From 2dd2126379d953c8556802f666c2512aa5e0161a Mon Sep 17 00:00:00 2001
From: Yesudeep Mangalapilly <yesudeep@gmail.com>
Date: Mon, 27 Sep 2021 12:07:04 -0700
Subject: [PATCH] Fix linker errors on (Free|Open)BSD. (#6860)

* Fix linker errors on (Free|Open)BSD.

* Adds a TODO for the FreeBSD linker flags: -lm and moves platform config to main BUILD.bazel
---
 BUILD.bazel     | 14 ++++++++++++++
 src/BUILD.bazel |  9 +++++++++
 2 files changed, 23 insertions(+)

diff --git a/BUILD.bazel b/BUILD.bazel
index 4e40b718b..395008cc2 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -10,6 +10,20 @@ exports_files([
     "LICENSE",
 ])
 
+config_setting(
+    name = "platform_freebsd",
+    constraint_values = [
+        "@platforms//os:freebsd",
+    ],
+)
+
+config_setting(
+    name = "platform_openbsd",
+    constraint_values = [
+        "@platforms//os:openbsd",
+    ],
+)
+
 # Public flatc library to compile flatbuffer files at runtime.
 cc_library(
     name = "flatbuffers",
diff --git a/src/BUILD.bazel b/src/BUILD.bazel
index d41d0fc52..a1cad077f 100644
--- a/src/BUILD.bazel
+++ b/src/BUILD.bazel
@@ -17,6 +17,15 @@ cc_library(
         "util.cpp",
     ],
     hdrs = ["//:public_headers"],
+    linkopts = select({
+        # TODO: Bazel uses `clang` instead of `clang++` to link
+        # C++ code on BSD. Temporarily adding these linker flags while
+        # we wait for Bazel to resolve
+        # https://github.com/bazelbuild/bazel/issues/12023.
+        "//:platform_freebsd": ["-lm"],
+        "//:platform_openbsd": ["-lm"],
+        "//conditions:default": [],
+    }),
     strip_include_prefix = "/include",
     visibility = ["//:__pkg__"],
 )