7181 - type checks for 'address' instruction

3 files changed, 595 insertions, 2 deletions

diff --git a/apps/mu b/apps/mu
index c8cceb3c..e1e16dcf 100755
--- a/apps/mu
+++ b/apps/mu
Binary files differdiff --git a/apps/mu.subx b/apps/mu.subx
index 479a2808..e5cd2f58 100644
--- a/apps/mu.subx
+++ b/apps/mu.subx
@@ -7596,6 +7596,366 @@ test-compare-non-scalar:
     5d/pop-to-ebp
     c3/return
 
+test-address-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 $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: boolean <- address\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-address-with-no-inout: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'address' expects an inout"  "F - test-address-with-no-inout: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-address-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-address-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 $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: boolean <- address 0, 0\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-address-with-multiple-inouts: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'address' must have just one inout"  "F - test-address-with-multiple-inouts: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-address-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-address-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 $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  address 0\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-address-with-no-output: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'address' expects an output"  "F - test-address-with-no-output: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-address-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-address-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 $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: boolean <- copy 0\n")
+    (write _test-input-stream "  var y/ecx: boolean <- copy 0\n")
+    (write _test-input-stream "  x, y <- address 0\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-address-with-multiple-outputs: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt 'address' must have just one output"  "F - test-address-with-multiple-outputs: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-address-with-multiple-outputs: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+# silly but it works
+test-address-of-deref:
+    # . 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 $_test-output-buffered-file->buffer)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: (addr int) <- copy 0\n")
+    (write _test-input-stream "  var y/ecx: (addr int) <- address *x\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file Stderr 0)
+    (flush _test-output-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # not bothering checking output
+    (check-next-stream-line-equal _test-error-stream  ""  "F - test-address-of-deref: error message")
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-address-to-non-register:
+    # . 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 $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x: (addr int)\n")
+    (write _test-input-stream "  x <- address 0\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-address-to-non-register: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt address: output 'x' not in a register"  "F - test-address-to-non-register: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-address-to-non-register: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-address-with-wrong-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 $_test-error-buffered-file->buffer)
+    # var ed/edx: exit-descriptor = tailor-exit-descriptor(16)
+    68/push 0/imm32
+    68/push 0/imm32
+    89/<- %edx 4/r32/esp
+    (tailor-exit-descriptor %edx 0x10)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x: int\n")
+    (write _test-input-stream "  var y/eax: (addr boolean) <- address x\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file _test-error-buffered-file %edx)
+    # registers except esp clobbered at this point
+    # restore ed
+    89/<- %edx 4/r32/esp
+    (flush _test-output-buffered-file)
+    (flush _test-error-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # check output
+    (check-stream-equal _test-output-stream  ""  "F - test-address-with-wrong-type: output should be empty")
+    (check-next-stream-line-equal _test-error-stream  "fn foo: stmt address: output 'y' cannot hold address of 'x'"  "F - test-address-with-wrong-type: error message")
+    # check that stop(1) was called
+    (check-ints-equal *(edx+4) 2 "F - test-address-with-wrong-type: exit status")
+    # don't restore from ebp
+    81 0/subop/add %esp 8/imm32
+    # . epilogue
+    5d/pop-to-ebp
+    c3/return
+
+test-address-with-right-type-for-array:
+    # . 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 $_test-output-buffered-file->buffer)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x: (array int 3)\n")
+    (write _test-input-stream "  var y/eax: (addr array int) <- address x\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file Stderr 0)
+    (flush _test-output-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # no error
+    (check-next-stream-line-equal _test-error-stream  ""  "F - test-address-with-right-type-for-array: error message")
+    # don't bother checking output
+    # . epilogue
+    89/<- %esp 5/r32/ebp
+    5d/pop-to-ebp
+    c3/return
+
+test-address-with-right-type-for-stream:
+    # . 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 $_test-output-buffered-file->buffer)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x: (stream int 3)\n")
+    (write _test-input-stream "  var y/eax: (addr stream int) <- address x\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file Stderr 0)
+    (flush _test-output-buffered-file)
+#?     # dump _test-error-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-error-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-error-stream)
+#?     # }}}
+    # no error
+    (check-next-stream-line-equal _test-error-stream  ""  "F - test-address-with-right-type-for-stream: error message")
+    # don't bother checking output
+    # . epilogue
+    89/<- %esp 5/r32/ebp
+    5d/pop-to-ebp
+    c3/return
+
 test-get-with-wrong-field:
     # . prologue
     55/push-ebp
@@ -17942,8 +18302,241 @@ check-mu-address-stmt:  # stmt: (addr stmt), fn: (addr function), err: (addr buf
     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
+$check-mu-address-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-address-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-!= $check-mu-address-stmt:error-too-many-outputs/disp32
+$check-mu-address-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-address-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-!= $check-mu-address-stmt:error-too-many-inouts/disp32
+$check-mu-address-stmt:types:
+    # 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-address-stmt:error-output-not-in-register/disp32
+    # var output-type/edx: (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
+    89/<- %edx 0/r32/eax
+    # if output-type not an addr, abort
+    (is-mu-addr-type? %edx)  # => eax
+    3d/compare-eax-and 0/imm32/false
+    0f 84/jump-if-= $check-mu-address-stmt:error-output-not-address/disp32
+    # output-type = output-type->right
+    (lookup *(edx+0xc) *(edx+0x10))  # Type-tree-right Type-tree-right => eax
+    # if output-type->right is null, output-type = output-type->left
+    81 7/subop/compare *(eax+0xc) 0/imm32  # Type-tree-right
+    {
+      75/jump-if-!= break/disp8
+      (lookup *(eax+4) *(eax+8))  # Type-tree-left Type-tree-left => eax
+    }
+    89/<- %edx 0/r32/eax
+    # 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
+    # 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
+      (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
+        (lookup *(eax+4) *(eax+8))  # Type-tree-left Type-tree-left => eax
+      }
+      89/<- %ecx 0/r32/eax
+    }
+    # if (inout-type != output-type) abort
+    (type-equal-ignoring-capacity? %edx %ecx)  # => eax
+    3d/compare-eax-and 0/imm32
+    0f 84/jump-if-= $check-mu-address-stmt:error-type-mismatch/disp32
 $check-mu-address-stmt:end:
     # . restore registers
+    5f/pop-to-edi
+    5e/pop-to-esi
+    5a/pop-to-edx
+    59/pop-to-ecx
+    58/pop-to-eax
+    # . epilogue
+    89/<- %esp 5/r32/ebp
+    5d/pop-to-ebp
+    c3/return
+
+$check-mu-address-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 'address' expects an inout\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-address-stmt:error-too-many-inouts:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt 'address' must have just one inout\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-address-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 'address' expects an output\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-address-stmt:error-output-not-in-register:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt address: output '")
+    (lookup *edi *(edi+4))  # Stmt-var-value Stmt-var-value => eax
+    (lookup *eax *(eax+4))  # Var-name Var-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) "' not in a register\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-address-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 'address' must have just one output\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-address-stmt:error-output-not-address:
+    (write-buffered *(ebp+0x10) "fn ")
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # Function-name Function-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) ": stmt address: output '")
+    (lookup *edi *(edi+4))  # Stmt-var-value Stmt-var-value => eax
+    (lookup *eax *(eax+4))  # Var-name Var-name => eax
+    (write-buffered *(ebp+0x10) %eax)
+    (write-buffered *(ebp+0x10) "' is not an addr\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+$check-mu-address-stmt:error-type-mismatch:
+    (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 address: 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) "' cannot hold address of '")
+    (lookup *esi *(esi+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) "'\n")
+    (flush *(ebp+0x10))
+    (stop *(ebp+0x14) 1)
+    # never gets here
+
+type-equal-ignoring-capacity?:  # a: (addr type-tree), b: (addr type-tree) -> result/eax: boolean
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # . save registers
+    51/push-ecx
+    52/push-edx
+    53/push-ebx
+    # var curr-a/ecx: (addr type-tree) = a
+    8b/-> *(ebp+8) 1/r32/ecx
+    # var curr-b/ebx: (addr type-tree) = b
+    8b/-> *(ebp+0xc) 3/r32/ebx
+    # if (curr-a->is-atom?) fall back to regular equality
+    81 7/subop/compare *ecx 0/imm32/false  # Type-tree-is-atom
+    0f 85/jump-if-!= $type-equal-ignoring-capacity?:base-case/disp32
+    # if (curr-a->left != curr-b->left) return false
+    (lookup *(ecx+4) *(ecx+8))  # Type-tree-left Type-tree-left => eax
+    89/<- %edx 0/r32/eax
+    (lookup *(ebx+4) *(ebx+8))  # Type-tree-left Type-tree-left => eax
+    (type-equal? %edx %eax)  # => eax
+    3d/compare-eax-and 0/imm32/false
+    0f 84/jump-if-= $type-equal-ignoring-capacity?:end/disp32  # eax switches meaning
+    # HERE
+    # if (curr-a->left == "array") curr-a = curr-a->element-type
+    {
+      (is-mu-array? %edx)  # => eax
+      3d/compare-eax-and 0/imm32/false
+      75/jump-if-!= break/disp8
+$type-equal-ignoring-capacity?:array:
+      # curr-a = curr-a->right->left
+      (lookup *(ecx+0xc) *(ecx+0x10))  # Type-tree-right Type-tree-right => eax
+      (lookup *(eax+4) *(eax+8))  # Type-tree-left Type-tree-left => eax
+      89/<- %ecx 0/r32/eax
+      # curr-b = curr-b->right->left
+      (lookup *(ebx+0xc) *(ebx+0x10))  # Type-tree-right Type-tree-right => eax
+      (lookup *(eax+4) *(eax+8))  # Type-tree-left Type-tree-left => eax
+      89/<- %ebx 0/r32/eax
+      eb/jump $type-equal-ignoring-capacity?:base-case/disp8
+    }
+    # if (curr-a->left == "stream") curr-a = curr-a->element-type
+    {
+      (is-mu-stream? %edx)  # => eax
+      3d/compare-eax-and 0/imm32/false
+      75/jump-if-!= break/disp8
+$type-equal-ignoring-capacity?:stream:
+      # curr-a = curr-a->right->left
+      (lookup *(ecx+0xc) *(ecx+0x10))  # Type-tree-right Type-tree-right => eax
+      (lookup *(eax+4) *(eax+8))  # Type-tree-left Type-tree-left => eax
+      89/<- %ecx 0/r32/eax
+      # curr-b = curr-b->right->left
+      (lookup *(ebx+0xc) *(ebx+0x10))  # Type-tree-right Type-tree-right => eax
+      (lookup *(eax+4) *(eax+8))  # Type-tree-left Type-tree-left => eax
+      89/<- %ebx 0/r32/eax
+      eb/jump $type-equal-ignoring-capacity?:base-case/disp8
+    }
+$type-equal-ignoring-capacity?:base-case:
+    # return type-equal?(curr-a, curr-b)
+    (type-equal? %ecx %ebx)  # => eax
+$type-equal-ignoring-capacity?:end:
+    # . restore registers
+    5b/pop-to-ebx
+    5a/pop-to-edx
+    59/pop-to-ecx
     # . epilogue
     89/<- %esp 5/r32/ebp
     5d/pop-to-ebp
diff --git a/apps/tile/word.mu b/apps/tile/word.mu
index 64d03ff8..61c0646e 100644
--- a/apps/tile/word.mu
+++ b/apps/tile/word.mu
@@ -523,7 +523,7 @@ fn word-is-decimal-integer? _self: (addr word) -> _/eax: boolean {
 
 # ABSOLUTELY GHASTLY
 fn word-exists? _haystack-ah: (addr handle word), _needle: (addr word) -> _/ebx: boolean {
-  var needle-name-storage: (handle addr byte)
+  var needle-name-storage: (handle array byte)
   var needle-name-ah/eax: (addr handle array byte) <- address needle-name-storage
   word-to-string _needle, needle-name-ah  # profligate leak
   var _needle-name/eax: (addr array byte) <- lookup *needle-name-ah
@@ -537,7 +537,7 @@ fn word-exists? _haystack-ah: (addr handle word), _needle: (addr word) -> _/ebx:
     return 0  # false
   }
   # check curr
-  var curr-name-storage: (handle addr byte)
+  var curr-name-storage: (handle array byte)
   var curr-name-ah/ecx: (addr handle array byte) <- address curr-name-storage
   word-to-string curr, curr-name-ah  # profligate leak
   var curr-name/eax: (addr array byte) <- lookup *curr-name-ah