From e18ad4d6111eb9e975ccce028baf5e4bb786bfcf Mon Sep 17 00:00:00 2001 From: Bozhidar Batsov Date: Fri, 13 Jan 2023 12:58:16 +0200 Subject: [PATCH] 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 a6e4e91a0..b5f128cd6 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)