bug#54728: [PATCH 2/2] gnu: valgrind: fix ld.so symbols not found

[Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>]

* gnu/packages/valgrind.scm (valgrind/interactive)[native-inputs]:
  Add libc:debug
  [arguments]: Add patch-default-debuginfo-path phase
* gnu/packages/commencement.scm (glibc-final): Export variable.

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
---
 gnu/packages/commencement.scm |  2 +-
 gnu/packages/valgrind.scm     | 66 +++++++++++++++++++++++++++++++----
 2 files changed, 61 insertions(+), 7 deletions(-)

diff --git a/gnu/packages/commencement.scm b/gnu/packages/commencement.scm
index e8b47fbeab..c2de02411c 100644
--- a/gnu/packages/commencement.scm
+++ b/gnu/packages/commencement.scm
@@ -3381,7 +3381,7 @@ (define gettext-boot0
                         (("^PROGRAMS =.*$")
                          "PROGRAMS =\n")))))))))
 
-(define glibc-final
+(define-public glibc-final
   ;; The final glibc, which embeds the statically-linked Bash built above.
   ;; Use 'package/inherit' so we get the 'replacement' of 'glibc', if any.
   (package/inherit
diff --git a/gnu/packages/valgrind.scm b/gnu/packages/valgrind.scm
index 6648f17dfa..a09721071d 100644
--- a/gnu/packages/valgrind.scm
+++ b/gnu/packages/valgrind.scm
@@ -25,8 +25,10 @@
 (define-module (gnu packages valgrind)
   #:use-module (guix build-system gnu)
   #:use-module (guix download)
+  #:use-module (guix gexp)
   #:use-module (guix licenses)
   #:use-module (guix packages)
+  #:use-module (guix utils)
   #:use-module (gnu packages)
   #:use-module (gnu packages gdb)
   #:use-module (gnu packages perl))
@@ -91,12 +93,64 @@ (define-public valgrind
     (properties '((hidden? . #t)))))
 
 (define-public valgrind/interactive
-  (package/inherit
-   valgrind
-   (inputs
-    ;; GDB is needed to provide a sane default for `--db-command'.
-    `(("gdb" ,gdb)))
-   (properties '())))
+  (package/inherit valgrind
+    (inputs
+     ;; GDB is needed to provide a sane default for `--db-command'.
+     `(("gdb" ,gdb)
+       ("libc:debug" ,(@@ (gnu packages commencement) glibc-final) "debug")))
+    (arguments
+     (substitute-keyword-arguments (package-arguments valgrind)
+       ((#:phases those-phases #~%standard-phases)
+        #~(let* ((those-phases #$those-phases)
+                 (unpack (assoc-ref those-phases 'unpack)))
+            (modify-phases those-phases
+              (add-before 'build 'patch-default-debuginfo-path
+                (lambda _
+                  ;; This helps Valgrind find the debug symbols of ld.so.
+                  ;; Without it, Valgrind does not work in a Guix shell
+                  ;; container and cannot be used as-is during packages tests
+                  ;; phases
+                  (substitute* '
+                    ("coregrind/m_debuginfo/readelf.c"
+                      "docs/xml/manual-core-adv.xml"
+                      "docs/xml/manual-core.xml")
+                    (("/usr/lib/debug")
+                     (string-append
+                       (assoc-ref %build-inputs "libc:debug")
+                       "/lib/debug")))
+                  ;; We also need to account for the bigger path in
+                  ;; the malloc-ed variables
+                  (substitute* '
+                    ("coregrind/m_debuginfo/readelf.c")
+                    (("VG_\\(strlen\\)\\(buildid\\) \\+ 33")
+                      (string-append
+                        "VG_(strlen)(buildid) + "
+                        (number->string
+                         (+ (string-length
+                            (string-append
+                              (assoc-ref %build-inputs "libc:debug")
+                              "/lib/debug"))
+                            (string-length "/.build-id//.debug")
+                            1)))))
+                  (substitute* '
+                    ("coregrind/m_debuginfo/readelf.c")
+                    ((string-append
+                      "VG_\\(strlen\\)\\(objdir\\) \\+ "
+                      "VG_\\(strlen\\)\\(debugname\\) \\+ 64")
+                     (string-append
+                      "VG_(strlen)(objdir) + VG_(strlen)(debugname) + "
+                      (number->string
+                        (+ (string-length
+                            (string-append
+                             (assoc-ref
+                              %build-inputs
+                              "libc:debug")
+                             "/lib/debug"))
+                           (string-length
+                            "/usr/lib/debug")
+                           1)))))
+                  #t)))))))
+    (properties '())))
 
 (define-public valgrind-3.18
   (package
-- 
2.35.1