On Oct 28, 2006, at 10:32 PM, John Reppy wrote:
I'm trying to help someone port a compiler (http://mlton.org) that
generates
x86 assembly code, but we are having difficulty with calls to
external C functions.
If we are calling a function _foo directly, we get a error from ld:
external relocation entries in non- writable section
(__TEXT,__text) symbols:
_foo
but if we put in a stub as suggested by the "Mac OS X Assembler
Reference"
.symbol_stub
L_foo_stub:
.indirect_symbol _foo
hlt ; hlt ; hlt ; hlt ; hlt
we get the following error from the assembler:
missing indirect symbols for section (__TEXT,__symbol_stub)
Can someone explain what the root cause of this error message
might be?
That Mac OS X Assembler Reference page is out of date. Please file
a bug report at <http://bugreport.apple.com/>.
If you look at the assembly output for a simple C file (using gcc -
S), you'll see that instead of .symbol_stub the compiler emits this:
.section __IMPORT,__jump_table,symbol_stubs,self_modifying_code
+pure_instructions,5
Use that instead and your stub will work.
In other words, when in doubt with your own compiler, look at what
a known working compiler does. :)
Hope this helps,
Eric
