support runtime/test-time compiler invokations

This commit changes the cc_wrapper.sh script to allow for it to find
paths when invoked at runtime with runfiles as apposed to strictly using
build-rule invokes.

Author: TroyKomodo

toolchain/cc_wrapper.sh.tpl

@@ -14,17 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# OS X relpath is not really working. This is a wrapper script around gcc
-# to simulate relpath behavior.
-#
-# This wrapper uses install_name_tool to replace all paths in the binary
-# (bazel-out/.../path/to/original/library.so) by the paths relative to
-# the binary. It parses the command line to behave as rpath is supposed
-# to work.
-#
-# See https://blogs.oracle.com/dipol/entry/dynamic_libraries_rpath_and_mac
-# on how to set those paths for Mach-O binaries.
-
 # shellcheck disable=SC1083
 
 set -euo pipefail
@@ -42,27 +31,41 @@ trap cleanup EXIT
 # See note in toolchain/internal/configure.bzl where we define
 # `wrapper_bin_prefix` for why this wrapper is needed.
 
-if [[ -f %{toolchain_path_prefix}bin/clang ]]; then
-  execroot_path=""
-elif [[ ${BASH_SOURCE[0]} == "/"* ]]; then
-  # Some consumers of `CcToolchainConfigInfo` (e.g. `cmake` from rules_foreign_cc)
-  # change CWD and call $CC (this script) with its absolute path.
-  # For cases like this, we'll try to find `clang` through an absolute path.
-  # This script is at _execroot_/external/_repo_name_/bin/cc_wrapper.sh
-  execroot_path="${BASH_SOURCE[0]%/*/*/*/*}/"
-else
-  echo >&2 "ERROR: could not find clang; PWD=\"${PWD}\"; PATH=\"${PATH}\"."
+# this script is located at either
+# - <execroot>/external/<repo_name>/bin/cc_wrapper.sh
+# - <runfiles>/<repo_name>/bin/cc_wrapper.sh
+# The clang is located at
+# - <execroot>/external/<repo_name2>/bin/clang
+# - <runfiles>/<repo_name2>/bin/clang
+#
+# In both cases, getting to clang can be done via
+# Finding the current dir of this script,
+# - <execroot>/external/<repo_name>/bin/
+# - <runfiles>/<repo_name>/bin/
+# going back 2 directories
+# - <execroot>/external
+# - <runfiles>
+#
+# Going into %{toolchain_path_prefix} without the `external/` prefix + bin/clang
+#
+
+script_dir=$(dirname ${BASH_SOURCE[0]})
+toolchain_path_prefix="%{toolchain_path_prefix}"
+toolchain_path_prefix="$script_dir/../../${toolchain_path_prefix#external/}"
+
+if [[ ! -f ${toolchain_path_prefix}bin/clang ]]; then
+  echo >&2 "ERROR: could not find clang; PWD=\"${PWD}\"; PATH=\"${PATH}\"; toolchain_path_prefix=${toolchain_path_prefix}."
   exit 5
 fi
 
 function sanitize_option() {
   local -r opt=$1
   if [[ ${opt} == */cc_wrapper.sh ]]; then
-    printf "%s" "${execroot_path}%{toolchain_path_prefix}bin/clang"
-  elif [[ ${opt} =~ ^-fsanitize-(ignore|black)list=[^/] ]]; then
+    printf "%s" "${toolchain_path_prefix}bin/clang"
+  elif [[ ${opt} =~ ^-fsanitize-(ignore|black)list=[^/] ]] && [[ ${script_dir} == /* ]]; then
     # shellcheck disable=SC2206
     parts=(${opt/=/ }) # Split flag name and value into array.
-    printf "%s" "${parts[0]}=${execroot_path}${parts[1]}"
+    printf "%s" "${parts[0]}=$script_dir/../../../${parts[1]}"
   else
     printf "%s" "${opt}"
   fi

toolchain/osx_cc_wrapper.sh.tpl

@@ -63,31 +63,47 @@ function parse_option() {
   fi
 }
 
-if [[ -f %{toolchain_path_prefix}bin/clang ]]; then
-  execroot_path=""
-  execroot_abs_path="${PWD}/"
-elif [[ ${BASH_SOURCE[0]} == "/"* ]]; then
-  # Some consumers of `CcToolchainConfigInfo` (e.g. `cmake` from rules_foreign_cc)
-  # change CWD and call $CC (this script) with its absolute path.
-  # For cases like this, we'll try to find `clang` through an absolute path.
-  # This script is at _execroot_/external/_repo_name_/bin/cc_wrapper.sh
-  execroot_path="${BASH_SOURCE[0]%/*/*/*/*}/"
-  execroot_abs_path="$(cd "${execroot_path}" && pwd -P)/"
-else
-  echo >&2 "ERROR: could not find clang; PWD=\"${PWD}\"; PATH=\"${PATH}\"."
+# See note in toolchain/internal/configure.bzl where we define
+# `wrapper_bin_prefix` for why this wrapper is needed.
+
+# this script is located at either
+# - <execroot>/external/<repo_name>/bin/cc_wrapper.sh
+# - <runfiles>/<repo_name>/bin/cc_wrapper.sh
+# The clang is located at
+# - <execroot>/external/<repo_name2>/bin/clang
+# - <runfiles>/<repo_name2>/bin/clang
+#
+# In both cases, getting to clang can be done via
+# Finding the current dir of this script,
+# - <execroot>/external/<repo_name>/bin/
+# - <runfiles>/<repo_name>/bin/
+# going back 2 directories
+# - <execroot>/external
+# - <runfiles>
+#
+# Going into %{toolchain_path_prefix} without the `external/` prefix + `bin/clang`
+#
+
+script_dir=$(dirname ${BASH_SOURCE[0]})
+toolchain_path_prefix="%{toolchain_path_prefix}"
+toolchain_path_prefix="$script_dir/../../${toolchain_path_prefix#external/}"
+toolchain_path_prefix_abs="$(cd "$toolchain_path_prefix" && pwd -P)/"
+
+if [[ ! -f ${toolchain_path_prefix}bin/clang ]]; then
+  echo >&2 "ERROR: could not find clang; PWD=\"${PWD}\"; PATH=\"${PATH}\"; toolchain_path_prefix=${toolchain_path_prefix}."
   exit 5
 fi
 
 function sanitize_option() {
   local -r opt=$1
   if [[ ${opt} == */cc_wrapper.sh ]]; then
-    printf "%s" "${execroot_path}%{toolchain_path_prefix}bin/clang"
+    printf "%s" "${toolchain_path_prefix}bin/clang"
   elif [[ ${opt} == "-fuse-ld=ld64.lld" ]]; then
-    echo "--ld-path=${execroot_abs_path}%{toolchain_path_prefix}bin/ld64.lld"
-  elif [[ ${opt} =~ ^-fsanitize-(ignore|black)list=[^/] ]]; then
+    echo "--ld-path=${toolchain_path_prefix_abs}bin/ld64.lld"
+  elif [[ ${opt} =~ ^-fsanitize-(ignore|black)list=[^/] ]] && [[ ${script_dir} == /* ]]; then
     # shellcheck disable=SC2206
     parts=(${opt/=/ }) # Split flag name and value into array.
-    printf "%s" "${parts[0]}=${execroot_path}${parts[1]}"
+    printf "%s" "${parts[0]}=$script_dir/../../../${parts[1]}"
   else
     printf "%s" "${opt}"
   fi