RFC: Avoid calling XXX_skip_prologue for assembly code

[Fred Fish <fnf at fishpond dot ninemoons dot com>]

Does anyone have any issues with the attached patch?

There is little point in attempting to skip over prologues if we
already know for a fact that the source language is assembly.

In fact, attempting to do so may actually be incorrect if the user has
taken the output of the compiler, used that as the basis for his code,
and hand optimized it in some way to produce an assembly version.
There could still be prologue code in the hand crafted version.

Another way to handle this issue would be to have each of the
"XXX_skip_prologue" functions in the various XXX-tdep.c files do their
own checking first to see if the language is assembly, but they don't
have easy access to that info, and each of them would have to do
something similar to this patch anyway, so it seems more logical to
just do the test in one place.

-Fred

==================================================================

2001-10-05  Fred Fish  <fnf@cygnus.com>

	* symtab.c (find_function_start_sal): Do not attempt to skip over
	prologues for assembly functions.

Index: symtab.c
===================================================================
RCS file: /cvs/src/src/gdb/symtab.c,v
retrieving revision 1.42
diff -u -p -r1.42 symtab.c
--- symtab.c	2001/07/07 17:19:50	1.42
+++ symtab.c	2001/10/05 19:42:05
@@ -2031,7 +2031,7 @@ find_function_start_sal (struct symbol *
 
   pc = BLOCK_START (SYMBOL_BLOCK_VALUE (sym));
   fixup_symbol_section (sym, NULL);
-  if (funfirstline)
+  if (funfirstline && SYMBOL_LANGUAGE(sym) != language_asm)
     {				/* skip "first line" of function (which is actually its prologue) */
       asection *section = SYMBOL_BFD_SECTION (sym);
       /* If function is in an unmapped overlay, use its unmapped LMA