1- use std:: { collections:: HashSet , hash:: BuildHasherDefault } ;
2-
3- use indexmap:: IndexSet ;
4- use rustc_hash:: { FxHashMap , FxHashSet , FxHasher } ;
5- use swc_atoms:: { js_word, JsWord } ;
6- use swc_common:: {
7- collections:: { AHashMap , AHashSet } ,
8- SyntaxContext ,
9- } ;
1+ use swc_atoms:: js_word;
2+ use swc_common:: { collections:: AHashMap , SyntaxContext } ;
103use swc_ecma_ast:: * ;
114use swc_ecma_utils:: { find_pat_ids, IsEmpty , StmtExt } ;
125use swc_ecma_visit:: { noop_visit_type, Visit , VisitWith } ;
136use swc_timer:: timer;
147
15- use self :: {
16- ctx:: Ctx ,
17- storage:: { Storage , * } ,
18- } ;
8+ pub use self :: ctx:: Ctx ;
9+ use self :: storage:: { Storage , * } ;
1910use crate :: {
20- alias:: { collect_infects_from, Access , AccessKind , AliasConfig } ,
11+ alias:: { collect_infects_from, AliasConfig } ,
2112 marks:: Marks ,
2213 util:: can_end_conditionally,
2314} ;
2415
2516mod ctx;
26- pub ( crate ) mod storage;
27-
28- #[ derive( Debug , Default ) ]
29- pub ( crate ) struct ModuleInfo {
30- /// Imported identifiers which should be treated as a black box.
31- ///
32- /// Imports from `@swc/helpers` are excluded as helpers are not modified by
33- /// accessing/calling other modules.
34- pub blackbox_imports : AHashSet < Id > ,
35- }
36-
37- pub ( crate ) fn analyze < N > ( n : & N , _module_info : & ModuleInfo , marks : Option < Marks > ) -> ProgramData
38- where
39- N : VisitWith < UsageAnalyzer > ,
40- {
41- analyze_with_storage :: < ProgramData , _ > ( n, marks)
42- }
17+ pub mod storage;
4318
4419/// TODO: Track assignments to variables via `arguments`.
4520/// TODO: Scope-local. (Including block)
4621///
4722/// If `marks` is [None], markers are ignored.
48- pub ( crate ) fn analyze_with_storage < S , N > ( n : & N , marks : Option < Marks > ) -> S
23+ pub fn analyze_with_storage < S , N > ( n : & N , marks : Option < Marks > ) -> S
4924where
5025 S : Storage ,
5126 N : VisitWith < UsageAnalyzer < S > > ,
@@ -68,292 +43,21 @@ where
6843 v. data
6944}
7045
71- #[ derive( Debug , Clone ) ]
72- pub ( crate ) struct VarUsageInfo {
73- pub inline_prevented : bool ,
74-
75- /// The number of direct reference to this identifier.
76- pub ref_count : u32 ,
77-
78- /// `true` if a variable is conditionally initialized.
79- pub cond_init : bool ,
80-
81- /// `false` if it's only used.
82- pub declared : bool ,
83- pub declared_count : u32 ,
84-
85- /// `true` if the enclosing function defines this variable as a parameter.
86- pub declared_as_fn_param : bool ,
87-
88- pub declared_as_fn_decl : bool ,
89- pub declared_as_fn_expr : bool ,
90-
91- pub assign_count : u32 ,
92- pub mutation_by_call_count : u32 ,
93-
94- /// The number of direct and indirect reference to this identifier.
95- /// ## Things to note
96- ///
97- /// - Update is counted as usage, but assign is not
98- pub usage_count : u32 ,
99-
100- /// The variable itself is modified.
101- reassigned_with_assignment : bool ,
102- reassigned_with_var_decl : bool ,
103- /// The variable itself or a property of it is modified.
104- pub mutated : bool ,
105-
106- pub has_property_access : bool ,
107- pub has_property_mutation : bool ,
108-
109- pub exported : bool ,
110- /// True if used **above** the declaration or in init. (Not eval order).
111- pub used_above_decl : bool ,
112- /// `true` if it's declared by function parameters or variables declared in
113- /// a closest function and used only within it and not used by child
114- /// functions.
115- pub is_fn_local : bool ,
116-
117- pub executed_multiple_time : bool ,
118- pub used_in_cond : bool ,
119-
120- pub var_kind : Option < VarDeclKind > ,
121- pub var_initialized : bool ,
122-
123- pub declared_as_catch_param : bool ,
124-
125- pub no_side_effect_for_member_access : bool ,
126-
127- pub callee_count : u32 ,
128-
129- pub used_as_arg : bool ,
130-
131- pub indexed_with_dynamic_key : bool ,
132-
133- pub pure_fn : bool ,
134-
135- /// `infects_to`. This should be renamed, but it will be done with another
136- /// PR. (because it's hard to review)
137- infects : Vec < Access > ,
138-
139- pub used_in_non_child_fn : bool ,
140- /// Only **string** properties.
141- pub accessed_props : Box < AHashMap < JsWord , u32 > > ,
142-
143- pub used_recursively : bool ,
144- }
145-
146- impl Default for VarUsageInfo {
147- fn default ( ) -> Self {
148- Self {
149- inline_prevented : Default :: default ( ) ,
150- ref_count : Default :: default ( ) ,
151- cond_init : Default :: default ( ) ,
152- declared : Default :: default ( ) ,
153- declared_count : Default :: default ( ) ,
154- declared_as_fn_param : Default :: default ( ) ,
155- declared_as_fn_decl : Default :: default ( ) ,
156- declared_as_fn_expr : Default :: default ( ) ,
157- assign_count : Default :: default ( ) ,
158- mutation_by_call_count : Default :: default ( ) ,
159- usage_count : Default :: default ( ) ,
160- reassigned_with_assignment : Default :: default ( ) ,
161- reassigned_with_var_decl : Default :: default ( ) ,
162- mutated : Default :: default ( ) ,
163- has_property_access : Default :: default ( ) ,
164- has_property_mutation : Default :: default ( ) ,
165- exported : Default :: default ( ) ,
166- used_above_decl : Default :: default ( ) ,
167- is_fn_local : true ,
168- executed_multiple_time : Default :: default ( ) ,
169- used_in_cond : Default :: default ( ) ,
170- var_kind : Default :: default ( ) ,
171- var_initialized : Default :: default ( ) ,
172- declared_as_catch_param : Default :: default ( ) ,
173- no_side_effect_for_member_access : Default :: default ( ) ,
174- callee_count : Default :: default ( ) ,
175- used_as_arg : Default :: default ( ) ,
176- indexed_with_dynamic_key : Default :: default ( ) ,
177- pure_fn : Default :: default ( ) ,
178- infects : Default :: default ( ) ,
179- used_in_non_child_fn : Default :: default ( ) ,
180- accessed_props : Default :: default ( ) ,
181- used_recursively : Default :: default ( ) ,
182- }
183- }
184- }
185-
186- impl VarUsageInfo {
187- pub fn is_mutated_only_by_one_call ( & self ) -> bool {
188- self . assign_count == 0 && self . mutation_by_call_count == 1
189- }
190-
191- pub fn is_infected ( & self ) -> bool {
192- !self . infects . is_empty ( )
193- }
194-
195- pub fn reassigned ( & self ) -> bool {
196- self . reassigned_with_assignment
197- || self . reassigned_with_var_decl
198- || ( u32:: from ( self . var_initialized )
199- + u32:: from ( self . declared_as_catch_param )
200- + u32:: from ( self . declared_as_fn_param )
201- + self . assign_count )
202- > 1
203- }
204-
205- pub fn can_inline_var ( & self ) -> bool {
206- !self . mutated
207- || ( self . assign_count == 0 && !self . reassigned ( ) && !self . has_property_mutation )
208- }
209-
210- pub fn can_inline_fn_once ( & self ) -> bool {
211- self . callee_count > 0
212- || !self . executed_multiple_time && ( self . is_fn_local || !self . used_in_non_child_fn )
213- }
214- }
215-
21646#[ derive( Debug , Clone , Copy , PartialEq , Eq ) ]
217- pub ( crate ) enum ScopeKind {
47+ pub enum ScopeKind {
21848 Fn ,
21949 Block ,
22050}
22151
222- #[ derive( Debug , Default , Clone ) ]
223- pub ( crate ) struct ScopeData {
224- pub has_with_stmt : bool ,
225- pub has_eval_call : bool ,
226- pub used_arguments : bool ,
227- }
228-
22952#[ derive( Debug , Clone ) ]
23053enum RecursiveUsage {
23154 FnOrClass ,
23255 Var { can_ignore : bool } ,
23356}
23457
235- /// Analyzed info of a whole program we are working on.
236- #[ derive( Debug , Default ) ]
237- pub ( crate ) struct ProgramData {
238- pub vars : FxHashMap < Id , VarUsageInfo > ,
239-
240- pub top : ScopeData ,
241-
242- pub scopes : FxHashMap < SyntaxContext , ScopeData > ,
243-
244- initialized_vars : IndexSet < Id , ahash:: RandomState > ,
245- }
246-
247- impl ProgramData {
248- pub ( crate ) fn expand_infected (
249- & self ,
250- module_info : & ModuleInfo ,
251- ids : FxHashSet < Access > ,
252- max_num : usize ,
253- ) -> Result < FxHashSet < Access > , ( ) > {
254- let init =
255- HashSet :: with_capacity_and_hasher ( max_num, BuildHasherDefault :: < FxHasher > :: default ( ) ) ;
256- ids. into_iter ( ) . try_fold ( init, |mut res, id| {
257- let mut ids = Vec :: with_capacity ( max_num) ;
258- ids. push ( id) ;
259- let mut ranges = vec ! [ 0 ..1usize ] ;
260- loop {
261- let range = ranges. remove ( 0 ) ;
262- for index in range {
263- let iid = ids. get ( index) . unwrap ( ) ;
264-
265- // Abort on imported variables, because we can't analyze them
266- if module_info. blackbox_imports . contains ( & iid. 0 ) {
267- return Err ( ( ) ) ;
268- }
269- if !res. insert ( iid. clone ( ) ) {
270- continue ;
271- }
272- if res. len ( ) >= max_num {
273- return Err ( ( ) ) ;
274- }
275- if let Some ( info) = self . vars . get ( & iid. 0 ) {
276- let infects = & info. infects ;
277- if !infects. is_empty ( ) {
278- let old_len = ids. len ( ) ;
279-
280- // This is not a call, so effects from call can be skipped
281- let can_skip_non_call = matches ! ( iid. 1 , AccessKind :: Reference )
282- || ( info. declared_count == 1
283- && info. declared_as_fn_decl
284- && !info. reassigned ( ) ) ;
285-
286- if can_skip_non_call {
287- ids. extend (
288- infects
289- . iter ( )
290- . filter ( |( _, kind) | * kind != AccessKind :: Call )
291- . cloned ( ) ,
292- ) ;
293- } else {
294- ids. extend_from_slice ( infects. as_slice ( ) ) ;
295- }
296- let new_len = ids. len ( ) ;
297- ranges. push ( old_len..new_len) ;
298- }
299- }
300- }
301- if ranges. is_empty ( ) {
302- break ;
303- }
304- }
305- Ok ( res)
306- } )
307- }
308-
309- pub ( crate ) fn contains_unresolved ( & self , e : & Expr ) -> bool {
310- match e {
311- Expr :: Ident ( i) => {
312- if let Some ( v) = self . vars . get ( & i. to_id ( ) ) {
313- return !v. declared ;
314- }
315-
316- true
317- }
318-
319- Expr :: Member ( MemberExpr { obj, prop, .. } ) => {
320- if self . contains_unresolved ( obj) {
321- return true ;
322- }
323-
324- if let MemberProp :: Computed ( prop) = prop {
325- if self . contains_unresolved ( & prop. expr ) {
326- return true ;
327- }
328- }
329-
330- false
331- }
332-
333- Expr :: Call ( CallExpr {
334- callee : Callee :: Expr ( callee) ,
335- args,
336- ..
337- } ) => {
338- if self . contains_unresolved ( callee) {
339- return true ;
340- }
341-
342- if args. iter ( ) . any ( |arg| self . contains_unresolved ( & arg. expr ) ) {
343- return true ;
344- }
345-
346- false
347- }
348-
349- _ => false ,
350- }
351- }
352- }
353-
35458/// This assumes there are no two variable with same name and same span hygiene.
35559#[ derive( Debug ) ]
356- pub ( crate ) struct UsageAnalyzer < S = ProgramData >
60+ pub struct UsageAnalyzer < S >
35761where
35862 S : Storage ,
35963{
@@ -1504,10 +1208,8 @@ where
15041208 } = e
15051209 {
15061210 // TODO: merge with may_have_side_effects
1507- let can_ignore = match & * * init {
1508- Expr :: Call ( call) if call. span . has_mark ( marks. pure ) => true ,
1509- _ => false ,
1510- } ;
1211+ let can_ignore =
1212+ matches ! ( & * * init, Expr :: Call ( call) if call. span. has_mark( marks. pure) ) ;
15111213 let id = id. to_id ( ) ;
15121214 self . used_recursively
15131215 . insert ( id. clone ( ) , RecursiveUsage :: Var { can_ignore } ) ;
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