fix replacement logic in collapse_vars (#2475)
This commit is contained in:
Alex Lam S.L
216
lib/compress.js
216
lib/compress.js
@@ -839,6 +839,113 @@ merge(Compressor.prototype, {
|
|||||||
var args;
|
var args;
|
||||||
var candidates = [];
|
var candidates = [];
|
||||||
var stat_index = statements.length;
|
var stat_index = statements.length;
|
||||||
|
var scanner = new TreeTransformer(function(node, descend) {
|
||||||
|
if (abort) return node;
|
||||||
|
// Skip nodes before `candidate` as quickly as possible
|
||||||
|
if (!hit) {
|
||||||
|
if (node === candidate) {
|
||||||
|
hit = true;
|
||||||
|
return node;
|
||||||
|
}
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
// Stop immediately if these node types are encountered
|
||||||
|
var parent = scanner.parent();
|
||||||
|
if (node instanceof AST_Assign && node.operator != "=" && lhs.equivalent_to(node.left)
|
||||||
|
|| node instanceof AST_Call && lhs instanceof AST_PropAccess && lhs.equivalent_to(node.expression)
|
||||||
|
|| node instanceof AST_Debugger
|
||||||
|
|| node instanceof AST_IterationStatement && !(node instanceof AST_For)
|
||||||
|
|| node instanceof AST_SymbolRef && !node.is_declared(compressor)
|
||||||
|
|| node instanceof AST_Try
|
||||||
|
|| node instanceof AST_With
|
||||||
|
|| parent instanceof AST_For && node !== parent.init) {
|
||||||
|
abort = true;
|
||||||
|
return node;
|
||||||
|
}
|
||||||
|
// Replace variable with assignment when found
|
||||||
|
if (can_replace
|
||||||
|
&& !(node instanceof AST_SymbolDeclaration)
|
||||||
|
&& lhs.equivalent_to(node)) {
|
||||||
|
if (is_lhs(node, parent)) {
|
||||||
|
if (candidate.multiple) replaced++;
|
||||||
|
return node;
|
||||||
|
}
|
||||||
|
CHANGED = abort = true;
|
||||||
|
replaced++;
|
||||||
|
compressor.info("Collapsing {name} [{file}:{line},{col}]", {
|
||||||
|
name: node.print_to_string(),
|
||||||
|
file: node.start.file,
|
||||||
|
line: node.start.line,
|
||||||
|
col: node.start.col
|
||||||
|
});
|
||||||
|
if (candidate instanceof AST_UnaryPostfix) {
|
||||||
|
return make_node(AST_UnaryPrefix, candidate, candidate);
|
||||||
|
}
|
||||||
|
if (candidate instanceof AST_VarDef) {
|
||||||
|
if (candidate.multiple) {
|
||||||
|
abort = false;
|
||||||
|
return node;
|
||||||
|
}
|
||||||
|
var def = candidate.name.definition();
|
||||||
|
if (def.references.length - def.replaced == 1 && !compressor.exposed(def)) {
|
||||||
|
def.replaced++;
|
||||||
|
return maintain_this_binding(parent, node, candidate.value);
|
||||||
|
}
|
||||||
|
return make_node(AST_Assign, candidate, {
|
||||||
|
operator: "=",
|
||||||
|
left: make_node(AST_SymbolRef, candidate.name, candidate.name),
|
||||||
|
right: candidate.value
|
||||||
|
});
|
||||||
|
}
|
||||||
|
candidate.write_only = false;
|
||||||
|
return candidate;
|
||||||
|
}
|
||||||
|
// These node types have child nodes that execute sequentially,
|
||||||
|
// but are otherwise not safe to scan into or beyond them.
|
||||||
|
var sym;
|
||||||
|
if (node instanceof AST_Call
|
||||||
|
|| node instanceof AST_Exit
|
||||||
|
|| node instanceof AST_PropAccess
|
||||||
|
&& (side_effects || node.expression.may_throw_on_access(compressor))
|
||||||
|
|| node instanceof AST_SymbolRef
|
||||||
|
&& (lvalues[node.name]
|
||||||
|
|| side_effects && !references_in_scope(node.definition()))
|
||||||
|
|| (sym = lhs_or_def(node))
|
||||||
|
&& (sym instanceof AST_PropAccess || sym.name in lvalues)
|
||||||
|
|| (side_effects || !replace_all)
|
||||||
|
&& (parent instanceof AST_Binary && lazy_op(parent.operator)
|
||||||
|
|| parent instanceof AST_Case
|
||||||
|
|| parent instanceof AST_Conditional
|
||||||
|
|| parent instanceof AST_If)) {
|
||||||
|
if (!(node instanceof AST_Scope)) descend(node, scanner);
|
||||||
|
abort = true;
|
||||||
|
return node;
|
||||||
|
}
|
||||||
|
// Skip (non-executed) functions and (leading) default case in switch statements
|
||||||
|
if (node instanceof AST_Default || node instanceof AST_Scope) return node;
|
||||||
|
});
|
||||||
|
var multi_replacer = new TreeTransformer(function(node) {
|
||||||
|
if (abort) return node;
|
||||||
|
// Skip nodes before `candidate` as quickly as possible
|
||||||
|
if (!hit) {
|
||||||
|
if (node === candidate) {
|
||||||
|
hit = true;
|
||||||
|
return node;
|
||||||
|
}
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
// Replace variable when found
|
||||||
|
if (node instanceof AST_SymbolRef
|
||||||
|
&& node.name == def.name) {
|
||||||
|
if (!--replaced) abort = true;
|
||||||
|
if (is_lhs(node, multi_replacer.parent())) return node;
|
||||||
|
def.replaced++;
|
||||||
|
value_def.replaced--;
|
||||||
|
return candidate.value;
|
||||||
|
}
|
||||||
|
// Skip (non-executed) functions and (leading) default case in switch statements
|
||||||
|
if (node instanceof AST_Default || node instanceof AST_Scope) return node;
|
||||||
|
});
|
||||||
while (--stat_index >= 0) {
|
while (--stat_index >= 0) {
|
||||||
// Treat parameters as collapsible in IIFE, i.e.
|
// Treat parameters as collapsible in IIFE, i.e.
|
||||||
// function(a, b){ ... }(x());
|
// function(a, b){ ... }(x());
|
||||||
@@ -862,121 +969,24 @@ merge(Compressor.prototype, {
|
|||||||
var side_effects = value_has_side_effects(candidate);
|
var side_effects = value_has_side_effects(candidate);
|
||||||
var hit = candidate.name instanceof AST_SymbolFunarg;
|
var hit = candidate.name instanceof AST_SymbolFunarg;
|
||||||
var abort = false, replaced = 0, can_replace = !args || !hit;
|
var abort = false, replaced = 0, can_replace = !args || !hit;
|
||||||
var tt = new TreeTransformer(function(node, descend) {
|
|
||||||
if (abort) return node;
|
|
||||||
// Skip nodes before `candidate` as quickly as possible
|
|
||||||
if (!hit) {
|
|
||||||
if (node === candidate) {
|
|
||||||
hit = true;
|
|
||||||
return node;
|
|
||||||
}
|
|
||||||
return;
|
|
||||||
}
|
|
||||||
// Stop immediately if these node types are encountered
|
|
||||||
var parent = tt.parent();
|
|
||||||
if (node instanceof AST_Assign && node.operator != "=" && lhs.equivalent_to(node.left)
|
|
||||||
|| node instanceof AST_Call && lhs instanceof AST_PropAccess && lhs.equivalent_to(node.expression)
|
|
||||||
|| node instanceof AST_Debugger
|
|
||||||
|| node instanceof AST_IterationStatement && !(node instanceof AST_For)
|
|
||||||
|| node instanceof AST_SymbolRef && !node.is_declared(compressor)
|
|
||||||
|| node instanceof AST_Try
|
|
||||||
|| node instanceof AST_With
|
|
||||||
|| parent instanceof AST_For && node !== parent.init) {
|
|
||||||
abort = true;
|
|
||||||
return node;
|
|
||||||
}
|
|
||||||
// Replace variable with assignment when found
|
|
||||||
if (can_replace
|
|
||||||
&& !(node instanceof AST_SymbolDeclaration)
|
|
||||||
&& !is_lhs(node, parent)
|
|
||||||
&& lhs.equivalent_to(node)) {
|
|
||||||
CHANGED = abort = true;
|
|
||||||
replaced++;
|
|
||||||
compressor.info("Collapsing {name} [{file}:{line},{col}]", {
|
|
||||||
name: node.print_to_string(),
|
|
||||||
file: node.start.file,
|
|
||||||
line: node.start.line,
|
|
||||||
col: node.start.col
|
|
||||||
});
|
|
||||||
if (candidate instanceof AST_UnaryPostfix) {
|
|
||||||
return make_node(AST_UnaryPrefix, candidate, candidate);
|
|
||||||
}
|
|
||||||
if (candidate instanceof AST_VarDef) {
|
|
||||||
if (candidate.multiple) {
|
|
||||||
abort = false;
|
|
||||||
return node;
|
|
||||||
}
|
|
||||||
var def = candidate.name.definition();
|
|
||||||
if (def.references.length - def.replaced == 1 && !compressor.exposed(def)) {
|
|
||||||
def.replaced++;
|
|
||||||
return maintain_this_binding(parent, node, candidate.value);
|
|
||||||
}
|
|
||||||
return make_node(AST_Assign, candidate, {
|
|
||||||
operator: "=",
|
|
||||||
left: make_node(AST_SymbolRef, candidate.name, candidate.name),
|
|
||||||
right: candidate.value
|
|
||||||
});
|
|
||||||
}
|
|
||||||
candidate.write_only = false;
|
|
||||||
return candidate;
|
|
||||||
}
|
|
||||||
// These node types have child nodes that execute sequentially,
|
|
||||||
// but are otherwise not safe to scan into or beyond them.
|
|
||||||
var sym;
|
|
||||||
if (node instanceof AST_Call
|
|
||||||
|| node instanceof AST_Exit
|
|
||||||
|| node instanceof AST_PropAccess
|
|
||||||
&& (side_effects || node.expression.may_throw_on_access(compressor))
|
|
||||||
|| node instanceof AST_SymbolRef
|
|
||||||
&& (lvalues[node.name]
|
|
||||||
|| side_effects && !references_in_scope(node.definition()))
|
|
||||||
|| (sym = lhs_or_def(node))
|
|
||||||
&& (sym instanceof AST_PropAccess || sym.name in lvalues)
|
|
||||||
|| (side_effects || !replace_all)
|
|
||||||
&& (parent instanceof AST_Binary && lazy_op(parent.operator)
|
|
||||||
|| parent instanceof AST_Case
|
|
||||||
|| parent instanceof AST_Conditional
|
|
||||||
|| parent instanceof AST_If)) {
|
|
||||||
if (!(node instanceof AST_Scope)) descend(node, tt);
|
|
||||||
abort = true;
|
|
||||||
return node;
|
|
||||||
}
|
|
||||||
// Skip (non-executed) functions and (leading) default case in switch statements
|
|
||||||
if (node instanceof AST_Default || node instanceof AST_Scope) return node;
|
|
||||||
});
|
|
||||||
if (!can_replace) {
|
if (!can_replace) {
|
||||||
for (var j = compressor.self().argnames.lastIndexOf(candidate.name) + 1; !abort && j < args.length; j++) {
|
for (var j = compressor.self().argnames.lastIndexOf(candidate.name) + 1; !abort && j < args.length; j++) {
|
||||||
args[j].transform(tt);
|
args[j].transform(scanner);
|
||||||
}
|
}
|
||||||
can_replace = true;
|
can_replace = true;
|
||||||
}
|
}
|
||||||
for (var i = stat_index; !abort && i < statements.length; i++) {
|
for (var i = stat_index; !abort && i < statements.length; i++) {
|
||||||
statements[i].transform(tt);
|
statements[i].transform(scanner);
|
||||||
}
|
}
|
||||||
if (candidate.multiple) {
|
if (candidate.multiple) {
|
||||||
var def = candidate.name.definition();
|
var def = candidate.name.definition();
|
||||||
if (abort && def.references.length > replaced) replaced = false;
|
if (abort && def.references.length - def.replaced > replaced) replaced = false;
|
||||||
else {
|
else {
|
||||||
abort = false;
|
abort = false;
|
||||||
hit = candidate.name instanceof AST_SymbolFunarg;
|
hit = candidate.name instanceof AST_SymbolFunarg;
|
||||||
var value_def = candidate.value.definition();
|
var value_def = candidate.value.definition();
|
||||||
for (var i = stat_index; !abort && i < statements.length; i++) {
|
for (var i = stat_index; !abort && i < statements.length; i++) {
|
||||||
statements[i].transform(new TreeTransformer(function(node) {
|
statements[i].transform(multi_replacer);
|
||||||
if (abort) return node;
|
|
||||||
if (!hit) {
|
|
||||||
if (node === candidate) {
|
|
||||||
hit = true;
|
|
||||||
return node;
|
|
||||||
}
|
|
||||||
return;
|
|
||||||
}
|
|
||||||
if (node instanceof AST_SymbolRef && node.name == def.name) {
|
|
||||||
def.replaced++;
|
|
||||||
value_def.replaced--;
|
|
||||||
if (!--replaced) abort = true;
|
|
||||||
return candidate.value;
|
|
||||||
}
|
|
||||||
}));
|
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
@@ -2549,12 +2559,14 @@ merge(Compressor.prototype, {
|
|||||||
var def = tail.pop();
|
var def = tail.pop();
|
||||||
compressor.warn("Converting duplicated definition of variable {name} to assignment [{file}:{line},{col}]", template(def.name));
|
compressor.warn("Converting duplicated definition of variable {name} to assignment [{file}:{line},{col}]", template(def.name));
|
||||||
remove(var_defs, def);
|
remove(var_defs, def);
|
||||||
drop_decl(def.name.definition());
|
|
||||||
side_effects.unshift(make_node(AST_Assign, def, {
|
side_effects.unshift(make_node(AST_Assign, def, {
|
||||||
operator: "=",
|
operator: "=",
|
||||||
left: make_node(AST_SymbolRef, def.name, def.name),
|
left: make_node(AST_SymbolRef, def.name, def.name),
|
||||||
right: def.value
|
right: def.value
|
||||||
}));
|
}));
|
||||||
|
def = def.name.definition();
|
||||||
|
drop_decl(def);
|
||||||
|
def.replaced--;
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
if (head.length > 0 || tail.length > 0) {
|
if (head.length > 0 || tail.length > 0) {
|
||||||
|
|||||||
@@ -3518,3 +3518,63 @@ issue_2436_12: {
|
|||||||
}
|
}
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
|
issue_2436_13: {
|
||||||
|
options = {
|
||||||
|
collapse_vars: true,
|
||||||
|
reduce_vars: true,
|
||||||
|
unused: true,
|
||||||
|
}
|
||||||
|
input: {
|
||||||
|
var a = "PASS";
|
||||||
|
(function() {
|
||||||
|
function f(b) {
|
||||||
|
(function g(b) {
|
||||||
|
var b = b && (b.null = "FAIL");
|
||||||
|
})(a);
|
||||||
|
}
|
||||||
|
f();
|
||||||
|
})();
|
||||||
|
console.log(a);
|
||||||
|
}
|
||||||
|
expect: {
|
||||||
|
var a = "PASS";
|
||||||
|
(function() {
|
||||||
|
(function(b) {
|
||||||
|
(function(b) {
|
||||||
|
a && (a.null = "FAIL");
|
||||||
|
})();
|
||||||
|
})();
|
||||||
|
})();
|
||||||
|
console.log(a);
|
||||||
|
}
|
||||||
|
expect_stdout: "PASS"
|
||||||
|
}
|
||||||
|
|
||||||
|
issue_2436_14: {
|
||||||
|
options = {
|
||||||
|
collapse_vars: true,
|
||||||
|
reduce_vars: true,
|
||||||
|
unused: true,
|
||||||
|
}
|
||||||
|
input: {
|
||||||
|
var a = "PASS";
|
||||||
|
var b = {};
|
||||||
|
(function() {
|
||||||
|
var c = a;
|
||||||
|
c && function(c, d) {
|
||||||
|
console.log(c, d);
|
||||||
|
}(b, c);
|
||||||
|
})();
|
||||||
|
}
|
||||||
|
expect: {
|
||||||
|
var a = "PASS";
|
||||||
|
var b = {};
|
||||||
|
(function() {
|
||||||
|
a && function(c, d) {
|
||||||
|
console.log(c, d);
|
||||||
|
}(b, a);
|
||||||
|
})();
|
||||||
|
}
|
||||||
|
expect_stdout: true
|
||||||
|
}
|
||||||
|
|||||||
Reference in New Issue
Block a user