Intial commit

h8536/analysis.py

@@ -0,0 +1,61 @@
+from __future__ import annotations
+
+from collections.abc import Iterable
+
+from .decoder import H8536Decoder
+from .formatting import label_for
+from .model import Instruction
+from .tables import FLOW_STOP
+
+
+def trace(decoder: H8536Decoder, starts: Iterable[int], start_limit: int, end_limit: int) -> dict[int, Instruction]:
+    decoded: dict[int, Instruction] = {}
+    queue = [(addr, decoder.br) for addr in starts if start_limit <= addr < end_limit]
+    seen_starts: set[tuple[int, int | None]] = set()
+
+    while queue:
+        pc, br = queue.pop(0)
+        if (pc, br) in seen_starts:
+            continue
+        seen_starts.add((pc, br))
+
+        while start_limit <= pc < end_limit:
+            decoder.br = br
+            if pc in decoded:
+                break
+            ins = decoder.decode(pc)
+            decoded[pc] = ins
+            next_br = ins.br_value if ins.writes_br else br
+            for target in ins.targets:
+                if start_limit <= target < end_limit and (target, next_br) not in seen_starts:
+                    queue.append((target, next_br))
+            if ins.kind in FLOW_STOP or not ins.fallthrough:
+                break
+            pc = (pc + max(ins.size, 1)) & 0xFFFF
+            br = next_br
+
+    return decoded
+
+
+def linear_sweep(decoder: H8536Decoder, start: int, end: int) -> dict[int, Instruction]:
+    decoded: dict[int, Instruction] = {}
+    pc = start
+    br = decoder.br
+    while pc < end:
+        decoder.br = br
+        ins = decoder.decode(pc)
+        decoded[pc] = ins
+        if ins.writes_br:
+            br = ins.br_value
+        pc += max(ins.size, 1)
+    return decoded
+
+
+def collect_labels(instructions: Iterable[Instruction], vectors: dict[int, tuple[str, int]]) -> dict[int, str]:
+    labels: dict[int, str] = {}
+    for _vector_addr, (name, target) in vectors.items():
+        labels.setdefault(target, f"vec_{name}_{target:04X}")
+    for ins in instructions:
+        for target in ins.targets:
+            labels.setdefault(target, label_for(target))
+    return labels