[bazel] Patch rules_foreign_cc to clean build logs

Move rules_foreign_cc from the root MODULE.bazel to its own
`third_party/foreign_cc` directory so that we can patch it to fix an
issue that has not yet been supported upstream yet, in the same way as
we do for e.g. `rules_rust`.

When `rules_foreign_cc` builds using tools such as e.g. Configure+Make,
output files Configure.log and BootstrapGNUMake.log are generated and
emitted which contain references to the absolute path. When building
inside Bazel's sandbox, this produces a non-determinstic output which
changes between each run, preventing builds of openocd from being
cached. The OpenOCD binary defined as an execution environment
attribute, and so will be built when running tests, stopping FPGA test
results from being cached when they should be.

To fix this, this PR introduces a simple patch to completely remove this
logging output, as it is not needed by any later steps as part of the
build.

Signed-off-by: Alex Jones <[email protected]>

MODULE.bazel

@@ -10,7 +10,6 @@ bazel_dep(name = "bazel_skylib", version = "1.7.1")
 bazel_dep(name = "googletest", version = "1.14.0.bcr.1")
 bazel_dep(name = "platforms", version = "0.0.10")
 bazel_dep(name = "rules_cc", version = "0.0.14")
-bazel_dep(name = "rules_foreign_cc", version = "0.9.0")
 bazel_dep(name = "rules_fuzzing", version = "0.5.2")
 bazel_dep(name = "rules_pkg", version = "1.0.1")
 
@@ -35,6 +34,8 @@ include("//third_party/rust:rust.MODULE.bazel")
 
 include("//third_party/python:python.MODULE.bazel")
 
+include("//third_party/foreign_cc:foreign_cc.MODULE.bazel")
+
 # Repository rules:
 bitstreams_repo = use_repo_rule("//rules:bitstreams.bzl", "bitstreams_repo")
 

third_party/foreign_cc/BUILD

@@ -0,0 +1,5 @@
+# Copyright lowRISC contributors (OpenTitan project).
+# Licensed under the Apache License, Version 2.0, see LICENSE for details.
+# SPDX-License-Identifier: Apache-2.0
+
+package(default_visibility = ["//visibility:public"])

third_party/foreign_cc/foreign_cc.MODULE.bazel

@@ -0,0 +1,15 @@
+# Copyright lowRISC contributors (OpenTitan project).
+# Licensed under the Apache License, Version 2.0, see LICENSE for details.
+# SPDX-License-Identifier: Apache-2.0
+
+# Dependencies:
+bazel_dep(name = "rules_foreign_cc", version = "0.9.0")
+
+# Overrides and patches:
+single_version_override(
+    module_name = "rules_foreign_cc",
+    patches = [
+        "//third_party/foreign_cc/patches:rules_foreign_cc.remove_log_output.patch",
+    ],
+    version = "0.9.0",
+)

third_party/foreign_cc/patches/BUILD

@@ -0,0 +1,5 @@
+# Copyright lowRISC contributors (OpenTitan project).
+# Licensed under the Apache License, Version 2.0, see LICENSE for details.
+# SPDX-License-Identifier: Apache-2.0
+
+package(default_visibility = ["//visibility:public"])

third_party/foreign_cc/patches/rules_foreign_cc.remove_log_output.patch

@@ -0,0 +1,13 @@
+diff --git foreign_cc/private/framework.bzl foreign_cc/private/framework.bzl
+index c84c217..f43da2c 100644
+--- foreign_cc/private/framework.bzl
++++ foreign_cc/private/framework.bzl
+@@ -561,7 +561,7 @@ def wrap_outputs(ctx, lib_name, configure_name, script_text, build_script_file =
+     cleanup_on_success_function = create_function(
+         ctx,
+         "cleanup_on_success",
+-        "rm -rf $BUILD_TMPDIR $EXT_BUILD_DEPS",
++        "rm -rf $BUILD_TMPDIR $EXT_BUILD_DEPS && echo > $BUILD_LOG",
+     )
+     cleanup_on_failure_function = create_function(
+         ctx,