--- gcc/NEWS 2018/04/24 18:06:53 1.1.1.1 +++ gcc/NEWS 2018/04/24 18:17:53 1.1.1.3 @@ -1,3 +1,334 @@ +Noteworthy changes in GCC version 2.6.3: + +A few more bugs have been fixed. + +Noteworthy changes in GCC version 2.6.2: + +A few bugs have been fixed. + +Names of attributes can now be preceded and followed by double underscores. + +Noteworthy changes in GCC version 2.6.1: + +Numerous (mostly minor) bugs have been fixed. + +The following new configurations are supported: + + GNU on x86 (instead of treating it like MACH) + NetBSD on Sparc and Motorola 68k + AIX 4.1 on RS/6000 and PowerPC systems + Sequent DYNUX/ptx 1.x and 2.x. + Both COFF and ELF configurations on AViiON without using /bin/gcc + Windows/NT on x86 architecture; preliminary + AT&T DSP1610 digital signal processor chips + i960 systems on bare boards using COFF + PDP11; target only and not extensively tested + +The -pg option is now supported for Alpha under OSF/1 V3.0 or later. + +Files with an extension of ".c++" are treated as C++ code. + +The -Xlinker and -Wl arguments are now passed to the linker in the +position they were specified on the command line. This makes it +possible, for example, to pass flags to the linker about specific +object files. + +The use of positional arguments to the configure script is no longer +recommended. Use --target= to specify the target; see the GCC manual. + +The 386 now supports two new switches: -mreg-alloc= changes +the default register allocation order used by the compiler, and +-mno-wide-multiply disables the use of the mul/imul instructions that +produce 64 bit results in EAX:EDX from 32 bit operands to do long long +multiplies and 32-bit division by constants. + +Noteworthy changes in GCC version 2.6.0: + +Numerous bugs have been fixed, in the C and C++ front-ends, as +well as in the common compiler code. + +This release includes the C, Objective-C, and C++ compilers. However, +we have moved the files for the C++ compiler (G++) files to a +subdirectory, cp. Subsequent releases of GCC will split these files +to a separate TAR file. + +The G++ team has been tracking the development of the ANSI standard for C++. +Here are some new features added from the latest working paper: + + * built-in boolean type 'bool', with constants 'true' and 'false'. + * array new and delete (operator new [] and delete []). + * WP-conforming lifetime of temporaries. + * explicit instantiation of templates (template class A;), + along with an option (-fno-implicit-templates) to disable emission + of implicitly instantiated templates, obsoletes -fexternal-templates. + * static member constants (static const int foo = 4; within the + class declaration). + +Many error messages have been improved to tell the user more about the +problem. Conformance checking with -pedantic-errors has been +improved. G++ now compiles Fresco. + +There is now an experimental implementation of virtual functions using +thunks instead of Cfront-style vtables, enabled with -fvtable-thunks. +This option also enables a heuristic which causes the compiler to only +emit the vtable in the translation unit where its first non-inline +virtual function is defined; using this option and +-fno-implicit-templates, users should be able to avoid #pragma +interface/implementation altogether. + +Signatures have been added as a GNU C++ extension. Using the option +-fhandle-signatures, users are able to turn on recognition of +signatures. A short introduction on signatures is in the section +`Extension to the C++ Language' in the manual. + +The `g++' program is now a C program, rather than a shell script. + +Lots and lots and lots of bugs fixes, in nested types, access control, +pointers to member functions, the parser, templates, overload +resolution, etc, etc. + +There have been two major enhancements to the Objective-C compiler: + +1) Added portability. It now runs on Alpha, and some problems with + message forwarding have been addressed on other platforms. + +2) Selectors have been redefined to be pointers to structs like: + { void *sel_id, char *sel_types }, where the sel_id is the unique + identifier, the selector itself is no longer unique. + + Programmers should use the new function sel_eq to test selector + equivalence. + +The following major changes have been made to the base compiler and +machine-specific files. + +- The MIL-STD-1750A is a new port, but still preliminary. + +- The h8/300h is now supported; both the h8/300 and h8/300h ports come + with 32 bit IEEE 754 software floating point support. + +- The 64-bit Sparc (v9) and 64-bit MIPS chips are supported. + +- NetBSD is supported on m68k, Intel x86, and pc523 systems and FreeBSD + on x86. + +- COFF is supported on x86, m68k, and Sparc systems running LynxOS. + +- 68K systems from Bull and Concurrent are supported and System V + Release 4 is supported on the Atari. + +- GCC supports GAS on the Motorola 3300 (sysV68) and debugging + (assuming GAS) on the Plexus 68K system. (However, GAS does not yet + work on those systems). + +- System V Release 4 is supported on MIPS (Tandem). + +- For DG/UX, an ELF configuration is now supported, and both the ELF + and BCS configurations support ELF and COFF object file formats. + +- OSF/1 V2.0 is supported on Alpha. + +- Function profiling is also supported on Alpha. + +- GAS and GDB is supported for Irix 5 (MIPS). + +- "common mode" (code that will run on both POWER and PowerPC + architectures) is now supported for the RS/6000 family; the + compiler knows about more PPC chips. + +- Both NeXTStep 2.1 and 3 are supported on 68k-based architectures. + +- On the AMD 29k, the -msoft-float is now supported, as well as + -mno-sum-in-toc for RS/6000, -mapp-regs and -mflat for Sparc, and + -membedded-pic for MIPS. + +- GCC can now convert division by integer constants into the equivalent + multiplication and shift operations when that is faster than the + division. + +- Two new warning options, -Wbad-function-cast and + -Wmissing-declarations have been added. + +- Configurations may now add machine-specific __attribute__ options on + type; many machines support the `section' attribute. + +- The -ffast-math flag permits some optimization that violate strict + IEEE rules, such as converting X * 0.0 to 0.0. + +Noteworthy changes in GCC version 2.5.8: + +This release only fixes a few serious bugs. These include fixes for a +bug that prevented most programs from working on the RS/6000, a bug +that caused invalid assembler code for prgrams with a `switch' +statement on the NS32K, a G++ problem that caused undefined names in +some configurations, and several less erious problems, some of which +can affect most configuration. + +Noteworthy change in GCC version 2.5.7: + +This release only fixes a few bugs, one of which was causing bootstrap +compare errors on some systems. + +Noteworthy change in GCC version 2.5.6: + +A few backend bugs have been fixed, some of which only occur on one +machine. + +The C++ compiler in 2.5.6 includes: + + * fixes for some common crashes + * correct handling of nested types that are referenced as `foo::bar' + * spurious warnings about friends being declared static and never + defined should no longer appear + * enums that are local to a method in a class, or a class that's + local to a function, are now handled correctly. For example: + class foo { void bar () { enum { x, y } E; x; } }; + void bar () { class foo { enum { x, y } E; E baz; }; } + +Noteworthy change in GCC version 2.5.5: + +A large number of C++ bugs have been fixed. + +The fixproto script adds prototypes conditionally on __cplusplus. + +Noteworthy change in GCC version 2.5.4: + +A bug fix in passing of structure arguments for the HP-PA architecture +makes code compiled with GCC 2.5.4 incompatible with code compiled +with earlier versions (if it passes struct arguments of 33 to 64 bits, +interspersed with other types of arguments). + +Noteworthy change in gcc version 2.5.3: + +The method of "mangling" C++ function names has been changed. So you +must recompile all C++ programs completely when you start using GCC +2.5. Also, GCC 2.5 requires libg++ version 2.5. Earlier libg++ +versions won't work with GCC 2.5. (This is generally true--GCC +version M.N requires libg++ version M.N.) + +Noteworthy GCC changes in version 2.5: + +* There is now support for the IBM 370 architecture as a target. +Currently the only operating system supported is MVS; GCC does not run +on MVS, so you must produce .s files using GCC as a cross compiler, +then transfer them to MVS to assemble them. This port is not reliable +yet. + +* The Power PC is now supported. + +* The i860-based Paragon machine is now supported. + +* The Hitachi 3050 (an HP-PA machine) is now supported. + +* The variable __GNUC_MINOR__ holds the minor version number of GCC, as +an integer. For version 2.5.X, the value is 5. + +* In C, initializers for static and global variables are now processed +an element at a time, so that they don't need a lot of storage. + +* The C syntax for specifying which structure field comes next in an +initializer is now `.FIELDNAME='. The corresponding syntax for +array initializers is now `[INDEX]='. For example, + + char whitespace[256] + = { [' '] = 1, ['\t'] = 1, ['\n'] = 1 }; + +This was changed to accord with the syntax proposed by the Numerical +C Extensions Group (NCEG). + +* Complex numbers are now supported in C. Use the keyword __complex__ +to declare complex data types. See the manual for details. + +* GCC now supports `long double' meaningfully on the Sparc (128-bit +floating point) and on the 386 (96-bit floating point). The Sparc +support is enabled on on Solaris 2.x because earlier system versions +(SunOS 4) have bugs in the emulation. + +* All targets now have assertions for cpu, machine and system. So you +can now use assertions to distinguish among all supported targets. + +* Nested functions in C may now be inline. Just declare them inline +in the usual way. + +* Packed structure members are now supported fully; it should be possible +to access them on any supported target, no matter how little alignment +they have. + +* To declare that a function does not return, you must now write +something like this (works only in 2.5): + + void fatal () __attribute__ ((noreturn)); + +or like this (works in older versions too): + + typedef void voidfn (); + + volatile voidfn fatal; + +It used to be possible to do so by writing this: + + volatile void fatal (); + +but it turns out that ANSI C requires that to mean something +else (which is useless). + +Likewise, to declare that a function is side-effect-free +so that calls may be deleted or combined, write +something like this (works only in 2.5): + + int computation () __attribute__ ((const)); + +or like this (works in older versions too): + + typedef int intfn (); + + const intfn computation; + +* The new option -iwithprefixbefore specifies a directory to add to +the search path for include files in the same position where -I would +put it, but uses the specified prefix just like -iwithprefix. + +* Basic block profiling has been enhanced to record the function the +basic block comes from, and if the module was compiled for debugging, +the line number and filename. A default version of the basic block +support module has been added to libgcc2 that appends the basic block +information to a text file 'bb.out'. Machine descriptions can now +override the basic block support module in the target macro file. + +New features in g++: + +* The new flag `-fansi-overloading' for C++. Use a newly implemented +scheme of argument matching for C++. It makes g++ more accurately +obey the rules set down in Chapter 13 of the Annotated C++ Reference +Manual (the ARM). This option will be turned on by default in a +future release. + +* The -finline-debug flag is now gone (it was never really used by the + compiler). + +* Recognizing the syntax for pointers to members, e.g., "foo::*bar", has been + dramatically improved. You should not get any syntax errors or incorrect + runtime results while using pointers to members correctly; if you do, it's + a definite bug. + +* Forward declaration of an enum is now flagged as an error. + +* Class-local typedefs are now working properly. + +* Nested class support has been significantly improved. The compiler + will now (in theory) support up to 240 nested classes before hitting + other system limits (like memory size). + +* There is a new C version of the `g++' driver, to replace the old + shell script. This should significantly improve the performance of + executing g++ on a system where a user's PATH environment variable + references many NFS-mounted filesystems. This driver also works + under MS-DOS and OS/2. + +* The ANSI committee working on the C++ standard has adopted a new + keyword `mutable'. This will allow you to make a specific member be + modifiable in an otherwise const class. + Noteworthy GCC changes in version 2.4.4: A crash building g++ on various hosts (including m68k) has been @@ -101,7 +432,6 @@ accepts either ++obj or obj++, unless -p * If you are using version 2.3 of libg++, you need to rebuild it with `make CC=gcc' to avoid mismatches in the definition of `size_t'. - Newly documented compiler options: -fnostartfiles @@ -139,3 +469,4 @@ Newly documented compiler options: +eN Control how C++ virtual function definitions are used (like cfront 1.x). +