The changes from GCC 2.95.3 to 3.1 are large and it is hard to figure
out how to apply our changes. Once BDE can properly test GCC 3.1 he'll
add back in our changes.
Remove our definition for FUNCTION_PROFILER as it is wrong.
Note that "jsr $28,_mcount" is a macro for
ldq $27, _mcount($29) !literal!1
jsr $28, ($27), _mcount !lituse_jsr!1
1. The call to _mcount is added by alpha_expand_prologue after we load the gp.
Our _mcount uses $27 for the incoming address, unlike OSF/1 and Linux,
which use $28. This probably doesn't matter since we probably don't use $27
within _mcount itself.
2. You can't use this insn with _mcount because it uses the PLT, which clobbers
the return address in $28. Note that the prologue_mcount pattern carefully
avoids adding the lituse_jsr relocation so that we call through the GOT
directly.
Submitted by: Richard Henderson <rth@redhat.com>
When rtld runs the .fini section in a shared lib (C++), the code in
question from .../contrib/gdb/config/alpha/crtbegin.asm first calls
__do_globals_dtors_aux and then __do_frame_takedown. Unfortunately, the
value of gp after a jsr is undefined and in this case had changed from before
the call, probably as a result of calling code in some other shared library.
The normal calling convention for alpha is to re-initialize gp using
'ldgp gp,0(ra)' after a jsr instruction but in this case no such
re-initialization is done. This leads to a bogus value being read for the
address of __do_frame_takedown and a quick segfault.
Submitted by: dfr
Obtained from: GCC 3.0
If "WANT_DWARF2_UNWIND" you get it. Note that this is a different C++ ABI
than the FreeBSD default. So you will need to recompile all your C++ apps
that uses exceptions if you turn this on. I am adding it here for Yahoo!'s
use and for those that want to be early adopters to what I will make as the
default with the GCC 3.0 import.
header to reduce the difference of our sources to the stock GNU/FSF ones.
While the mix binary format support was nice to have in the FreeBSD MI
header as a frame work, it just clutters up too much and makes the FreeBSD
MI header more different from the FSF/GNU stock one than it needs to be.
into the i386 MD FreeBSD header. Also comment tweaking, continuation line
style changes, and other minor changes to make this closer to the latest
FSF/GNU 3.0 sources (to reduce my headache when 3.0 is imported).
linked in addition to libc rather than instead of libc.
Ideally, "-pthread" would now be equivalent to adding "-lc_r" to the
end of the link command. But it is slightly different in this
implementation. Adding "-lc_r" to the link command would produce a
"ld" command line containing this:
... -lc_r /usr/lib/libgcc.a -lc /usr/lib/libgcc.a ...
but this implementation of the "-pthread" option produces this:
... /usr/lib/libgcc.a -lc_r -lc /usr/lib/libgcc.a ...
It would be possible to make them identical, but that doesn't fit
as nicely into GCC's way of doing things. I don't think the ordering
change will make any difference in practice.
This option depended on bits not part of the base system and required
people to install the LinuxThreads port in a manner non-consistent with
the workings of our Ports Collection.
The directions for properly linking with LinuxThreads are given by that
port at install time.
Requested by: jasone
to generate the special .type and .size directives which are used to set
the corresponding fields of the linker symbol table entries in the ELF
object file. As such they are not i386-specific and thus belong in our
MI header. Otherwise on the Alpha we don't properly give the type and
size of dynamic symbols. Bintuil versions past 2.9.1 warn of this and
w/o this change, `ld' generates a lot of warnings during a `make world'.
"The problem is that egcs/gcc-2.95's reorganisation of the prologue and
epilogue code to use rtl instead of output_asm_insn() completely broke our
hooks. rtl is emitted in a different order, only after optimisation, while
output_asm_insn() is emitted immediately. rtl is presumably used so that
the prologue and epilogue can be optimised.
I couldn't find any good examples to copy. gcc's own
FUNCTION_BLOCK_PROFILER still uses output_asm_insn() and seems to be
completely broken. One of the XXX comments points to this.
IIRC, the hacks here basically arrange to emit magic label names; then when
the magic names are output, they are transformed into prologue and epilogue
code."
Submitted by: bde
