] - [6, 18]))))))))))

Issue Analytics

State:
Created 2 years ago
Comments:6 (4 by maintainers)

Top GitHub Comments

1reaction

damiengcommented, Jul 27, 2021

Yes, this is the same underlying cause and limitation. There is no way anything other than a compiler can definitively resolve that kind of fragmented condition - you would need to evaluate all the preprocessor conditions to know which paths are valid.

0reactions

damiengcommented, Jul 27, 2021

That said, it is my intention to adopt something similar to what the C grammar is doing that Max described above which will at least let us parse/recover even if we don’t definitively know what was intended (I’m just wrapping up a paid project and hope to have some time to devote to tree-sitter-c-sharp again in the next week or so)

Top Results From Across the Web

Conditional Compilation Errors in Pl/SQL

Here's a list of common Pl/SQL Conditional Compilation errors, ... PLS-00177: '$IF' preprocessor directive does not end properly.

C# preprocessor directives | Microsoft Learn

In this article. Nullable context; Conditional compilation; Defining symbols; Defining regions; Error and warning information; Pragmas.

How do I show conditional error using C preprocessor during ...

This is just a way to use the C preprocessor #error directive for showing errors according to condition during compilation Like for example:...

8.2 Conditional Compilation (#if, #ifdef, #ifndef, #else, #elif ...

They delimit blocks of program text that are compiled only if a specified condition is true. These directives can be nested. The program...

What is the #error directive in C++? - Educative.io

#error is a Preprocessor Directive that has the following structure: ... #error directive is normally used to throw an error during conditional compilation....