62 lines
2.6 KiB
Plaintext
62 lines
2.6 KiB
Plaintext
# Helper to check an array's bounds, and to abort if they're violated.
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# Really only intended to be called from code generated by mu.subx.
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== code
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__check-mu-array-bounds: # index: int, elem-size: int, arr-size: int, function-name: (addr array byte), array-name: (addr array byte)
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# . prologue
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55/push-ebp
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89/<- %ebp 4/r32/esp
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# . save registers
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50/push-eax
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51/push-ecx
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52/push-edx
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# . not bothering saving ebx; it's only clobbered if we're going to abort
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# ecx = arr-size
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8b/-> *(ebp+0x10) 1/r32/ecx
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# var overflow/edx: int = 0
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ba/copy-to-edx 0/imm32
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# var offset/eax: int = index * elem-size
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8b/-> *(ebp+8) 0/r32/eax
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f7 4/subop/multiply-eax-with *(ebp+0xc)
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# check for overflow
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81 7/subop/compare %edx 0/imm32
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0f 85/jump-if-!= __check-mu-array-bounds:overflow/disp32
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# check bounds
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39/compare %eax 1/r32/ecx
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0f 82/jump-if-unsigned< $__check-mu-array-bounds:end/disp32 # negative index should always abort
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# abort if necessary
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(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "fn " 3 0) # 3=cyan
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(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 *(ebp+0x14) 3 0) # 3=cyan
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(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 ": offset " 3 0) # 3=cyan
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(draw-int32-hex-wrapping-right-then-down-from-cursor-over-full-screen 0 %eax 3 0) # 3=cyan
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(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 " is too large for array '" 3 0) # 3=cyan
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(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 *(ebp+0x18) 3 0) # 3=cyan
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(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "'" 3 0) # 3=cyan
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(abort "")
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# never gets here
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$__check-mu-array-bounds:end:
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# . restore registers
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5a/pop-to-edx
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59/pop-to-ecx
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58/pop-to-eax
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# . epilogue
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89/<- %esp 5/r32/ebp
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5d/pop-to-ebp
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c3/return
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__check-mu-array-bounds:overflow:
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(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "fn " 3 0) # 3=cyan
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(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 *(ebp+0x14) 3 0) # 3=cyan
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(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 ": offset to array '" 3 0) # 3=cyan
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(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 *(ebp+0x18) 3 0) # 3=cyan
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(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "' overflowed 32 bits" 3 0) # 3=cyan
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(abort "")
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# never gets here
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__mu-abort-null-index-base-address:
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(abort "null address in 'index'")
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__mu-abort-null-get-base-address:
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(abort "null address in 'get'")
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