The test program writes 3 values of a discriminated record to a stream
('Output) and then reads them back ('Input).
It then uses 'Write and 'Read for a single value.
No problem arises with 32-bit compilations, or with 64-bit compilations with
-O0.
With -O1 or -O2, the values read back are incorrect (in some cases).
Same behaviour reported on Debian:
gnat-4.4_4.4.2-5_amd64.deb:
-O0 OK
-O1 bug
-O2 bug
gnat-4.4_4.4.2-5_i386.deb:
-O0 OK
-O1 OK
-O2 OK
That version of GNAT was taken from the FSF's gcc-4_4-branch on
2009-12-28 so is very recent.
The correct output is
1234
'z'
4.32100E-01
4.32100E-01
The incorrect output is
1234
NUL
0.00000E+00
0.00000E+00
--
Summary: Problem reading discriminated values from streams
Product: gcc
Version: 4.4.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: ada
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: simon at pushface dot org
GCC host triplet: x86_64-apple-darwin10
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42618
