Subject: [bug#39013] [PATCH] gnu: Add abseil-cpp.

From: Roel Janssen <[email-masked]>
Date: Tue, 07 Jan 2020 16:07:21 +0100

Dear Guix,

The following patch adds abseil-cpp.  I want to add it because it seems
to be a dependency of tensorflow-1.15.0 (which I am trying to update
to).

There are two not-so-perfect things with the patch:
1. I had to use the latest Git commit because it adds bits to build
shared libraries.
2. I disabled the tests because it attempts to download "googletest". 
I tried modifying the build system to use "googletest" from Guix but
that wasn't succesful.

Nevertheless, I hope this patch is acceptable.

Kind regards,
Roel Janssen

From 06ed0284561463c087ec0f16f9c35fc7926f22df Mon Sep 17 00:00:00 2001
From: Roel Janssen <[email-masked]>
Date: Tue, 7 Jan 2020 16:02:28 +0100
Subject: [PATCH] gnu: Add abseil-cpp.

* gnu/packages/machine-learning.scm (abseil-cpp): New variable.
---
 gnu/packages/machine-learning.scm | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/gnu/packages/machine-learning.scm b/gnu/packages/machine-learning.scm
index 719401d69a..91cc4fe091 100644
--- a/gnu/packages/machine-learning.scm
+++ b/gnu/packages/machine-learning.scm
@@ -1316,6 +1316,34 @@ mile of distributed computing to connect devices, mobile applications and
 browsers to backend services.")
     (license license:asl2.0)))
 
+(define-public abseil-cpp
+  ;; We use this commit because it contains changes to the build system to
+  ;; allow building shared libraries.
+  (let ((commit "a048203a881f11f4b7b8df5fb563aec85522f8db"))
+    (package
+      (name "abseil-cpp")
+      (version (string-append "20190808-" (string-take commit 7)))
+      (source (origin
+                (method git-fetch)
+                (uri (git-reference
+                      (url "https://github.com/abseil/abseil-cpp.git")
+                      (commit commit)))
+                (file-name (git-file-name name version))
+                (sha256
+                 (base32
+                  "13v3bkfyhrcl9am0jcz4cfbfc5rn3acm9z4wm01pn36vcgvw2l4s"))))
+      (build-system cmake-build-system)
+      (arguments `(#:configure-flags (list "-DBUILD_SHARED_LIBS=ON")
+                   #:tests? #f)) ; Tests attempt to download googletest.
+      (home-page "https://abseil.io")
+      (synopsis "Augmented C++ standard library")
+      (description "Abseil is an open-source collection of C++ library code
+designed to augment the C++ standard library.  The Abseil library code is
+collected from Google's own C++ code base, has been extensively tested and
+used in production, and is the same code we depend on in our daily coding
+lives.")
+      (license license:asl2.0))))
+
 ;; Note that Tensorflow includes a "third_party" directory, which seems to not
 ;; only contain modified subsets of upstream library source code, but also
 ;; adapter headers provided by Google (such as the fft.h header, which is not
-- 
2.17.1