Bug 597848

+++ This bug was initially created as a clone of Bug #589467 +++

Created an attachment (id=411878)
sra-1.c

On the attached testcase:

(gdb) b 20
(gdb) b 31
(gdb) b 42
(gdb) r

(gdb) p a
$1 = {i = 4, j = 14}
(gdb) p a.i
$2 = 4
(gdb) p a.j
$3 = 4
(gdb) c

$3 is wrong, should have been 14.  The debug info looks correct and, after all,
p a printed it correctly too.

(gdb) p a
$4 = {4, 14}
(gdb) p a[0]
Can't take address of "a" which isn't an lvalue.
(gdb) p a[1]
Can't take address of "a" which isn't an lvalue.
(gdb) c

When p a is able to print it, so should IMHO p a[0] or p a[1].
(gdb) p a
Unhandled dwarf expression opcode 0x9d
(gdb) p a.i
Unhandled dwarf expression opcode 0x9d
(gdb) p a.j
Unhandled dwarf expression opcode 0x9d

And here DW_OP_bit_piece is unsupported.

--- Additional comment from jakub on 2010-05-06 04:55:33 EDT ---

This is with http://gcc.gnu.org/PR43983 #c5 patch.

--- Additional comment from jakub on 2010-05-06 04:56:23 EDT ---

Created an attachment (id=411881)
sra-1.s

gcc -g -O2 -dA generated x86-64 assembly.

--- Additional comment from jakub on 2010-05-06 04:59:26 EDT ---

Created an attachment (id=411883)
sra-1.s

gcc -g -O2 -dA generated x86-64 assembly.

--- Additional comment from tromey on 2010-05-21 17:19:33 EDT ---

I've checked in 4 patches to upstream gdb that should fix these problems.
The unavailable piece patch is not really complete (it warns and fills in
zeroes), but it is better than not getting any results at all.

--- Additional comment from jan.kratochvil on 2010-05-30 14:19:37 EDT ---

gdb-bz589467-pieces1of4.patch
 = http://sourceware.org/ml/gdb-cvs/2010-05/msg00186.html
gdb-bz589467-pieces2of4.patch
 = http://sourceware.org/ml/gdb-cvs/2010-05/msg00188.html
 = http://sourceware.org/ml/gdb-cvs/2010-05/msg00189.html
gdb-bz589467-pieces3of4.patch 
 = http://sourceware.org/ml/gdb-cvs/2010-05/msg00190.html
gdb-bz589467-pieces4of4.patch 
 = http://sourceware.org/ml/gdb-cvs/2010-05/msg00191.html


qa_ack:
+Running gdb/testsuite/gdb.dwarf2/pieces.exp ...
+PASS: gdb.dwarf2/pieces.exp: set f1 breakpoint for pieces
+PASS: gdb.dwarf2/pieces.exp: continue to breakpoint: continue to f1 breakpoint for pieces
+PASS: gdb.dwarf2/pieces.exp: print a in pieces:f1
+PASS: gdb.dwarf2/pieces.exp: print a.j in pieces:f1
+PASS: gdb.dwarf2/pieces.exp: set f2 breakpoint for pieces
+PASS: gdb.dwarf2/pieces.exp: continue to breakpoint: continue to f2 breakpoint for pieces
+PASS: gdb.dwarf2/pieces.exp: print a in pieces:f2
+PASS: gdb.dwarf2/pieces.exp: print a[0] in pieces:f2
+PASS: gdb.dwarf2/pieces.exp: print a[1] in pieces:f2
+PASS: gdb.dwarf2/pieces.exp: set f3 breakpoint for pieces
+PASS: gdb.dwarf2/pieces.exp: continue to breakpoint: continue to f3 breakpoint for pieces
+PASS: gdb.dwarf2/pieces.exp: print a.i in pieces:f3
+PASS: gdb.dwarf2/pieces.exp: print a.j in pieces:f3
+KFAIL: gdb.dwarf2/pieces.exp: set a.i in pieces:f3 (PRMS: no bug yet)
+PASS: gdb.dwarf2/pieces.exp: print new a.i in pieces:f3
+PASS: gdb.dwarf2/pieces.exp: set f6 breakpoint for pieces
+PASS: gdb.dwarf2/pieces.exp: continue to breakpoint: continue to f6 breakpoint for pieces
+PASS: gdb.dwarf2/pieces.exp: print a with optimized out piece
+PASS: gdb.dwarf2/pieces.exp: print a.i with optimized out piece