4.36. gcc

GCC did not, under rare circumstances, handle exceptions properly when GCC 4.1 libstdc++ was used with GCC 4.4 or later C++11 code. This update improves exception handling so that GCC now processes exceptions as expected when using GCC 4.4 or later to compile code written in C++11.

GCC was missing a lazy declaration of a class type destructor in the locate_dtor function in the method implementation. As a consequence, exception handling did not work as expected under certain circumstances and the generated code could terminate unexpectedly. This update adds the missing destructor declaration and the problem no longer occurs.

Previously, GCC did not correctly handle processor registers and used an incorrect memory operand when processing the CMPXCHG8B instruction. As a consequence, the compiler generated erroneous code if the "-fPIC" option was used. This update modifies the underlying source code so that GCC now handles memory operands correctly and compiles position-independent code with the "fPIC" option as expected.

GCC previously used incorrect flags for IBM System z specific options, such as "-m31", "-m64", "-mesa", "-mzarch", "-msoft-float", "-mhard-float", "-mlong-double-64" and "-mlong-double-128". As a consequence, when compiling code with any of these options, GCC did not recognize the option and the command failed. With this update, negative flags are now used for these options and code can be compiled successfully in this scenario.

GCC did not, under rare circumstances, handle exceptions properly when GCC 4.1 libstdc++ was used with GCC 4.4 or later C++11 code. This update improves exception handling so that GCC now processes exceptions as expected when using GCC 4.4 or later to compile code written in C++11.