about summary refs log tree commit diff stats
path: root/subx/065error-byte.subx
diff options
context:
space:
mode:
authorKartik Agaram <vc@akkartik.com>2018-12-04 12:26:27 -0800
committerKartik Agaram <vc@akkartik.com>2018-12-04 12:26:27 -0800
commit79328f9ad6f3118fd86c1f99f672d2807917d848 (patch)
tree0a9ad5f6de74f53ee727b30640b05d2e1055ab80 /subx/065error-byte.subx
parenta94b60b5cc217f08e4fd6c949e6af590c55a176b (diff)
downloadmu-79328f9ad6f3118fd86c1f99f672d2807917d848.tar.gz
4841
New helper: print an error message, then a numeric byte, then abort.
Diffstat (limited to 'subx/065error-byte.subx')
-rw-r--r--subx/065error-byte.subx94
1 files changed, 94 insertions, 0 deletions
diff --git a/subx/065error-byte.subx b/subx/065error-byte.subx
new file mode 100644
index 00000000..82cfd21e
--- /dev/null
+++ b/subx/065error-byte.subx
@@ -0,0 +1,94 @@
+# 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
+
+# main:
+    # manual test
+#?     # . var ed/EAX : exit-descriptor
+#?     81          5/subop/subtract    3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # subtract from ESP
+#?     8d/copy-address                 0/mod/indirect  4/rm32/sib    4/base/ESP  4/index/none  .           0/r32/EAX   .               .                 # copy ESP to EAX
+#?     # . configure ed to really exit()
+#?     # . . ed->target = 0
+#?     c7/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  Stdout/imm32
+#?     50/push-EAX
+#?     e8/call  error-byte/disp32
+    # automatic test
+    e8/call  run-tests/disp32  # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'.
+    # . 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
+    b8/copy-to-EAX  1/imm32
+    cd/syscall  0x80/imm8
+
+# write(out, "Error: "+msg+": "+byte) then stop(ed, 1)
+error-byte:  # ed : (address exit-descriptor), out : (address buffered-file), msg : (address array byte), n : byte -> <void>
+    # . prolog
+    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   4/rm32/sib    5/base/EBP  4/index/none  .           .           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   4/rm32/sib    5/base/EBP  4/index/none  .           .           0x10/disp8      .                 # push *(EBP+16)
+    ff          6/subop/push        1/mod/*+disp8   4/rm32/sib    5/base/EBP  4/index/none  .           .           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   4/rm32/sib    5/base/EBP  4/index/none  .           .           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
+    # print-byte(out, byte)
+    # . . push args
+    ff          6/subop/push        1/mod/*+disp8   4/rm32/sib    5/base/EBP  4/index/none  .           .           0x14/disp8      .                 # push *(EBP+20)
+    ff          6/subop/push        1/mod/*+disp8   4/rm32/sib    5/base/EBP  4/index/none  .           .           0xc/disp8       .                 # push *(EBP+12)
+    # . . call
+    e8/call  print-byte/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   4/rm32/sib    5/base/EBP  4/index/none  .           .           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   4/rm32/sib    5/base/EBP  4/index/none  .           .           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   4/rm32/sib    5/base/EBP  4/index/none  .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  stop/disp32
+    # should never get past this point
+$error-byte:dead-end:
+    # . epilog
+    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