Meta+CMake: Use lldb on macOS for debugging

Ladybird/CMakeLists.txt

@@ -107,10 +107,17 @@ add_custom_target(run
     VERBATIM
 )
 
-add_custom_target(debug-ladybird
+if (APPLE)
-    COMMAND "${CMAKE_COMMAND}" -E env "LADYBIRD_SOURCE_DIR=${LADYBIRD_SOURCE_DIR}" gdb -ex "set follow-fork-mode child" "$<TARGET_FILE:ladybird>"
+    add_custom_target(debug-ladybird
-    USES_TERMINAL
+        COMMAND "${CMAKE_COMMAND}" -E env "LADYBIRD_SOURCE_DIR=${LADYBIRD_SOURCE_DIR}" lldb "$<TARGET_BUNDLE_DIR:ladybird>"
-)
+        USES_TERMINAL
+    )
+else()
+    add_custom_target(debug-ladybird
+        COMMAND "${CMAKE_COMMAND}" -E env "LADYBIRD_SOURCE_DIR=${LADYBIRD_SOURCE_DIR}" gdb "$<TARGET_FILE:ladybird>"
+        USES_TERMINAL
+    )
+endif()
 
 add_subdirectory(ImageDecoder)
 add_subdirectory(RequestServer)

Meta/ladybird.sh

@@ -142,6 +142,14 @@ run_gdb() {
     local GDB_ARGS=()
     local PASS_ARG_TO_GDB=""
     local LAGOM_EXECUTABLE=""
+    local GDB=gdb
+    if ! command -v "$GDB" > /dev/null 2>&1; then
+      GDB=lldb
+      if ! command -v "$GDB" > /dev/null 2>&1; then
+        die "Please install gdb or lldb!"
+      fi
+    fi
+
     for arg in "${CMD_ARGS[@]}"; do
         if [ "$PASS_ARG_TO_GDB" != "" ]; then
             GDB_ARGS+=( "$PASS_ARG_TO_GDB" "$arg" )
@@ -168,7 +176,7 @@ run_gdb() {
             LAGOM_EXECUTABLE="Ladybird"
         fi
     fi
-    gdb "$BUILD_DIR/bin/$LAGOM_EXECUTABLE" "${GDB_ARGS[@]}"
+    "$GDB" "$BUILD_DIR/bin/$LAGOM_EXECUTABLE" "${GDB_ARGS[@]}"
 }
 
 build_and_run_lagom_target() {