Re: [PATCH v2] docs: Integrate rustdoc into Rust documentation

[Akira Yokosawa]

On Mon, 5 Dec 2022 10:36:11 -0600, Carlos Bilbao wrote:
> On 12/4/22 19:06, Akira Yokosawa wrote:
> 
>> Hi,
>>
>> On Thu, 1 Dec 2022 14:48:14 -0600, Carlos Bilbao wrote:
>>> Include HTML output generated with rustdoc into the Linux kernel
>>> documentation on Rust. Change target `make htmldocs` to combine RST Sphinx
>>> and the generation of Rust documentation, when support is available.
>>>
>>> Signed-off-by: Carlos Bilbao <carlos.bilbao@xxxxxxx>
>>> ---
>>>
>>> Changes since V1:
>>>   - Work on top of v6.1-rc1.
>> Thank you for the rebase.
>>
>>>   - Don't use rustdoc.rst, instead add link to Documentation/rust/index.rst.
>>>   - In Documentation/Makefile, replace @make rustdoc for $(Q)$(MAKE) rustdoc.
>>>   - Don't do LLVM=1 for all rustdoc generation within `make htmldocs`.
>>>   - Add spaces on definition of RUSTDOC_OUTPUT, for consistency.
>>>
>>> ---
>>>   Documentation/Makefile       |  4 ++++
>>>   Documentation/rust/index.rst |  3 +++
>>>   rust/Makefile                | 15 +++++++++------
>>>   3 files changed, 16 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/Documentation/Makefile b/Documentation/Makefile
>>> index 64d44c1ecad3..f537cf558af6 100644
>>> --- a/Documentation/Makefile
>>> +++ b/Documentation/Makefile
>>> @@ -92,6 +92,10 @@ quiet_cmd_sphinx = SPHINX  $@ --> file://$(abspath $(BUILDDIR)/$3/$4)
>>>       fi
>>>     htmldocs:
>>> +# If Rust support is available, add rustdoc generated contents
>>> +ifdef CONFIG_RUST
>>> +    $(Q)$(MAKE) rustdoc
>>> +endif
>>>       @$(srctree)/scripts/sphinx-pre-install --version-check
>>>       @+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,html,$(var),,$(var)))
>> So, this means "make htmldocs" will require kernel .config if CONFIG_RUST=y.
>> I'm not sure this new requirement is acceptable for kernel documentation
>> testers who just want to build kernel documentation.
> 
> 
> This is already kind of the case for Rust-related business.
> 
> 
>>
>> You are doing three things in this patch.
>>
>>   1) Change the destination of rustdoc to under Documentation/output/
>>   2) Add a cross reference to the generated rustdoc in
>>      Documentation/rust/index.rst.
>>   3) Integrate rustdoc generation into htmldocs.
>>
>> I'm OK with 1) and 2).
>> Can you separate 3) into another patch and respin?
> 
> 
> Glad we can agree on 1) and 2). Why moving 3)? This is a small patch with
> one overall purpose (Integrate rustdoc into website).

Yes, I agree that 3) is a small change. I understand what you want to
do. But there are a couple of options for _how_ to do it.
My current position is that Documentation/Makefile is _not_ the right
place for the change, as mentioned in my reply to Miguel.

> 
> 
>>
>> By the way, is rustdoc's requirement of .config only for CONFIG_RUST?
>> In other words, are contents of rustdoc affected by other config settings?
>>
>> If not, I think rustdoc can be generated regardless of config settings as
>> far as necessary tools (rustc, bindgen, etc.) are available.
> 
> 
> Yes, but someone with the tools may not want to use them. Keep in mind that
> generating rustdoc takes a few extra seconds.

As mentioned in another reply, I'm convinced of the dependency on .config.

> 
> 
>>
>>>   diff --git a/Documentation/rust/index.rst b/Documentation/rust/index.rst
>>> index 4ae8c66b94fa..4005326c3ba9 100644
>>> --- a/Documentation/rust/index.rst
>>> +++ b/Documentation/rust/index.rst
>>> @@ -6,6 +6,9 @@ Rust
>>>   Documentation related to Rust within the kernel. To start using Rust
>>>   in the kernel, please read the quick-start.rst guide.
>>>   +If this documentation includes rustdoc-generated HTML, the entry point can
>>> +be found `here. <rustdoc/kernel/index.html>`_
>> This cross reference will only make sense in htmldocs build.
>> Perhaps, you can use the "only::" directive [1] as follows:
>>
>> .. only:: html
> 
> 
> This I can gladly do on a V3. I will wait for an answer on issues above.

OK.

So if you split this into a two-patch series, 1/2 for 1) and 2), and 2/2
for 3) (or an updated one), I'm glad to give my RB tag to 1/2 for Miguel
to be able take it for v6.2 (timing is tight!). 2/2 will need at least
a couple of respins, I guess.

        Thanks, Akira
> 
> 
>>
>>      If this documentation includes rustdoc-generated HTML, the entry point can
>>      be found `here. <rustdoc/kernel/index.html>`_
>>
>> [1]: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.sphinx-doc.org%2Fen%2Fmaster%2Fusage%2Frestructuredtext%2Fdirectives.html%23directive-only&amp;data=05%7C01%7Ccarlos.bilbao%40amd.com%7C163763a795284a542e4f08dad65cf4c6%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C638057991984040258%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=DU8nmQp7gCCGNMUR6urtHHCz5nXAtomeV17%2BzB%2F4L38%3D&amp;reserved=0
>>
>>          Thanks, Akira
>>
>>> +
>>>   .. toctree::
>>>       :maxdepth: 1
>>>   diff --git a/rust/Makefile b/rust/Makefile
>>> index 7700d3853404..080c07048065 100644
>>> --- a/rust/Makefile
>>> +++ b/rust/Makefile
>>> @@ -1,5 +1,8 @@
>>>   # SPDX-License-Identifier: GPL-2.0
>>>   +# Where to place rustdoc generated documentation
>>> +RUSTDOC_OUTPUT = $(objtree)/Documentation/output/rust/rustdoc
>>> +
>>>   always-$(CONFIG_RUST) += target.json
>>>   no-clean-files += target.json
>>>   @@ -58,7 +61,7 @@ quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
>>>       OBJTREE=$(abspath $(objtree)) \
>>>       $(RUSTDOC) $(if $(rustdoc_host),$(rust_common_flags),$(rust_flags)) \
>>>           $(rustc_target_flags) -L$(objtree)/$(obj) \
>>> -        --output $(objtree)/$(obj)/doc \
>>> +        --output $(RUSTDOC_OUTPUT) \
>>>           --crate-name $(subst rustdoc-,,$@) \
>>>           @$(objtree)/include/generated/rustc_cfg $<
>>>   @@ -75,15 +78,15 @@ quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
>>>   # and then retouch the generated files.
>>>   rustdoc: rustdoc-core rustdoc-macros rustdoc-compiler_builtins \
>>>       rustdoc-alloc rustdoc-kernel
>>> -    $(Q)cp $(srctree)/Documentation/images/logo.svg $(objtree)/$(obj)/doc
>>> -    $(Q)cp $(srctree)/Documentation/images/COPYING-logo $(objtree)/$(obj)/doc
>>> -    $(Q)find $(objtree)/$(obj)/doc -name '*.html' -type f -print0 | xargs -0 sed -Ei \
>>> +    $(Q)cp $(srctree)/Documentation/images/logo.svg $(RUSTDOC_OUTPUT)
>>> +    $(Q)cp $(srctree)/Documentation/images/COPYING-logo $(RUSTDOC_OUTPUT)
>>> +    $(Q)find $(RUSTDOC_OUTPUT) -name '*.html' -type f -print0 | xargs -0 sed -Ei \
>>>           -e 's:rust-logo\.svg:logo.svg:g' \
>>>           -e 's:rust-logo\.png:logo.svg:g' \
>>>           -e 's:favicon\.svg:logo.svg:g' \
>>>           -e 's:<link rel="alternate icon" type="image/png" href="[./]*favicon-(16x16|32x32)\.png">::g'
>>>       $(Q)echo '.logo-container > img { object-fit: contain; }' \
>>> -        >> $(objtree)/$(obj)/doc/rustdoc.css
>>> +        >> $(RUSTDOC_OUTPUT)/rustdoc.css
>>>     rustdoc-macros: private rustdoc_host = yes
>>>   rustdoc-macros: private rustc_target_flags = --crate-type proc-macro \
>>> @@ -141,7 +144,7 @@ quiet_cmd_rustdoc_test = RUSTDOC T $<
>>>           @$(objtree)/include/generated/rustc_cfg \
>>>           $(rustc_target_flags) $(rustdoc_test_target_flags) \
>>>           --sysroot $(objtree)/$(obj)/test/sysroot $(rustdoc_test_quiet) \
>>> -        -L$(objtree)/$(obj)/test --output $(objtree)/$(obj)/doc \
>>> +        -L$(objtree)/$(obj)/test --output $(RUSTDOC_OUTPUT) \
>>>           --crate-name $(subst rusttest-,,$@) $<
>>>     # We cannot use `-Zpanic-abort-tests` because some tests are dynamic,
>>>
>>> base-commit: 9abf2313adc1ca1b6180c508c25f22f9395cc780
> 
> 
> Thanks,
> Carlos