http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51517
Bug #: 51517
Summary: [4.4 regression ] Wrong debug information for pointers
with negative strides.
Classification: Unclassified
Product: gcc
Version: 4.6.2
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: debug
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: niko...@totalviewtech.com
Created attachment 26062
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26062
Example to demostrate
Consider attached examples, pointer ip:
integer, dimension (:), pointer :: ip
If you associate it twice for two variables,
.....
ip => it (10:1:-2)
....
ip => unpleasant%small_pad
than stride calculated as zero
<2><b2>: Abbrev Number: 7 (DW_TAG_variable)
DW_AT_name : ip
DW_AT_decl_file : 1
DW_AT_decl_line : 8
DW_AT_type : <165>
DW_AT_location : 3 byte block: 91 b0 7e (DW_OP_fbreg: -208)
<1><165>: Abbrev Number: 15 (DW_TAG_array_type)
DW_AT_data_location: 2 byte block: 97 6 (DW_OP_push_object_address;
DW_OP_deref)
DW_AT_associated : 4 byte block: 97 6 30 2e
(DW_OP_push_object_address; DW_OP_deref; DW_OP_lit0; DW_OP_ne)
DW_AT_type : <60>
DW_AT_sibling : <189>
<2><176>: Abbrev Number: 14 (DW_TAG_subrange_type)
DW_AT_lower_bound : 4 byte block: 97 23 20 6
(DW_OP_push_object_address; DW_OP_plus_uconst: 32; DW_OP_deref)
DW_AT_upper_bound : 4 byte block: 97 23 28 6
(DW_OP_push_object_address; DW_OP_plus_uconst: 40; DW_OP_deref)
DW_AT_stride : 6 byte block: 97 23 18 6 30 1e
(DW_OP_push_object_address; DW_OP_plus_uconst: 24; DW_OP_deref; DW_OP_lit0;
DW_OP_mul)
I think error is in: DW_OP_lit0. Should be something like DW_OP_lit2
This is regression from 4.4 and is broken in 4.5 and 4.6
I have attached an example that you can compile and verify.
