http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52151
Bug #: 52151
Summary: Segfault with realloc on assignment and RESHAPE to
unallocated LHS
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: fortran
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: bur...@gcc.gnu.org
CC: pa...@gcc.gnu.org
Follow up to PR 52012 and 52117.
* B is allocated with the shape (n1,n2,n3):
-> Works since the patch for PR 52012
(Before, it had the wrong result for the last two elements)
* B is not allocated
-> Segfault since the patch for PR 52012
-> Before: no segfault but wrong result in for the last two elements
* B allocated with shape (1,1,1)
-> Since patch for PR 52012: No crash, but wrong result ("2.0" and 3.0 appear
multiple times, 5., 6., 7., 8. are missing and 4. is at the wrong
position)
-> Before: no segfault but wrong result in for the last two elements
The test case has been taken from PR 52117 with adaption to show this bug.
chapter08/puppeteer_f2003 of Damian's/Xia's/Xu's book is also affected.
I think there might be an ordering issue with regards to the zero condition and
the bounds condition. Something like the following might work (completely
untested; note also the "ORIF"):
--- trans-expr.c (revision 183971)
+++ trans-expr.c (working copy)
@@ -6296 +6296 @@ fcncall_realloc_result (gfc_se *se, int
- tree zero_cond;
+ tree zero_cond, cond;
@@ -6324,0 +6325 @@ fcncall_realloc_result (gfc_se *se, int
+ cond = boolean_true_node;
@@ -6344 +6345 @@ fcncall_realloc_result (gfc_se *se, int
- zero_cond);
+ cond);
@@ -6345,0 +6347,4 @@ fcncall_realloc_result (gfc_se *se, int
+
+ zero_cond = fold_build2_loc (input_location, TRUTH_ORIF_EXPR,
+ boolean_type_node, zero_cond,
+ cond);
! Based on the example of PR 52117 by Steven Hirshman
PROGRAM RESHAPEIT
INTEGER, PARAMETER :: n1=2, n2=2, n3=2
INTEGER :: m1, m2, m3, lc
REAL, ALLOCATABLE :: A(:,:), B(:,:,:)
REAL :: val
ALLOCATE (A(n1,n2*n3))
! <<< No allocation: Segfault
! ALLOCATE (B(1,1,1)) ! << Does not segfault, but result is wrong
! ALLOCATE (B(n1,n2,n3)) ! << WORKS
val = 0
lc = 0
DO m3=1,n3
DO m2=1,n2
lc = lc+1
DO m1=1,n1
val = val+1
A(m1, lc) = val
END DO
END DO
END DO
B = RESHAPE(A, [n1,n2,n3])
lc = 0
DO m3=1,n3
DO m2=1,n2
lc = lc+1
DO m1=1,n1
PRINT *,'A(',m1,',',lc,') = ',A(m1,lc),' B = ',B(m1,m2,m3)
if (A(m1,lc) /= B(m1,m2,m3)) call abort ()
END DO
END DO
END DO
DEALLOCATE(A, B)
END PROGRAM RESHAPEIT
