1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
use core:lang;
use core:asm;
use lang:asm;
use lang:bs:macro;
class CppDtorDecl extends CppDecl {
FnBody? body;
init(SStr name, FnBody? body) {
init(name) {
body = body;
}
if (body)
body.stmt.pos.end++;
}
void create(NameSet inside) : override {
unless (body)
return;
if (name.v != inside.name)
throw SyntaxError(name.pos, "The destructor should be named ~${inside.name}.");
CppDtor fn(cppScope(inside), name.pos, inside, body);
if (visibility)
fn.visibility = visibility;
inside.add(fn);
inside.add(wrapCppDtor(fn));
}
}
// Find the C++ dtor for a type.
Function cppDtor(Type type) on Compiler {
if (fn = type.find(SimplePart("__cpp_destroy", [thisPtr(type)]), cppScope(type)) as Function) {
fn;
} else {
named{cppGenericDtor<unsafe:RawPtr>};
}
}
// Generic destructor for C++ types.
void cppGenericDtor(unsafe:RawPtr obj) {
// print("Destroying an object ${obj}");
Nat filled = obj.readFilled;
filled &= ~AllocFlags:sizeMask.v;
obj.writeFilled(filled);
}
// Wrap a previously created C++ destructor to make it suitable to call from our array allocations.
// Supports arrays as well!
Function wrapCppDtor(Function dtor) on Compiler {
Listing l;
Var param = l.createParam(ptrDesc);
Var current = l.createVar(l.root, sPtr);
Var target = l.createVar(l.root, sPtr);
Label again = l.label();
Label start = l.label();
// Size of each element.
Nat elemSize = dtor.params[0].asRef(false).size.current;
l << prolog();
// Initialize the loop.
l << mov(ptrA, param);
l << mov(current, ptrConst(0));
l << mov(target, ptrRel(ptrA, Offset(sPtr)));
l << and(target, ptrConst(AllocFlags:sizeMask.v));
l << jmp(start);
l << again;
// Compute offset.
l << mov(ptrB, current);
l << mul(ptrB, ptrConst(elemSize));
l << add(ptrB, ptrConst(sPtr * 2));
// Call the original destructor.
l << mov(ptrA, param);
l << add(ptrA, ptrB);
l << ucast(ecx, ptrB);
l << fnParam(ptrDesc, ptrA);
l << fnParam(intDesc, ecx);
l << fnCall(dtor.ref, true);
// Next element.
l << add(current, ptrConst(1));
// Try again.
l << start;
l << cmp(current, target);
l << jmp(again, CondFlag:ifBelow);
// Mark it as 'empty' by clearing the size (and keeping other flags).
l << mov(ptrA, param);
l << and(ptrRel(ptrA, Offset(sPtr)), ptrConst(~AllocFlags:sizeMask.v));
l << fnRet();
Function f(Value(), "__cpp_destroy", [dtor.params[0]]);
f.setCode(DynamicCode(l));
f;
}
class CppDtor extends CppFunction {
private FnBody? body;
init(Scope scope, SrcPos pos, NameSet inside, FnBody? body) {
Value[] fTypes;
SStr[] fNames;
if (inside as Type) {
fTypes << Value(thisPtr(inside));
fNames << SStr("this", pos);
// We also need a hidden 'offset' ptr, that allows us to reconstruct a Ptr<> object.
fTypes << Value(named{Nat});
fNames << SStr("offset", pos);
}
init(scope, pos, Value(), "__destroy", fTypes) {
body = body;
}
setCode(LazyCode(&this.code));
}
// Generate code on demand.
private CodeGen code() {
FnRoot root = if (body) {
FnRoot fn(body.stmt.pos, this);
body.stmt.transform(fn);
fn;
} else {
FnRoot(pos, this);
};
CodeGen gen(runOn, isMember, result);
gen.l << prolog();
if (!root.code(gen))
throw SyntaxError(pos, "This implementation does not support using 'return' in the destructor!");
// Destroy all member variables.
if (type = params[0].type) {
for (var in type.variables) {
if (varType = var.type.type) {
destroyVar(gen, varType, var.offset, root);
}
}
if (s = type.super) {
// Destroy any super-classes.
destroyVar(gen, s, OffsetRef(), root);
}
}
gen.l << fnRet();
// print("Generated code for ${params[0]}:\n${gen.l}");
gen;
}
// Destroy a variable.
private void destroyVar(CodeGen gen, Type type, OffsetRef offset, FnRoot root) {
// C++ dtor.
if (dtor = type.find(SimplePart("__destroy", [thisPtr(type), Value(named{Nat})]), scope) as Function) {
gen.l << mov(ptrA, root.thisPtr);
gen.l << add(ptrA, ptrConst(offset));
gen.l << mov(ecx, root.thisOffset);
gen.l << add(ecx, intConst(offset));
gen.l << fnParam(ptrDesc, ptrA);
gen.l << fnParam(intDesc, ecx);
gen.l << fnCall(dtor.ref, true);
return;
}
// Regular dtor.
if (dtor = type.find(SimplePart("__destroy", [thisPtr(type)]), scope) as Function) {
gen.l << mov(ptrA, root.thisPtr);
gen.l << add(ptrA, ptrConst(offset));
gen.l << fnParam(ptrDesc, ptrA);
gen.l << fnCall(dtor.ref, true);
return;
}
}
}
|
