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Issues from previous releases  

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General issues with the tools

• For Solaris:

...-R/usr/progressive/lib...

• For DEC Unix/OSF1 and Irix 5:

...-Wl, -rpath,/usr/progressive/lib...

• Removed or renamed completely the shared libraries under the installation directory ('/usr/progressive/lib/libg++.s* ' and '/usr/progressive/lib/libstdc++.s* ').
• Linked with -static to avoid using any shared libraries.
• The library directory, '/usr/progressive/lib ', was different if GNUPro Toolkit was installed in a non-standard location. This directory was thought of as '$GCC_EXEC_PREFIX/../ ' if using 'GCC_EXEC_PREFIX '.
• After rebuilding from source, in order to report problems, a user reran install-sid in order to reset customer-id in send-pr . Previously, the default value was the value in the send-pr program in a path at the time of configuration.

 

• The following issues were pertinent to the PowerPC environment.

 

• Added '/usr/progressive/lib' to LD_LIBRARY_PATH environment variable.
• -mno-fused-madd was a new option, preventing the compiler from combining a floating point multiply with an addition or subtraction. Generally, the compiler would do this optimization, if it was important to get the exact rounding as specified by the IEEE 754 floating point standard (on the Power and PowerPC machines, the combined multiply and add/subtract instruction does not do a round operation between the multiply and the addition/subtraction).
• The -mcpu=403 switch did a -mstrict-align operation, since the 403 had no support for unaligned memory operations.
• With the previous release, better code was generated when adding or doing logical operations with large constants.
• Two new switches, -mads and -myellowknife, were added to the powerpc-eabi toolchain.
• The -mads switch links in the appropriate libraries for the Motorola ADS target boards (860/821/823).
• -myellowknife, the other switch, links in the appropriate libraries for the Motorola Yellowknife target boards (603e/604e).
• Jump tables, for switch statements, were in the .rodata section, and not the .text section, so it wasn't necessary to include the text section in the data address mapping.
• wchar_t became 4 bytes instead of 2 (and "a"l -strings consisted of 4 byte characters instead of 2).
• The -mregnames switch was only passed to the assembler for assembling .s and .S files (i.e., it was not passed to the assembler when assembling the output of the compiler). This is so that global symbols like "r0" in C code wouldn't get confused with register names.
• PowerPC configuration included a simulator contributed by Andrew Cagney.
• The following support enhancements were made to both the powerpc-aix and powerpc-eabi configurations.

•  Support was added for -mcpu=505, -mcpu=602, -mcpu=860, -mcpu=821, and -mcpu=power2.
• The default PowerPC model is now 604, not 601.
• -mtune=xxx was added to select scheduling parameters such as -mcpu=xxx, but not to select use of cpu specific instructions.
• If configuring and building the compiler, the switch, --with-cpu=xxx, will allow for selecting the default processor.
• Instruction timings had been improved.
• The compiler was set to generate correct code for a nor instruction combined with a compare instruction.

• __attribute__((longcall)) was added to function attributes so that the function is now always called through a pointer. This allows the function to be located anywhere in program memory.

 

• The following enhancements were made only to the powerpc-eabi support.

 
• The default PowerPC model is now 604, not 601.
• A new switch, -msdata was added to put small static and global items in small data regions. This allows them to be referenced with 1 instruction instead of 2.
• long long was set to pass according to the System V/EABI specifications, (in other words, they always pass in odd/even register pairs, never even/odd).
• Code was changed for the functions prolog and epilog so that references beyond the end of the current stack pointer never generate.
• The assembler added support for generating negative address, GOT, PLT, and small data, relative to section start relocations.
• The linker added support for negative address, GOT, and small data, relative to section start relocations. PLT relocations were not handled.
• An enhancement was made to the powerpc-aix support. The default for AIX 4.1 was changed to -mcpu=common. This replaced the default of the machine on which the compiler was configured (either Power or PowerPC)
• The PowerPC simulator must be built with the gcc compiler. It uses several gcc extensions, as well as requiring an ISO standard compiler. If you configure your powerpc-eabi build without using gcc, it will not build the simulator.

 

• The following issues are pertinent to the m68k environments.

 

• The m68k-aout and m68k-coff toolchains now include support for converting executables files into IEEE-695 format. The IEEE-695 format is used by some emulators.
• To convert a file, first link your program into a fully linked executable. Then run the following script.

m68k-coff-objcopy -O ieee --debugging file file.x

This converts a m68k-coff file 'file' into the IEEE-695 file, 'file.x'.
• To use the m68k-aout toolchain, m68k-aout-objcopy is the corresponding tool.
• The --debugging option directs objcopy to translate debugging information into the IEEE-695 format. This option only works if you use the stabs debugging format. The stabs debugging format is the default for the m68k-aout toolchain.
• For the m68k-coff toolchain, you must compile your files using the option, -gstabs+ , rather than a simple -g, in order to get stabs debugging information.
• A conversion facility is available for other toolchains, but the binaries built by Cygnus do not provide it. To use it, you must rebuild the programs from source, as described in Rebuilding from source.
• gcc has an option, '-m68332', to be used specifically when compiling for the Motorola 68332 board. ( gcc also has an updated option, -m68302. The 68302 technically isn't a cpu 32 chip.)
• Running the configure script, add '--enable-targets=CPU-ieee', where CPU is the processor type (such as i960). Cygnus had not tested the convertor for processors other than the m68k .
• The Motorola cpu 32 and cpu 32+ targets are part of the family of 68000 chips, which Cygnus supports. There are a few options to help you compile code for these targets.

It is also possible to configure gcc for a target of 'm68332-aout' or 'm68332-coff' when rebuilding from source, in which case '-m68332' is the default.
GNU as accepts the following board-specific options: -mcpu32, -m68331, -m68332, -m68333, -m68340, and -m68302.
Contact Cygnus for more information on our support for cpu 32 and cpu 32+ targets.

C and C++ compiler issues

• GNUPro Toolkit includes the compiler, egcs 1.0, which is similar to gcc 2.8.x.
• There have been further enhancements to the Global Common Sub-Elimination (gcse) routines in the libraries.
• There have been improvements to the general induction variable identification and elimination, along with improvements to the loop invariant code motion.
• There are now accurate warnings, especially when using exception handling (such as when using uninitialized variables, for example)
• There is improved global constant and copy propogation.
• There are several new switches: -Os (for optimizing space), -fmove-all-movables (for forcing all invariant computations in loops to be moved outside the loop), -freduce-all-givs (for forcing all general induction variables in loops to be strength reduced), and -frerun-loop-opt (for rerunning loop optimizations twice).
• There is now partial redundancy elimination with lazy code motion and critical edge splitting.
• There is now global code hoisting and unification.
• For those users who've had to use @file in their makefiles, the -@file is no longer necessary. The @file option has the general standard usage whose purpose is of replacing a string of text that represents a file's path for a string of text of another file's path.
• GNUPro Toolkit fully supports the following functionality for the GNU C++ programming.
• Thread-safe exception handling, including nested exceptions and placement delete. operator new now throws bad_alloc .
• Member class templates.
• Local classes in templates.
• Template parameters.
• Template friends.
• Protected virtual inheritance.
• Loop optimization improvements (with the test at the end in more cases); for class D derived from B, which has a member, int i , &D::i is now of type int B::* instead of int D::* .
• Compact name mangling with -fsquangle . Future versions of the compiler may use the new mangling to indicate a different, incompatible ABI. To use this, rebuild the libraries (including libgcc ) with this option.
• Member function and template support.
• Cygnus fully supports the m68k-elf toolchain. An earlier version of m68k-elf that was previously available is obsolete. Migrating to the new m68k-elf toolchain will require rebuilding existing object files and modifying any existing source code written in assembly language. Source code that was written in C will not need to be changed.
Any object files that were created with the old toolchain will not be link-compatible with object files created with the new toolchain. Even if old object files are successfully linked with new object files, they will not be compatible at run-time, because the calling convention has changed. To circumvent this problem, recompile all object files from their source code with the new m68k-elf toolchain.
The assembly language format expected by the new assembler has changed slightly to make it more similar to the format of m68k-coff and m68k-aout assembly language. Programs that are written in C do not need modification. Programs written in assembly language will need to be modified in the following ways:
• The fp register must be referred to instead as the a6 register. link %fp,&0 must be replaced with link %a6,#0 as a modification.
• Incidences of the & symbol must be replaced with # . link %fp,&0 must be replaced with link %a6,#0 as a modification.
There have been some ABI changes:
• Pointers are now returned in register d0 , not a0 .
• Long doubles are now returned in fp0 when an FPU is present, not d0 .
• Two functions resembling __attribute__ functionality, -ffunction-sections and -fdata-sections , move elements that don't have section attributes set. -ffunction-sections moves function elements and -fdata-sections moves data elements.
GCC uses `.text.objectname' if transforming a function, and uses `.data.objectname' or `.rodata.objectname' if transforming constant data elements (which are read-only elements). `.data. objectname' is the default.
 

Debugger issues

Note:
The command shared library is always available to load shared library symbols manually.
 
•  Use the command, dont-repeat, in user-defined commands to defeat the auto-repeat of gdb when an empty command is entered.
• The symbol reader for AIX gdb now uses partial symbol tables. This can greatly improve startup time, especially for large executables.
• When printing the type of a variable declared with a typedef, gdb uses the typedef name if possible instead of the typedef definition.
• Performance is improved in MIPS IDT debugging (MIPS targets), both for stepping and for downloads.
• The remotedelay option is set by default to 1. Loading executables can be considerably slower with remotedelay set to 1, but it gets around a loading bug on certain H8/300 boards.
• To see a noticeable speed-up in loading when you're not using an H8/300 board, set remotedelay to 0. Use set remotedelay 0 as input.
• A common hurdle in cross development is to get the communications set up properly between the target board and the development platform.
• The debugger's 'set remotedebug' command can help. It was designed to help develop new remote targets; it displays the packets transmitted back and forth between the debugger and the target environment. This command can be helpful in diagnosing communications problems, for example, allowing you to observe packets not getting through or picking up noise on the line.
• The set remotedebug command is now consistent among the MIPS remote target; remote targets using the gdb-specific protocol; UDI (the AMD debug protocol for the 29k); the 88k bug monitor; and Hitachi ROM monitors. You can set it to an integer specifying a protocol-debug level (normally 0 or 1 , but 2 means more protocol information for the MIPS target). See GDB and remote MIPS boards in Debugging with GDB in GNUPro Debugging Tools for details.
• If you use the gcc option, '-gstabs+', gcc embeds extended debugging information in coff object files. The extended debug information is based on the stabs debugging format, which was originally used only with the a.out object file format; see The stabs debug format , in your sources as 'src/gdb/doc/stabs.texinfo', or contact Cygnus for more information. With this additional debugging information, you can debug C++ programs with gdb, even on systems that use COFF. You can get better C++ debugging by compiling with '-gstabs+' for the a29k-amd-udi, h8300-hms, m68k-coff, m88k-coff, sh-hms, and z8k-coff targets.

Utilities issues

• There are two binary utilities that are new to GNUPro Toolkit development tools.
• addr2line

Converts addresses into file names and line numbers; see addr2line in Using binutils in GNUPro Utilities.
• windres

Manipulates Windows resources; see windres in Using binutils in GNUPro Utilities.
• Of the hosts we currently support, we do not support the linker (ld) for the alpha-dec-osf, hppa-hp-hpux or mips-sgi-irix configurations. These are not normally configured, but the sources are included with every release.
• DejaGnu is a framework for testing other programs. Its purpose is to provide a single front end for all tests and several of the following advantages for testing:
• The flexibility and consistency of writing tests for any program.
• Providing a layer of abstraction in order to write tests that port to any host or target where a program must test. For instance, a test for gdb can run (from any Unix based host) on any target that DejaGnu supports. DejaGnu runs tests on several single board computers, whose operating software ranges from a boot monitor to a full Unix-like realtime operating system.
• All tests have the same output format, making it easy to integrate testing into other development, to parse by other filtering scripts, and to be readable.
DejaGnu is written in expect, which in turn uses the Tcl command language.
Running tests requires two things: the testing framework, and the testsuites themselves. Tests are usually written in expect, using Tcl, but you can also use a Tcl script to run a test suite not based on expect. expect script filenames conventionally use .exp as a suffix; for example, the main implementation of the DejaGnu test driver is in the file, runtest.exp .

Assembler issues

Linker issues

Rebuilding issues

 Details on issues with past releases about rebuilding specific platforms and features are shown in the following discussions. See Rebuilding from source for more detailed instructions.

• The default mode is to support native Win32 makefiles. In this mode, Makefile rules may use either backslashes or forward slashes as filename directory separators. Makefile rules may invoke "del", "copy", or other Win32 shell builtins since make will now invoke a native Win32 subshell when necessary. Note that some programs like del do not support filenames containing forward slash directory separators so you probably want to use backslashes if you intend to use those types of programs. make does not automatically convert forward slashes to backslashes because doing so would break the use of the forward slash as the option specifier for some Win32 programs.

For this mode to work correctly, the correct Win32 subshell must be in your path (cmd.exe under Windows NT or command.com under Windows 95). When writing your makefiles, avoid the use of backslashes as end of line continuation characters because Win32 shell commands like "del" will interpret that backslash as a reference to the root partition of the current drive! Finally, command line lengths are limited to what's supported by the Win32 subshell: 255 characters under cmd.exe, 127 characters under command.com.
 
• An optional Unix compatibility mode to support Unix-style Makefiles.

There are two ways to tell make to operate in this mode: you can either set the environment variable, MAKE_MODE, to "unix" before running make or you can invoke make as "make --unix" (in this mode, backslashes retain the usual Unix semantics and cannot be used in filenames as directory separators; however, Win32 paths without backslashes are still supported). Use of Bourne shell built-ins is permitted but Win32 shell built-ins like del and copy are unavailable. You must provide a working Bourne shell for this mode to work correctly. It should be named "sh.exe" and needs to be in your path so make can find it.
After rebuilding from source, it is now necessary to rerun install-sid in order to reset your customer-id in send-pr. Previously, the default value was the value in the send-pr program in your path at the time of configuration.

   
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