Fix extraction of Final_Util metric

~ Reimplemented extraction to use  a new `metrics.json` that is output by the DRT step.

scripts/openroad/droute.tcl

@@ -40,3 +40,5 @@ detailed_route\
     -verbose 1
 
 write
+
+report_design_area_metrics

scripts/report/report.py

@@ -11,13 +11,13 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
-from collections import defaultdict
 import os
 import re
 import sys
+import json
 import yaml
 import fnmatch
+from collections import defaultdict
 from typing import Iterable, Optional, Dict
 
 sys.path.append(os.path.dirname(os.path.dirname(__file__)))
@@ -415,15 +415,13 @@ def re_get_last_capture(rx, string):
                 hpwl = float(match)
 
         final_utilization = -1
-        # ./reports/signoff/26-rcx_sta.area.rpt
         final_utilization_report = Artifact(
-            rp, "reports", "signoff", "rcx_sta.area.rpt"
+            rp, "reports", "routing", "drt_metrics.json"
         )
         final_utilization_content = final_utilization_report.get_content()
         if final_utilization_content is not None:
-            match = re.search(r"\s+([\d]+\.*[\d]*)%", final_utilization_content)
-            if match is not None:
-                final_utilization = float(match[1])
+            metrics = json.loads(final_utilization_content)
+            final_utilization = metrics["design__instance__utilization"] * 100
 
         # TritonRoute Logged Info Extraction
         tr_log = Artifact(rp, "logs", "routing", "detailed.log")

scripts/tcl_commands/routing.tcl

@@ -66,7 +66,7 @@ proc global_routing_fastroute {args} {
             set log [index_file $::env(routing_logs)/antenna_route_$iter.log]
             run_openroad_script $::env(SCRIPTS_DIR)/openroad/repair_antennas.tcl\
                 -indexed_log $log\
-                -save "to=$::env(routing_tmpfiles),name=global_$iter,def,guide,odb"\
+                -save "to=$::env(routing_tmpfiles),name=global_$iter,def,guide,odb"
 
             set antennae [groute_antenna_extract -from_log $log]
 
@@ -137,7 +137,7 @@ proc detailed_routing_tritonroute {args} {
     set ::env(_tmp_drt_rpt_prefix) $::env(routing_reports)/drt
     run_openroad_script $::env(SCRIPTS_DIR)/openroad/droute.tcl\
         -indexed_log $log\
-        -save "to=$::env(routing_results),noindex,def,odb,netlist,powered_netlist"
+        -save "to=$::env(routing_results),metrics=[index_file $::env(routing_reports)/drt_metrics.json],noindex,def,odb,netlist,powered_netlist"
 
     try_exec python3 $::env(SCRIPTS_DIR)/drc_rosetta.py tr to_klayout \
         -o $::env(routing_reports)/drt.klayout.xml \