Revert "remove support for const (#1910)"

This reverts commit c391576d52.
This commit is contained in:
alexlamsl
2017-05-15 18:38:16 +08:00
parent ff526be61d
commit cd6e849555
20 changed files with 591 additions and 36 deletions

View File

@@ -486,7 +486,8 @@ merge(Compressor.prototype, {
if (def.fixed === false) return false;
if (def.fixed != null && (!value || def.references.length > 0)) return false;
return !def.orig.some(function(sym) {
return sym instanceof AST_SymbolDefun
return sym instanceof AST_SymbolConst
|| sym instanceof AST_SymbolDefun
|| sym instanceof AST_SymbolLambda;
});
}
@@ -503,7 +504,7 @@ merge(Compressor.prototype, {
def.escaped = false;
if (def.scope.uses_eval) {
def.fixed = false;
} else if (!def.global || compressor.toplevel(def)) {
} else if (!def.global || def.orig[0] instanceof AST_SymbolConst || compressor.toplevel(def)) {
def.fixed = undefined;
} else {
def.fixed = false;
@@ -537,6 +538,14 @@ merge(Compressor.prototype, {
return lhs instanceof AST_SymbolRef && lhs.definition().orig[0] instanceof AST_SymbolLambda;
}
function is_reference_const(ref) {
if (!(ref instanceof AST_SymbolRef)) return false;
var orig = ref.definition().orig;
for (var i = orig.length; --i >= 0;) {
if (orig[i] instanceof AST_SymbolConst) return true;
}
}
function find_variable(compressor, name) {
var scope, i = 0;
while (scope = compressor.parent(i++)) {
@@ -802,7 +811,8 @@ merge(Compressor.prototype, {
return make_node(AST_SymbolRef, expr.name, expr.name);
}
} else {
return expr[expr instanceof AST_Assign ? "left" : "expression"];
var lhs = expr[expr instanceof AST_Assign ? "left" : "expression"];
return !is_reference_const(lhs) && lhs;
}
}
@@ -1990,6 +2000,7 @@ merge(Compressor.prototype, {
&& node instanceof AST_Assign
&& node.operator == "="
&& node.left instanceof AST_SymbolRef
&& !is_reference_const(node.left)
&& scope === self) {
node.right.walk(tw);
return true;
@@ -3196,7 +3207,7 @@ merge(Compressor.prototype, {
&& (left.operator == "++" || left.operator == "--")) {
left = left.expression;
} else left = null;
if (!left || is_lhs_read_only(left)) {
if (!left || is_lhs_read_only(left) || is_reference_const(left)) {
expressions[++i] = cdr;
continue;
}