fix(precheck): rewrite the boundary check

The previous version of the boundary check was a quick heuristic where
we compared the bounding box of the design to that of the prBoundary layer.
Over time we came across some designs where this is insufficient.

The new check compares the bounding box to the correct project size
based on the .def template and verifies that there is a rectangle of
this exact size in the prBoundary layer at the top level.

The patch also abstracts parsing the .def template into a separate
function since we now use it in two different checks.

precheck/precheck.py

@@ -14,7 +14,7 @@ import klayout.db as pya
 import klayout.rdb as rdb
 import yaml
 from klayout_tools import parse_lyp_layers
-from pin_check import pin_check
+from pin_check import parse_def, pin_check
 from precheck_failure import PrecheckFailure
 from tech_data import (
     analog_pin_rects,
@@ -190,21 +190,43 @@ def klayout_checks(gds: str, expected_name: str, tech: str):
         raise PrecheckFailure(f"{layer_name} ({calma_index}) layer not found in {gds}")
 
 
-def boundary_check(gds: str, tech: str):
+def boundary_check(gds: str, template_def: str, tech: str):
     """Ensure that there are no shapes outside the project area."""
+    template = parse_def(template_def)
     lib = gdstk.read_gds(gds)
     tops = lib.top_level()
     if len(tops) != 1:
         raise PrecheckFailure("GDS top level not unique")
     top = tops[0]
-    boundary = top.copy("test_boundary")
-
+    ((lx, by), (rx, ty)) = top.bounding_box()
+    lx = int(lx * 1000)
+    by = int(by * 1000)
+    rx = int(rx * 1000)
+    ty = int(ty * 1000)
+    if ((lx, by), (rx, ty)) != ((0, 0), (template.die_width, template.die_height)):
+        if lx < 0 or by < 0 or rx > template.die_width or ty > template.die_height:
+            raise PrecheckFailure("Shapes outside project area")
+        else:
+            raise PrecheckFailure("Boundary layer doesn't cover project area")
     layers = load_layers(tech)
     layer_name = boundary_layer[tech]
     layer_info = layers[layer_name]
-    boundary.filter([(layer_info.layer, layer_info.data_type)], False)
-    if top.bounding_box() != boundary.bounding_box():
-        raise PrecheckFailure("Shapes outside project area")
+    found_boundary = False
+    for p in top.polygons:
+        if (p.layer, p.datatype) == (layer_info.layer, layer_info.data_type):
+            ((lx, by), (rx, ty)) = p.bounding_box()
+            lx = int(lx * 1000)
+            by = int(by * 1000)
+            rx = int(rx * 1000)
+            ty = int(ty * 1000)
+            if ((lx, by), (rx, ty)) == (
+                (0, 0),
+                (template.die_width, template.die_height),
+            ):
+                found_boundary = True
+                break
+    if not found_boundary:
+        raise PrecheckFailure("Missing top-level prBoundary rectangle with right size")
 
 
 def power_pin_check(verilog: str, lef: str, uses_vapwr: bool):
@@ -501,7 +523,10 @@ def main():
                 gds_file, lef_file, template_def, top_module, uses_vapwr, tech
             ),
         },
-        {"name": "Boundary check", "check": lambda: boundary_check(gds_file, tech)},
+        {
+            "name": "Boundary check",
+            "check": lambda: boundary_check(gds_file, template_def, tech),
+        },
         {
             "name": "Power pin check",
             "check": lambda: power_pin_check(verilog_file, lef_file, uses_vapwr),