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diff --git a/Misc/AIX-NOTES b/Misc/AIX-NOTES new file mode 100644 index 0000000..f23cb65 --- /dev/null +++ b/Misc/AIX-NOTES @@ -0,0 +1,144 @@ +Subject: HERE IS AIX-NOTES +From: Manus Hand <Manus.Hand@evolving.com> +To: Guido van Rossum <guido@CNRI.Reston.VA.US> +Cc: Vladimir.Marangozov@imag.fr +Date: Thu, 8 Aug 1996 16:11:10 -0600 (MDT) + +============================================================================== + COMPILER INFORMATION +------------------------------------------------------------------------------ + +(1) A problem has been reported with "make test" failing because of "weird + indentation." Searching the comp.lang.python newsgroup reveals several + threads on this subject, and it seems to be a compiler bug in an old + version of the AIX CC compiler. However, the compiler/OS combination + which has this problem is not identified. In preparation for the 1.4 + release, Vladimir Marangozov (Vladimir.Marangozov@imag.fr) and Manus Hand + (mhand@csn.net) reported no such troubles for the following compilers and + operating system versions: + AIX C compiler version 3.1.2 on AIX 4.1.3 and AIX 4.1.4 + AIX C compiler version 1.3.0 on AIX 3.2.5 + If you have this problem, please report the compiler/OS version. + +(2) Stefan Esser (se@MI.Uni-Koeln.DE), in work done to compile Python + 1.0.0 on AIX 3.2.4, reports that AIX compilers don't like the LANG + environment varaiable set to European locales. This makes the compiler + generate floating point constants using "," as the decimal seperator, + which the assembler doesn't understand (or perhaps it is the other way + around, with the assembler expecting, but not getting "," in float + numbers). "LANG=C; export LANG" solves the problem, as does + "LANG=C $(MAKE) ..." in the master Makefile. + +(3) The cc (or xlc) compiler considers "Python/ceval.c" too complex to + optimize, except when invoked with "-qmaxmem=4000" + +(4) Some problems (due to _AIX not being #defined) when python 1.0.0 was + compiled using 'gcc -ansi' were reported by Stefan Esser, but were not + investigated. + +(5) The cc compiler has internal variables named "__abs" and "__div". These + names are reserved and may not be used as program variables in compiled + source. (As an anecdote in support of this, the implementation of + Python/operator.c had this problem in the 1.4 beta releases, and the + solution was to re#define some core-source variables having these names, + to give these python variables different names if the build is being done + on AIX.) + +(6) As mentioned in the README, builds done immediately after previous builds + (without "make clean" or "make clobber") sometimes fail for mysterious + reasons. There are some unpredictable results when the configuration + is changed (that is, if you "configure" with different parameters) or if + intermediate changes are made to some files. Performing "make clean" or + "make clobber" resolves the problems. + +============================================================================== + THREAD SUPPORT +------------------------------------------------------------------------------ + +AIX uses pthreads. However, as of AIX version 4, there are two (incompatible) +types of pthreads on AIX: + a) AIX DCE pthreads (on AIX 3.2.5) + b) AIX 4 pthreads (on AIX 4.1 and up) +Support has been added to Python to handle the distinction. + +The cc and gcc compilers do not initialize pthreads properly. The only +compilers that can initialize pthreads properly are IBM *_r* compilers, +which use the crt0_r.o module, and which invoke ld with the reentrant +version of libc (libc_r). + +In order to enable thread support, follow these steps: + 1. Uncomment the thread module in Modules/Setup + 2. configure --without-gcc --with-thread ... + 3. make CC="cc_r" OPT="-O -qmaxmem=4000" + +For example, to make with both threads and readline, use: + ./configure --without-gcc --with-thread --with-readline=/usr/local/lib + make CC=cc_r OPT="-O2 -qmaxmem=4000" + +If the "make" which is used ignores the "CC=cc_r" directive, one could alias +the cc command to cc_r (for example, in C-shell, perform an "alias cc cc_r"). + +Vladimir Marangozov (Vladimir.Marangozov@imag.fr) provided this information, +and he reports that a cc_r build initializes threads properly and that all +demos on threads run okay with cc_r. + +============================================================================== + SHARED LIBRARY SUPPORT +------------------------------------------------------------------------------ + +AIX shared library support was added to Python in the 1.4 release by Manus +Hand (mhand@csn.net) and Vladimir Marangozov (Vladimir.Marangozov@imag.fr). + +Python modules may now be built as shared libraries on AIX using the normal +process of uncommenting the "*noconfig*" line in Modules/Setup.in before the +build. There is one additional step required, and that is to also uncomment +the line in Modules/Setup.in which reads + LINKCC= makexp_aix python.exp "" $(MYLIBS) $(ADDOBJS) ; $(CC) + +AIX shared libraries require that an "export" and "import" file be provided +at compile time to list all extern symbols which may be shared between +modules. The effect of uncommenting the LINKCC line in Modules/Setup.in is +to create the "export" file for the modules and the libraries that belong to +the Python core. This is done by the "makexp_aix" script, which creates a +file named python.exp before performing the link of the python binary. + +When shared library modules (.so files) are made, a second shell script +is invoked. This script is named "ld_so_aix" and is also provided with +the distribution in the Modules subdirectory. This script acts as an "ld" +wrapper which hides the explicit management of "export" and "import" files; +it adds the appropriate arguments (in the appropriate order) to the link +command that creates the shared module. Among other things, it specifies +that the "python.exp" file is an "import" file for the shared module. + +A default python.exp file is provided with the distribution. It will be +overwritten (by the action of the makexp_aix script) if you build with shared +libraries. The python.exp file which comes with the distribution contains +all extern symbols of a completely statically build python executable. +Any python.exp file which is created from a build of python with some of the +modules linked as shared modules will obviously not list symbols from the now +dynamic modules. The distributed python.exp is provided so that, with +assistance from the ld_so_aix and makexp_aix scripts, shared extension +modules may be added to an otherwise completely static python build. + +At the time of this writing, neither the python.exp file nor the makexp_aix +or ld_so_aix scripts are installed by the make procedure, so you should +remember to keep these and/or copy them to a different location for +safekeeping if you wish to use them to add shared extension modules to +python. However, if the make process has been updated since this writing, +these files MAY have been installed for you during the make by the +LIBAINSTALL rule, in which case the need to make safe copies is obviated. + +If you wish to add a shared extension module to the language, you would follow +the steps given in the example below (the example adds the shared extension +module "spam" to python): + 1. Make sure that "ld_so_aix" and "makexp_aix" are in your path. + 2. The "python.exp" file should be in the current directory. + 3. Issue the following commands or include them in your Makefile: + cc -c spammodule.c + ld_so_aix cc spammodule.o -o spammodule.so + +For more detailed information on the shared library support, examine the +contents of the "ld_so_aix" and "makexp_aix" scripts or refer to the AIX +documentation. + +============================================================================== |