Remove workarounds for rules_go support (#95)

It looks like rules_go can work without these now.

This will simplify the setup of the LLVM distribution repo.

tests/scripts/run_external_tests.sh

@@ -22,11 +22,6 @@ source "$(dirname "${BASH_SOURCE[0]}")/bazel.sh"
 "${bazel}" fetch @io_bazel_rules_go//tests/core/cgo:all
 "$("${bazel}" info output_base)/external/io_bazel_rules_go/tests/core/cgo/generate_imported_dylib.sh"
 
-# We exclude the following targets:
-# - cc_libs_test from rules_go because it assumes that stdlibc++ has been dynamically linked, but we
-#   link it statically on linux.
-# - opts_test from rules_go because its include path assumes that the main repo is rules_go (see
-#   https://github.com/bazelbuild/rules_go/issues/2955).
 test_args=(
   --incompatible_enable_cc_toolchain_resolution
   --symlink_prefix=/
@@ -42,8 +37,12 @@ if [[ "${TEST_MIGRATION:-}" ]]; then
   # This flag is not quite ready -- https://github.com/bazelbuild/bazel/issues/7347
   test_args+=("--incompatible_disallow_struct_provider_syntax=false")
 fi
+
+# We exclude the following targets:
+# - opts_test from rules_go because its include path assumes that the main repo is rules_go (see
+#   https://github.com/bazelbuild/rules_go/issues/2955).
 "${bazel}" --bazelrc=/dev/null test "${test_args[@]}" \
   //tests/foreign:pcre \
   @openssl//:libssl \
   $("${bazel}" query 'attr(timeout, short, tests(@com_google_absl//absl/...))') \
-  $("${bazel}" query 'tests(@io_bazel_rules_go//tests/core/cgo:all) except set(@io_bazel_rules_go//tests/core/cgo:cc_libs_test @io_bazel_rules_go//tests/core/cgo:opts_test)')
+  $("${bazel}" query 'tests(@io_bazel_rules_go//tests/core/cgo:all) except set(@io_bazel_rules_go//tests/core/cgo:opts_test)')

toolchain/BUILD.llvm_repo

@@ -35,11 +35,7 @@ filegroup(
     name = "ld",
     srcs = [
         "bin/ld.lld",
-    ] + glob([
-        # Optional symlinks needed to support rules_go and some other applications.
-        "bin/ld",  # -> /usr/bin/ld
-        "bin/ld.gold",  # -> /usr/bin/ld.gold (or empty)
-    ]),
+    ],
 )
 
 filegroup(
@@ -78,10 +74,7 @@ filegroup(
 
 filegroup(
     name = "ar",
-    srcs = ["bin/llvm-ar"] + glob([
-        # Optional symlinks needed to support rules_go and some other applications.
-        "bin/ar",  # -> /usr/bin/ar
-    ]),
+    srcs = ["bin/llvm-ar"],
 )
 
 filegroup(

toolchain/cc_wrapper.sh.tpl

@@ -33,9 +33,6 @@ set -eu
 # Call the C++ compiler.
 if [[ -f %{toolchain_path_prefix}bin/clang ]]; then
   %{toolchain_path_prefix}bin/clang "$@"
-elif [[ ":${PATH}:" == *":%{toolchain_path_prefix}bin:"* ]]; then
-  # GoCompile sets the PATH to the directory containing the linker, and changes CWD.
-  clang "$@"
 elif [[ "${BASH_SOURCE[0]}" == "/"* ]]; then
   # Some consumers of `CcToolchainConfigInfo` (e.g. `cmake` from rules_foreign_cc)
   # change CWD and call $CC (this script) with its absolute path.

toolchain/internal/repo.bzl

@@ -40,21 +40,6 @@ def llvm_repo_impl(rctx):
         executable = False,
     )
 
+    # TODO: Replace download_llvm with standard http_archive rules.
     if not _download_llvm(rctx, _os_arch_pair(os, arch)):
         _download_llvm_preconfigured(rctx)
-
-    # TODO: Are these symlinks still needed? Remove from here and
-    # BUILD.llvm_repo if not. If these symlinks are removed, then we can
-    # leverage http_archive rule instead of _download_llvm. Or maybe we can
-    # still leverage it with a patch file.
-
-    rctx.symlink("/usr/bin/ar", "bin/ar")  # For GoLink.
-
-    # For GoCompile on macOS; compiler path is set from linker path.
-    # It also helps clang driver sometimes for the linker to be colocated with the compiler.
-    rctx.symlink("/usr/bin/ld", "bin/ld")
-    if rctx.path("/usr/bin/ld.gold").exists:
-        rctx.symlink("/usr/bin/ld.gold", "bin/ld.gold")
-    else:
-        # Add dummy file for non-linux so we don't have to put conditional logic in BUILD.
-        rctx.file("bin/ld.gold")

toolchain/osx_cc_wrapper.sh.tpl

@@ -52,9 +52,6 @@ done
 # Call the C++ compiler.
 if [[ -f %{toolchain_path_prefix}bin/clang ]]; then
   %{toolchain_path_prefix}bin/clang "$@"
-elif [[ ":${PATH}:" == *":%{toolchain_path_prefix}bin:"* ]]; then
-  # GoCompile sets the PATH to the directory containing the linker, and changes CWD.
-  clang "$@"
 elif [[ "${BASH_SOURCE[0]}" == "/"* ]]; then
   # Some consumers of `CcToolchainConfigInfo` (e.g. `cmake` from rules_foreign_cc)
   # change CWD and call $CC (this script) with its absolute path.