Re: RFA: tolerate unavailable struct return values

[Michael Snyder <msnyder at cygnus dot com>]

Jim Blandy wrote:
> 
> On some architectures, it's impossible for GDB to find structs
> returned by value.  These shouldn't be failures.  Should they be
> passes?

I kinda like the idea of their being xfails.  The functionality
is not there, it's just not a surprise.


> 
> 2001-11-29  Jim Blandy  <jimb@redhat.com>
> 
>         If GDB says it can't find the struct the function returned, treat
>         that as an expected failure.
>         * gdb.base/structs.exp (call_struct_func): New function.
>         (do_function_calls): Use call_struct_func to call the functions
>         returning structs.
> 
> Index: gdb/testsuite/gdb.base/structs.exp
> ===================================================================
> RCS file: /cvs/cvsfiles/devo/gdb/testsuite/gdb.base/structs.exp,v
> retrieving revision 1.17
> diff -c -r1.17 structs.exp
> *** gdb/testsuite/gdb.base/structs.exp  2001/08/09 18:02:02     1.17
> --- gdb/testsuite/gdb.base/structs.exp  2001/11/29 17:46:25
> ***************
> *** 54,59 ****
> --- 54,85 ----
>       continue
>   }
> 
> +
> + # Call FUNC with no arguments, and expect to see the regexp RESULT in
> + # the output.  If we get back the error message "Function return value
> + # unknown", call that an expected failure; on some architectures, it's
> + # impossible to find structs returned by value reliably.
> + proc call_struct_func { func result } {
> +     global gdb_prompt
> +
> +     set command "p ${func}()"
> +     send_gdb "${command}\n"
> +     gdb_expect {
> +         -re "$result\[\r\n\]+$gdb_prompt $" {
> +             pass "$command"
> +         }
> +         -re "Function return value unknown.\[\r\n\]+$gdb_prompt $" {
> +             xfail "$command"
> +         }
> +         -re "$gdb_prompt $" {
> +             fail "$command"
> +         }
> +         timeout {
> +             fail "$command (timeout)"
> +         }
> +     }
> + }
> +
>   # FIXME:  Before calling this proc, we should probably verify that
>   # we can call inferior functions and get a valid integral value
>   # returned.
> ***************
> *** 67,85 ****
>       global gdb_prompt
> 
>       # First, call the "fun" functions and examine the value they return.
> !     gdb_test "p fun1()" " = {a = 49 '1'}"
> !     gdb_test "p fun2()" " = {a = 97 'a', b = 98 'b'}"
> !     gdb_test "p fun3()" " = {a = 65 'A', b = 66 'B', c = 67 'C'}"
> !     gdb_test "p fun4()" " = {a = 49 '1', b = 50 '2', c = 51 '3', d = 52 '4'}"
> !     gdb_test "p fun5()" " = {a = 97 'a', b = 98 'b', c = 99 'c', d = 100 'd', e = 101 'e'}"
> !     gdb_test "p fun6()" " = {a = 65 'A', b = 66 'B', c = 67 'C', d = 68 'D', e = 69 'E', f = 70 'F'}"
> !     gdb_test "p fun7()" " = {a = 49 '1', b = 50 '2', c = 51 '3', d = 52 '4', e = 53 '5', f = 54 '6', g = 55 '7'}"
> !     gdb_test "p fun8()" " = {a = 49 '1', b = 50 '2', c = 51 '3', d = 52 '4', e = 53 '5', f = 54 '6', g = 55 '7', h = 56 '8'}"
> !     gdb_test "p fun9()" " = {a = 97 'a', b = 98 'b', c = 99 'c', d = 100 'd', e = 101 'e', f = 102 'f', g = 103 'g', h = 104 'h', i = 105 'i'}"
> !     gdb_test "p fun10()" " = {a = 65 'A', b = 66 'B', c = 67 'C', d = 68 'D', e = 69 'E', f = 70 'F', g = 71 'G', h = 72 'H', i = 73 'I', j = 74 'J'}"
> !     gdb_test "p fun11()" " = {a = 49 '1', b = 50 '2', c = 51 '3', d = 52 '4', e = 53 '5', f = 54 '6', g = 55 '7', h = 56 '8', i = 57 '9', j = 65 'A', k = 66 'B'}"
> !     gdb_test "p fun12()" " = {a = 65 'A', b = 66 'B', c = 67 'C', d = 68 'D', e = 69 'E', f = 70 'F', g = 71 'G', h = 72 'H', i = 73 'I', j = 74 'J', k = 75 'K', l = 76 'L'}"
> !     gdb_test "p fun16()" " = {a = 97 'a', b = 98 'b', c = 99 'c', d = 100 'd', e = 101 'e', f = 102 'f', g = 103 'g', h = 104 'h', i = 105 'i', j = 106 'j', k = 107 'k', l = 108 'l', m = 109 'm', n = 110 'n', o = 111 'o', p = 112 'p'}"
> 
>       # Now call the Fun functions to set the L* variables.  This
>       # tests that gdb properly passes structures to functions.
> --- 93,111 ----
>       global gdb_prompt
> 
>       # First, call the "fun" functions and examine the value they return.
> !     call_struct_func "fun1" " = {a = 49 '1'}"
> !     call_struct_func "fun2" " = {a = 97 'a', b = 98 'b'}"
> !     call_struct_func "fun3" " = {a = 65 'A', b = 66 'B', c = 67 'C'}"
> !     call_struct_func "fun4" " = {a = 49 '1', b = 50 '2', c = 51 '3', d = 52 '4'}"
> !     call_struct_func "fun5" " = {a = 97 'a', b = 98 'b', c = 99 'c', d = 100 'd', e = 101 'e'}"
> !     call_struct_func "fun6" " = {a = 65 'A', b = 66 'B', c = 67 'C', d = 68 'D', e = 69 'E', f = 70 'F'}"
> !     call_struct_func "fun7" " = {a = 49 '1', b = 50 '2', c = 51 '3', d = 52 '4', e = 53 '5', f = 54 '6', g = 55 '7'}"
> !     call_struct_func "fun8" " = {a = 49 '1', b = 50 '2', c = 51 '3', d = 52 '4', e = 53 '5', f = 54 '6', g = 55 '7', h = 56 '8'}"
> !     call_struct_func "fun9" " = {a = 97 'a', b = 98 'b', c = 99 'c', d = 100 'd', e = 101 'e', f = 102 'f', g = 103 'g', h = 104 'h', i = 105 'i'}"
> !     call_struct_func "fun10" " = {a = 65 'A', b = 66 'B', c = 67 'C', d = 68 'D', e = 69 'E', f = 70 'F', g = 71 'G', h = 72 'H', i = 73 'I', j = 74 'J'}"
> !     call_struct_func "fun11" " = {a = 49 '1', b = 50 '2', c = 51 '3', d = 52 '4', e = 53 '5', f = 54 '6', g = 55 '7', h = 56 '8', i = 57 '9', j = 65 'A', k = 66 'B'}"
> !     call_struct_func "fun12" " = {a = 65 'A', b = 66 'B', c = 67 'C', d = 68 'D', e = 69 'E', f = 70 'F', g = 71 'G', h = 72 'H', i = 73 'I', j = 74 'J', k = 75 'K', l = 76 'L'}"
> !     call_struct_func "fun16" " = {a = 97 'a', b = 98 'b', c = 99 'c', d = 100 'd', e = 101 'e', f = 102 'f', g = 103 'g', h = 104 'h', i = 105 'i', j = 106 'j', k = 107 'k', l = 108 'l', m = 109 'm', n = 110 'n', o = 111 'o', p = 112 'p'}"
> 
>       # Now call the Fun functions to set the L* variables.  This
>       # tests that gdb properly passes structures to functions.