8.63. gcc

Updated gcc packages that fix numerous bugs and add one enhancement are now available for Red Hat Enterprise Linux 6.
The gcc packages provide compilers for C, C++, Java, Fortran, Objective C, and Ada 95 GNU, as well as related support libraries.

Bug Fixes

Previously, the GNU Compiler Collection (GCC) did not handle compiling partial specialization invalid C++ code correctly. As a consequence, GCC could terminate unexpectedly with a segmentation fault. The bug has been fixed and GCC now provides a translation-time error instead of crashing.
Previously, the GNU Compiler Collection (GCC) did not handle loop vectorization correctly. Consequently, GCC could terminate with a segmentation fault. With this update, GCC correctly ignores the debug statements when the vectorizer is looking for a loop-exit PHI node, and GCC now compiles the code as expected.
Previously, after compiling the source code of a program using the "-fprofile-arcs" and "-ftest-coverage" command-line options, the program was run and the gcov utility was started, but after that, a new source code file was created and gcov was started again. As a consequence, gcov damaged the existing .gcda files. After this update, functions are properly restored if a failure occurs, and gcov no longer damages other files.
Previously, if an invalid code in gnu++11 mode used an initializer list with an invalid value in its constructor, the g++ compiler terminated with a segmentation fault. With this update, the constructor is better tested for incorrect values, and g++ no longer crashes in the described scenario.
Previously, the Clang compiler did not handle certain headers correctly. As a consequence, a program using the typeinfo and exception headers failed to compile, and an "incomplete type" error message was displayed. With this update, the exception header in the libstdc++ library has been adjusted, and programs now compile as expected with the Clang compiler.
Previously, the standard uncaught_exception() function returned the "True" value even when the initialization of the exception object was not complete. As a consequence, the GNU Compiler Collection (GCC) could generate wrong code. With this update, uncaught_exception() returns the "True" value only after the exception object is created, and GCC always generates correct code as expected.
Prior to this update, the g++ compiler rejected code that tried to pass a type with a non-trivial copy constructor through variable arguments. As a consequence, programs compiled with the GNU Compiler Collection (GCC) terminated unexpectedly with an "Illegal instruction" error message. With this update g++ now accepts the code because it treats passing variadic arguments of non-trivial types as a pass-by-invisible reference.
Previously, the gfortran compiler did not correctly handle compiling code that involved invalid old-style initialization for derived type components. As a consequence, gfortran could terminate unexpectedly with a segmentation fault. A patch has been applied to address this bug, and the code is now properly rejected when needed, and an appropriate error message is displayed.
Larger aggregate contains the same fields as the smaller one with just some fields added at the end. Prior to this update, optimizing code that contained conversion from a larger aggregate to a smaller aggregate could cause the GNU Compiler Collection (GCC) to generate incorrect code. Consequently, using GCC with turned on optimizations failed and a segmentation fault occurred. With this update, conversions between aggregates with different sizes are never considered useless, and GCC no longer generates incorrect code in the described situation.


OpenMP 4.0 support has been added to the GNU OpenMP library, which allows applications built with DTS 3.0 and using OpenMP to link on Red Hat Enterprise Linux 6.
Users of gcc are advised to upgrade to these updated packages, which which fix these bugs and add this enhancement.