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-rw-r--r--linux/119error-byte.subx90
1 files changed, 90 insertions, 0 deletions
diff --git a/linux/119error-byte.subx b/linux/119error-byte.subx
new file mode 100644
index 00000000..1ce0a3d6
--- /dev/null
+++ b/linux/119error-byte.subx
@@ -0,0 +1,90 @@
+# Print an error message followed by the text representation of a byte. Then exit.
+
+== code
+#   instruction                     effective address                                                   register    displacement    immediate
+# . op          subop               mod             rm32          base        index         scale       r32
+# . 1-3 bytes   3 bits              2 bits          3 bits        3 bits      3 bits        2 bits      2 bits      0/1/2/4 bytes   0/1/2/4 bytes
+
+#? Entry:  # manual test
+#?     # . var ed/eax: exit-descriptor
+#?     81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # subtract from esp
+#?     89/copy                         3/mod/direct    0/rm32/eax    .           .             .           4/r32/esp   .               .                 # copy esp to eax
+#?     # . configure ed to really exit()
+#?     # . . ed->target = 0
+#?     c7          0/subop/copy        0/mod/direct    0/rm32/eax    .           .             .           .           .               0/imm32           # copy to *eax
+#?     # . error-byte(ed, Stdout, msg, 34)
+#?     68/push  0x34/imm32
+#?     68/push  "abc"/imm32
+#?     68/push  Stderr/imm32
+#?     50/push-eax
+#?     e8/call  error-byte/disp32
+#?     # . syscall(exit, Num-test-failures)
+#?     8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           3/r32/ebx   Num-test-failures/disp32          # copy *Num-test-failures to ebx
+#?     e8/call  syscall_exit/disp32
+
+# write(out, "Error: "+msg+": "+byte) then stop(ed, 1)
+error-byte:  # ed: (addr exit-descriptor), out: (addr buffered-file), msg: (addr array byte), n: byte
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # write-buffered(out, "Error: ")
+    # . . push args
+    68/push  "Error: "/imm32
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
+    # . . call
+    e8/call  write-buffered/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+    # write-buffered(out, msg)
+    # . . push args
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x10/disp8      .                 # push *(ebp+16)
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
+    # . . call
+    e8/call  write-buffered/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+    # write-buffered(out, ": ")
+    # . . push args
+    68/push  ": "/imm32
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
+    # . . call
+    e8/call  write-buffered/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+    # write-byte-hex-buffered(out, byte)
+    # . . push args
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x14/disp8      .                 # push *(ebp+20)
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
+    # . . call
+    e8/call  write-byte-hex-buffered/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+    # write-buffered(out, Newline)
+    # . . push args
+    68/push  Newline/imm32
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
+    # . . call
+    e8/call  write-buffered/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+    # flush(out)
+    # . . push args
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
+    # . . call
+    e8/call  flush/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+    # stop(ed, 1)
+    # . . push args
+    68/push  1/imm32
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
+    # . . call
+    e8/call  stop/disp32
+    # should never get past this point
+$error-byte:dead-end:
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+# . . vim:nowrap:textwidth=0