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++) { | ^
Best regards
Heinrich