bug#46256: [feature/native-comp] AOT eln files ignored if run from build tree

[Andrea Corallo via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Andrea Corallo via "Bug reports for GNU Emacs, the Swiss army knife of
text editors" <bug-gnu-emacs@gnu.org> writes:

> Andy Moreton <andrewjmoreton@gmail.com> writes:
>
>> On Fri 26 Feb 2021, Andrea Corallo via "Bug reports for GNU Emacs, the Swiss army knife of text editors" wrote:
>>
>>> Andy Moreton <andrewjmoreton@gmail.com> writes:
>>>
>>> [...]
>>>
>>>> The problem is with the file names used to generate the hashes, where
>>>> comparison of file names.
>>>>
>>>> As an experiment, I changed epaths.h from:
>>>> #define PATH_DUMPLOADSEARCH "C:/emacs/git/emacs/native/lisp"
>>>>
>>>> to:
>>>> #define PATH_DUMPLOADSEARCH "c:/emacs/git/emacs/native/lisp"
>>>>
>>>> and then ran make (to build without regenerating the header).
>>>> The resulting emacs did not complain about mismatched filenames.
>>>>
>>>> Thus the fix outlined by Eli above looks like it will solve the problem.
>>>>
>>>>     AndyM
>>>
>>> Hi Andy,
>>>
>>> could you give it a try to the attached patch?  It follows Eli's
>>> suggestion of using 'Fw32_long_file_name'.
>>
>> The patch looks good - please apply it.
>
> Thanks for verifying it, installed as 312deba530.
>
>> I tried building with the patch applied to a clean tree, and the
>> resulting emacs runs without the filename mismatch messages, and did not
>> recompile the AOT files into the per-user eln-cache.
>>
>> There were also a couple of errors in the build:
>>
>> Backtrace:
>> 00007ff78467a2a2
>> 00007ff78453be26
>> 00007ff7845a98ac
>> ...[snipped]...
>> 00007ff784626548
>> Eager macro-expansion failure: (file-error "Renaming" "Permission
>> denied"
>> "c:/emacs/git/emacs/native/build/mingw64-x86_64-O2-native/native-lisp/28.0.50-e09cfb99/cc-bytecomp-4817e810-d16f606e.eln"
>> "c:/emacs/git/emacs/native/build/mingw64-x86_64-O2-native/native-lisp/28.0.50-e09cfb99/cc-bytecomp-4817e810-d16f606e.elnGMMUdn.eln.tmp")
>> C:/emacs/git/emacs/native/src/alloc.c:3160: Emacs fatal error: assertion failed: cu->handle
>> make[2]: *** [Makefile:319: progmodes/antlr-mode.elc] Error 3
>>
>> The backtrace addresses did not give anything useful from addr2line.
>>
>> There are still some elisp files that did not get native compiled when
>> the build was done with "make -j8 NATIVE_FULL_AOT=1", and so get async
>> compiled when running the built emacs:
>>
>>   ansi-color auth_source byte-opt bytecomp cconv cl-extra cl-lib cl-macs
>>   cl-seq comint comp comp-cstr cus-edit cus-start desktop
>>   display-fill-column-indicator easy-mmode easymenu edmacro eieio
>>   eieio-core frameset gv help-mode hl-line image-file info json kmacro
>>   map minibuf-eldef package paren password-cache pcase pp ring rx seq
>>   subr-x time-date warnings wid-edit
>>
>> That may be a result of the error during the build.
>
> Mmmmh, that's strange some of these are even compiled as COMPILE_FIRST
> therfore are certainly native compiled.
>
> One thing you could do (before one of these is recompiled) is to use
> `comp-el-to-eln-filename' to check what the native compiler is expecting
> as eln filename and if this is present in any of the folders in your
> `comp-eln-load-path'.

Apologies, to be more precise: if the file is compiled during the build
(as should be in this case) it should be in the "native-lisp/" dir in
the build tree.

  Andrea