From d040b627b1b2f604746963a91449821c6a58c7d6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Wed, 2 Feb 2022 15:36:06 +0100
Subject: [PATCH] gnu: perf: Help 'perf report --symfs' find separate debug
 info files.

* gnu/packages/linux.scm (perf)[arguments]: In 'configure' phase, modify
"util/dso.c".
---
 gnu/packages/linux.scm | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/gnu/packages/linux.scm b/gnu/packages/linux.scm
index e496b5e2b2..cd64fdc076 100644
--- a/gnu/packages/linux.scm
+++ b/gnu/packages/linux.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2021 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2012-2021, 2021-2022 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2013, 2014, 2015, 2016 Andreas Enge <andreas@enge.fr>
 ;;; Copyright © 2012 Nikita Karetnikov <nikita@karetnikov.org>
 ;;; Copyright © 2014, 2015, 2016, 2017, 2018, 2019, 2020 Mark H Weaver <mhw@netris.org>
@@ -4555,7 +4555,15 @@ in a digital read-out.")
            (lambda* (#:key inputs #:allow-other-keys)
              (setenv "SHELL_PATH" (which "bash"))
              (chdir "tools/perf")
-             #t)))
+
+             ;; This file hard-codes file system layouts for specific distros
+             ;; but not for ours; address that.  With this change, one can run
+             ;; "perf report --symfs=$HOME/.guix-profile" (without
+             ;; "/lib/debug") and 'perf' should be able to find separate debug
+             ;; info files.
+             (substitute* "util/dso.c"
+               (("/usr/lib/debug")
+                "/lib/debug")))))
        #:make-flags (list (string-append "prefix="
                                          (assoc-ref %outputs "out"))
                           "CC=gcc"