Add support for creating the debug probes '.ltx' file (#413)

* Add debug probes

* Fix bug.

* Fix lint.

Author: stridge-tnp

vivado/defs.bzl

@@ -322,6 +322,12 @@ def _vivado_synthesis_optimize_impl(ctx):
     timing_summary_report = ctx.actions.declare_file("{}_timing.rpt".format(ctx.label.name))
     util_report = ctx.actions.declare_file("{}_util.rpt".format(ctx.label.name))
     drc_report = ctx.actions.declare_file("{}_drc.rpt".format(ctx.label.name))
+    if ctx.attr.with_probes:
+        probes_file = ctx.actions.declare_file("{}.ltx".format(ctx.label.name))
+        probes_file_path = probes_file.path
+    else:
+        probes_file = None
+        probes_file_path = ""
 
     checkpoint_in = ctx.attr.checkpoint[VivadoSynthCheckpointInfo].checkpoint
 
@@ -330,12 +336,15 @@ def _vivado_synthesis_optimize_impl(ctx):
         "{{CHECKPOINT_OUT}}": synth_checkpoint.path,
         "{{DRC_REPORT}}": drc_report.path,
         "{{OPT_DIRECTIVE}}": ctx.attr.opt_directive,
+        "{{PROBES_FILE}}": probes_file_path,
         "{{THREADS}}": "{}".format(ctx.attr.threads),
         "{{TIMING_REPORT}}": timing_summary_report.path,
         "{{UTIL_REPORT}}": util_report.path,
     }
 
     outputs = [synth_checkpoint, timing_summary_report, util_report, drc_report]
+    if ctx.attr.with_probes:
+        outputs.append(probes_file)
 
     default_info = run_tcl_template(
         ctx,
@@ -372,6 +381,10 @@ vivado_synthesis_optimize = rule(
             doc = "Threads to pass to vivado which defines the amount of parallelism.",
             default = 8,
         ),
+        "with_probes": attr.bool(
+            doc = "Create debug probes.",
+            default = False,
+        ),
         "xilinx_env": attr.label(
             doc = "A shell script to source the vivado environment and " +
                   "point to license server",

vivado/synth_optimize.tcl.template

@@ -5,4 +5,7 @@ opt_design -directive {{OPT_DIRECTIVE}}
 report_timing_summary -file {{TIMING_REPORT}}
 report_utilization -file {{UTIL_REPORT}}
 report_drc -file {{DRC_REPORT}}
+if {"{{PROBES_FILE}}" != ""} {
+    write_debug_probes {{PROBES_FILE}}
+}
 write_checkpoint -force {{CHECKPOINT_OUT}}