* Support for our dual ELF/a.out building ability
* Our custom ASM_* definitions
* Our custom debugger and profiling related definitions
* Our custom STARTFILE/ENDFILE specs
* The stock EGCS 1.1.2 freebsd-elf.h file depended on
egcs-1.1.2/gcc/config/linux.h, which included "svr4.h". We will
include "svr4.h" via our "tm.h" definition. So add the few bits
from "linux.h" we actually needed.
* Using our current crtbegin.o/crtend.o we cannot support the DWARF2
unwinding mechanisms. In the future we will switch to the
non-sjlj-exceptions type exception machanism. However the `make world'
bootstrap problems with the EGCS crtstuff.c must be overcome first.
* Our a.out gas doesn't "know" to use NOP's for aligns while in the text
section. Thus the a.out alignment generation needed tweaking from
what we did with GCC 2.7.2. [from BDE]
* The definition of SUPPORTS_ONE_ONLY prevents the compiler from trying
to use "linkonce" sections for a.out. The definition of
NO_DBX_FUNCTION_END we had causes it to avoid .stabs symbols that the
assembler cannot handle for a.out. [from JDP]
* The previous "EXCEPTION_SECTION_FUNCTION" is the wrong name for EGCS.
It also needed tweaking for EGCS. [from JDP]
Also bump __FreeBSD_cc_version to 400002 in case we need to know we are
using EGCS at some point.
with a numeric value that describes the feature level of the
compiler. This can be used to check for the presence/absence of
FreeBSD-specific compiler features. The value is a decimal number
whose digits have the form VRRRRFF, where:
V = Compiler vendor. 0 (elided) means gcc.
RRRR = Vendor's version number, e.g., 2721 for the current
gcc version (2.7.2.1).
FF = FreeBSD-specific revision level. 00 means the stock
compiler from the vendor.
The value of "__FreeBSD_cc_version" is hard-coded in
"src/contrib/gcc/config/i386/freebsd.h" and must be incremented
when new FreeBSD-specific compiler features are added. I considered
simply picking up the value of FreeBSD_version from <osreldate.h>.
But that would break cross compiles of gcc.
PR: Part of the fix for gnu/8452
Suggested by: bde
the executable file, so it will work for both a.out and ELF format
files. I have split the object format specific code into separate
source files. It's cleaner than it was before, but it's still
pretty crufty.
Don't cheat on your make world for this update. A lot of things
have to be rebuilt for it to work, including the compiler and all
of the profiled libraries.
a.out gas and the binutils gas (elf or a.out) with a single compiler.
This uses other infrastructure not yet committed, in order to support
both a.out and elf it needs to be able to get to both a.out and elf
gas, ld, libs, crt* etc. So for now, the support is pretty much dormant.
The new freebsd.h file is based on the old freebsd-elf.h file (which has a
long lineage, right back through linux and svr4 files). The change is
pretty dramatic from a gcc internals standpoint as it overrides a lot of
definitions in order to generate different output based on target mode.
There is potential for screw-ups, so please be on the lookout - gcc's
configuration mechanism wasn't really meant for this kind of thing.
It's believed to compile world etc just fine under both a.out and elf, can
handle global constructors and destructors, handles the differences in
a.out and elf stabs, and what sections things like exceptions go in.
The initial idea came from i386/osfrose.h which is a dual rose/elf format
target. These two are not as diverse as a.out and elf it would seem.
The cc front-end uses external configuration to determine default object
format (still being thrashed out, so read the source if you want to see
it so far), and has a '-aout' and '-elf' override command line switch.
There are some other internal switches that can be accessed, namely -maout,
-mno-aout, -munderscores and -mnounderscores. The underscore and local
symbol prefixing rules are controllable seperately to the output format.
(ie: it's possible to generate a.out without the _ prefixes on symbols and
also to generate elf with the _ prefixes. This isn't quite optimal, but
does seem to work pretty well, except the linkers don't always recognise
the local symbols without their normal names)
The default format is a.out (still), nobody should see any major changes.
With both elf and a.out tools and libraries installed:
[1:26pm]/tmp-223> cc -elf -o hello hello.c
peter@beast[1:27pm]/tmp-224> file hello
hello: ELF 32-bit LSB executable, Intel 80386, version 1 (FreeBSD), dynamically linked, not stripped
[1:27pm]/tmp-225> ./hello
hello world!
[1:27pm]/tmp-226> cc -aout -o hello hello.c
[1:27pm]/tmp-227> file hello
hello: FreeBSD/i386 compact demand paged dynamically linked executable not stripped
1:27pm]/tmp-228> ./hello
hello world!
Since my co-conspirators put a lot of effort into this too, I'll add them
so they can share the blame^H^H^H^H^Hglory. :-)
Reviewed by: sos, jdp
"-pg" and gprof(1) instead. FreeBSD does not support plain "-p" or
prof(1).
Plain "-p" is still allowed when just compiling. In the compile
phase, "-p" is identical "-pg". It is used by <bsd.lib.mk> for
building profiled object files.
non-i386, non-unix, and generatable files have been trimmed, but can easily
be added in later if needed.
gcc-2.7.2.1 will follow shortly, it's a very small delta to this and it's
handy to have both available for reference for such little cost.
The freebsd-specific changes will then be committed, and once the dust has
settled, the bmakefiles will be committed to use this code.
