Re: [PATCH] configure: check for bison, flex before dtc submodule build

[Claudio Fontana]

On 4/8/20 10:00 AM, David Gibson wrote:
> On Wed, Apr 08, 2020 at 09:52:40AM +0200, Claudio Fontana wrote:
>> On 4/8/20 3:57 AM, David Gibson wrote:
>>> On Tue, Apr 07, 2020 at 12:20:15PM +0100, Peter Maydell wrote:
>>>> On Tue, 7 Apr 2020 at 12:16, Claudio Fontana <address@hidden> wrote:
>>>>>
>>>>> if fdt is required, and the system DTC (libfdt) is not usable,
>>>>> check for the dtc submodule requirements before trying to build it,
>>>>> and error out with a helpful message in case the dependencies are not met.
>>>>>
>>>>> Signed-off-by: Claudio Fontana <address@hidden>
>>>>
>>>> Does the dtc module actually need bison/flex, or does it just
>>>> print an ugly warning about it? We only want the 'libfdt' part
>>>> of dtc, which doesn't need the parser, we don't need to build
>>>> the actual dtc compiler.
>>>
>>> Assuming we're just invoking "make libfdt" within the submodule,
>>> rather than "make" which will build dtc as well, then bison / flex
>>> shouldn't be needed.
>>>
>>
>> Indeed; I just sent a patch that works for me,
>> tried a few in-tree and out-of-tree full builds, and it seems to work as 
>> intended.
>> patchew complains about docker builds/tests though, although running the 
>> same TEST SCRIPTs manually with docker works for me.
>>
>> The libfdt target inside dtc/Makefile actually causes more than just libfdt 
>> to be built:
>>
>> ~/git/qemu/dtc> make libdtc
>>       DEP tests/dumptrees.c
>>       DEP tests/trees.S
>>       DEP tests/testutils.c
>>       DEP tests/value-labels.c
>>       DEP tests/asm_tree_dump.c
>>       DEP tests/truncated_memrsv.c
>>       DEP tests/truncated_string.c
>>       DEP tests/truncated_property.c
>>       DEP tests/check_full.c
>>       DEP tests/check_header.c
>>       DEP tests/check_path.c
>>       DEP tests/overlay_bad_fixup.c
>>       DEP tests/overlay.c
>>       DEP tests/subnode_iterate.c
>>       DEP tests/property_iterate.c
>>       DEP tests/integer-expressions.c
>>       DEP tests/utilfdt_test.c
>>       DEP tests/path_offset_aliases.c
>>       DEP tests/add_subnode_with_nops.c
>>       DEP tests/dtbs_equal_unordered.c
>>       DEP tests/dtb_reverse.c
>>       DEP tests/dtbs_equal_ordered.c
>>       DEP tests/extra-terminating-null.c
>>       DEP tests/incbin.c
>>       DEP tests/boot-cpuid.c
>>       DEP tests/phandle_format.c
>>       DEP tests/path-references.c
>>       DEP tests/references.c
>>       DEP tests/string_escapes.c
>>       DEP tests/propname_escapes.c
>>       DEP tests/appendprop2.c
>>       DEP tests/appendprop1.c
>>       DEP tests/del_node.c
>>       DEP tests/del_property.c
>>       DEP tests/setprop.c
>>       DEP tests/set_name.c
>>       DEP tests/rw_tree1.c
>>       DEP tests/open_pack.c
>>       DEP tests/nopulate.c
>>       DEP tests/mangle-layout.c
>>       DEP tests/move_and_save.c
>>       DEP tests/sw_states.c
>>       DEP tests/sw_tree1.c
>>       DEP tests/nop_node.c
>>       DEP tests/nop_property.c
>>       DEP tests/setprop_inplace.c
>>       DEP tests/stringlist.c
>>       DEP tests/addr_size_cells2.c
>>       DEP tests/addr_size_cells.c
>>       DEP tests/notfound.c
>>       DEP tests/sized_cells.c
>>       DEP tests/char_literal.c
>>       DEP tests/get_alias.c
>>       DEP tests/node_offset_by_compatible.c
>>       DEP tests/node_check_compatible.c
>>       DEP tests/node_offset_by_phandle.c
>>       DEP tests/node_offset_by_prop_value.c
>>       DEP tests/parent_offset.c
>>       DEP tests/supernode_atdepth_offset.c
>>       DEP tests/get_path.c
>>       DEP tests/get_phandle.c
>>       DEP tests/getprop.c
>>       DEP tests/get_name.c
>>       DEP tests/path_offset.c
>>       DEP tests/subnode_offset.c
>>       DEP tests/find_property.c
>>       DEP tests/root_node.c
>>       DEP tests/get_mem_rsv.c
>>       DEP libfdt/fdt_overlay.c
>>       DEP libfdt/fdt_addresses.c
>>       DEP libfdt/fdt_empty_tree.c
>>       DEP libfdt/fdt_strerror.c
>>       DEP libfdt/fdt_rw.c
>>       DEP libfdt/fdt_sw.c
>>       DEP libfdt/fdt_wip.c
>>       DEP libfdt/fdt_ro.c
>>       DEP libfdt/fdt.c
>>       DEP util.c
>>       DEP fdtoverlay.c
>>       DEP fdtput.c
>>       DEP fdtget.c
>>       DEP fdtdump.c
>>       LEX convert-dtsv0-lexer.lex.c
>> make: flex: Command not found
>>       DEP srcpos.c
>>       BISON dtc-parser.tab.c
>> make: bison: Command not found
>>       LEX dtc-lexer.lex.c
>> make: flex: Command not found
>>       DEP treesource.c
>>       DEP livetree.c
>>       DEP fstree.c
>>       DEP flattree.c
>>       DEP dtc.c
>>       DEP data.c
>>       DEP checks.c
>>      CHK version_gen.h
>>       LEX convert-dtsv0-lexer.lex.c
>> make: flex: Command not found
>>       BISON dtc-parser.tab.c
>> make: bison: Command not found
>>       LEX dtc-lexer.lex.c
>> make: flex: Command not found
>> make: *** No rule to make target 'libdtc'.  Stop.
>>
>>
>> so I just used dtc/libfdt/Makefile.libfdt directly and removed the
>> recursion altogether.
> 
> The Makefile setup of dtc/libfdt is a bit weird (mostly to allow for
> Makefile fragments to be used in weird build environments).  But for
> this case you might be better off still doing the recursion, but just
> changing the target from 'all' to 'libfdt'.

Hi David,

that approach (recursing the same way, just building libfdt instead of all) is 
what I tried first,
however as showcased above the libfdt target seems to cause more stuff to be 
built than necessary.

Do you think we should change the external module to make the minimal build of 
libfdt work, instead of removing the recursion?

Thanks,

Claudio


> 
>> Let me know what you think about the idea in general, or if anybody knows 
>> what is wrong in the patch that makes patchew complain?
>>
>> Ciao,
>>
>> Claudio
>>
>