Re: RFA: GCC stabs don't contain prototype info

[Jim Blandy <jimb@zwingli.cygnus.com>]

I've committed this change.

Jim Blandy <jimb@cygnus.com> writes:
> This comes as a bit of a surprise to me, but it seems that stabs
> generated by GCC don't indicate whether a given function was defined
> with a prototype or not.  The argument types should appear after the
> return types, each preceded by a semicolon, but for the following
> input program:
> 
>         int foo (int a, float b) { return a + b; }
> 
> `gcc -save-temps -O2 -g -c' generates the following relevant stabs:
> 
>     .stabs "int:t(0,1)=r(0,1);0020000000000;0017777777777;",128,0,0,0
>     .stabs "float:t(0,12)=r(0,1);4;0;",128,0,0,0
>     .stabs "foo:F(0,1)",36,0,1,foo
>     .stabs "a:P(0,1)",64,0,1,8
>     .stabs "b:P(0,12)",64,0,1,9
>     .stabs "",36,0,0,.LLscope0-foo
>             .stabs "",100,0,0,.Letext
> 
> There is no no prototype info here.  There's no way for GDB to know
> that the function expects its second argument to be passed as a float,
> not promoted to a double, as the K&R-style rules specify.
> 
> Thus:
> 
> 2001-11-26  Jim Blandy  <jimb@redhat.com>
> 
> 	* gdb.base/callfuncs.exp: The stabs generated by GCC don't tell us
> 	whether functions are prototyped or not, so we can't possibly pass
> 	arguments to t_float_values2 properly.
> 
> Index: gdb/testsuite/gdb.base/callfuncs.exp
> ===================================================================
> RCS file: /cvs/cvsfiles/devo/gdb/testsuite/gdb.base/callfuncs.exp,v
> retrieving revision 1.46
> diff -c -r1.46 callfuncs.exp
> *** gdb/testsuite/gdb.base/callfuncs.exp	2001/11/10 00:08:23	1.46
> --- gdb/testsuite/gdb.base/callfuncs.exp	2001/11/27 03:24:59
> ***************
> *** 142,147 ****
> --- 142,150 ----
>   	gdb_test "p t_float_values(float_val1,-2.3765)" " = 1"
>   
>   	# Test passing of arguments which might not be widened.
> +         # Under stabs, GCC doesn't tell us whether the function was
> +         # prototyped or not.
> +         if {$gcc_compiled} { setup_xfail_format "stabs" }
>   	gdb_test "p t_float_values2(0.0,0.0)" " = 0"
>   
>   	# Although PR 5318 mentions SunOS specifically, this seems
> ***************
> *** 152,158 ****
> --- 155,166 ----
>   		setup_xfail "alpha-dec-osf2*" "i*86-*-sysv4*" 5318
>   	    }
>   	}
> +         
> +         # Under stabs, GCC doesn't tell us whether the function was
> +         # prototyped or not.
> +         if {$gcc_compiled} { setup_xfail_format "stabs" }
>   	gdb_test "p t_float_values2(3.14159,float_val2)" " = 1"
> + 
>   	gdb_test "p t_small_values(1,2,3,4,5,6,7,8,9,10)" " = 55"
>   
>   	gdb_test "p t_double_values(0.0,0.0)" " = 0"
> ***************
> *** 289,294 ****
> --- 297,304 ----
>   	}
>       }
>   }
> + 
> + get_debug_format
>   
>   # Make sure that malloc gets called and that the floating point unit
>   # is initialized via a call to t_double_values.
>