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On Sun, Nov 22, 2009 at 05:43:14PM +0100, Luigi Rizzo wrote: > Hi, > there is a well known problem with tcc and FreeBSD in the generation > of elf objects -- see > http://lists.gnu.org/archive/html/tinycc-devel/2005-07/msg00070.html > > Apparently Sergey Lyubka has tried a partial fix to the problem. > I was wondering if Sergey or someone can post some more detail on > what needs to be done so we can try to help fixing this issue I think i have managed to solve the problem and produce almost valid elf files on FreeBSD. The two patches attached address a few problems (trying to explain to the best of my knowledge; i am not very familiar with ELF and the FreeBSD ELF conventions): 1. ELF file format tcc produces an ELF executable which is good for linux but not for FreeBSD. It misses the PHDR section which is almost mandatory for shared executables, puts in the .dynsym section some relocation info that FreeBSD expects to be in .got, and expect the relocation sections to be contiguous. patch-tccelf.c tries to address the above problem using conditional sections (so hopefully can be imported upstream) and also adds the ability to override the name of the dynamic loader through an environment variable (this is important to debug tcc). 2. predefined macros patch-libtcc.c adds/fixes some predefined macros when compiling on FreeBSD: these are __FreeBSD__ and the usual set of __i386__ and __unix__ variants. It also sets __INTEL_COMPILER so we can grab the __aligned macro from cdefs.h , otherwise many programs would fail The resulting elf file is still not 100% correct -- if you strip it, the program will not run (presumably there is some dangling reference). Other than that, program do seem to run correctly. It would be nice to integrate these patches in the main repository. The FreeBSD specific code is in #ifdef so it should not harm linux users cheers luigi
Tiny C Compiler - C Scripting Everywhere - The Smallest ANSI C compiler ----------------------------------------------------------------------- Features: -------- - SMALL! You can compile and execute C code everywhere, for example on rescue disks. - FAST! tcc generates optimized x86 code. No byte code overhead. Compile, assemble and link about 7 times faster than 'gcc -O0'. - UNLIMITED! Any C dynamic library can be used directly. TCC is heading torward full ISOC99 compliance. TCC can of course compile itself. - SAFE! tcc includes an optional memory and bound checker. Bound checked code can be mixed freely with standard code. - Compile and execute C source directly. No linking or assembly necessary. Full C preprocessor included. - C script supported : just add '#!/usr/local/bin/tcc -run' at the first line of your C source, and execute it directly from the command line. Documentation: ------------- 1) Installation on a i386 Linux host (for Windows read tcc-win32.txt) ./configure make make test make install By default, tcc is installed in /usr/local/bin. ./configure --help shows configuration options. 2) Introduction We assume here that you know ANSI C. Look at the example ex1.c to know what the programs look like. The include file <tcclib.h> can be used if you want a small basic libc include support (especially useful for floppy disks). Of course, you can also use standard headers, although they are slower to compile. You can begin your C script with '#!/usr/local/bin/tcc -run' on the first line and set its execute bits (chmod a+x your_script). Then, you can launch the C code as a shell or perl script :-) The command line arguments are put in 'argc' and 'argv' of the main functions, as in ANSI C. 3) Examples ex1.c: simplest example (hello world). Can also be launched directly as a script: './ex1.c'. ex2.c: more complicated example: find a number with the four operations given a list of numbers (benchmark). ex3.c: compute fibonacci numbers (benchmark). ex4.c: more complicated: X11 program. Very complicated test in fact because standard headers are being used ! ex5.c: 'hello world' with standard glibc headers. tcc.c: TCC can of course compile itself. Used to check the code generator. tcctest.c: auto test for TCC which tests many subtle possible bugs. Used when doing 'make test'. 4) Full Documentation Please read tcc-doc.html to have all the features of TCC. Additional information is available for the Windows port in tcc-win32.txt. License: ------- TCC is distributed under the GNU Lesser General Public License (see COPYING file). Fabrice Bellard.