hdl.mem,lib.fifo: use keyword-only arguments for memory geometry.

Fixes #230.

nmigen/compat/genlib/fifo.py

@@ -1,6 +1,7 @@
 from ...tools import deprecated, extend
-from ...lib.fifo import FIFOInterface as NativeFIFOInterface, \
-  SyncFIFO, SyncFIFOBuffered, AsyncFIFO, AsyncFIFOBuffered
+from ...lib.fifo import (FIFOInterface as NativeFIFOInterface,
+  SyncFIFO as NativeSyncFIFO, SyncFIFOBuffered as NativeSyncFIFOBuffered,
+  AsyncFIFO as NativeAsyncFIFO, AsyncFIFOBuffered as NativeAsyncFIFOBuffered)
 
 
 __all__ = ["_FIFOInterface", "SyncFIFO", "SyncFIFOBuffered", "AsyncFIFO", "AsyncFIFOBuffered"]
@@ -9,13 +10,10 @@
 class CompatFIFOInterface(NativeFIFOInterface):
     @deprecated("attribute `fwft` must be provided to FIFOInterface constructor")
     def __init__(self, width, depth):
-        super().__init__(width, depth, fwft=False)
+        super().__init__(width=width, depth=depth, fwft=False)
         del self.fwft
 
 
-_FIFOInterface = CompatFIFOInterface
-
-
 @extend(NativeFIFOInterface)
 def read(self):
     """Read method for simulation."""
@@ -36,3 +34,30 @@ def write(self, data):
     yield
     yield self.w_en.eq(0)
     yield
+
+
+class CompatSyncFIFO(NativeSyncFIFO):
+    def __init__(self, width, depth, fwft=True):
+        super().__init__(width=width, depth=depth, fwft=fwft)
+
+
+class CompatSyncFIFOBuffered(NativeSyncFIFOBuffered):
+    def __init__(self, width, depth):
+        super().__init__(width=width, depth=depth)
+
+
+class CompatAsyncFIFO(NativeAsyncFIFO):
+    def __init__(self, width, depth):
+        super().__init__(width=width, depth=depth)
+
+
+class CompatAsyncFIFOBuffered(NativeAsyncFIFOBuffered):
+    def __init__(self, width, depth):
+        super().__init__(width=width, depth=depth)
+
+
+_FIFOInterface = CompatFIFOInterface
+SyncFIFO = CompatSyncFIFO
+SyncFIFOBuffered = CompatSyncFIFOBuffered
+AsyncFIFO = CompatAsyncFIFO
+AsyncFIFOBuffered = CompatAsyncFIFOBuffered

nmigen/hdl/mem.py

@@ -9,7 +9,7 @@
 
 
 class Memory:
-    def __init__(self, width, depth, *, init=None, name=None, simulate=True):
+    def __init__(self, *, width, depth, init=None, name=None, simulate=True):
         if not isinstance(width, int) or width < 0:
             raise TypeError("Memory width must be a non-negative integer, not '{!r}'"
                             .format(width))

nmigen/lib/fifo.py

@@ -60,7 +60,7 @@ class FIFOInterface:
     w_attributes="",
     r_attributes="")
 
-    def __init__(self, width, depth, *, fwft):
+    def __init__(self, *, width, depth, fwft):
         if not isinstance(width, int) or width < 0:
             raise TypeError("FIFO width must be a non-negative integer, not '{!r}'"
                             .format(width))
@@ -184,8 +184,8 @@ class SyncFIFO(Elaboratable, FIFOInterface):
     """.strip(),
     w_attributes="")
 
-    def __init__(self, width, depth, *, fwft=True):
-        super().__init__(width, depth, fwft=fwft)
+    def __init__(self, *, width, depth, fwft=True):
+        super().__init__(width=width, depth=depth, fwft=fwft)
 
         self.level = Signal.range(depth + 1)
 
@@ -199,7 +199,7 @@ def elaborate(self, platform):
         do_read  = self.r_rdy & self.r_en
         do_write = self.w_rdy & self.w_en
 
-        storage = Memory(self.width, self.depth)
+        storage = Memory(width=self.width, depth=self.depth)
         w_port  = m.submodules.w_port = storage.write_port()
         r_port  = m.submodules.r_port = storage.read_port(
             domain="comb" if self.fwft else "sync", transparent=self.fwft)
@@ -279,8 +279,8 @@ class SyncFIFOBuffered(Elaboratable, FIFOInterface):
     """.strip(),
     w_attributes="")
 
-    def __init__(self, width, depth):
-        super().__init__(width, depth, fwft=True)
+    def __init__(self, *, width, depth):
+        super().__init__(width=width, depth=depth, fwft=True)
 
         self.level = Signal.range(depth + 1)
 
@@ -289,7 +289,8 @@ def elaborate(self, platform):
 
         # Effectively, this queue treats the output register of the non-FWFT inner queue as
         # an additional storage element.
-        m.submodules.unbuffered = fifo = SyncFIFO(self.width, self.depth - 1, fwft=False)
+        m.submodules.unbuffered = fifo = SyncFIFO(width=self.width, depth=self.depth - 1,
+                                                  fwft=False)
 
         m.d.comb += [
             fifo.w_data.eq(self.w_data),
@@ -336,14 +337,14 @@ class AsyncFIFO(Elaboratable, FIFOInterface):
     r_attributes="",
     w_attributes="")
 
-    def __init__(self, width, depth, *, r_domain="read", w_domain="write", exact_depth=False):
+    def __init__(self, *, width, depth, r_domain="read", w_domain="write", exact_depth=False):
         try:
             depth_bits = log2_int(depth, need_pow2=exact_depth)
         except ValueError as e:
             raise ValueError("AsyncFIFO only supports depths that are powers of 2; requested "
                              "exact depth {} is not"
                              .format(depth)) from None
-        super().__init__(width, 1 << depth_bits, fwft=True)
+        super().__init__(width=width, depth=1 << depth_bits, fwft=True)
 
         self._r_domain = r_domain
         self._w_domain = w_domain
@@ -397,7 +398,7 @@ def elaborate(self, platform):
             r_empty.eq(consume_r_gry == produce_r_gry),
         ]
 
-        storage = Memory(self.width, self.depth)
+        storage = Memory(width=self.width, depth=self.depth)
         w_port  = m.submodules.w_port = storage.write_port(domain=self._w_domain)
         r_port  = m.submodules.r_port = storage.read_port (domain=self._r_domain,
                                                            transparent=False)
@@ -454,21 +455,21 @@ class AsyncFIFOBuffered(Elaboratable, FIFOInterface):
     r_attributes="",
     w_attributes="")
 
-    def __init__(self, width, depth, *, r_domain="read", w_domain="write", exact_depth=False):
+    def __init__(self, *, width, depth, r_domain="read", w_domain="write", exact_depth=False):
         try:
             depth_bits = log2_int(max(0, depth - 1), need_pow2=exact_depth)
         except ValueError as e:
             raise ValueError("AsyncFIFOBuffered only supports depths that are one higher "
                              "than powers of 2; requested exact depth {} is not"
                              .format(depth)) from None
-        super().__init__(width, (1 << depth_bits) + 1, fwft=True)
+        super().__init__(width=width, depth=(1 << depth_bits) + 1, fwft=True)
 
         self._r_domain = r_domain
         self._w_domain = w_domain
 
     def elaborate(self, platform):
         m = Module()
-        m.submodules.unbuffered = fifo = AsyncFIFO(self.width, self.depth - 1,
+        m.submodules.unbuffered = fifo = AsyncFIFO(width=self.width, depth=self.depth - 1,
             r_domain=self._r_domain, w_domain=self._w_domain)
 
         m.d.comb += [

nmigen/test/test_lib_fifo.py

@@ -49,8 +49,8 @@ class FIFOModel(Elaboratable, FIFOInterface):
     """
     Non-synthesizable first-in first-out queue, implemented naively as a chain of registers.
     """
-    def __init__(self, width, depth, *, fwft, r_domain, w_domain):
-        super().__init__(width, depth, fwft=fwft)
+    def __init__(self, *, width, depth, fwft, r_domain, w_domain):
+        super().__init__(width=width, depth=depth, fwft=fwft)
 
         self.r_domain = r_domain
         self.w_domain = w_domain
@@ -60,7 +60,7 @@ def __init__(self, width, depth, *, fwft, r_domain, w_domain):
     def elaborate(self, platform):
         m = Module()
 
-        storage = Memory(self.width, self.depth)
+        storage = Memory(width=self.width, depth=self.depth)
         w_port  = m.submodules.w_port = storage.write_port(domain=self.w_domain)
         r_port  = m.submodules.r_port = storage.read_port (domain="comb")
 
@@ -110,7 +110,7 @@ def __init__(self, fifo, r_domain, w_domain):
     def elaborate(self, platform):
         m = Module()
         m.submodules.dut  = dut  = self.fifo
-        m.submodules.gold = gold = FIFOModel(dut.width, dut.depth, fwft=dut.fwft,
+        m.submodules.gold = gold = FIFOModel(width=dut.width, depth=dut.depth, fwft=dut.fwft,
                                              r_domain=self.r_domain, w_domain=self.w_domain)
 
         m.d.comb += [
@@ -141,11 +141,11 @@ class FIFOContractSpec(Elaboratable):
     consecutively, they must be read out consecutively at some later point, no matter all other
     circumstances, with the exception of reset.
     """
-    def __init__(self, fifo, r_domain, w_domain, bound):
-        self.fifo    = fifo
+    def __init__(self, fifo, *, r_domain, w_domain, bound):
+        self.fifo     = fifo
         self.r_domain = r_domain
         self.w_domain = w_domain
-        self.bound   = bound
+        self.bound    = bound
 
     def elaborate(self, platform):
         m = Module()