Optimize Bazel external dependencies

This change does the following:

- Always use {,new_}http_archive rather than git_repository
- Make liberal use of strip_prefix
- Clarify licenses() in BUILD files
- On POSIX include headers like a normal C/C++ program

This change accomplishes the following:

- Reduce download size >100MB: The biggest culprit is grpc which has
  tens of thousands of commits in its GitHub repository.

- Reduce disk size >200MB: On disk, grpc takes up 250MB when cloned even
  though the tarball of the git repo is 3.2MB. By never using git
  externals, we save on network.

- Consume less cpu: Cloning git repositories is much slower than
  downloading and extracting a tarball.
Change: 133895791

1 files changed, 5 insertions, 17 deletions

diff --git a/farmhash.BUILD b/farmhash.BUILD
index fe19e14430..8111cd61f9 100644
--- a/farmhash.BUILD
+++ b/farmhash.BUILD
@@ -1,21 +1,9 @@
-package(default_visibility = ["//visibility:public"])
-
-prefix_dir = "farmhash-34c13ddfab0e35422f4c3979f360635a8c050260"
-
-genrule(
-    name = "configure",
-    srcs = glob(
-        ["**/*"],
-        exclude = [prefix_dir + "/config.h"],
-    ),
-    outs = [prefix_dir + "/config.h"],
-    cmd = "pushd external/farmhash_archive/%s; workdir=$$(mktemp -d -t tmp.XXXXXXXXXX); cp -a * $$workdir; pushd $$workdir; ./configure; popd; popd; cp $$workdir/config.h $(@D); rm -rf $$workdir;" % prefix_dir,
-)
+licenses(["notice"])  # MIT
 
 cc_library(
     name = "farmhash",
-    srcs = [prefix_dir + "/src/farmhash.cc"],
-    hdrs = [prefix_dir + "/src/farmhash.h"] + [":configure"],
-    includes = [prefix_dir],
-    visibility = ["//visibility:public"]
+    srcs = ["farmhash.cc"],
+    hdrs = ["farmhash.h"],
+    includes = ["."],
+    visibility = ["//visibility:public"],
 )