add max segment size checked at build time

tools/build/check_section_sizes.py

@@ -0,0 +1,41 @@
+from sys import argv
+import json
+import subprocess
+import sys
+
+# Checks each segment-size pair in JSON object are valid for the given ELF.
+# usage: python3 check_section_sizes.py <elf> <json>
+
+argv.pop(0) # python3
+elf_path = argv.pop(0)
+jsonstr = argv.pop(0)
+
+def read_elf():
+    result = subprocess.run(["mips-linux-gnu-nm", elf_path], stdout=subprocess.PIPE)
+    lines = result.stdout.decode().split("\n")
+    symbols = {}
+    for line in lines:
+        splitted = line.split(" ")
+        if len(splitted) == 3:
+            address, kind, symbol = splitted
+            if symbol.endswith("_VRAM") or symbol.endswith("_VRAM_END"):
+                symbols[symbol] = int(address, 16)
+    return symbols
+
+segment_size_map = json.loads(jsonstr)
+symbols = read_elf()
+
+fail = False
+for segment_name, max_size in segment_size_map.items():
+    start_address = symbols[segment_name + "_VRAM"]
+    end_address = symbols[segment_name + "_VRAM_END"]
+    true_size = end_address - start_address
+    if true_size > max_size:
+        size_diff = true_size - max_size
+        print(f"\033[31msegment '{segment_name}' is oversized!\033[0m (size is {true_size:X}; +{size_diff:X} compared to max size {max_size:X})", file=sys.stderr)
+        fail = True
+if fail:
+    print("help: segment(s) are too big to fit in their overlay(s). to fix this, write less code/data, or modify the engine and splat.yaml to increase the limit", file=sys.stderr)
+    exit(1)
+else:
+    print("ok")

tools/build/configure.py

@@ -9,6 +9,7 @@
 import sys
 import ninja_syntax
 from glob import glob
+import json
 
 # Configuration:
 VERSIONS = ["us"]
@@ -327,6 +328,8 @@ def write_ninja_rules(
 
     ninja.rule("flips", command=f"bash -c '{BUILD_TOOLS}/floating/flips $baserom $in $out || true'")
 
+    ninja.rule("check_section_sizes", command=f"$python {BUILD_TOOLS}/check_section_sizes.py $in $data > $out")
+
 
 def write_ninja_for_tools(ninja: ninja_syntax.Writer):
     ninja.rule(
@@ -1275,6 +1278,13 @@ def build(
                 f"ver/{self.version}/checksum.sha1",
                 implicit=[str(self.rom_path())],
             )
+        else:
+            ninja.build(
+                str(self.rom_ok_path()),
+                "check_section_sizes",
+                str(self.elf_path()),
+                variables={"data": json.dumps(json.dumps(self.get_segment_max_sizes(), separators=(',', ':')))}
+            )
 
         ninja.build(
             str(self.patch_path()),
@@ -1286,6 +1296,23 @@ def build(
         ninja.build("generated_code_" + self.version, "phony", generated_code)
         ninja.build("inc_img_bins_" + self.version, "phony", inc_img_bins)
 
+
+
+    def get_segment_max_sizes(self):
+        assert self.linker_entries is not None
+        segment_size_map = {}
+
+        # depth-first search
+        def visit(segment):
+            if hasattr(segment, "parent") and segment.parent is not None:
+                visit(segment.parent)
+            if hasattr(segment, "yaml") and isinstance(segment.yaml, dict) and "max_size" in segment.yaml:
+                segment_size_map[segment.name] = segment.yaml["max_size"]
+        for entry in self.linker_entries:
+            visit(entry.segment)
+
+        return segment_size_map
+
     def make_current(self, ninja: ninja_syntax.Writer):
         current = Path("ver/current")
 
@@ -1505,8 +1532,5 @@ def make_current(self, ninja: ninja_syntax.Writer):
     assert first_configure, "no versions configured"
     first_configure.make_current(ninja)
 
-    if non_matching:
-        ninja.build("all", "phony", [str(first_configure.rom_path())])
-    else:
-        ninja.build("all", "phony", all_rom_oks)
+    ninja.build("all", "phony", all_rom_oks)
     ninja.default("all")