[U-Boot] Build warnings in libfdt

[Heinrich Schuchardt]

On 11/17/19 4:39 PM, Simon Glass wrote:
> Hi,
>
> On Sun, 17 Nov 2019 at 06:14, Tom Rini <trini at konsulko.com> wrote:
>>
>> On Sun, Nov 17, 2019 at 11:11:43AM +0100, Heinrich Schuchardt wrote:
>>> Hello Simon,
>>>
>>> when building U-Boot HEAD with GCC 9.2.1 I get a bunch of build warnings
>>> which I did not see before your recent libfdt update.
>>>
>>> scripts/dtc/libfdt/fdt.c: In function ‘fdt_offset_ptr’:
>>> scripts/dtc/libfdt/fdt.c:137:18: warning: comparison of integer
>>> expressions of different signedness: ‘unsigned int’ and ‘int’
>>> [-Wsign-compare]
>>>    137 |   if ((absoffset < offset)
>>>        |                  ^
>>> scripts/dtc/libfdt/fdt.c:143:23: warning: comparison of integer
>>> expressions of different signedness: ‘unsigned int’ and ‘int’
>>> [-Wsign-compare]
>>>    143 |   if (((offset + len) < offset)
>>>        |                       ^
>>> scripts/dtc/libfdt/fdt.c: In function ‘fdt_move’:
>>> scripts/dtc/libfdt/fdt.c:307:25: warning: comparison of integer
>>> expressions of different signedness: ‘uint32_t’ {aka ‘unsigned int’} and
>>> ‘int’ [-Wsign-compare]
>>>    307 |  if (fdt_totalsize(fdt) > bufsize)
>>>        |                         ^
>>> scripts/dtc/libfdt/fdt_ro.c: In function ‘fdt_get_string’:
>>> scripts/dtc/libfdt/fdt_ro.c:56:16: warning: comparison of integer
>>> expressions of different signedness: ‘uint32_t’ {aka ‘unsigned int’} and
>>> ‘int32_t’ {aka ‘int’} [-Wsign-compare]
>>>     56 |  if (absoffset >= totalsize)
>>>        |                ^~
>>> scripts/dtc/libfdt/fdt_ro.c:64:18: warning: comparison of integer
>>> expressions of different signedness: ‘int’ and ‘uint32_t’ {aka ‘unsigned
>>> int’} [-Wsign-compare]
>>>     64 |    if (stroffset >= fdt_size_dt_strings(fdt))
>>>        |                  ^~
>>> scripts/dtc/libfdt/fdt_ro.c:71:21: warning: comparison of integer
>>> expressions of different signedness: ‘int’ and ‘uint32_t’ {aka ‘unsigned
>>> int’} [-Wsign-compare]
>>>     71 |       || (stroffset < -fdt_size_dt_strings(fdt)))
>>>        |                     ^
>>> scripts/dtc/libfdt/fdt_ro.c:73:20: warning: comparison of integer
>>> expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long
>>> unsigned int’} [-Wsign-compare]
>>>     73 |   if ((-stroffset) < len)
>>>        |                    ^
>>> scripts/dtc/libfdt/fdt_ro.c: In function ‘fdt_mem_rsv’:
>>> scripts/dtc/libfdt/fdt_ro.c:164:17: warning: comparison of integer
>>> expressions of different signedness: ‘int’ and ‘uint32_t’ {aka ‘unsigned
>>> int’} [-Wsign-compare]
>>>    164 |   if (absoffset < fdt_off_mem_rsvmap(fdt))
>>>        |                 ^
>>> scripts/dtc/libfdt/fdt_ro.c:166:17: warning: comparison of integer
>>> expressions of different signedness: ‘int’ and ‘long unsigned int’
>>> [-Wsign-compare]
>>>    166 |   if (absoffset > fdt_totalsize(fdt) -
>>>        |                 ^
>>> scripts/dtc/libfdt/fdt_ro.c: In function ‘fdt_node_offset_by_phandle’:
>>> scripts/dtc/libfdt/fdt_ro.c:682:33: warning: comparison of integer
>>> expressions of different signedness: ‘uint32_t’ {aka ‘unsigned int’} and
>>> ‘int’ [-Wsign-compare]
>>>    682 |  if ((phandle == 0) || (phandle == -1))
>>>        |                                 ^~
>>> scripts/dtc/libfdt/fdt_wip.c: In function
>>> ‘fdt_setprop_inplace_namelen_partial’:
>>> scripts/dtc/libfdt/fdt_wip.c:26:14: warning: comparison of integer
>>> expressions of different signedness: ‘int’ and ‘uint32_t’ {aka ‘unsigned
>>> int’} [-Wsign-compare]
>>>     26 |  if (proplen < (len + idx))
>>>        |              ^
>>> scripts/dtc/libfdt/fdt_sw.c: In function ‘fdt_grab_space_’:
>>> scripts/dtc/libfdt/fdt_sw.c:105:20: warning: comparison of integer
>>> expressions of different signedness: ‘size_t’ {aka ‘long unsigned int’}
>>> and ‘int’ [-Wsign-compare]
>>>    105 |  if ((offset + len < offset) || (offset + len > spaceleft))
>>>        |                    ^
>>> scripts/dtc/libfdt/fdt_sw.c:105:47: warning: comparison of integer
>>> expressions of different signedness: ‘size_t’ {aka ‘long unsigned int’}
>>> and ‘int’ [-Wsign-compare]
>>>    105 |  if ((offset + len < offset) || (offset + len > spaceleft))
>>>        |                                               ^
>>> scripts/dtc/libfdt/fdt_sw.c: In function ‘fdt_create_with_flags’:
>>> scripts/dtc/libfdt/fdt_sw.c:118:14: warning: comparison of integer
>>> expressions of different signedness: ‘int’ and ‘long unsigned int’
>>> [-Wsign-compare]
>>>    118 |  if (bufsize < hdrsize)
>>>        |              ^
>>> scripts/dtc/libfdt/fdt_sw.c: In function ‘fdt_resize’:
>>> scripts/dtc/libfdt/fdt_sw.c:164:28: warning: comparison of integer
>>> expressions of different signedness: ‘size_t’ {aka ‘long unsigned int’}
>>> and ‘int’ [-Wsign-compare]
>>>    164 |  if ((headsize + tailsize) > bufsize)
>>>        |                            ^
>>> scripts/dtc/libfdt/fdt_sw.c: In function ‘fdt_add_string_’:
>>> scripts/dtc/libfdt/fdt_sw.c:258:34: warning: comparison of integer
>>> expressions of different signedness: ‘uint32_t’ {aka ‘unsigned int’} and
>>> ‘int’ [-Wsign-compare]
>>>    258 |  if (fdt_totalsize(fdt) + offset < struct_top)
>>>        |                                  ^
>>> scripts/dtc/libfdt/fdt_strerror.c: In function ‘fdt_strerror’:
>>> scripts/dtc/libfdt/fdt_strerror.c:51:18: warning: comparison of integer
>>> expressions of different signedness: ‘int’ and ‘long unsigned int’
>>> [-Wsign-compare]
>>>     51 |  else if (errval > -FDT_ERRTABSIZE) {
>>>        |                  ^
>>> scripts/dtc/libfdt/fdt_overlay.c: In function
>>> ‘overlay_update_local_node_references’:
>>> scripts/dtc/libfdt/fdt_overlay.c:253:17: warning: comparison of integer
>>> expressions of different signedness: ‘int’ and ‘long unsigned int’
>>> [-Wsign-compare]
>>>    253 |   for (i = 0; i < (fixup_len / sizeof(uint32_t)); i++) {
>>>        |                 ^
>>
>> Since these also exist in upstream dtc, fixing them there is the best
>> place to start.  Thanks!
>
> Yes I noticed that on a sandbox build just recently. +1 to fixing it upstream.
>
> Regards,
> Simon
>

In upstream the warnings are  only shown when changing the build flags
adding -Wextra (and -Wno-error to see them all).

That seems to be the reason that nobody fixed them there.

Best regards

Heinrich