Re: [PATCH 3/4] Add tests for gdb.Value(bufobj, type) constructor

[Simon Marchi <simon.marchi@polymtl.ca>]

On 2019-02-18 10:07, Kevin Buettner wrote:
> gdb/testsuite/ChangeLog:
> 
>             * gdb.python/py-value.exp (test_value_from_buffer): New 
> proc with
>             call from main program.
> ---
>  gdb/testsuite/gdb.python/py-value.exp | 42 
> +++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
> 
> diff --git a/gdb/testsuite/gdb.python/py-value.exp
> b/gdb/testsuite/gdb.python/py-value.exp
> index 4f04aa9417..ba7de2166e 100644
> --- a/gdb/testsuite/gdb.python/py-value.exp
> +++ b/gdb/testsuite/gdb.python/py-value.exp
> @@ -510,6 +510,47 @@ proc test_float_conversion {} {
>      gdb_test "python print(float(gdb.Value(0)))" "0\\.0"
>  }
> 
> +proc test_value_from_buffer {} {
> +  global gdb_prompt
> +  global gdb_py_is_py3k
> +
> +  gdb_py_test_silent_cmd "python tp=gdb.lookup_type('int')" "look up
> int type" 0
> +  gdb_py_test_silent_cmd "python 
> size_a=gdb.parse_and_eval('sizeof(a)')" \
> +                         "find size of a" 0
> +  gdb_py_test_silent_cmd "python
> size_a0=gdb.parse_and_eval('sizeof(a\[0\])')" \
> +                         "find size of element of a" 0
> +  gdb_py_test_silent_cmd "python addr=gdb.parse_and_eval('&a')" \
> +                         "find address of a" 0
> +  gdb_py_test_silent_cmd "python
> b=gdb.selected_inferior().read_memory(addr,size_a)" \
> +                         "read buffer from memory" 1
> +  gdb_test "python v=gdb.Value(b,tp); print(v)" "1" \
> +            "construct value from buffer"
> +  gdb_test "python v=gdb.Value(b\[size_a0:\],tp); print(v)" "2" \
> +            "convert 2nd elem of buffer to value"
> +  gdb_test "python v=gdb.Value(b\[2*size_a0:\],tp); print(v)" "3" \
> +           "convert 3rd elem of buffer to value"
> +  gdb_test "python v=gdb.Value(b\[2*size_a0+1:\],tp); print(v)" \
> +           "TypeError: Size of type is larger than that of buffer 
> object\..*" \
> +	   "attempt to convert smaller buffer than size of type"
> +  gdb_py_test_silent_cmd "python atp=tp.array(2) ; print(atp)" \
> +                         "make array type" 0
> +  gdb_py_test_silent_cmd "python va=gdb.Value(b,atp)" \
> +                         "construct array value from buffer" 0
> +  gdb_test "python print(va)" "\\{1, 2, 3\\}" "print array value"
> +  gdb_test "python print(va\[0\])" "1" "print first array element"
> +  gdb_test "python print(va\[1\])" "2" "print second array element"
> +  gdb_test "python print(va\[2\])" "3" "print third array element"
> +  gdb_test "python print(va\[3\])" "gdb\.error: no such vector 
> element.*" \
> +           "print out of bounds array element"
> +  gdb_py_test_silent_cmd "python atpbig=tp.array(3)" "make bigger 
> array type" 0
> +  gdb_test "python vabig=gdb.Value(b,atpbig)" \
> +           "TypeError: Size of type is larger than that of buffer 
> object\..*" \
> +	   "attempt to construct large value with small buffer"
> +  gdb_test "python v=gdb.Value(2048,tp)" \
> +           "TypeError: Object must support the python buffer 
> protocol\..*" \
> +           "attempt to construct value from buffer with non-buffer 
> object"
> +}

Just a nit: I would suggest testing the code path when the second 
argument does not have the right type (is not a gdb.Type).

Simon