Re: [PATCH,v2] Make gdb.arch/i386-biarch-core.exp more robust

[Pedro Alves <palves at redhat dot com>]

On 02/07/2017 10:11 AM, Luis Machado wrote:
> This test attempts to load a x86 core file no matter what target
> architectures the tested GDB supports. If GDB doesn't know how to handle
> a i386 target, it is very likely the core file will not be recognized.
> 
> In this case we should still attempt to load a core file to make sure GDB
> doesn't crash or throws an internal error.  But we should not proceed to
> try to read memory unconditionally.
> 
> This patch makes the test check for proper i386 arch support in GDB and bails
> out if i386 is not supported and the core file format is not recognized.
> 
> This addresses the spurious aarch64-elf failures i'm seeing for this test.
> 
> gdb/testsuite/ChangeLog:
> 
> YYYY-MM-DD  Luis Machado  <lgustavo@codesourcery.com>
> 
> 	* gdb.arch/i386-biarch-core.exp: Check for i386 arch support and
> 	return if core file is not recognized
> ---
>  gdb/testsuite/gdb.arch/i386-biarch-core.exp | 30 ++++++++++++++++++++++++++++-
>  1 file changed, 29 insertions(+), 1 deletion(-)
> 
> diff --git a/gdb/testsuite/gdb.arch/i386-biarch-core.exp b/gdb/testsuite/gdb.arch/i386-biarch-core.exp
> index 4c5f450..a05096c 100644
> --- a/gdb/testsuite/gdb.arch/i386-biarch-core.exp
> +++ b/gdb/testsuite/gdb.arch/i386-biarch-core.exp
> @@ -54,6 +54,18 @@ if {$corestat(size) != 102400} {
>      return -1
>  }
>  
> +# First check if this particular GDB supports i386, otherwise we should not
> +# expect the i386 core file to be loaded successfully.
> +set supports_arch_i386 1
> +set test "complete set architecture i386"
> +gdb_test_multiple $test $test {
> +    -re ".*\r\nset architecture i386\r\n(.*\r\n)?$gdb_prompt $" {

".*" at the start of a -re is implicit/redundant.

> +    }
> +    -re "\r\n$gdb_prompt $" {
> +        set supports_arch_i386 0
> +    }
> +}
> +
>  # Wrongly built GDB complains by:
>  # "..." is not a core dump: File format not recognized
>  # As the provided test core has 64bit PRSTATUS i386 built GDB cannot parse it.
> @@ -62,7 +74,23 @@ if {$corestat(size) != 102400} {
>  # objcopy as it corrupts the core file beyond all recognition.
>  # The output therefore does not matter much, just we should not get GDB
>  # internal error.
> -gdb_test "core-file ${corefile}" ".*" "core-file"
> +#
> +# If this particular GDB does not support i386, it is expected GDB will not
> +# recognize the core file.  If it does anyway, it should not crash.
> +set test "load core file"
> +gdb_test_multiple "core-file ${corefile}" $test {
> +    -re ".* no core file handler recognizes format(.*\r\n)?$gdb_prompt $" {

Ditto.  Also, why the "(....)?" in "(.*\r\n)?" ?

> +	if { $supports_arch_i386 } {
> +	    fail $test
> +	} else {
> +	    untested $test

The "load core file" test was a pass, this "else" outcome is expected.
What's untested is the next test.  Either write something like:

            pass $test
            untested ".text is readable (core file unrecognized)"
            return

or here write only:

            pass $test

and put the untested after the gdb_test_multiple, close to
the following gdb_test.

> +	    return
> +	}
> +    }
> +    -re "\r\n$gdb_prompt $" {
> +	pass $test
> +    }
> +}
>  

Thanks,
Pedro Alves