7285

2 files changed, 1042 insertions, 12 deletions

diff --git a/apps/mu b/apps/mu
index 8ebf2cb3..b1439126 100755
--- a/apps/mu
+++ b/apps/mu
Binary files differdiff --git a/apps/mu.subx b/apps/mu.subx
index b47de2a6..4e8c6721 100644
--- a/apps/mu.subx
+++ b/apps/mu.subx
@@ -7890,7 +7890,7 @@ test-copy-to-with-no-inout:
     5d/pop-to-ebp
     c3/return
 
-test-copy-to-with-no-input:
+test-copy-to-with-no-source:
     # . prologue
     55/push-ebp
     89/<- %ebp 4/r32/esp
@@ -7925,10 +7925,10 @@ test-copy-to-with-no-input:
 #?     (rewind-stream _test-error-stream)
 #?     # }}}
     # check output
-    (check-stream-equal _test-output-stream  ""  "F - test-copy-to-with-no-input: output should be empty")
-    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-to' must have two inouts"  "F - test-copy-to-with-no-input: error message")
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-to-with-no-source: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-to' must have two inouts"  "F - test-copy-to-with-no-source: error message")
     # check that stop(1) was called
-    (check-ints-equal *(edx+4) 2 "F - test-copy-to-with-no-input: exit status")
+    (check-ints-equal *(edx+4) 2 "F - test-copy-to-with-no-source: exit status")
     # don't restore from ebp
     81 0/subop/add %esp 8/imm32
     # . epilogue
@@ -8325,6 +8325,741 @@ test-copy-to-from-non-scalar-inout:
     5d/pop-to-ebp
     c3/return
 
+test-copy-byte-with-no-inout:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: byte <- copy-byte\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-with-no-inout: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-byte' expects an inout"  "F - test-copy-byte-with-no-inout: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-with-no-inout: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-with-multiple-inouts:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: byte <- copy-byte 0, 0\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-with-multiple-inouts: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-byte' must have just one inout"  "F - test-copy-byte-with-multiple-inouts: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-with-multiple-inouts: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-with-no-output:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  copy-byte 0\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-with-no-output: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-byte' expects an output"  "F - test-copy-byte-with-no-output: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-with-no-output: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-with-multiple-outputs:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: byte <- copy 0\n")
+    (write _test-input-stream "  var y/ecx: byte <- copy 0\n")
+    (write _test-input-stream "  x, y <- copy-byte 0\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-with-multiple-outputs: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-byte' must have just one output"  "F - test-copy-byte-with-multiple-outputs: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-with-multiple-outputs: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-deref-address:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: (addr byte) <- copy 0\n")
+    (write _test-input-stream "  var y/ecx: byte <- copy-byte *x\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file Stderr 0)
+    (flush _test-output-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # not bothering checking output
+    (check-next-stream-line-equal _test-error-stream  ""  "F - test-copy-byte-deref-address: error message")
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-with-invalid-output-type:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: (addr byte) <- copy 0\n")
+    (write _test-input-stream "  var y/eax: int <- copy-byte *x\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-with-invalid-output-type: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-byte' must write to output of type byte"  "F - test-copy-byte-with-invalid-output-type: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-with-invalid-output-type: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-from-invalid-type:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: (addr byte) <- copy 0\n")
+    (write _test-input-stream "  var y/eax: int <- copy-byte x\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-from-invalid-type: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt copy-byte: inout must have type byte"  "F - test-copy-byte-from-invalid-type: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-from-invalid-type: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-with-literal-inout:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: byte <- copy-byte 0\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-with-literal-inout: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt copy-byte: inout must have type byte"  "F - test-copy-byte-with-literal-inout: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-with-literal-inout: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-to-with-no-inout:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  copy-byte-to\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-to-with-no-inout: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-byte-to' must have two inouts"  "F - test-copy-byte-to-with-no-inout: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-to-with-no-inout: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-to-with-no-source:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: (addr byte) <- copy 0\n")
+    (write _test-input-stream "  copy-byte-to *x\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-to-with-no-source: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-byte-to' must have two inouts"  "F - test-copy-byte-to-with-no-source: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-to-with-no-source: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-to-with-too-many-inouts:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: (addr byte) <- copy 0\n")
+    (write _test-input-stream "  copy-byte-to *x, 0, 0\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-to-with-too-many-inouts: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-byte-to' must have two inouts"  "F - test-copy-byte-to-with-too-many-inouts: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-to-with-too-many-inouts: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-to-with-output:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: byte <- copy 0\n")
+    (write _test-input-stream "  var y/ecx: (addr byte) <- copy 0\n")
+    (write _test-input-stream "  x <- copy-byte-to *y, 0\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-to-with-output: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-byte-to' must not have any outputs"  "F - test-copy-byte-to-with-output: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-to-with-output: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-to-with-invalid-output-type:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: byte <- copy 0\n")
+    (write _test-input-stream "  var y: int\n")
+    (write _test-input-stream "  copy-byte-to y, x\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-to-with-invalid-output-type: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt copy-byte-to: 'y' must be a byte"  "F - test-copy-byte-to-with-invalid-output-type: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-to-with-invalid-output-type: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-to-with-literal-inout:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: (addr byte) <- copy 0\n")
+    (write _test-input-stream "  copy-byte-to *x, 0\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-to-with-literal-inout: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt copy-byte-to: source (second inout) must be in a register"  "F - test-copy-byte-to-with-literal-inout: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-to-with-literal-inout: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-to-from-invalid-type:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: (addr byte) <- copy 0\n")
+    (write _test-input-stream "  var y: int\n")
+    (write _test-input-stream "  copy-byte-to y, x\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-to-from-invalid-type: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt copy-byte-to: source (second inout) must have type byte"  "F - test-copy-byte-to-from-invalid-type: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-to-from-invalid-type: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-to-deref-address:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: byte <- copy 0\n")
+    (write _test-input-stream "  var y/ecx: (addr byte) <- copy 0\n")
+    (write _test-input-stream "  copy-byte-to *y, x\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file Stderr 0)
+    (flush _test-output-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # not bothering checking output
+    (check-next-stream-line-equal _test-error-stream  ""  "F - test-copy-byte-to-deref-address: error message")
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-copy-byte-to-from-non-scalar-inout:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    (clear-stream _test-error-stream)
+    (clear-stream $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x: (handle int)\n")
+    (write _test-input-stream "  var y: int\n")
+    (write _test-input-stream "  copy-byte-to y, x\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-byte-to-from-non-scalar-inout: output should be empty")
+#?     (check-next-stream-line-equal _test-error-stream  "fn foo: stmt copy-byte-to: 'x' is too large to copy"  "F - test-copy-byte-to-from-non-scalar-inout: error message")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt copy-byte-to: source (second inout) must be in a register"  "F - test-copy-byte-to-from-non-scalar-inout: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-copy-byte-to-from-non-scalar-inout: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
 test-compare-with-no-inout:
     # . prologue
     55/push-ebp
@@ -8370,7 +9105,7 @@ test-compare-with-no-inout:
     5d/pop-to-ebp
     c3/return
 
-test-compare-with-no-input:
+test-compare-with-just-one-inout:
     # . prologue
     55/push-ebp
     89/<- %ebp 4/r32/esp
@@ -8405,10 +9140,10 @@ test-compare-with-no-input:
 #?     (rewind-stream _test-error-stream)
 #?     # }}}
     # check output
-    (check-stream-equal _test-output-stream  ""  "F - test-compare-with-no-input: output should be empty")
-    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'compare' must have two inouts"  "F - test-compare-with-no-input: error message")
+    (check-stream-equal _test-output-stream  ""  "F - test-compare-with-just-one-inout: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'compare' must have two inouts"  "F - test-compare-with-just-one-inout: error message")
     # check that stop(1) was called
-    (check-ints-equal *(edx+4) 2 "F - test-compare-with-no-input: exit status")
+    (check-ints-equal *(edx+4) 2 "F - test-compare-with-just-one-inout: exit status")
     # don't restore from ebp
     81 0/subop/add %esp 8/imm32
     # . epilogue
@@ -13224,7 +13959,7 @@ test-copy-object-with-no-inout:
     5d/pop-to-ebp
     c3/return
 
-test-copy-object-with-no-input:
+test-copy-object-with-no-source:
     # . prologue
     55/push-ebp
     89/<- %ebp 4/r32/esp
@@ -13259,10 +13994,10 @@ test-copy-object-with-no-input:
 #?     (rewind-stream _test-error-stream)
 #?     # }}}
     # check output
-    (check-stream-equal _test-output-stream  ""  "F - test-copy-object-with-no-input: output should be empty")
-    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-object' must have two inouts"  "F - test-copy-object-with-no-input: error message")
+    (check-stream-equal _test-output-stream  ""  "F - test-copy-object-with-no-source: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'copy-object' must have two inouts"  "F - test-copy-object-with-no-source: error message")
     # check that stop(1) was called
-    (check-ints-equal *(edx+4) 2 "F - test-copy-object-with-no-input: exit status")
+    (check-ints-equal *(edx+4) 2 "F - test-copy-object-with-no-source: exit status")
     # don't restore from ebp
     81 0/subop/add %esp 8/imm32
     # . epilogue
@@ -21449,25 +22184,320 @@ check-mu-copy-byte-stmt:  # stmt: (addr stmt), fn: (addr function), err: (addr b
     55/push-ebp
     89/<- %ebp 4/r32/esp
     # . save registers
+    50/push-eax
+    51/push-ecx
+    52/push-edx
+    56/push-esi
+    57/push-edi
+    # var type-parameters/edx: (addr table (handle array byte) (addr type-tree) 8)
+    81 5/subop/subtract %esp 0x60/imm32
+    68/push 0x60/imm32/size
+    68/push 0/imm32/read
+    68/push 0/imm32/write
+    89/<- %edx 4/r32/esp
+$check-mu-copy-byte-stmt:get-output:
+    # esi = stmt
+    8b/-> *(ebp+8) 6/r32/esi
+    # var output/edi: (addr stmt-var) = stmt->outputs
+    (lookup *(esi+0x14) *(esi+0x18))  # Stmt1-outputs Stmt1-outputs => eax
+    89/<- %edi 0/r32/eax
+    # zero outputs
+    3d/compare-eax-and 0/imm32
+    0f 84/jump-if-= $check-mu-copy-byte-stmt:error-no-output/disp32
+    # > 1 output
+    (lookup *(edi+8) *(edi+0xc))  # Stmt-var-next Stmt-var-next => eax
+    3d/compare-eax-and 0/imm32
+    0f 85/jump-if-!= $check-mu-copy-byte-stmt:error-too-many-outputs/disp32
+$check-mu-copy-byte-stmt:get-inout:
+    # var inout/esi: (addr stmt-var) = stmt->inouts
+    (lookup *(esi+0xc) *(esi+0x10))  # Stmt1-inouts Stmt1-inouts => eax
+    89/<- %esi 0/r32/eax
+    # zero inouts
+    3d/compare-eax-and 0/imm32
+    0f 84/jump-if-= $check-mu-copy-byte-stmt:error-no-inout/disp32
+    # > 1 inout
+    (lookup *(esi+8) *(esi+0xc))  # Stmt-var-next Stmt-var-next => eax
+    3d/compare-eax-and 0/imm32
+    0f 85/jump-if-!= $check-mu-copy-byte-stmt:error-too-many-inouts/disp32
+$check-mu-copy-byte-stmt:types:
+    # var inout-type/ecx: (addr type-tree) = inout->value->type
+    (lookup *esi *(esi+4))  # Stmt-var-value Stmt-var-value => eax
+    (lookup *(eax+8) *(eax+0xc))  # Var-type Var-type => eax
+    89/<- %ecx 0/r32/eax
+$check-mu-copy-byte-stmt:check-inout-deref:
+    # if (inout->is-deref?) inout-type = inout-type->payload
+    8b/-> *(esi+0x10) 0/r32/eax  # Stmt-var-is-deref
+    3d/compare-eax-and 0/imm32/false
+    {
+      74/jump-if-= break/disp8
+$check-mu-copy-byte-stmt:inout-is-deref:
+      (lookup *(ecx+0xc) *(ecx+0x10))  # Type-tree-right Type-tree-right => eax
+      # if inout-type->right is null, t = inout-type->left
+      81 7/subop/compare *(eax+0xc) 0/imm32  # Type-tree-right
+      {
+        75/jump-if-!= break/disp8
+$check-mu-copy-byte-stmt:inout-is-deref2:
+        (lookup *(eax+4) *(eax+8))  # Type-tree-left Type-tree-left => eax
+      }
+      89/<- %ecx 0/r32/eax
+    }
+    # if inout is not of type byte, abort
+    (is-simple-mu-type? %ecx 8)  # byte => eax
+    3d/compare-eax-and 0/imm32
+    0f 84/jump-if-= $check-mu-copy-byte-stmt:error-invalid-inout-type/disp32
+    # if output not in register, abort
+    (lookup *edi *(edi+4))  # Stmt-var-value Stmt-var-value => eax
+    (lookup *(eax+0x18) *(eax+0x1c))  # Var-register Var-register => eax
+    3d/compare-eax-and 0/imm32
+    0f 84/jump-if-= $check-mu-copy-byte-stmt:error-output-not-in-register/disp32
+    # var output-type/eax: (addr type-tree) = output->value->type
+    (lookup *edi *(edi+4))  # Stmt-var-value Stmt-var-value => eax
+    (lookup *(eax+8) *(eax+0xc))  # Var-type Var-type => eax
+    # if output is not of type byte, abort
+    (is-simple-mu-type? %eax 8)  # byte => eax
+    3d/compare-eax-and 0/imm32
+    0f 84/jump-if-= $check-mu-copy-byte-stmt:error-invalid-output-type/disp32
 $check-mu-copy-byte-stmt:end:
+    # . reclaim locals
+    81 0/subop/add %esp 0x6c/imm32
     # . restore registers
+    5f/pop-to-edi
+    5e/pop-to-esi
+    5a/pop-to-edx
+    59/pop-to-ecx
+    58/pop-to-eax
     # . epilogue
     89/<- %esp 5/r32/ebp
     5d/pop-to-ebp
     c3/return
 
+$check-mu-copy-byte-stmt:error-no-inout:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt 'copy-byte' expects an inout\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-copy-byte-stmt:error-too-many-inouts:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt 'copy-byte' must have just one inout\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-copy-byte-stmt:error-no-output:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt 'copy-byte' expects an output\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-copy-byte-stmt:error-output-not-in-register:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt copy-byte: output '")
+    (lookup *edi *(edi+4))  # Stmt-var-value Stmt-var-value => eax
+    (lookup *eax *(eax+4))  # Var-name Var-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) "' not in a register\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-copy-byte-stmt:error-too-many-outputs:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt 'copy-byte' must have just one output\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-copy-byte-stmt:error-invalid-output-type:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt 'copy-byte' must write to output of type byte\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-copy-byte-stmt:error-invalid-inout-type:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt copy-byte: inout must have type byte\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
 check-mu-copy-byte-to-stmt:  # stmt: (addr stmt), fn: (addr function), err: (addr buffered-file), ed: (addr exit-descriptor)
     # . prologue
     55/push-ebp
     89/<- %ebp 4/r32/esp
     # . save registers
+    50/push-eax
+    51/push-ecx
+    52/push-edx
+    53/push-ebx
+    56/push-esi
+    57/push-edi
+    # var type-parameters/edx: (addr table (handle array byte) (addr type-tree) 8)
+    81 5/subop/subtract %esp 0x60/imm32
+    68/push 0x60/imm32/size
+    68/push 0/imm32/read
+    68/push 0/imm32/write
+    89/<- %edx 4/r32/esp
+    # esi = stmt
+    8b/-> *(ebp+8) 6/r32/esi
+$check-mu-copy-byte-to-stmt:check-for-output:
+    # if stmt->outputs abort
+    (lookup *(esi+0x14) *(esi+0x18))  # Stmt1-outputs Stmt1-outputs => eax
+    3d/compare-eax-and 0/imm32
+    0f 85/jump-if-!= $check-mu-copy-byte-to-stmt:error-too-many-outputs/disp32
+$check-mu-copy-byte-to-stmt:get-dest:
+    # var dest/edi: (addr stmt-var) = stmt->inouts
+    (lookup *(esi+0xc) *(esi+0x10))  # Stmt1-inouts Stmt1-inouts => eax
+    89/<- %edi 0/r32/eax
+    # zero inouts
+    3d/compare-eax-and 0/imm32
+    0f 84/jump-if-= $check-mu-copy-byte-to-stmt:error-incorrect-inouts/disp32
+$check-mu-copy-byte-to-stmt:get-src:
+    # var src/esi: (addr stmt-var) = dest->next
+    (lookup *(edi+8) *(edi+0xc))  # Stmt-var-next Stmt-var-next => eax
+    89/<- %esi 0/r32/eax
+    # 1 inout
+    3d/compare-eax-and 0/imm32
+    0f 84/jump-if-= $check-mu-copy-byte-to-stmt:error-incorrect-inouts/disp32
+    # > 2 inouts
+    (lookup *(esi+8) *(esi+0xc))  # Stmt-var-next Stmt-var-next => eax
+    3d/compare-eax-and 0/imm32
+    0f 85/jump-if-!= $check-mu-copy-byte-to-stmt:error-incorrect-inouts/disp32
+$check-mu-copy-byte-to-stmt:types:
+    # var src-type/ecx: (addr type-tree) = src->value->type
+    (lookup *esi *(esi+4))  # Stmt-var-value Stmt-var-value => eax
+    (lookup *(eax+8) *(eax+0xc))  # Var-type Var-type => eax
+    89/<- %ecx 0/r32/eax
+    # if src not in register, abort
+    {
+      (lookup *esi *(esi+4))  # Stmt-var-value Stmt-var-value => eax
+      (lookup *(eax+0x18) *(eax+0x1c))  # Var-register Var-register => eax
+      3d/compare-eax-and 0/imm32
+      75/jump-if-!= break/disp8
+      e9/jump $check-mu-copy-byte-to-stmt:error-src-not-in-register/disp32
+    }
+    # if src is not a byte, abort
+    (is-simple-mu-type? %ecx 8)  # byte => eax
+    3d/compare-eax-and 0/imm32/false
+    0f 84/jump-if-= $check-mu-copy-byte-to-stmt:error-invalid-src-type/disp32
+    # var dest-type/ebx: (addr type-tree) = dest->value->type
+    (lookup *edi *(edi+4))  # Stmt-var-value Stmt-var-value => eax
+    (lookup *(eax+8) *(eax+0xc))  # Var-type Var-type => eax
+    89/<- %ebx 0/r32/eax
+    # if (dest->is-deref?) dest-type = dest-type->payload
+$check-mu-copy-byte-to-stmt:check-dest-deref:
+    8b/-> *(edi+0x10) 0/r32/eax  # Stmt-var-is-deref
+    3d/compare-eax-and 0/imm32/false
+    {
+      74/jump-if-= break/disp8
+      (lookup *(ebx+0xc) *(ebx+0x10))  # Type-tree-right Type-tree-right => eax
+$check-mu-copy-byte-to-stmt:dest-is-deref:
+      # if dest-type->right is null, dest-type = dest-type->left
+      81 7/subop/compare *(eax+0xc) 0/imm32  # Type-tree-right
+      {
+        75/jump-if-!= break/disp8
+$check-mu-copy-byte-to-stmt:dest-is-deref2:
+        (lookup *(eax+4) *(eax+8))  # Type-tree-left Type-tree-left => eax
+      }
+      89/<- %ebx 0/r32/eax
+    }
+    # if dest is not a byte, abort
+    (is-simple-mu-type? %ebx 8)  # byte => eax
+    3d/compare-eax-and 0/imm32/false
+    0f 84/jump-if-= $check-mu-copy-byte-to-stmt:error-invalid-dest-type/disp32
 $check-mu-copy-byte-to-stmt:end:
+    # . reclaim locals
+    81 0/subop/add %esp 0x6c/imm32
     # . restore registers
+    5f/pop-to-edi
+    5e/pop-to-esi
+    5b/pop-to-ebx
+    5a/pop-to-edx
+    59/pop-to-ecx
+    58/pop-to-eax
     # . epilogue
     89/<- %esp 5/r32/ebp
     5d/pop-to-ebp
     c3/return
 
+$check-mu-copy-byte-to-stmt:error-incorrect-inouts:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt 'copy-byte-to' must have two inouts\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-copy-byte-to-stmt:error-too-many-outputs:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt 'copy-byte-to' must not have any outputs\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-copy-byte-to-stmt:error-src-not-in-register:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt copy-byte-to: source (second inout) must be in a register\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-copy-byte-to-stmt:error-invalid-dest-type:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt copy-byte-to: '")
+    (lookup *edi *(edi+4))  # Stmt-var-value Stmt-var-value => eax
+    (lookup *eax *(eax+4))  # Var-name Var-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) "' must be a byte\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-copy-byte-to-stmt:error-invalid-src-type:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt copy-byte-to: source (second inout) must have type byte\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
 check-mu-compare-stmt:  # stmt: (addr stmt), fn: (addr function), err: (addr buffered-file), ed: (addr exit-descriptor)
     # . prologue
     55/push-ebp