Qual è l'ordine delle fasi scala compilatore?
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13-10-2019 - |
Domanda
Voglio affinare la mia foto delle fasi di compilazione Scala. So che certe cose devono accadere nel compilatore, ma non sanno l'ordine in cui si verificano e come l'ordine dovrebbe pregiudicare la mia programmazione.
ho ragione nel dire che le seguenti cose sono l'elenco completo di ciò che il compilatore fa?
- programma di analisi
- tipi controllati
- non la cancellazione
- conversione implicita ??li>
- byte-codice generato
- ottimizzare
Se sì, qual è l'ordine che fa queste fasi? In che modo questo ordine influisce il programmatore, in particolare il programmatore tipo di livello?
Soluzione
Si vede le fasi, il loro ordine e spiegazione utilizzando scalac -Xshow-phases
.
In 2.11, l'uso -Xshow-phases -Ydebug
per mostrare entrambe le fasi abilitati e disabilitati.
Ecco come è per 2.10.0:
» scalac -Xshow-phases
phase name id description
---------- -- -----------
parser 1 parse source into ASTs, perform simple desugaring
namer 2 resolve names, attach symbols to named trees
packageobjects 3 load package objects
typer 4 the meat and potatoes: type the trees
patmat 5 translate match expressions
superaccessors 6 add super accessors in traits and nested classes
extmethods 7 add extension methods for inline classes
pickler 8 serialize symbol tables
refchecks 9 reference/override checking, translate nested objects
selectiveanf 10
selectivecps 11
uncurry 12 uncurry, translate function values to anonymous classes
tailcalls 13 replace tail calls by jumps
specialize 14 @specialized-driven class and method specialization
explicitouter 15 this refs to outer pointers, translate patterns
erasure 16 erase types, add interfaces for traits
posterasure 17 clean up erased inline classes
lazyvals 18 allocate bitmaps, translate lazy vals into lazified defs
lambdalift 19 move nested functions to top level
constructors 20 move field definitions into constructors
flatten 21 eliminate inner classes
mixin 22 mixin composition
cleanup 23 platform-specific cleanups, generate reflective calls
icode 24 generate portable intermediate code
inliner 25 optimization: do inlining
inlineExceptionHandlers 26 optimization: inline exception handlers
closelim 27 optimization: eliminate uncalled closures
dce 28 optimization: eliminate dead code
jvm 29 generate JVM bytecode
terminal 30 The last phase in the compiler chain
Altri suggerimenti
Hai guardato href="http://www.scala-lang.org/sid/2" qui ? Quella pagina punta a http://www.scala-lang.org/sites/default/files/sids/nielsen/Thu,%202009-05-28,%2008:13/compiler-phases-sid .pdf (PDF), che descrive le fasi del compilatore per la Scala 2.8.
Si dovrebbe non preoccupare l'ordine delle fasi del compilatore a meno che non si sta scrivendo un plugin compilatore. Anche per la programmazione tipo di livello, si dovrebbe concentrare sulla semantica della lingua, invece.
Per quanto riguarda la cancellazione è interessato, per esempio, è importante capire i tipi vs dinamici statici e il modello di compilazione separata. Analogamente, è importante capire le condizioni in cui il compilatore applicherà una conversione implicita. Dove questi si verificano nel ciclo di compilazione è solo un dettaglio di implementazione.
Scala.js 0.6.23
phase name id description
---------- -- -----------
parser 1 parse source into ASTs, perform simple desugaring
jspretyper 2 capture pre-typer only tree info (for Scala.js)
namer 3 resolve names, attach symbols to named trees
packageobjects 4 load package objects
typer 5 the meat and potatoes: type the trees
jsinterop 6 prepare ASTs for JavaScript interop
patmat 7 translate match expressions
superaccessors 8 add super accessors in traits and nested classes
extmethods 9 add extension methods for inline classes
pickler 10 serialize symbol tables
xsbt-api 11
xsbt-dependency 12
refchecks 13 reference/override checking, translate nested objects
uncurry 14 uncurry, translate function values to anonymous classes
tailcalls 15 replace tail calls by jumps
specialize 16 @specialized-driven class and method specialization
explicitouter 17 this refs to outer pointers
erasure 18 erase types, add interfaces for traits
posterasure 19 clean up erased inline classes
lazyvals 20 allocate bitmaps, translate lazy vals into lazified defs
lambdalift 21 move nested functions to top level
constructors 22 move field definitions into constructors
flatten 23 eliminate inner classes
mixin 24 mixin composition
jscode 25 generate JavaScript code from ASTs
cleanup 26 platform-specific cleanups, generate reflective calls
delambdafy 27 remove lambdas
icode 28 generate portable intermediate code
inliner xx optimization: do inlining
inlinehandlers xx optimization: inline exception handlers
closelim xx optimization: eliminate uncalled closures
constopt xx optimization: optimize null and other constants
dce xx optimization: eliminate dead code
jvm 29 generate JVM bytecode
xsbt-analyzer 30
terminal 31 the last phase during a compilation run
Scala-Native 0.3.7
phase name id description
---------- -- -----------
parser 1 parse source into ASTs, perform simple desugaring
namer 2 resolve names, attach symbols to named trees
packageobjects 3 load package objects
typer 4 the meat and potatoes: type the trees
nativeinterop 5 prepare ASTs for Native interop
patmat 6 translate match expressions
superaccessors 7 add super accessors in traits and nested classes
extmethods 8 add extension methods for inline classes
pickler 9 serialize symbol tables
xsbt-api 10
xsbt-dependency 11
refchecks 12 reference/override checking, translate nested objects
uncurry 13 uncurry, translate function values to anonymous classes
tailcalls 14 replace tail calls by jumps
specialize 15 @specialized-driven class and method specialization
explicitouter 16 this refs to outer pointers
erasure 17 erase types, add interfaces for traits
posterasure 18 clean up erased inline classes
lazyvals 19 allocate bitmaps, translate lazy vals into lazified defs
lambdalift 20 move nested functions to top level
constructors 21 move field definitions into constructors
flatten 22 eliminate inner classes
mixin 23 mixin composition
nir 24
cleanup 25 platform-specific cleanups, generate reflective calls
delambdafy 26 remove lambdas
icode 27 generate portable intermediate code
inliner xx optimization: do inlining
inlinehandlers xx optimization: inline exception handlers
closelim xx optimization: eliminate uncalled closures
constopt xx optimization: optimize null and other constants
dce xx optimization: eliminate dead code
jvm 28 generate JVM bytecode
xsbt-analyzer 29
terminal 30 the last phase during a compilation run