Subject: [bug#40267] [PATCH 1/2] gnu: Add unicorn.

From: Jakub Kądziołka <[email-masked]>
Date: Sat, 28 Mar 2020 01:50:52 +0100

* gnu/packages/emulators.scm (unicorn-next): New variable.
---

If I package a -rc version, should it have a -next suffix in its name
even though the "stable" version isn't packaged?

Maybe I should also package the non-rc unicorn? The test suite for that
version fails to compile, so it's not entirely trivial.

I'd also like to bring these build phases to your attention - I feel
like they need a review the most.

 gnu/packages/emulators.scm | 110 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 109 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/emulators.scm b/gnu/packages/emulators.scm
index 3591b1740c..5b5e1359e3 100644
--- a/gnu/packages/emulators.scm
+++ b/gnu/packages/emulators.scm
@@ -44,6 +44,7 @@
   #:use-module (gnu packages boost)
   #:use-module (gnu packages backup)
   #:use-module (gnu packages cdrom)
+  #:use-module (gnu packages check)
   #:use-module (gnu packages compression)
   #:use-module (gnu packages curl)
   #:use-module (gnu packages elf)
@@ -88,7 +89,8 @@
   #:use-module (gnu packages web)
   #:use-module (guix build-system cmake)
   #:use-module (guix build-system glib-or-gtk)
-  #:use-module (guix build-system gnu))
+  #:use-module (guix build-system gnu)
+  #:use-module (guix build-system python))
 
 (define-public desmume
   (package
@@ -1628,3 +1630,109 @@ derived from Gens.  Project goals include clean source code, combined features
 from various forks of Gens, and improved platform portability.")
     (supported-systems '("i686-linux" "x86_64-linux"))
     (license license:gpl2+)))
+
+;; python-pwntools requires a -rc release of unicorn
+(define-public unicorn-next
+  (package
+    (name "unicorn-next")
+    (version "1.0.2-rc2")
+    ;; NOTE: unicorn ships a bundled QEMU, but with custom modifications.
+    (source
+     (origin
+       (method git-fetch)
+       (uri (git-reference
+             (url "https://github.com/unicorn-engine/unicorn")
+             (commit version)))
+       (file-name (git-file-name name version))
+       (sha256
+        (base32
+         "0v5sc8sniv2w0bki1f7n3pgsk17y7hggw55fvkjzk2sv8z8w4bsj"))))
+    (outputs '("out" "python"))
+    ;; The main library is not written in Python, but the build process has
+    ;; little in common with any defined build system, so we might as well
+    ;; build on top of python-build-system and make use of all
+    ;; the Python-specific phases that can be reused.
+    (build-system python-build-system)
+    (arguments
+     `(#:modules ((srfi srfi-26)
+                  (guix build python-build-system)
+                  (guix build utils))
+       #:phases
+       (modify-phases %standard-phases
+         (add-after 'unpack 'install-bindings-to-python-output
+           (lambda* (#:key outputs #:allow-other-keys)
+             ;; python-build-system will build the bindings and install them to
+             ;; the "out" output, so change the build-internal names of the
+             ;; outputs.
+             (set-car! (assoc "out" outputs) "lib")
+             (set-car! (assoc "python" outputs) "out")
+             #t))
+         (add-before 'build 'build-library
+           (lambda* (#:key inputs #:allow-other-keys)
+             (invoke "make"
+                     "-j" (number->string (parallel-job-count))
+                     (string-append
+                      "UNICORN_QEMU_FLAGS=--python="
+                      (assoc-ref inputs "python-for-qemu")
+                      "/bin/python2")
+                     "UNICORN_STATIC=no"
+                     "CC=gcc")))
+         (add-after 'build-library 'install-library
+           (lambda* (#:key outputs #:allow-other-keys)
+             (invoke "make" "install"
+                     "UNICORN_STATIC=no"
+                     (string-append
+                      "PREFIX="
+                      (assoc-ref outputs "lib")))))
+         (add-before 'build 'prepare-bindings
+           (lambda* (#:key outputs #:allow-other-keys)
+             (chdir "bindings/python")
+             ;; Set this environment variable so that the Python bindings
+             ;; don't build their own copy of the shared object, but use
+             ;; a dummy value such that the bindings test suite uses the
+             ;; same mechanism for loading the library as any other user.
+             (setenv "LIBUNICORN_PATH" "1")
+             (substitute* "unicorn/unicorn.py"
+               (("_path_list = \\[.*")
+                (string-append
+                 "_path_list = [\""
+                 (assoc-ref outputs "lib")
+                 ;; eat the rest of the list
+                 "/lib\"] + 0*[")))
+             #t))
+         (add-before 'check 'check-library
+           (lambda* (#:key outputs #:allow-other-keys)
+             ;; TODO: running the tests on non-x86 requires a cross-binutils
+             ;; with x86 as target.
+             ,@(if (member (%current-system) '("x86_64-linux" "i686-linux"))
+                   '((for-each
+                      (lambda (suite)
+                        (with-directory-excursion
+                            (string-append "../../tests/" suite)
+                          (invoke "make" "test" "CC=gcc")))
+                      '("unit" "regress")))
+                   '())
+             #t))
+         (add-after 'install 'install-samples
+           (lambda* (#:key outputs #:allow-other-keys)
+             (let* ((python-samples (find-files "." "sample_.*"))
+                    (c-samples (find-files "../../samples" ".*\\.c"))
+                    (python-docdir
+                      (string-append (assoc-ref outputs "out")
+                                     "/share/doc/unicorn/samples"))
+                    (c-docdir
+                      (string-append (assoc-ref outputs "lib")
+                                     "/share/doc/unicorn/samples")))
+               (for-each (cut install-file <> c-docdir) c-samples)
+               (for-each (cut install-file <> python-docdir) python-samples)
+               #t))))))
+    (native-inputs
+     `(("cmocka" ,cmocka)
+       ("python-for-qemu" ,python-2)
+       ("hexdump-for-tests" ,util-linux)))
+    (home-page "http://www.unicorn-engine.org")
+    (synopsis "Unicorn CPU emulator framework")
+    (description
+     "Unicorn is a lightweight, multi-platform, multi-architecture CPU emulator
+framework based on QEMU.")
+    (license license:gpl2+)))
-- 
2.26.0