Pass nm/ar/objcopy paths from CMake to localize_rust_c_symbols.sh

The script used to call `llvm-nm` via $PATH and derive `llvm-ar`'s path
from `llvm-objcopy` by basename substitution. Both lookups were fragile:
they failed when `llvm-nm` was missing from $PATH and silently picked
the wrong archiver when the toolchain's naming did not match.

Resolve all three tools (`llvm-nm`, `llvm-ar`, `llvm-objcopy`) via
`ch_find_program` in `cmake/tools.cmake` and pass the full paths as
script arguments, mirroring how `cmake/strip_rust_symbols.sh` is
invoked.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

cmake/localize_rust_c_symbols.sh

@@ -12,15 +12,22 @@
 # our own implementations instead.  All other symbols (Rust-mangled, crate
 # FFI, etc.) are left untouched.
 #
-# Usage: localize_rust_c_symbols.sh <library.a> <objcopy>
+# Usage: localize_rust_c_symbols.sh <library.a> <ar> <objcopy> <nm>
+#
+# The ar/objcopy/nm tools must come from a compatible LLVM toolchain
+# (e.g. llvm-ar, llvm-objcopy, llvm-nm).  CMake resolves them via
+# ch_find_program and passes the full paths so this script never has to
+# search $PATH or infer one tool's name from another.
 
 set -eu
 
-LIB_PATH="$1"
-OBJCOPY="$2"
+LIB_PATH="${1:-}"
+AR="${2:-}"
+OBJCOPY="${3:-}"
+NM="${4:-}"
 
-if [ -z "$LIB_PATH" ] || [ -z "$OBJCOPY" ]; then
-    echo "Usage: $0 <library.a> <objcopy>" >&2
+if [ -z "$LIB_PATH" ] || [ -z "$AR" ] || [ -z "$OBJCOPY" ] || [ -z "$NM" ]; then
+    echo "Usage: $0 <library.a> <ar> <objcopy> <nm>" >&2
     exit 1
 fi
 
@@ -80,22 +87,17 @@ WORK_DIR=""
 cleanup() { rm -f "$TMPFILE"; [ -n "$WORK_DIR" ] && rm -rf "$WORK_DIR"; true; }
 trap cleanup EXIT
 
-if ! command -v llvm-nm >/dev/null 2>&1; then
-    echo "Error: llvm-nm not found in PATH (required for Rust C-symbol localization)" >&2
-    exit 1
-fi
-
-# Get all global defined symbols from the library. llvm-nm may print per-member errors for non-ELF archive
+# Get all global defined symbols from the library. nm may print per-member errors for non-ELF archive
 # members (e.g. debug metadata objects) - those are non-fatal as long as at least one ELF member is read.
 # A truly broken/missing archive produces empty output and is caught below.
-llvm-nm "$LIB_PATH" 2>/dev/null \
+"$NM" "$LIB_PATH" 2>/dev/null \
     | grep -E '^[0-9a-f]+ [TDBCWV] ' \
     | awk '{print $3}' \
     | sort -u \
     > "$TMPFILE" || true
 
 if [ ! -s "$TMPFILE" ]; then
-    echo "Error: llvm-nm produced no symbols for $LIB_PATH; cannot localize Rust C symbols" >&2
+    echo "Error: $NM produced no symbols for $LIB_PATH; cannot localize Rust C symbols" >&2
     exit 1
 fi
 
@@ -113,16 +115,6 @@ if [ -n "$LOCALIZE_FLAGS" ]; then
     # that cause llvm-objcopy to fail.  In that case, fall back to extracting
     # individual members, processing only valid ELF objects, and repacking.
     if ! $OBJCOPY $LOCALIZE_FLAGS "$LIB_PATH" 2>/dev/null; then
-        # Substitute only inside the basename so a directory containing `objcopy`
-        # is not rewritten and a versioned name like `llvm-objcopy-21` still maps
-        # to `llvm-ar-21`.
-        OBJCOPY_NAME="${OBJCOPY##*/}"
-        AR_NAME="${OBJCOPY_NAME/objcopy/ar}"
-        if [ "$OBJCOPY_NAME" = "$OBJCOPY" ]; then
-            AR="$AR_NAME"
-        else
-            AR="${OBJCOPY%/*}/$AR_NAME"
-        fi
         WORK_DIR=$(mktemp -d)
 
         (cd "$WORK_DIR" && "$AR" x "$LIB_PATH")

cmake/tools.cmake

@@ -98,6 +98,14 @@ else ()
     message (FATAL_ERROR "Cannot find objcopy.")
 endif ()
 
+# nm (used by helper scripts that inspect symbol tables, e.g. cmake/localize_rust_c_symbols.sh)
+ch_find_program (NM_PATH NAMES "llvm-nm-${COMPILER_VERSION_MAJOR}" "llvm-nm" "nm")
+if (NM_PATH)
+    message (STATUS "Using nm: ${NM_PATH}")
+else ()
+    message (FATAL_ERROR "Cannot find nm.")
+endif ()
+
 # Strip
 ch_find_program (STRIP_PATH NAMES "llvm-strip-${COMPILER_VERSION_MAJOR}" "llvm-strip" "strip")
 if (STRIP_PATH)

contrib/corrosion-cmake/CMakeLists.txt

@@ -293,7 +293,7 @@ function(clickhouse_config_crate_flags target_name)
 
         add_custom_target(localize_rust_c_${target_name}
             COMMAND bash "${ClickHouse_SOURCE_DIR}/cmake/localize_rust_c_symbols.sh"
-                "${_rust_lib_path}" "${CMAKE_OBJCOPY}"
+                "${_rust_lib_path}" "${CMAKE_AR}" "${CMAKE_OBJCOPY}" "${NM_PATH}"
             COMMENT "Localizing C-namespace symbols in ${target_name}"
             VERBATIM
         )