Writin a C Compiler [Early Access ed.]

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✠❨ ✍ ❘ ❆ ✌❙ ✟ ☞ ☛ ✡

❇✞■✆☎ ✂ ✁✝✂✆ ▲✁ ●✁✂▼▼■◆● ✆✂◆●✞✂●✝ ❊✁ ▼ ✄❈✁✂❚❈❍ ◆ ✁✂ ✄✂◆☎✆✝✁

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✤✣ ✛✚ ✙✘✗ ✁✙ ✕ ✕ ✚ ✙ ✔✓ ✚ ✘ ✘ ✕ ✁ ✙ ✣ ✒ ✙ ✚ ✑✏ ✎✕✕✂✌✚✘☞ ☛✕✔✘✣✑✕✡

❚❤❡ ✄❛r❧② ☎❝❝❡ss ✆r✝❣r❛♠ ❧❡ts ②✝✉ r❡❛❞ s✐❣♥✐✞❝❛♥t ✆✝rt✐✝♥s ✝❢ ❛♥ ✉✆❝✝♠✐♥❣ ❜✝✝❦ ✟❤✐❧❡ ✐t➆s st✐❧❧ ✐♥ t❤❡ ❡❞✐t✐♥❣ ❛♥❞ ✆r✝❞✉❝t✐✝♥ ✆❤❛s❡s✱ s✝ ②✝✉ ♠❛② ❝✝♠❡ ❛❝r✝ss ❡rr✝rs ✝r ✝t❤❡r ✐ss✉❡s ②✝✉ ✟❛♥t t✝ ❝✝♠♠❡♥t ✝♥✳ ✠✉t ✟❤✐❧❡ ✟❡ s✐♥❝❡r❡❧② ❛✆✆r❡❝✐❛t❡ ②✝✉r ❢❡❡❞❜❛❝❦ ❞✉r✐♥❣ ❛ ❜✝✝❦➆s ✄☎ ✆❤❛s❡✱ ✆❧❡❛s❡ ✉s❡ ②✝✉r ❜❡st ❞✐s✲ ❝r❡t✐✝♥ ✟❤❡♥ ❞❡❝✐❞✐♥❣ ✟❤❛t t✝ r❡✆✝rt✳ ☎t t❤❡ ✄☎ st❛❣❡✱ ✟❡➆r❡ ♠✝st ✐♥t❡r❡st❡❞ ✐♥ ❢❡❡❞❜❛❝❦ r❡❧❛t❡❞ t✝ ❝✝♥t❡♥t➋ ❣❡♥❡r❛❧ ❝✝♠♠❡♥ts t✝ t❤❡ ✟r✐t❡r✱ t❡❝❤♥✐❝❛❧ ❡rr✝rs✱ ✍❡rs✐✝♥✐♥❣ ❝✝♥❝❡r♥s✱ ✝r ✝t❤❡r ❤✐❣❤✲❧❡✍❡❧ ✐ss✉❡s ❛♥❞ ✝❜s❡r✍❛t✐✝♥s✳ ☎s t❤❡s❡ t✐t❧❡s ❛r❡ st✐❧❧ ✐♥ ❞r❛❢t ❢✝r♠✱ ✟❡ ❛❧r❡❛❞② ❦♥✝✟ t❤❡r❡ ♠❛② ❜❡ t②✆✝s✱ ❣r❛♠♠❛t✐❝❛❧ ♠✐st❛❦❡s✱ ♠✐ss✲ ✐♥❣ ✐♠❛❣❡s ✝r ❝❛✆t✐✝♥s✱ ❧❛②✝✉t ✐ss✉❡s✱ ❛♥❞ ✐♥st❛♥❝❡s ✝❢ ✆❧❛❝❡❤✝❧❞❡r t❡①t✳ ✖✝ ♥❡❡❞ t✝ r❡✆✝rt t❤❡s❡➋t❤❡② ✟✐❧❧ ❛❧❧ ❜❡ ❝✝rr❡❝t❡❞ ❧❛t❡r✱ ❞✉r✐♥❣ t❤❡ ❝✝✆②❡❞✐t✲ ✐♥❣✱ ✆r✝✝❢r❡❛❞✐♥❣✱ ❛♥❞ t②✆❡s❡tt✐♥❣ ✆r✝❝❡ss❡s✳ ■❢ ②✝✉ ❡♥❝✝✉♥t❡r ❛♥② ❡rr✝rs ✜➇❡rr❛t❛➈✮ ②✝✉➆❞ ❧✐❦❡ t✝ r❡✆✝rt✱ ✆❧❡❛s❡ ✞❧❧ ✝✉t ✢✥✦✧ ★♦♦✩✪✫ ✬♦✭✯ s✝ ✟❡ ❝❛♥ r❡✍✐❡✟ ②✝✉r ❝✝♠♠❡♥ts✳

✁✂✄☎ ✆✝✝✞✟✟ ✞✠✡☛✡☞✌✍ ✎✏✑✎✒✑✓✔ ✕✖✗✘✙✚✛✜✢ ✣ ✤✥✤✦ ✧✘ ★✖✙✩ ✪✩✫✬✭✮✙✯ ✰✪✱★ ✲✳✴ ✵✶✷✸✲✸✶✲✷✹✸✺✺✻✼✸✽ ✾✗✙✚✫✢✿ ✰✪✱★ ✲✳✴ ✵✶✷✸✲✸✶✲✷✹✸✺✺✻✳✸✳ ✾✮✧✖✖❀✿ ❁❂✧✭✚❃✜✮✙✴ ❄✚✭✭✚✩❅ ❁✖✭✭✖❆❀ ❇✩✫✩✛✚✫✛ ❈✬✚✢✖✙✴ ❉✚✭✭ ❊✙✩✫❀✭✚✫ ❁✙✖✬❂❆✢✚✖✫ ❇✩✫✩✛✮✙✴ ✪✩✧✙✚✫✩ ❁✭✖❅✚✢✩✭✭✖✸❋✖✫●❍✭✮● ◆■ ❏❑▲▼❖P ◗▼❘❙❙ ▲❚❯ ❑P❘ ◆■ ❏❑▲▼❖P ◗▼❘❙❙ ❱■❲■ ▲▼❘ ▼❘❲❳❙❑❘▼❘❯ ❑▼▲❯❘❨▲▼❩❙ ■❬ ◆■ ❏❑▲▼❖P ◗▼❘❙❙❭ ❪❚❖❫ ❴❑P❘▼ ❵▼■❯❛❖❑ ▲❚❯ ❖■❨❵▲❚❜ ❚▲❨❘❙ ❨❘❚❑❳■❚❘❯ P❘▼❘❳❚ ❨▲❜ ❝❘ ❑P❘ ❑▼▲❯❘❨▲▼❩❙ ■❬ ❑P❘❳▼ ▼❘❙❵❘❖❑❳r❘ ■❞❚❘▼❙❫ ❡▲❑P❘▼ ❑P▲❚ ❛❙❘ ▲ ❑▼▲❯❘❨▲▼❩ ❙❜❨❝■❱ ❞❳❑P ❘r❘▼❜ ■❖❖❛▼▼❘❚❖❘ ■❬ ▲ ❑▼▲❯❘❢ ❨▲▼❩❘❯ ❚▲❨❘❭ ❞❘ ▲▼❘ ❛❙❳❚❲ ❑P❘ ❚▲❨❘❙ ■❚❱❜ ❳❚ ▲❚ ❘❯❳❑■▼❳▲❱ ❬▲❙P❳■❚ ▲❚❯ ❑■ ❑P❘ ❝❘❚❘❬❳❑ ■❬ ❑P❘ ❑▼▲❯❘❨▲▼❩ ■❞❚❘▼❭ ❞❳❑P ❚■ ❳❚❑❘❚❑❳■❚ ■❬ ❳❚❬▼❳❚❲❘❨❘❚❑ ■❬ ❑P❘ ❑▼▲❯❘❨▲▼❩❫ ❣❱❱ ▼❳❲P❑❙ ▼❘❙❘▼r❘❯❫ ◆■ ❵▲▼❑ ■❬ ❑P❳❙ ❞■▼❩ ❨▲❜ ❝❘ ▼❘❵▼■❯❛❖❘❯ ■▼ ❑▼▲❚❙❨❳❑❑❘❯ ❳❚ ▲❚❜ ❬■▼❨ ■▼ ❝❜ ▲❚❜ ❨❘▲❚❙❭ ❘❱❘❖❑▼■❚❳❖ ■▼ ❨❘❖P▲❚❳❖▲❱❭ ❳❚❖❱❛❯❳❚❲ ❵P■❑■❖■❵❜❳❚❲❭ ▼❘❖■▼❯❳❚❲❭ ■▼ ❝❜ ▲❚❜ ❳❚❬■▼❨▲❢ ❑❳■❚ ❙❑■▼▲❲❘ ■▼ ▼❘❑▼❳❘r▲❱ ❙❜❙❑❘❨❭ ❞❳❑P■❛❑ ❑P❘ ❵▼❳■▼ ❞▼❳❑❑❘❚ ❵❘▼❨❳❙❙❳■❚ ■❬ ❑P❘ ❖■❵❜▼❳❲P❑ ■❞❚❘▼ ▲❚❯ ❑P❘ ❵❛❝❱❳❙P❘▼❫ ❤P❘ ❳❚❬■▼❨▲❑❳■❚ ❳❚ ❑P❳❙ ❝■■❩ ❳❙ ❯❳❙❑▼❳❝❛❑❘❯ ■❚ ▲❚ ✐❣❙ ❪❙❥ ❝▲❙❳❙❭ ❞❳❑P■❛❑ ❞▲▼▼▲❚❑❜❫ ❦P❳❱❘ ❘r❘▼❜ ❵▼❘❖▲❛❑❳■❚ P▲❙ ❝❘❘❚ ❑▲❩❘❚ ❳❚ ❑P❘ ❵▼❘❵▲▼▲❑❳■❚ ■❬ ❑P❳❙ ❞■▼❩❭ ❚❘❳❑P❘▼ ❑P❘ ▲❛❑P■▼ ❚■▼ ◆■ ❏❑▲▼❖P ◗▼❘❙❙❭ ❪❚❖❫ ❙P▲❱❱ P▲r❘ ▲❚❜ ❱❳▲❝❳❱❳❑❜ ❑■ ▲❚❜ ❵❘▼❙■❚ ■▼ ❘❚❑❳❑❜ ❞❳❑P ▼❘❙❵❘❖❑ ❑■ ▲❚❜ ❱■❙❙ ■▼ ❯▲❨▲❲❘ ❖▲❛❙❘❯ ■▼ ▲❱❱❘❲❘❯ ❑■ ❝❘ ❖▲❛❙❘❯ ❯❳▼❘❖❑❱❜ ■▼ ❳❚❯❳▼❘❖❑❱❜ ❝❜ ❑P❘ ❳❚❬■▼❨▲❑❳■❚ ❖■❚❑▲❳❚❘❯ ❳❚ ❳❑❫

✘✣✤ ✁✤ ✜

✂✄☎✆✝✞✟✠☎✡✝✄ ☛☞✆☎ ✂✌ ✍✎✏ ✑☞✒✡✠✒ ✓✎☞✔☎✏✆ ✕✌ ✖ ✗✡✄✡✙☞✚ ✓✝✙✔✡✚✏✆ ✓✎☞✔☎✏✆ ✛✌ ✢✄☞✆✥ ✦✔✏✆☞☎✝✆✒ ✓✎☞✔☎✏✆ ✧✌ ✑✡✄☞✆✥ ✦✔✏✆☞☎✝✆✒ ✓✎☞✔☎✏✆ ★✌ ✩✝✪✡✠☞✚ ☞✄✞ ✫✏✚☞☎✡✝✄☞✚ ✦✔✏✆☞☎✝✆✒ ✓✎☞✔☎✏✆ ✬✌ ✩✝✠☞✚ ✭☞✆✡☞✮✚✏✒ ✓✎☞✔☎✏✆ ✯✌ ✂✰ ✱☎☞☎✏✙✏✄☎✒ ☞✄✞ ✓✝✄✞✡☎✡✝✄☞✚ ✲✳✔✆✏✒✒✡✝✄✒ ✓✎☞✔☎✏✆ ✴✌ ✓✝✙✔✝✟✄✞ ✱☎☞☎✏✙✏✄☎✒ ✓✎☞✔☎✏✆ ✵✌ ✩✝✝✔✒ ✓✎☞✔☎✏✆ ✶✌ ✷✟✄✠☎✡✝✄✒ ✓✎☞✔☎✏✆ ✕✸✌ ✷✡✚✏✹✒✠✝✔✏ ✭☞✆✡☞✮✚✏✒ ☞✄✞ ✱☎✝✆☞✪✏✹✠✚☞✒✒ ✱✔✏✠✡✰✡✏✆✒ ☛☞✆☎ ✂✂✌ ✍✥✔✏✒ ✑✏✥✝✄✞ ✡✄☎ ✓✎☞✔☎✏✆ ✕✕✌ ✩✝✄✪ ✂✄☎✏✪✏✆✒ ✓✎☞✔☎✏✆ ✕✛✌ ✢✄✒✡✪✄✏✞ ✂✄☎✏✪✏✆✒ ✓✎☞✔☎✏✆ ✕✧✌ ✷✚✝☞☎✡✄✪✹✔✝✡✄☎ ✺✟✙✮✏✆✒ ✓✎☞✔☎✏✆ ✕★✌ ☛✝✡✄☎✏✆✒ ✓✎☞✔☎✏✆ ✕✬✌ ✖✆✆☞✥✒ ☞✄✞ ☛✝✡✄☎✏✆ ✖✆✡☎✎✙✏☎✡✠ ✓✎☞✔☎✏✆ ✕✯✌ ✓✎☞✆☞✠☎✏✆✒ ☞✄✞ ✱☎✆✡✄✪✒ ✓✎☞✔☎✏✆ ✕✴✌ ✱✟✔✔✝✆☎✡✄✪ ✻✥✄☞✙✡✠ ✗✏✙✝✆✥ ✖✚✚✝✠☞☎✡✝✄ ✓✎☞✔☎✏✆ ✕✵✌ ✱☎✆✟✠☎✟✆✏✒ ☛☞✆☎ ✂✂✂✌ ✦✔☎✡✙✡✼☞☎✡✝✄✒ ✓✎☞✔☎✏✆ ✕✶✌ ✦✔☎✡✙✡✼✡✄✪ ✍☞✠✽✥ ☛✆✝✪✆☞✙✒ ✓✎☞✔☎✏✆ ✛✸✌ ✫✏✪✡✒☎✏✆ ✖✚✚✝✠☞☎✡✝✄ ✺✏✳☎ ✱☎✏✔✒ ✖✔✔✏✄✞✡✳ ✖ ✌✻✏✮✟✪✪✡✄✪ ✖✒✒✏✙✮✚✥ ✓✝✞✏ ✾✡☎✎ ✿✻✑ ✝✆ ✩✩✻✑ ✫✏✰✏✆✏✄✠✏✒ ✓✎☞✔☎✏✆✒ ✡✄ ✆✏✞ ☞✆✏ ✡✄✠✚✟✞✏✞ ✡✄ ☎✎✡✒ ✲☞✆✚✥ ✖✠✠✏✒✒ ☛✻✷❀

Writing a C Compiler (Early Access) © 2023 by Nora Sandler

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"5%!20*(&%*!)2,%!A#)!exp!34*38(&%'!&5(&!(4!%@0)%''3#4!8(4!9%!%3&5%)!(!8#4'&(4&!34&%$%)!#)!(!24()7! #0%)(&3#4:!J!24()7!#0%)(&3#4!8#4'3'&'!#A!#4%!#A!&5%!&6#!24()7!#0%)(&#)'+!Complement!#)!Negate+! (00,3%*!&#!(4!344%)!%@0)%''3#4:!U#&38%!&5(&!&5%!*%A343&3#4!#A!exp!3'!)%82)'3E%Y!&5%!Unary!8#4'&)28&#)!A#)! (4!exp!4#*%!8#4&(34'!(4#&5%)!exp!4#*%:!"53'!,%&'!2'!8#4'&)28&!()93&)()3,7!*%%0,7!4%'&%*!%@0)%''3#4'+!,3.%! -(~(-~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gR!#)!O63,,!&53'!E()3(9,%!(,6(7'!&5%!5(E%!'(1%!E(,2%g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

c#'&!8#103,%)'!2'%!'#1%!A#)1!#A!&5)%%>(**)%''!8#*%!34&%)4(,,7+!92&!&5%!*%&(3,'!E()7:!;-E%!*%83*%*!&#! 4(1%!&5%!34&%)1%*3(&%!)%0)%'%4&(&3#4!34!&53'!9##.!9:;=>:!BU(134$!7#2)!34&%)1%*3(&%!)%0)%'%4&(&3#4'!3'+! 34!17!#0343#4+!#4%!#A!&5%!9%'&!0()&'!#A!8#103,%)!*%'3$4:C!;!1(*%!20!"J/hH!A#)!&53'!9##.+!92&!3&-'!'313,()! &#!&5)%%>(**)%''!8#*%!34!#&5%)!8#103,%)':!

!"#$%$%&'()*+,' V%!*%A34%!"J/hH!34!J^XQ:! program = Program(function_definition) function_definition = Function(identifier, 1 instruction* body) instruction = Return(val) | Unary(unary_operator, val src, val dst) val = Constant(int) | Var(identifier) unary_operator = Complement | Negate

!"#$"%&'()J!

934'9+,KL'M>'

;4!"J/hH+!(!A248&3#4!9#*7!8#4'3'&'!#A!(!,3'&!#A!34'&)28&3#4'!1+!)(&5%)!&5(4!(!'34$,%!'&(&%1%4&:!;4!&53'! )%'0%8&+!3&-'!'313,()!&#!&5%!(''%19,7!J^"!6%!*%A34%*!34!&5%!0)%E3#2'!85(0&%):!F#)!4#6+!"J/hH!5('!&6#! 34'&)28&3#4'Y!Return!(4*!Unary:!Return!)%&2)4'!(!E(,2%I!Unary!0%)A#)1'!'#1%!24()7!#0%)(&3#4!#4! src+!&5%!'#2)8%!E(,2%!A#)!&5%!%@0)%''3#4+!(4*!'&#)%'!&5%!)%'2,&!34!dst+!&5%!*%'&34(&3#4:!P#&5!34'&)28&3#4'! #0%)(&%!#4!val'+!65385!8(4!9%!%3&5%)!8#4'&(4&!34&%$%)'!BConstantC!#)!&%10#)()7!E()3(9,%'!BVarC:!"5%! "J/hH!6%!$%4%)(&%!12'&!1%%&!#4%!)%L23)%1%4&!&5(&!3'4-&!%@0,383&!34!i:!"5%!&)38.7!0()&!3'!&2)434$!(4!exp!4#*%!34&#!(!,3'&!#A! 34'&)28&3#4'I!#48%!7#2!5(E%!&5(&!A3$2)%*!#2&+!5(4*,34$!&5%!#&5%)!J^"!4#*%'!3'!%('7:!"(9,%!=>?!,3'&'!(!A%6! %@(10,%'!#A!J^"'!(4*!&5%!)%'2,&34$!"J/hH:! %&'()$*+,$

%-./0$1)23)4)56&67"54$"8$95&3:$;#23)447"54$

*#!$

!*123$

Return(Constant(3)) Return(Unary(Complement, Constant(2)))

Return(Constant(3)) Unary(Complement, Constant(2), Var("tmp.0")) Return(Var("tmp.0"))! Unary(Negate, Constant(8), Var("tmp.0")) Unary(Complement, Var("tmp.0"), Var("tmp.1")) Unary(Negate, Var("tmp.1"), Var("tmp.2")) Return(Var("tmp.2"))!

Return(Unary(Negate, Unary(Complement, Unary(Negate, Constant(8)))))!

;4!&5%'%!%@(10,%'+!6%!8#4E%)&!%(85!24()7!#0%)(&3#4!34&#!(!Unary!"J/hH!34'&)28&3#4+!'&()&34$!63&5! &5%!344%)1#'&!%@0)%''3#4!(4*!6#).34$!#2)!6(7!#2&:!V%!'&#)%!&5%!)%'2,&!#A!%(85!Unary!34'&)28&3#4!34!(! &%10#)()7!E()3(9,%+!65385!6%!&5%4!2'%!34!&5%!#2&%)!%@0)%''3#4!#)!return!'&(&%1%4&:!*%A34%*!3*%4&3A3%)'!9%8(2'%!34&%$%)'!()%4-&!E(,3*!3*%4&3A3%)'!34!/:!;4!"(9,%!=>?+!6%!2'%!(!E()3(&3#4! #4!&53'!(00)#(85I!6%!8#48(&%4(&%!(!*%'8)30&3E%!'&)34$+!(!0%)3#*+!(4*!&5%!$,#9(,!8#24&%)!&#!0)#*28%!243L2%! 3*%4&3A3%)'!,3.%!tmp.0:!"5%'%!6#4-&!8#4A,38&!63&5!2'%)>*%A34%*!3*%4&3A3%)'!9%8(2'%!/!3*%4&3A3%)'!8(4-&! 8#4&(34!0%)3#*':!V3&5!&53'!4(134$!'85%1%+!7#2!8(4!%48#*%!2'%A2,!34A#)1(&3#4!34!(2&#$%4%)(&%*!4(1%'+! ,3.%!&5%!4(1%!#A!&5%!A248&3#4!65%)%!&5%7-)%!2'%*:!B;&-'!,%''!2'%A2,!3A!7#2!4(1%!%E%)7!E()3(9,%!tmp+!,3.%! ;-E%!*#4%!5%)%:C!

:5;/0$%&'0??+!348,2*%'!(!8#4'&)28&!8#))%'0#4*34$!&#!&5%!sub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

*556789:$

Program(function_definition) Function(name, instructions)

Program(function_definition) Function(name, instructions)

@5463?>67"54$ Return(val) Unary(unary_operator, src, dst)

Mov(val, Reg(AX)) Ret Mov(src, dst) Unary(unary_operator, dst)

A2)3&6"34$ Complement Negate

Not Neg

A2)3&5B4$ Constant(int) Var(identifier)

Imm(int) Pseudo(identifier)

^348%!#2)!4%6!(''%19,7!34'&)28&3#4'!2'%!&5%!'(1%!#0%)(&3#4!A#)!&5%!'#2)8%!(4*!*%'&34(&3#4+!6%!8#07! &5%!'#2)8%!E(,2%!34&#!&5%!*%'&34(&3#4!9%A#)%!3''234$!&5%!neg!#)!not!34'&)28&3#4:!U#&%!&5(&!6%-)%!4#&!2'34$! &5%!AllocateStack!34'&)28&3#4!7%&I!6%-,,!(**!3&!34!&5%!E%)7!,('&!0(''!9%A#)%!8#*%!%13''3#4+!#48%!6%! .4#6!5#6!1(47!97&%'!6%!4%%*!&#!(,,#8(&%:!V%-)%!(,'#!4#&!2'34$!(47!Stack!#0%)(4*'I!6%-,,!)%0,(8%! %E%)7!Pseudo!#0%)(4*!63&5!(!Stack!#0%)(4*!34!&5%!4%@&!8#103,%)!0('':!J4*!6%-)%!4#&!2'34$!&5%!G?WX! )%$3'&%)I!6%-,,!34&)#*28%!3&!65%4!6%!)%6)3&%!34E(,3*!34'&)28&3#4':!!

>"59/?$%&'@3"A;4."&$30".3' U%@&+!6%!6)3&%!(!8#103,%)!0(''!&#!)%0,(8%!%(85!Pseudo!#0%)(4*!63&5!(!Stack!#0%)(4*+!,%(E34$!&5%! )%'&!#A!&5%!(''%19,7!J^"!2485(4$%*:!;4!$ %"2+()"5463?>64$

4@>B@>$

Program(function_definition)

L%)53!#$3!3-+!/$5&3)#5!.+/)5)3)#5! N5!E)5$14!2..!23!+5.!#/!/)*+:! .section .note.GNU-stack,"",@progbits! .globl : pushq %rbp movq %rsp, %rbp

Function(name, instructions)

@5463?>67"54$ Mov(src, dst) Ret

Unary(unary_operator, operand) AllocateStack(int)

movl , ! movq %rbp, %rsp popq %rbp ret

subq $, %rsp

4B6?C>