gnu: abseil-cpp-20200923.3: Fix test suite on some architectures.

* gnu/packages/cpp.scm (abseil-cpp-20200923.3)[source]: Add patches.
* gnu/packages/patches/abseil-cpp-20200923.3-adjust-sysinfo.patch,
gnu/packages/patches/abseil-cpp-20200923.3-duration-test.patch: New
files.
* gnu/local.mk (dist_patch_DATA): Register them.

Change-Id: I3a0a6c3396a7c2854236c68ec77a68bbdd6af1f4

1 files changed, 60 insertions, 0 deletions

diff --git a/gnu/packages/patches/abseil-cpp-20200923.3-adjust-sysinfo.patch b/gnu/packages/patches/abseil-cpp-20200923.3-adjust-sysinfo.patch
new file mode 100644
index 0000000000..ae52e103a7
--- /dev/null
+++ b/gnu/packages/patches/abseil-cpp-20200923.3-adjust-sysinfo.patch
@@ -0,0 +1,60 @@
+https://sources.debian.org/data/main/a/abseil/0~20200923.3-2/debian/patches/cpu-frequency.diff
+This patch is taken from Debian instead of the upstream URL because the
+upstream URL contains far more changes than occur in this patch.
+
+It was then modified to also work for armhf.
+
+From: Benjamin Barenblat <bbaren@google.com>
+Subject: Ignore missing CPU frequency on more architectures
+Forwarded: yes
+Applied-Upstream: https://github.com/abseil/abseil-cpp/commit/1918ad2ae38aa32c74b558b322479a8efdd76363
+
+Linux on MIPS, PA-RISC, RISC-V, and SystemZ doesn’t expose the nominal CPU
+frequency via /sys, so don’t worry if `NominalCPUFrequency` returns 1.0 on those
+platforms.
+
+Some POWER machines expose the CPU frequency; others do not. Since we can’t
+predict which type of machine the tests will run on, simply disable testing for
+`NominalCPUFrequency` on POWER.
+
+The author works at Google. Upstream applied this patch as Piper revision
+347079873 and exported it to GitHub; the Applied-Upstream URL above points to
+the exported commit.
+
+--- a/absl/base/internal/sysinfo_test.cc
++++ b/absl/base/internal/sysinfo_test.cc
+@@ -37,17 +37,28 @@ TEST(SysinfoTest, NumCPUs) {
+       << "NumCPUs() should not have the default value of 0";
+ }
+ 
++// Ensure that NominalCPUFrequency returns a reasonable value, or 1.00 on
++// platforms where the CPU frequency is not available through sysfs.
++//
++// POWER is particularly problematic here; some Linux kernels expose the CPU
++// frequency, while others do not. Since we can't predict a priori what a given
++// machine is going to do, just disable this test on POWER on Linux.
++#if !(defined(__linux) && (defined(__ppc64__) || defined(__PPC64__)))
+ TEST(SysinfoTest, NominalCPUFrequency) {
+-#if !(defined(__aarch64__) && defined(__linux__)) && !defined(__EMSCRIPTEN__)
+-  EXPECT_GE(NominalCPUFrequency(), 1000.0)
+-      << "NominalCPUFrequency() did not return a reasonable value";
+-#else
+-  // Aarch64 cannot read the CPU frequency from sysfs, so we get back 1.0.
+-  // Emscripten does not have a sysfs to read from at all.
++  // Linux only exposes the CPU frequency on certain architectures, and
++  // Emscripten doesn't expose it at all.
++#if defined(__linux__) &&                                                  \
++        (defined(__aarch64__) || defined(__hppa__) || defined(__mips__) || \
++         defined(__arm__) || defined(__riscv) || defined(__s390x__)) ||                        \
++    defined(__EMSCRIPTEN__)
+   EXPECT_EQ(NominalCPUFrequency(), 1.0)
+       << "CPU frequency detection was fixed! Please update unittest.";
++#else
++  EXPECT_GE(NominalCPUFrequency(), 1000.0)
++      << "NominalCPUFrequency() did not return a reasonable value";
+ #endif
+ }
++#endif
+ 
+ TEST(SysinfoTest, GetTID) {
+   EXPECT_EQ(GetTID(), GetTID());  // Basic compile and equality test.