xref: /llvm-project/clang-tools-extra/docs/clang-tidy/checks/bugprone/assignment-in-if-condition.rst (revision 05130a6ba7d9974136388c1fbe63125596325d2e)
1.. title:: clang-tidy - bugprone-assignment-in-if-condition
2
3bugprone-assignment-in-if-condition
4===================================
5
6Finds assignments within conditions of `if` statements.
7Such assignments are bug-prone because they may have been intended as equality tests.
8
9This check finds all assignments within `if` conditions, including ones that are not flagged
10by `-Wparentheses` due to an extra set of parentheses, and including assignments that call
11an overloaded `operator=()`. The identified assignments violate
12`BARR group "Rule 8.2.c" <https://barrgroup.com/embedded-systems/books/embedded-c-coding-standard/statement-rules/if-else-statements>`_.
13
14.. code-block:: c++
15
16  int f = 3;
17  if(f = 4) { // This is identified by both `Wparentheses` and this check - should it have been: `if (f == 4)` ?
18    f = f + 1;
19  }
20
21  if((f == 5) || (f = 6)) { // the assignment here `(f = 6)` is identified by this check, but not by `-Wparentheses`. Should it have been `(f == 6)` ?
22    f = f + 2;
23  }
24