Henning Meier-Geinitz <henn...@meier-geinitz.de> writes: [...]
> sane-devel is usually the right place for such discussions/proposals > if the patch/change doesn't get too long. Thanks for listening ;-) >> SANE can be compiled with the HP ANSI C Compiler or GCC. On HP-UX 11 >> in 64-bit mode, if using the HP Compiler, for reasons having to do >> with dlopen(), I would recommend to use the +DA2.0W option to generate >> a 64-bit executable. (GCC can only produce 32-bit executables and >> behaves like on 10.20). > > Currently, README.hp-ux states: > > | Under HP-UX, it is necessary to add options -Aa and -D_HPUX_SOURCE to > | the compiler flags when using HP's C compiler (not gcc). This can be > | done by invoking configure with: > | > | CC=cc CPPFLAGS=-D_HPUX_SOURCE CFLAGS=-Aa ./configure > > Sorry for my cluelessness: Is -D_HPUX_SOURCE necessary, or does it > harm in your case? What's the difference between -Aa and -Ae? The information in README.hp-ux is correct, but there's more than one way... Here's the story: On HP-UX 10.20, the default mode of the compiler is to "[c]ompile in a mode compatible with HP-UX releases prior to 7.0", i.e., K&R 1st edition plus UNIX and HP-UX extensions. Really crufty. The option -Aa enables ANSI mode; this means that the header files only define those names specified by the Standard (ISO 9899:1990). To access UNIX macros and typedefs you have to explicitly define the namespace you want; you get the full set with _HPUX_SOURCE, or smaller subsets with _POSIX_SOURCE, _XOPEN_SOURCE, etc. c89, the POSIX compiler, corresponds to cc -Aa -D_POSIX_SOURCE. The option -Ae is an abbreviation for -Aa -D_HPUX_SOURCE +e. The +e option enables some extension, most importantly the long long type. On HP-UX 11, the -Ae behavior is the default. The +DA<architecture> option allows you to specify the PA-RISC version you want to generate code for; the default is to generate code for the platform you're running on. So, on HP-UX 10.20, you'd typically either use the default, or, if you're on a PA-RISC 2.0 machine, maybe +DAportable to produce an executable that also runs on PA-RISC 1.1 machines. However, on a PA-RISC 2.0 machine running HP-UX 11 in 64-bit mode, you have some more options: You can generate 32-bit PA2.0 or 64-bit PA2.0 code. This choice also implies a choice of data model (ILP32 vs. LP64) and of object file format (COFF vs. ELF). Furthermore, some things are only available to 64-bit (ELF) executables. Case in point: dlopen(). SANE checks first for dlopen(), and then for shl_load(), the corresponding 32-bit function. Since it finds dlopen() on an HP-UX 11 system, it will use it. But since the compiler generates 32-bit code by default (to which dlopen() is not available), the resulting executable will fail to load shared libraries. > Maybe you can rewrite the README.hp-ux for us? I'll be glad to help. I'll put something together from my build notes and post it here. Greetings -- Michael Piotrowski, M.A. <m...@dynalabs.de>
