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Bug #3315

infinite loop in mark_client_branch during annotations because of nest CAN-FINDs with temp and perm tables

Added by Greg Shah almost 7 years ago. Updated over 6 years ago.

Status:
WIP
Priority:
Normal
Assignee:
Eric Faulhaber
Target version:
-
Start date:
Due date:
% Done:

0%

billable:
No
vendor_id:
GCD
case_num:
version:

3315_20170810a.patch Magnifier - patch for rules/annotations/where_clause_prep2.rules infinite loop marking client branch (1.24 KB) Eric Faulhaber, 08/10/2017 12:46 PM

History

#1 Updated by Greg Shah almost 7 years ago

Bug report (from a customer):

The problem is with nested CAN-FINDs which mix ordinary table and temp-table. In this case FWD conversion process hangs.

I have located the reason: it is while-loop which gets executed infinitely: in rules/annotations/where_clause_prep2.rules (function mark_client_branch):

<action>topref = ref</action>
<action>level = topref.depth - expref.depth</action>
<while>topref.ancestor(level, prog.kw_where)
   <action>topref = topref.getAncestor(level, prog.kw_where)</action>
   <action>level = topref.depth - expref.depth</action>
</while>

The problem can be recreated using this code (checked in to testcases/uast/nested_can_find_mixing_temp_and_perm_tables.p):

def var res as logical.
def var id  as int init 14.

def temp-table tt no-undo 
    field txt as char.

res = CAN-FIND(FIRST book NO-LOCK
                     WHERE book.book-id = id
                       AND CAN-FIND (FIRST tt NO-LOCK
                                     WHERE tt.txt = book.book-title)).

When run, the following message is printed to the console before the hang:

INFO: CAN-FIND-only reference to buffer p2j_test.book,p2j_test.book,-1 from TABLE (219043332157 [7@22])

#2 Updated by Eric Faulhaber almost 7 years ago

I took a quick look at this and produced the attached fix to prevent the infinite loop. However, there is still a problem with the converted code for this test case, in that the HQL generated for the outer CAN-FIND is incorrect. The generated HQL is:

"book.bookId = ? and"

...but it should be:
"book.bookId = ?"

So, this will fail at runtime.

The KW_AND node associated with this where clause is being annotated incorrectly. This will require further investigation, but the attached patch should at least get the customer past the conversion hang.

#3 Updated by Eric Faulhaber almost 7 years ago

  • Assignee set to Eric Faulhaber
  • Status changed from New to WIP

TODO: add the fix from #3315-2 to an existing development branch or create a branch for it.

#4 Updated by Eric Faulhaber over 6 years ago

The patch from #3315-2 was added to task branch 3293a, which was merged to FWD trunk revision 11160.

Jaroslaw, at your convenience, please let us know if this patch fixes the infinite loop issue originally reported.

We still have to address the problem of incorrect HQL being generated.

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