[nongnu] elpa/projectile e18ad4d611: Make the tests work reliably with native compilation enabled

[ELPA Syncer]

branch: elpa/projectile
commit e18ad4d6111eb9e975ccce028baf5e4bb786bfcf
Author: Bozhidar Batsov <bozhidar@batsov.dev>
Commit: Bozhidar Batsov <bozhidar@batsov.dev>

    Make the tests work reliably with native compilation enabled
    
    I am the maintainer of projectile for debian. (Aymeric Agon-Rambosson)
    
    As part of the building process of our packages, we run the tests
    provided by the upstream maintainers in a clean and empty
    environment (no writable $HOME, no internet access, etc...). For
    this reason, we sometimes uncover bugs that would remain masked on
    the machines of the upstream maintainers, and of the users.
    
    The test "projectile-parse-dirconfig-file" can break in a very
    specific setting :
    
    Since version 28.1, emacs has been shipped with
    native-compilation, that is the possibility to compile elisp to
    native instructions using libgccjit. Since elisp allows the
    advising of functions implemented in C ("primitives"), it is
    necessary to compile trampolines to replace those functions if we
    want to advise them, in order to allow an arbitrary user-defined
    function to be run instead.
    
    The test library you use, buttercup, and more specifically its
    function spy-on, advises functions routinely.
    
    In the test we're interested in, buttercup (spy-on) changes the
    definition of a few primitives in the offending test
    (projectile-parse-dirconfig-file), namely file-exists-p,
    file-truename and insert-file-contents.
    
    The first one is advised so as to always return t, regardless of
    whether the file is really present or not.
    
    The first two are advised without error. The last one, however,
    can fail because, being a primitive, a trampoline needs to be
    compiled. We have the following backtrace in our build environment
    :
    
    comp-subr-trampoline-install(insert-file-contents)
    comp-trampoline-search(insert-file-contents)
    
native-elisp-load("/tmp/buttercupKuLmvD/28.2-4001e2a9/subr--trampoline-696...
    error: (native-lisp-load-failed "file does not exists"
    
"/tmp/buttercupKuLmvD/28.2-4001e2a9/subr--trampoline-696e736572742d66696c652d636f6e74656e7473_insert_file_contents_0.eln")
    
    What happens here is the following : if we are in a situation
    where the trampoline corresponding to the function
    insert-file-contents is not already present in some eln-cache
    directory on the machine, then the function comp-trampoline-search
    should return nil, which would trigger the compilation of said
    trampoline.
    
    However, since comp-trampoline-search relies on file-exists-p, and
    this last one has been advised so as to always answer yes,
    comp-trampoline-search tries to load a file that does not exists,
    hence our error.
    
    You or your users probably never reach that state, probably
    because you can always count on the trampoline being present
    beforehand. But if it is not there, you should be able to
    reproduce. We always reach that state because we run the tests in
    a clean environment, where the trampoline is never present.
    
    This error can be expected whenever a primitive is advised (in our
    case insert-file-contents) while file-exists-p is already advised
    so as to always return t, and the trampoline corresponding to the
    primitive does not already exists on the file system.
    
    There are two possible solutions : the first one is to try and
    ensure the trampoline is present by the time of the advice, for
    instance by compiling it unconditionally before the test. This is
    not entirely reliable, as some environments could inhibit the
    saving of this trampoline to the file system (this is what we do,
    for instance).
    
    The second one is to exclude the function insert-file-contents
    (and indeed, any primitive you would want to advise while
    file-exists-p is advised as to always return t) from trampoline
    optimisation completely. The variable
    native-comp-never-optimize-functions can be used to do just that.
    This patch tweaks it accordingly.
---
 test/projectile-test.el | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/test/projectile-test.el b/test/projectile-test.el
index a6e4e91a00..b5f128cd60 100644
--- a/test/projectile-test.el
+++ b/test/projectile-test.el
@@ -26,6 +26,11 @@
 
 ;;; Code:
 
+;; needed for the tests to work with native compilation
+(with-eval-after-load 'comp
+  (push 'insert-file-contents
+        native-comp-never-optimize-functions))
+
 (require 'projectile)
 (require 'buttercup)