Avoid Comparisons and Arithmetic with Identical Operands

WarningAnti-Patterns & Bad Practices#EC NO_SELF_COMPARERemote Enabled

Overview

Detect comparisons and arithmetic with identical operands.

ATC Finding Messages:

• Both sides of the comparison resolve to the same symbol
• Arithmetic operation uses the same symbol on both sides

Rationale

Comparing an expression with itself (lv_status = lv_status) always yields the same result, so the condition or assignment is meaningless and usually hides a copy-paste mistake. The same applies to arithmetic that always collapses to a constant (lv_diff = lv_x - lv_x). Operands are resolved through compiler symbols, so shadowed names and textually equal but different symbols are not confused. Statements with an AND/OR chain are left to no-dup-cond to avoid double findings.

Non-Compliant

IF lv_status = lv_status.
  lv_count = lv_count + 1.
ENDIF.
lv_diff = lv_x - lv_x.

Compliant

IF lv_status = c_status-done.
  lv_count = lv_count + 1.
ENDIF.
lv_diff = lv_x - lv_y.

Suppression

To suppress findings for this rule, append the pseudo-comment to the statement:

" Standard pseudo-comment:
... "#EC NO_SELF_COMPARE

" SAP CI_ prefix format:
... "#EC CI_NO_SELF_COMPARE

Related Rules

• Avoid Dead Code with Constant Conditions — #EC NO_DEAD_CODE
• Avoid Duplicate Branch Conditions — #EC NO_DUP_COND
• Remove Redundant Self-Assignments and Identity Moves — #EC NO_IDENTICAL_MOVE

Technical Details

• Native ATC Class: ZCL_SKYLINT_NO_SELF_COMPARE
• Implementation File: zcl_skylint_no_self_compare.clas.abap