GCC full changelog

GCC support for TI PRU I/O processors has been added.

GCC support for TI PRU I/O processors has been added.

# DWARF4 is now the default when generating DWARF debug information. When -g is used on a platform that uses DWARF debugging information, GCC will now default to -gdwarf-4 -fno-debug-types-section.
GDB 7.5, Valgrind 3.8.0 and elfutils 0.154 debug information consumers support DWARF4 by default. Before GCC 4.8 the default version used was DWARF2. To make GCC 4.8 generate an older DWARF version use -g together with -gdwarf-2 or -gdwarf-3. The default for Darwin and VxWorks is still -gdwarf-2 -gstrict-dwarf.
# A new general optimization level, -Og, has been introduced. It addresses the need for fast compilation and a superior debugging experience while providing a reasonable level of runtime performance. Overall experience for development should be better than the default optimization level -O0.
# A new option -ftree-partial-pre was added to control the partial redundancy elimination (PRE) optimization. This option is enabled by default at the -O3 optimization level.

#The -fconserve-space flag has been deprecated. The flag had no effect for most targets: only targets without a global .bss section and without support for switchable sections. Furthermore, the flag only had an effect for G++, where it could result in wrong semantics (please refer to the GCC manual for further details). The flag will be removed in GCC 4.8
#Support for a number of older systems and recently unmaintained or untested target ports of GCC has been declared obsolete in GCC 4.7. Unless there is activity to revive them, the next release of GCC will have their sources permanently removed.
All GCC ports for the following processor architectures have been declared obsolete:
* picoChip (picochip-*)
The following ports for individual systems on particular architectures have been obsoleted:
* IRIX 6.5 (mips-sgi-irix6.5)
* MIPS OpenBSD (mips*-*-openbsd*)
* Solaris 8 (*-*-solaris2.8). Details can be found in the announcement.

#The -fconserve-space flag has been deprecated. The flag had no effect for most targets: only targets without a global .bss section and without support for switchable sections. Furthermore, the flag only had an effect for G++, where it could result in wrong semantics (please refer to the GCC manual for further details). The flag will be removed in GCC 4.8
#Support for a number of older systems and recently unmaintained or untested target ports of GCC has been declared obsolete in GCC 4.7. Unless there is activity to revive them, the next release of GCC will have their sources permanently removed.

The following ports for individual systems on particular architectures have been obsoleted:

* IRIX 6.5 (mips-sgi-irix6.5)
* MIPS OpenBSD (mips*-*-openbsd*)
* Solaris 8 (*-*-solaris2.8). Details can be found in the announcement.
* Tru64 UNIX V5.1 (alpha*-dec-osf5.1*)

# The options -b <machine> and -V <version> have been removed because they were unreliable. Instead, users should directly run <machine>-gcc when cross-compiling, or <machine>-gcc-<version> to run a different version of gcc.
# GCC now has stricter checks for invalid command-line options. In particular, when gcc was called to link object files rather than compile source code, it would previously accept and ignore all options starting with --, including linker options such as --as-needed and --export-dynamic, although such options would result in errors if any source code was compiled. Such options, if unknown to the compiler, are now rejected in all cases; if the intent was to pass them to the linker, options such as -Wl,--as-needed should be used.
# Versions of the GNU C library up to and including 2.11.1 included an incorrect implementation of the cproj function. GCC optimizes its builtin cproj according to the behavior specified and allowed by the ISO C99 standard.

# The options -b <machine> and -V <version> have been removed because they were unreliable. Instead, users should directly run <machine>-gcc when cross-compiling, or <machine>-gcc-<version> to run a different version of gcc.
# GCC now has stricter checks for invalid command-line options. In particular, when gcc was called to link object files rather than compile source code, it would previously accept and ignore all options starting with --, including linker options such as --as-needed and --export-dynamic, although such options would result in errors if any source code was compiled. Such options, if unknown to the compiler, are now rejected in all cases; if the intent was to pass them to the linker, options such as -Wl,--as-needed should be used.
# Versions of the GNU C library up to and including 2.11.1 included an incorrect implementation of the cproj function. GCC optimizes its builtin cproj according to the behavior specified and allowed by the ISO C99 standard.