empty code block

Rule "emptyblock" searches for code blocks that do not have any code in them. For example, there may be a a repeat block where the import statement has been commented out.

REPEAT: 
/* 
  CREATE customer. 
  IMPORT customer. 
*/ 
END. 

Technically speaking, this rule belongs to an existing rule that checks for code that has no effect - but in this case, the warning message is more detailed, providing info on the type of a block that is empty.

Notes:

• The program locates 'Code_block' node and checks that node's first
  child. If child node is not found, then there was nothing in the
  block.
• The rule is really to flag 'empty' blocks, not meaningless blocks (
  i.e. blocks that don't do anything, like just define local variables).
• There may be a false positive when utilizing a super/persistent procedure, and a function has an input or output parameter that sets or returns a private variable or a table:
  

  DEFINE TEMP-TABLE ttData NO-UNDO FIELD dataLine AS CHAR. FUNCTION fnGetData RETURNS LOGICAL (OUTPUT TABLE ttData): /* In this case the function is not really empty */ END FUNCTION. FUNCTION fnSetData RETURNS LOGICAL (INPUT TABLE ttData): /* Code block is not useless either */ END FUNCTION.

• The rule should be enhanced to check for the input/output/input-
  output function parameters at some point and suppress a warning if the
  parameter refers to a global object (temp-tables are always global).
  Not sure what to do about buffer parameters ...
• It also needs to be enhanced to read the contents of non-empty
  blocks that have only local variables defined and no other code at
  all.