pysvp64dis: introduce disassembler script

diff --git a/src/openpower/sv/trans/dis.py b/src/openpower/sv/trans/dis.py
new file mode 100644 (file)
index 0000000..5acc2e6
--- /dev/null
+++ b/src/openpower/sv/trans/dis.py
@@ -0,0 +1,99 @@
+import argparse as _argparse
+import enum as _enum
+import sys as _sys
+
+
+class ByteOrder(_enum.Enum):
+    LITTLE = "little"
+    BIG = "big"
+
+    def __str__(self):
+        return self.name.lower()
+
+
+class Instruction(int):
+    def __new__(cls, value, byteorder=ByteOrder.LITTLE):
+        if isinstance(value, bytes):
+            value = int.from_bytes(value, byteorder=str(byteorder))
+        if not isinstance(value, int) or (value < 0):
+            raise ValueError(value)
+        return super().__new__(cls, value)
+
+    def __repr__(self):
+        return f"{self.__class__.__name__}({str(self)})"
+
+    def __str__(self):
+        return f".long 0x{self:08x}"
+
+    @property
+    def major(self):
+        return (((self & ((1 << 32) - 1)) >> 26) & 0x3f)
+
+
+class PrefixedInstruction(Instruction):
+    def __new__(cls, prefix, suffix, byteorder=ByteOrder.LITTLE):
+        (prefix, suffix) = map(Instruction, (prefix, suffix))
+        return super().__new__(cls, ((prefix << 32) | suffix))
+
+    def __str__(self):
+        return f".llong 0x{self:016x}"
+
+    @property
+    def prefix(self):
+        return Instruction((self >> 32) & ((1 << 32) - 1))
+
+    @property
+    def suffix(self):
+        return Instruction((self >> 0) & ((1 << 32) - 1))
+
+
+def load(ifile, byteorder, **_):
+    def load(ifile):
+        prefix = ifile.read(4)
+        length = len(prefix)
+        if length == 0:
+            return None
+        elif length < 4:
+            raise IOError(prefix)
+        prefix = Instruction(prefix, byteorder=byteorder)
+        if prefix.major != 0x1:
+            return prefix
+
+        suffix = ifile.read(4)
+        length = len(suffix)
+        if length == 0:
+            return prefix
+        elif length < 4:
+            raise IOError(suffix)
+
+        return PrefixedInstruction(prefix, suffix, byteorder=byteorder)
+
+    while True:
+        insn = load(ifile)
+        if insn is None:
+            break
+        yield insn
+
+
+def dump(insns, ofile, **_):
+    for insn in insns:
+        yield str(insn)
+
+
+def main():
+    parser = _argparse.ArgumentParser()
+    parser.add_argument("ifile", nargs="?",
+        type=_argparse.FileType("rb"), default=_sys.stdin.buffer)
+    parser.add_argument("ofile", nargs="?",
+        type=_argparse.FileType("w"), default=_sys.stdout)
+    parser.add_argument("-b", "--byteorder",
+        type=ByteOrder, default=ByteOrder.LITTLE)
+    args = dict(vars(parser.parse_args()))
+
+    insns = load(**args)
+    for line in dump(insns, **args):
+        print(line)
+
+
+if __name__ == "__main__":
+    main()