Bug #1429
Stack overflow reading long list (SEGV)
Description
On my computer CoCoAInterpreter generates a SEGV if I give as input a long list, namely
L := [ 1, 2, ... 550000 ];
valgrind reported the problem as a stack overflow (but why?)
The problem was originally reported by Bernhard Andraschko: his computer failed to read a list of about 14400 4x4 matrices.
Splitting the list into two separate parts, and then concatenating them worked fine (and quickly).
History
#1
Updated by John Abbott about 4 years ago
Updated by Yes, of course, inputting explicitly the long list of integers is not commonplace.
But it is embarrassing that CoCoA crashed when reading Bernhard's list of 14400 small matrices.
A first guess is that the parser uses a recursive technique to read a long list, and that this triggers a stack overflow. But then why does a list of matrices fail before 14400 elements (on his computer), whereas a list of integers can be much longer -- surely the stack consumption should depend almost solely on the list length...??
The original problem arose when Bernhard wanted to transfer a result from Sage into CoCoA.
The relevant code may be in Parser.C around lines 1771--1779 in the function Parser::parseListPrimary
#2
Updated by John Abbott about 3 years ago
- Target version changed from CoCoA-5.4.0 to CoCoA-5.4.2