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revert compute-offsets to segment-relative offsets 

The pseudocode was a mess here :/ I was saving the segment-offset but
tracing the file-offset.

Segments need file offsets (to tweak their starting address).
Labels need segment offsets (to add to segment starting address).
This commit is contained in:
Kartik Agaram 2019-07-11 21:31:00 -07:00
parent f57a458e7b
commit be995e2193
1 changed files with 7 additions and 7 deletions
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14
subx/apps/survey.subx
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@ -358,7 +358,7 @@ compute-offsets: # in : (address buffered-file), segments : (address stream {st
# x : (address label-info) = get-or-insert(labels, name)
# x->segment-offset = segment-offset
# trace("label '", word-slice, "' is in segment '", curr-segment-name, "'")
# trace("label '", word-slice, "' is at offset 0x", file-offset)
# trace("label '", word-slice, "' is at segment offset 0x", segment-offset)
# # labels occupy no space, so no need to increment offsets
# continue
# if slice-equal?(word-slice, "==")
@ -493,15 +493,15 @@ $compute-offsets:label:
e8/call trace-slsls/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0x14/imm32 # add to ESP
# trace-slsns("label '" word-slice/EDX "' is at offset '" *file-offset/EAX "'")
# trace-slsns("label '" word-slice/EDX "' is at segment offset '" *file-offset/EAX "'")
# . . EAX = file-offset
b8/copy-to-EAX compute-offsets:file-offset/imm32
b8/copy-to-EAX compute-offsets:segment-offset/imm32
# . . EAX = *file-offset/EAX
8b/copy 0/mod/indirect 0/rm32/EAX . . . 0/r32/EAX . . # copy *EAX to EAX
# . . push args
68/push "."/imm32
50/push-EAX
68/push "' is at offset "/imm32
68/push "' is at segment offset "/imm32
52/push-EDX
68/push "label '"/imm32
# . . call
@ -679,7 +679,7 @@ test-compute-offsets:
# segment 'code' has size 0x5
# segment 'data' is at file offset 0x5
# label 'x' is in segment 'data'
# label 'x' is at offset 0x5
# label 'x' is at segment offset 0x0
# segment 'data' has size 0x1
#
# . prolog
@ -821,10 +821,10 @@ test-compute-offsets:
e8/call check-trace-contains/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
# . check-trace-contains("label 'x' is at offset 0x00000005.", msg)
# . check-trace-contains("label 'x' is at segment offset 0x00000000.", msg)
# . . push args
68/push "F - test-compute-offsets/5"/imm32
68/push "label 'x' is at offset 0x00000005."/imm32
68/push "label 'x' is at segment offset 0x00000000."/imm32
# . . call
e8/call check-trace-contains/disp32
# . . discard args