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| author | Kartik Agaram <vc@akkartik.com> | 2019-08-12 23:18:31 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2019-08-12 23:18:31 -0700 |
| commit | 15a84e24497c107cc1572e8e85115d37179d83f4 (patch) | |
| tree | 5f7222de61a308b6e9214ad6bd550890a6101b14 /078table.subx | |
| parent | 94d68ac2444b24ddac693c5d0a06c82c07c4bc25 (diff) | |
| download | mu-15a84e24497c107cc1572e8e85115d37179d83f4.tar.gz | |
better error message when get aborts
Diffstat (limited to '078table.subx')
| -rw-r--r-- | 078table.subx | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/078table.subx b/078table.subx index cbe8222f..90976b11 100644 --- a/078table.subx +++ b/078table.subx @@ -1,7 +1,4 @@ -# - managing tables -# SubX has rudimentary support for tables. -# -# Each table is a stream of (key, value) rows. +# A table is a stream of (key, value) rows. # # Each row consists of a 4-byte key (address to a string) and a variable-size # value. @@ -9,13 +6,14 @@ # Accessing the table performs a linear scan for a key string, and always # requires passing in the row size. # -# Table primitives have the form <variant>(stream, <arg>, row-size) -> address/EAX +# Table primitives have the form <variant>(stream, <arg>, row-size, ...) -> address/EAX # # The following table shows available options for <variant>: # if not found: | arg=string arg=slice # ------------------------+--------------------------------------------------- # abort | get get-slice # insert key | get-or-insert leaky-get-or-insert-slice +# Some variants may take extra args. == code # instruction effective address register displacement immediate @@ -23,7 +21,7 @@ # . 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 # if no row is found, abort -get: # table : (address stream {string, _}), key : (address string), row-size : int -> EAX : (address _) +get: # table : (address stream {string, _}), key : (address string), row-size : int, abort-message-prefix : (address string) -> EAX : (address _) # pseudocode: # curr = table->data # max = &table->data[table->write] @@ -81,9 +79,17 @@ $get:end: c3/return $get:abort: + # . _write(2/stderr, abort-message-prefix) + # . . push args + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x14/disp8 . # push *(EBP+20) + 68/push 2/imm32/stderr + # . . call + e8/call _write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP # . _write(2/stderr, error) # . . push args - 68/push "get: key not found: "/imm32 + 68/push ": get: key not found: "/imm32 68/push 2/imm32/stderr # . . call e8/call _write/disp32 @@ -189,7 +195,7 @@ $test-get:end: c3/return # if no row is found, abort -get-slice: # table : (address stream {string, _}), key : (address slice), row-size : int -> EAX : (address _) +get-slice: # table : (address stream {string, _}), key : (address slice), row-size : int, abort-message-prefix : (address string) -> EAX : (address _) # pseudocode: # curr = table->data # max = &table->data[table->write] @@ -247,6 +253,14 @@ $get-slice:end: c3/return $get-slice:abort: + # . _write(2/stderr, abort-message-prefix) + # . . push args + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x14/disp8 . # push *(EBP+20) + 68/push 2/imm32/stderr + # . . call + e8/call _write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP # . _write(2/stderr, error) # . . push args 68/push "get-slice: key not found: "/imm32 |