Inappropriate loops behaviour <for(), foreach(), break, continue>, segmentation fault while producing stacktrace #62

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opened 2019-12-21 11:13:56 +01:00 by belliash · 3 comments

belliash commented

2019-12-21 11:13:56 +01:00

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AerScript Information

Aer Version (or commit ref): ab36234ff3
Operating System: Linux
System Architecture (eg. arm, x86_64, ...): x86_64

Your problem description

I have written another test - sudoku solver. It causes AerScript interpreter to fail. Sometimes it simply results in no solution, sometimes throws segmentation fault. When investigating issue, I realized this is connected with LOOP frames. After modifying code, to not declare variables repeatedly inside loops and removing OP_LOOP_START and OP_LOOP_START calls from PH7_CompileFor(), PH7_CompileBreak() and PH7_CompileContinue(), attached script has begun to work properly. Additionally, during investigation I have found another problem with for() loop statement:

for(int $a = 0; $a < 5; $a++) {
}
var_dump($a); // shows 4, while it should result in non-existent variable error.

Expected results

3 0 6 5 0 8 4 0 0
5 2 0 0 0 0 0 0 0
0 8 7 0 0 0 0 3 1
0 0 3 0 1 0 0 8 0
9 0 0 8 6 3 0 0 5
0 5 0 0 9 0 6 0 0
1 3 0 0 0 0 2 5 0
0 0 0 0 0 0 0 7 4
0 0 5 2 0 6 3 0 0
=================
3 1 6 5 7 8 4 9 2
5 2 9 1 3 4 7 6 8
4 8 7 6 2 9 5 3 1
2 6 3 4 1 5 9 8 7
9 7 4 8 6 3 1 2 5
8 5 1 7 9 2 6 4 3
1 3 8 9 4 7 2 5 6
6 9 2 3 5 1 8 7 4
7 4 5 2 8 6 3 1 9

Current results

3 0 6 5 0 8 4 0 0 
5 2 0 0 0 0 0 0 0
0 8 7 0 0 0 0 3 1 
0 0 3 0 1 0 0 8 0 
9 0 0 8 6 3 0 0 5
0 5 0 0 9 0 6 0 0 
1 3 0 0 0 0 2 5 0 
0 0 0 0 0 0 0 7 4
0 0 5 2 0 6 3 0 0 
=================
No solution found
AddressSanitizer:DEADLYSIGNAL
=================================================================
==13697==ERROR: AddressSanitizer: SEGV on unknown address 0x60e800050cb4 (pc 0x7f515465b959 bp 0x62d00000a424 sp 0x7fff6d5431d8 T0)
==13697==The signal is caused by a READ memory access.
#0 0x7f515465b958 in PH7_VmExtractActiveClass engine/vm.c:5383
#1 0x7f51546560dc in VmExtractDebugTrace engine/debug.c:47
#2 0x7f515465b292 in PH7_VmThrowError engine/vm.c:1785
#3 0x7f515465dc97 in VmByteCodeExec engine/vm.c:2375
#4 0x7f5154661495 in VmByteCodeExec engine/vm.c:4805
#5 0x7f51546627dd in PH7_VmCallClassMethod engine/vm.c:6193
#6 0x7f515466386a in PH7_VmByteCodeExec engine/vm.c:5082
#7 0x7f5154652f75 in ph7_vm_exec engine/api.c:616
#8 0x55a1e67910c7 in main (/home/Belliash/Documents/Repositories/AerScript/binary/aer+0x10c7)
#9 0x7f515446be9a in __libc_start_main (/lib64/libc.so.6+0x26e9a)
#10 0x55a1e6790be9 in _start (/home/Belliash/Documents/Repositories/AerScript/binary/aer+0xbe9)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV engine/vm.c:5383 in PH7_VmExtractActiveClass
==13697==ABORTING

# AerScript Information - Aer Version (or commit ref): ab36234ff3 - Operating System: Linux - System Architecture (eg. arm, x86_64, ...): x86_64 # Your problem description I have written another test - sudoku solver. It causes AerScript interpreter to fail. Sometimes it simply results in no solution, sometimes throws segmentation fault. When investigating issue, I realized this is connected with LOOP frames. After modifying code, to not declare variables repeatedly inside loops and removing OP_LOOP_START and OP_LOOP_START calls from PH7_CompileFor(), PH7_CompileBreak() and PH7_CompileContinue(), attached script has begun to work properly. Additionally, during investigation I have found another problem with for() loop statement: for(int $a = 0; $a < 5; $a++) { } var_dump($a); // shows 4, while it should result in non-existent variable error. # Expected results 3 0 6 5 0 8 4 0 0 5 2 0 0 0 0 0 0 0 0 8 7 0 0 0 0 3 1 0 0 3 0 1 0 0 8 0 9 0 0 8 6 3 0 0 5 0 5 0 0 9 0 6 0 0 1 3 0 0 0 0 2 5 0 0 0 0 0 0 0 0 7 4 0 0 5 2 0 6 3 0 0 ================= 3 1 6 5 7 8 4 9 2 5 2 9 1 3 4 7 6 8 4 8 7 6 2 9 5 3 1 2 6 3 4 1 5 9 8 7 9 7 4 8 6 3 1 2 5 8 5 1 7 9 2 6 4 3 1 3 8 9 4 7 2 5 6 6 9 2 3 5 1 8 7 4 7 4 5 2 8 6 3 1 9 # Current results 3 0 6 5 0 8 4 0 0 5 2 0 0 0 0 0 0 0 0 8 7 0 0 0 0 3 1 0 0 3 0 1 0 0 8 0 9 0 0 8 6 3 0 0 5 0 5 0 0 9 0 6 0 0 1 3 0 0 0 0 2 5 0 0 0 0 0 0 0 0 7 4 0 0 5 2 0 6 3 0 0 ================= No solution found AddressSanitizer:DEADLYSIGNAL ================================================================= ==13697==ERROR: AddressSanitizer: SEGV on unknown address 0x60e800050cb4 (pc 0x7f515465b959 bp 0x62d00000a424 sp 0x7fff6d5431d8 T0) ==13697==The signal is caused by a READ memory access. #0 0x7f515465b958 in PH7_VmExtractActiveClass engine/vm.c:5383 #1 0x7f51546560dc in VmExtractDebugTrace engine/debug.c:47 #2 0x7f515465b292 in PH7_VmThrowError engine/vm.c:1785 #3 0x7f515465dc97 in VmByteCodeExec engine/vm.c:2375 #4 0x7f5154661495 in VmByteCodeExec engine/vm.c:4805 #5 0x7f51546627dd in PH7_VmCallClassMethod engine/vm.c:6193 #6 0x7f515466386a in PH7_VmByteCodeExec engine/vm.c:5082 #7 0x7f5154652f75 in ph7_vm_exec engine/api.c:616 #8 0x55a1e67910c7 in main (/home/Belliash/Documents/Repositories/AerScript/binary/aer+0x10c7) #9 0x7f515446be9a in __libc_start_main (/lib64/libc.so.6+0x26e9a) #10 0x55a1e6790be9 in _start (/home/Belliash/Documents/Repositories/AerScript/binary/aer+0xbe9) AddressSanitizer can not provide additional info. SUMMARY: AddressSanitizer: SEGV engine/vm.c:5383 in PH7_VmExtractActiveClass ==13697==ABORTING

belliash commented

2019-12-21 11:21:41 +01:00

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Attached affected script.

sudoku_solver.aer

2.1 KiB

belliash added the

bug

label 2019-12-21 11:24:11 +01:00

belliash commented

2019-12-22 22:42:27 +01:00

Author

Owner

Revisions c730082fa0 and 709b5971c6 fixes the segmentation fault problem. There is still a need to investigate and resolve problem of variables scopes.

Revisions c730082fa0 and 709b5971c6 fixes the segmentation fault problem. There is still a need to investigate and resolve problem of variables scopes.

belliash commented

2019-12-22 22:44:50 +01:00

Author

Owner

Sudoku solver test added in 3eb82e632b.

Sudoku solver test added in 3eb82e632b.