Re: [Bug-apl] segmentation fault in svn 639

[alexweiner]

I think the problem is incorrect parsing. Note that there is no space between between the 'x' and the first '5'. you can also get a segfault if you use ⎕nc and a similar syntax. Its weird because ⎕nc5 and ⎕ex5 result in Domain errors as expected. 

It looks like the stack trace for both these functions call the same underlying function that the stack trace ends on:

Value::to_varnames(std::vector<UCS_string, std::allocator<UCS_string> >&, bool) const

My C++ is too rusty to figure this out. 

       ⎕nc5 5 ⍴ '3 3   '

====================================================

SEGMENTATION FAULT

----------------------------------------

-- Stack trace at main.cc:63

----------------------------------------

0x7f0d74089ec5 __libc_start_main

0x4432d5  main

0x577b8d   Workspace::immediate_execution(bool)

0x48ce1a    Command::process_line()

0x48cef8     Command::do_APL_expression(UCS_string&)

0x497e9b      Executable::execute_body() const

0x524af0       StateIndicator::run()

0x4cd254        Prefix::reduce_statements()

0x4cc54d         Prefix::reduce_MISC_F_B_()

0x4f5fd1          Quad_NC::eval_B(Value_P)

0x574842           Value::to_varnames(std::vector<UCS_string, std::allocator<UCS_string> >&, bool) const

0x7f0d74e90c90            

0x448227             

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-------- Original Message --------
Subject: Re: [Bug-apl] segmentation fault in svn 639
From: Louis Chretien <address@hidden>
Date: Sat, June 20, 2015 3:27 am
To: address@hidden

Why would you want to EXpunge an _expression_? Isn’t Quad-EX used to delete APL objects?

The APL2 manual states that the argument should be the name of an APL object in quotes.

I agree the error message should not be as dire as a segfault, but the basic intent seems dubious…

On 2015-06-20, at 01:18, address@hidden wrote:

Type this line:

      ⎕ex5 5 ⍴ '3 3   '

and then this segmentation error happens:

====================================================

SEGMENTATION FAULT

----------------------------------------

-- Stack trace at main.cc:63

----------------------------------------

0x7f78c4e6aead __libc_start_main

0x454215  main

0x544885   Workspace::immediate_execution(bool)

0x490922    Command::process_line()

0x490107     Command::do_APL_expression(UCS_string&)

0x499890      Executable::execute_body() const

0x5051f0       StateIndicator::run()

0x4c2d9e        Prefix::reduce_statements()

0x4c291f         Prefix::reduce_MISC_F_B_()

0x4e2eee          Quad_EX::eval_B(Value_P)

0x53eed0           Value::to_varnames(std::vector<UCS_string, std::allocator<UCS_string> >&, bool) const

0x7f78c5b9d0a0            

0x458f7a             

========================================

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---

Louis Chrétien

address@hidden