bazel: branch cc_configure from bazel repo to support libstdc++/libgc…

…c static linking.

We import cc_configure.bzl from https://github.com/bazelbuild/bazel at d6fec93 in this patch.
This allows us to workaround bazelbuild/bazel#2840 (see the header comment for further details).

WORKSPACE

@@ -1,5 +1,7 @@
 workspace(name = "envoy")
 
 load("//bazel:repositories.bzl", "envoy_dependencies")
+load("//bazel:cc_configure.bzl", "cc_configure")
 
 envoy_dependencies()
+cc_configure()

bazel/cc_configure.bzl

@@ -1,3 +1,13 @@
+# This file was imported from https://github.com/bazelbuild/bazel at d6fec93. We apply a number of
+# local modifications to deal with known issues in Bazel 0.4.5:
+#
+# * https://github.com/bazelbuild/bazel/issues/2840
+# * (and potentially) https://github.com/bazelbuild/bazel/issues/2805
+#
+# Specifically, for #2840 we replace gcc with g++ invocations and remove the mandatory -lstdc++
+# link. In the future, we can simplify our --build-id story resulting from #2805, but there's some
+# additional work necessary to plumb in the actual git hash.
+
 # Copyright 2016 The Bazel Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -232,7 +242,6 @@ def _crosstool_content(repository_ctx, cc, cpu_value, darwin):
           "-std=c++0x",
       ] + _cplus_include_paths(repository_ctx),
       "linker_flag": [
-          "-lstdc++",
           "-lm",  # Some systems expect -lm in addition to -lstdc++
           # Anticipated future default.
       ] + (
@@ -328,9 +337,8 @@ def _get_windows_msys_crosstool_content(repository_ctx):
       '   tool_path { name: "compat-ld" path: "%susr/bin/ld" }\n' % msys_root +
       '   tool_path { name: "cpp" path: "%susr/bin/cpp" }\n' % msys_root +
       '   tool_path { name: "dwp" path: "%susr/bin/dwp" }\n' % msys_root +
-      '   tool_path { name: "gcc" path: "%susr/bin/gcc" }\n' % msys_root +
+      '   tool_path { name: "gcc" path: "%susr/bin/g++" }\n' % msys_root +
       '   cxx_flag: "-std=gnu++0x"\n' +
-      '   linker_flag: "-lstdc++"\n' +
       '   cxx_builtin_include_directory: "%s"\n' % msys_root +
       '   cxx_builtin_include_directory: "/usr/"\n' +
       '   tool_path { name: "gcov" path: "%susr/bin/gcov" }\n' % msys_root +
@@ -387,18 +395,18 @@ def _get_system_root(repository_ctx):
 
 def _find_cc(repository_ctx):
   """Find the C++ compiler."""
-  cc_name = "gcc"
-  if "CC" in repository_ctx.os.environ:
-    cc_name = repository_ctx.os.environ["CC"].strip()
+  cc_name = "g++"
+  if "CXX" in repository_ctx.os.environ:
+    cc_name = repository_ctx.os.environ["CXX"].strip()
     if not cc_name:
-      cc_name = "gcc"
+      cc_name = "g++"
   if cc_name.startswith("/"):
     # Absolute path, maybe we should make this suported by our which function.
     return cc_name
   cc = repository_ctx.which(cc_name)
   if cc == None:
     fail(
-        "Cannot find gcc, either correct your path or set the CC" +
+        "Cannot find g++, either correct your path or set the CXX" +
         " environment variable")
   return cc
 

ci/WORKSPACE

@@ -1,6 +1,7 @@
 workspace(name = "ci")
 
 load("//bazel:repositories.bzl", "envoy_dependencies")
+load("//bazel:cc_configure.bzl", "cc_configure")
 
 envoy_dependencies(
     path = "//ci/prebuilt",
@@ -13,3 +14,5 @@ new_local_repository(
     # We only want protobuf.bzl, so don't support building out of this repo.
     build_file_content = "",
 )
+
+cc_configure()

ci/WORKSPACE.consumer

@@ -6,5 +6,8 @@ local_repository(
 )
 
 load("//bazel:repositories.bzl", "envoy_dependencies")
+load("//bazel:cc_configure.bzl", "cc_configure")
 
 envoy_dependencies(path = "@envoy//ci/prebuilt")
+
+cc_configure()

test/exe/BUILD

@@ -0,0 +1,7 @@
+package(default_visibility = ["//visibility:public"])
+
+sh_test(
+    name = "envoy_static_test",
+    srcs = ["envoy_static_test.sh"],
+    data = ["//source/exe:envoy-static"],
+)

test/exe/envoy_static_test.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+#
+
+set -e
+
+# Validate we statically link libstdc++ and libgcc.
+DYNDEPS=$(ldd source/exe/envoy-static | grep "libstdc++\|libgcc"; echo)
+[[ -z "$DYNDEPS" ]] || (echo "libstdc++ or libgcc dynamically linked: ${DYNDEPS}"; exit 1)