[bundle_static] Rework tooling to resolve internal references.

cmake/BundleStatic.cmake

@@ -22,10 +22,15 @@ function(_bundle_static_check_output VAR)
     set("${VAR}" "${${VAR}}" PARENT_SCOPE)
 endfunction()
 
-function(_bundle_static_is_apple_libtool result_var item)
-    _bundle_static_check_output(version_info "${item}" -V)
-    if (NOT version_info MATCHES "Apple,? Inc\\.")
-        set(${result_var} 0 PARENT_SCOPE)
+
+function(_bundle_static_is_apple_ld result_var ld_tool)
+    execute_process(COMMAND "${ld_tool}" -v 
+        OUTPUT_VARIABLE captured_output
+        ERROR_VARIABLE captured_error
+        RESULT_VARIABLE return_code
+    )
+    if (captured_error MATCHES "Apple")
+        set(${result_var} 1 PARENT_SCOPE)
     endif ()
 endfunction()
 
@@ -85,12 +90,13 @@ function(bundle_static TARGET)
         )
         return()
     endif ()
-
-    find_program(LIBTOOL libtool VALIDATOR _bundle_static_is_apple_libtool)
-    if (APPLE AND LIBTOOL)
+
+    find_program(LD_LINKER ld HINTS "${CMAKE_LD}")
+    _bundle_static_is_apple_ld(is_apple_ld "${LD_LINKER}")
+    if (APPLE AND is_apple_ld)
         add_custom_command(
             TARGET "${TARGET}" POST_BUILD
-            COMMAND "${LIBTOOL}" -static -o "$<TARGET_FILE:${TARGET}>" "$<TARGET_FILE:${TARGET}>.tmp" "${cmd}"
+            COMMAND "${CMAKE_SOURCE_DIR}/tools/bundle_static.sh" "--ar" "${CMAKE_AR}" "--ld" "${LD_LINKER}" "-o" "$<TARGET_FILE:${TARGET}>" "$<TARGET_FILE:${TARGET}>.tmp" "${cmd}"
             COMMAND_EXPAND_LISTS
             VERBATIM
         )
@@ -99,22 +105,10 @@ function(bundle_static TARGET)
 
     _bundle_static_check_output(version_info "${CMAKE_AR}" V)
     if (version_info MATCHES "GNU")
-        string(CONFIGURE [[
-            create $<TARGET_FILE:@TARGET@>
-            addlib $<TARGET_FILE:@TARGET@>.tmp
-            $<LIST:JOIN,$<LIST:TRANSFORM,@cmd@,PREPEND,addlib >,
-            >
-            save
-            end
-        ]] mri_script)
-        string(REGEX REPLACE "(^|\n) +" "\\1" mri_script "${mri_script}")
-
-        file(GENERATE OUTPUT "fuse-${TARGET}.mri"
-             CONTENT "${mri_script}" TARGET "${TARGET}")
-
         add_custom_command(
             TARGET "${TARGET}" POST_BUILD
-            COMMAND "${CMAKE_AR}" -M < "${CMAKE_CURRENT_BINARY_DIR}/fuse-${TARGET}.mri"
+            COMMAND "${CMAKE_SOURCE_DIR}/tools/bundle_static.sh" "--ar" "${CMAKE_AR}" "--ld" "${LD_LINKER}" "-o" "$<TARGET_FILE:${TARGET}>" "$<TARGET_FILE:${TARGET}>.tmp" "${cmd}"
+            COMMAND_EXPAND_LISTS
             VERBATIM
         )
         return()

tools/bundle_static.sh

@@ -0,0 +1,133 @@
+#!/bin/bash
+# This script combines a bunch of static libs and does a partial link across all object
+# files to resolve all internal references to produce a merged static lib.
+
+# Check if at least two arguments are provided (input libraries + output library)
+if [ "$#" -lt 2 ]; then
+    echo "Usage: $0 --ld <path-to-ld> --ar <path-to-ar> <output.a> <input1.a> [input2.a ...]"
+    exit 1
+fi
+
+POSITIONAL_ARGS=()
+LD_TOOL="ld"
+AR_TOOL="ar"
+OUTPUT_LIB=""
+
+while [[ $# -gt 0 ]]; do
+  case $1 in
+    -l|--ld)
+      LD_TOOL="$2"
+      shift # past argument
+      shift # past value
+      ;;
+    -a|--ar)
+      AR_TOOL="$2"
+      shift # past argument
+      shift # past value
+      ;;
+    -o|--output)
+      OUTPUT_LIB="$2"
+      shift # past argument
+      shift # past value
+      ;;
+    -*|--*)
+      echo "Unknown option $1"
+      exit 1
+      ;;
+    *)
+      POSITIONAL_ARGS+=("$1") # save positional arg
+      shift # past argument
+      ;;
+  esac
+done
+
+set -- "${POSITIONAL_ARGS[@]}" # restore positional parameters
+
+OS=$(uname -s)
+OS="`uname`"
+case $OS in
+  'Linux')
+    LD_FLAGS="-Ur"
+    ;;
+  'Darwin') 
+    LD_FLAGS="-r"
+    ;;
+  *) ;;
+esac
+
+echo "Creating merged library $OUTPUT_LIB ..."
+OUTPUT_OBJ="${OUTPUT_LIB%.*}.o"
+
+# Create a temporary directory to extract object files
+TEMP_DIR=$(mktemp -d)
+echo "Creating temporary directory $TEMP_DIR ..."
+if [ $? -ne 0 ]; then
+    echo "Error: Could not create temporary directory."
+    exit 1
+fi
+cd $TEMP_DIR
+
+# Process each input library
+MERGE_OBJS=()
+for LIB in "$@"; do
+    if [ ! -f "$LIB" ]; then
+        echo "Error: Input library '$LIB' not found."
+        rm -rf "$TEMP_DIR"
+        exit 1
+    fi
+    echo "Extracting objects from $LIB ..."
+    LIB_NAME="$(basename $LIB)"
+
+    # Extract object files from each input library into 
+    # a subdir in the temporary directory
+    mkdir "$TEMP_DIR/$LIB_NAME"
+    if [ $? -ne 0 ]; then
+        echo "Error: Failed to create dir $TEMP_DIR/$LIB_NAME."
+        exit 1
+    fi
+
+    cd "$TEMP_DIR/$LIB_NAME"
+    $AR_TOOL -x "$LIB"
+    if [ $? -ne 0 ]; then
+        echo "Error: Failed to extract objects from $LIB."
+        exit 1
+    fi
+
+    # Rename the library object files and prepend the library name 
+    # to the object file name in the top level temporary directory
+    cd "$TEMP_DIR"
+    for OBJ_FILE in "$LIB_NAME"/*.o; do
+        OBJ_NAME="$(basename $OBJ_FILE)"
+        mv "$OBJ_FILE" "$TEMP_DIR/$LIB_NAME-$OBJ_NAME"
+        MERGE_OBJS+=("$TEMP_DIR/$LIB_NAME-$OBJ_NAME")
+    done
+    if [ $? -ne 0 ]; then
+        echo "Error: Failed to extract objects from $LIB."
+        exit 1
+    fi
+done
+
+# Do a partial-link from all extracted object files to resolve internal references
+cd "$TEMP_DIR"
+echo "Creating merged object file $OUTPUT_OBJ ..."
+$LD_TOOL "$LD_FLAGS" -o "$OUTPUT_OBJ" "${MERGE_OBJS[@]}"
+if [ $? -ne 0 ]; then
+    echo "Error: Failed to create the merged library."
+    rm -r "$TEMP_DIR"
+    exit 1
+fi
+
+# Create the final static lib
+echo "Creating merged library $OUTPUT_LIB ..."
+$AR_TOOL -rcsv "$OUTPUT_LIB" "$OUTPUT_OBJ"
+if [ $? -ne 0 ]; then
+    echo "Error: Failed to create the merged library."
+    rm -r "$TEMP_DIR"
+    exit 1
+fi
+
+# Clean up the temporary directory
+echo "Cleaning up temporary directory..."
+rm -r "$TEMP_DIR"
+
+echo "Done!"