RHBA-2010:0232 - Bug Fix Advisory

Topic

A gcc update that resolves several compiler bugs is now available.

Description

The gcc packages include C, C++, Java, Fortran, Objective C, and Ada 95 GNU
compilers, along with related support libraries.

This update applies the following bug fixes:

• when compiling a debug version of a C++ program, it was possible for gcc

to lose debug information for some local variables in C++ constructors or
destructors. This was because gcc incorrectly released information on
abstract functions (specifically, contents of the DECL_INITIAL() function),
which are needed for creating debug information. With this release, nodes
containing abstract functions are flagged accordingly to prevent gcc from
prematurely discarding needed debug information. (BZ#513184)

• when issuing multiple -fno-builtin-* switches to gcc, gcc only registered

the last switch. With this release, gcc can now register multiple

• fno-builtin-* switches correctly. (BZ#515799)
• in some cases, aggregates returned by value could cause reload failures

in the caller function, resulting in an internal compiler error. This was
caused by a bug in the combining code that incorrectly lengthens the
lifetime of a hard register. This update applies a patch to expand_call
function in gcc/calls.c that resolves the issue. (BZ#516028)

• using g++ to compile code containing virtual inheritances could result in

a segmentation fault. This was because the dynamic_cast code in gcc did not
use src2dst hints as expected; as a result, g++ could search an
unnecessarily large address list for possible bases. With this release, the
dynamic_cast code now uses src2dst hints; this allows g++ to defer
searching bases that don't overlap with a virtual inheritance's address.
(BZ#519519)

• on PowerPC, it was possible for DWARF access to function parameters to

fail. This was caused by a bug in the GCC instruction set for PowerPC,
where compiling with -mno-sched-prolog could discard debug location lists.
This update fixes the bug, ensuring consistent DWARF access to function
parameters on PowerPC. (BZ#528792)

• the libgcc undwinder now supports DW_OP_swap handling. This update also

fixes bugs in the way unwinding code handled unwind information from
DW_OP_{gt,ge,lt,le} and DW_CFA_{remember,restore}_state. (BZ#555731)

All GCC users are advised to install this update.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 513184 - missing variable in debug info
• BZ - 515799 - [RHEL5] gcc: if more than one -fno-builtin-* options are specified, only the last one is effective
• BZ - 516028 - [RHEL5][GCC] UNABLE TO FIND A REGISTER TO SPILL IN CLASS `AREG'
• BZ - 519519 - [RHEL5 gcc-c++] Code with virtual inheritance compiled by g++ crash at run-time
• BZ - 555731 - Assorted unwinder fixes for RHEL 5.5

CVEs

(none)

References

(none)