https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67430
Bug ID: 67430
Summary: reallocate lhs with overloaded assignment operators
causes memory error and wrong size
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: alipasha.celeris at gmail dot com
Target Milestone: ---
Created attachment 36284
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36284&action=edit
the test file with line numbers matching the Valgrind output.
The following code produces a memory error in Valgrind (an invalid read) and
does not reallocate the LHS to the correct size.
MODULE A_TEST_M
TYPE :: A_TYPE
INTEGER :: INT
!
CONTAINS
!
GENERIC :: ASSIGNMENT (=) => ASGN_A
PROCEDURE, PRIVATE :: ASGN_A
END TYPE
CONTAINS
ELEMENTAL SUBROUTINE ASGN_A (A, B)
CLASS (A_TYPE), INTENT (INOUT) :: A
CLASS (A_TYPE), INTENT (IN) :: B
!
A%INT = 45
END SUBROUTINE
END MODULE A_TEST_M
PROGRAM ASGN_REALLOC_TEST
USE A_TEST_M
TYPE (A_TYPE), ALLOCATABLE :: A(:)
!
ALLOCATE (A(4))
A(1:2)%INT = 7
A(3:4)%INT = 13
!
A = A(1:2)
!
PRINT *, 'SIZE(A)', SIZE(A), 'A:', A
END PROGRAM
The results look like this (valgrind output):
==30070== Memcheck, a memory error detector
==30070== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==30070== Using Valgrind-3.11.0.SVN and LibVEX; rerun with -h for copyright
info
==30070== Command: ./a.out
==30070==
==30070== Invalid read of size 8
==30070== at 0x402F148: _intel_fast_memcpy (vg_replace_strmem.c:946)
==30070== by 0x400CA1: MAIN__ (asgn_realloc_test.f:29)
==30070== by 0x400DF3: main (asgn_realloc_test.f:22)
==30070== Address 0x50f37c8 is 0 bytes after a block of size 8 alloc'd
==30070== at 0x402BB20: malloc (vg_replace_malloc.c:299)
==30070== by 0x400C13: MAIN__ (asgn_realloc_test.f:29)
==30070== by 0x400DF3: main (asgn_realloc_test.f:22)
==30070==
SIZE(A) 4 A: 45 45 0 0
"A" should have size of 2 after assignment (being reallocated). It seems that
the overloaded operator is being used (it is rigged to assign 45).
The intrinsic assignment (when = is not overloaded) works fine.
