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
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
|
//
// WebAssembly intepreter for asm2wasm output, in a js environment.
//
// Receives asm.js, generates a runnable module that executes the code in a WebAssembly
// interpreter. This is suitable as a polyfill for WebAssembly support in browsers.
//
#include <emscripten.h>
#include "asm2wasm.h"
#include "wasm-interpreter.h"
using namespace cashew;
using namespace wasm;
// global singletons
Asm2WasmBuilder* asm2wasm = nullptr;
ModuleInstance* instance = nullptr;
Module* module = nullptr;
// receives asm.js code, parses into wasm and returns an instance handle.
// this creates a module, an external interface, a builder, and a module instance,
// all of which are then the responsibility of the caller to free.
// note: this modifies the input.
extern "C" void EMSCRIPTEN_KEEPALIVE load_asm(char *input) {
assert(instance == nullptr); // singleton
// emcc --separate-asm modules look like
//
// Module["asm"] = (function(global, env, buffer) {
// ..
// });
//
// we need to clean that up.
size_t num = strlen(input);
assert(*input == 'M');
while (*input != 'f') {
input++;
num--;
}
char *end = input + num - 1;
while (*end != '}') {
*end = 0;
end--;
}
#if WASM_JS_DEBUG
std::cerr << "parsing...\n";
#endif
cashew::Parser<Ref, DotZeroValueBuilder> builder;
Ref asmjs = builder.parseToplevel(input);
module = new Module();
module->memory.initial = module->memory.max = 16*1024*1024; // TODO: receive this from emscripten
#if WASM_JS_DEBUG
std::cerr << "wasming...\n";
#endif
asm2wasm = new Asm2WasmBuilder(*module);
asm2wasm->processAsm(asmjs);
#if WASM_JS_DEBUG
std::cerr << "optimizing...\n";
#endif
asm2wasm->optimize();
#if WASM_JS_DEBUG
std::cerr << *module << '\n';
#endif
#if WASM_JS_DEBUG
std::cerr << "generating exports...\n";
#endif
EM_ASM({
Module['asmExports'] = {};
});
for (auto& pair : module->exportsMap) {
auto& curr = pair.second;
EM_ASM_({
var name = Pointer_stringify($0);
Module['asmExports'][name] = function() {
Module['tempArguments'] = Array.prototype.slice.call(arguments);
return Module['_call_from_js']($0);
};
}, curr->name.str);
}
#if WASM_JS_DEBUG
std::cerr << "creating instance...\n";
#endif
struct JSExternalInterface : ModuleInstance::ExternalInterface {
Literal callImport(Import *import, ModuleInstance::LiteralList& arguments) override {
#ifdef WASM_JS_DEBUG
std::cout << "calling import " << import->name.str << '\n';
#endif
EM_ASM({
Module['tempArguments'] = [];
});
for (auto& argument : arguments) {
if (argument.type == i32) {
EM_ASM_({ Module['tempArguments'].push($0) }, argument.geti32());
} else if (argument.type == f64) {
EM_ASM_({ Module['tempArguments'].push($0) }, argument.getf64());
} else {
abort();
}
}
double ret = EM_ASM_DOUBLE({
var mod = Pointer_stringify($0);
var base = Pointer_stringify($1);
var tempArguments = Module['tempArguments'];
Module['tempArguments'] = null;
var lookup = Module['lookupImport'](mod, base);
return lookup.apply(null, tempArguments);
}, import->module.str, import->base.str);
#ifdef WASM_JS_DEBUG
std::cout << "calling import returning " << ret << '\n';
#endif
switch (import->type.result) {
case none: return Literal(0);
case i32: return Literal((int32_t)ret);
case f32: return Literal((float)ret);
case f64: return Literal((double)ret);
default: abort();
}
}
Literal load(Load* load, size_t addr) override {
assert(load->align == load->bytes);
if (!isWasmTypeFloat(load->type)) {
if (load->bytes == 1) {
if (load->signed_) {
return Literal(EM_ASM_INT({ return Module['info'].parent['HEAP8'][$0] }, addr));
} else {
return Literal(EM_ASM_INT({ return Module['info'].parent['HEAPU8'][$0] }, addr));
}
} else if (load->bytes == 2) {
if (load->signed_) {
return Literal(EM_ASM_INT({ return Module['info'].parent['HEAP16'][$0 >> 1] }, addr));
} else {
return Literal(EM_ASM_INT({ return Module['info'].parent['HEAPU16'][$0 >> 1] }, addr));
}
} else if (load->bytes == 4) {
if (load->signed_) {
return Literal(EM_ASM_INT({ return Module['info'].parent['HEAP32'][$0 >> 2] }, addr));
} else {
return Literal(EM_ASM_INT({ return Module['info'].parent['HEAPU32'][$0 >> 2] }, addr));
}
}
abort();
} else {
if (load->bytes == 4) {
return Literal(EM_ASM_DOUBLE({ return Module['info'].parent['HEAPF32'][$0 >> 2] }, addr)); // XXX expands into double
} else if (load->bytes == 8) {
return Literal(EM_ASM_DOUBLE({ return Module['info'].parent['HEAPF64'][$0 >> 3] }, addr));
}
abort();
}
}
void store(Store* store, size_t addr, Literal value) override {
assert(store->align == store->bytes);
if (!isWasmTypeFloat(store->type)) {
if (store->bytes == 1) {
EM_ASM_INT({ Module['info'].parent['HEAP8'][$0] = $1 }, addr, value.geti32());
} else if (store->bytes == 2) {
EM_ASM_INT({ Module['info'].parent['HEAP16'][$0 >> 1] = $1 }, addr, value.geti32());
} else if (store->bytes == 4) {
EM_ASM_INT({ Module['info'].parent['HEAP32'][$0 >> 2] = $1 }, addr, value.geti32());
} else {
abort();
}
} else {
if (store->bytes == 4) {
EM_ASM_DOUBLE({ Module['info'].parent['HEAPF32'][$0 >> 2] = $1 }, addr, value.getf64());
} else if (store->bytes == 8) {
EM_ASM_DOUBLE({ Module['info'].parent['HEAPF64'][$0 >> 3] = $1 }, addr, value.getf64());
} else {
abort();
}
}
}
void growMemory(size_t oldSize, size_t newSize) override {
abort();
}
void trap() override {
EM_ASM({
abort("wasm trap!");
});
}
};
instance = new ModuleInstance(*module, new JSExternalInterface());
}
// Ready the provided imported globals, copying them to their mapped locations.
extern "C" void EMSCRIPTEN_KEEPALIVE load_mapped_globals() {
for (auto& pair : asm2wasm->mappedGlobals) {
auto name = pair.first;
auto& global = pair.second;
if (!global.import) continue; // non-imports are initialized to zero in the typed array anyhow, so nothing to do here
double value = EM_ASM_DOUBLE({ return Module['lookupImport'](Pointer_stringify($0), Pointer_stringify($1)) }, global.module.str, global.base.str);
unsigned address = global.address;
switch (global.type) {
case i32: EM_ASM_({ Module['info'].parent['HEAP32'][$0 >> 2] = $1 }, address, value); break;
case f32: EM_ASM_({ Module['info'].parent['HEAPF32'][$0 >> 2] = $1 }, address, value); break;
case f64: EM_ASM_({ Module['info'].parent['HEAPF64'][$0 >> 3] = $1 }, address, value); break;
default: abort();
}
}
}
// Does a call from js into an export of the module.
extern "C" double EMSCRIPTEN_KEEPALIVE call_from_js(const char *target) {
#ifdef WASM_JS_DEBUG
std::cout << "call_from_js " << target << '\n';
#endif
IString exportName(target);
IString functionName = instance->wasm.exportsMap[exportName]->value;
Function *function = instance->wasm.functionsMap[functionName];
assert(function);
size_t seen = EM_ASM_INT_V({ return Module['tempArguments'].length });
size_t actual = function->params.size();
ModuleInstance::LiteralList arguments;
for (size_t i = 0; i < actual; i++) {
WasmType type = function->params[i].type;
// add the parameter, with a zero value if JS did not provide it.
if (type == i32) {
arguments.push_back(Literal(i < seen ? EM_ASM_INT({ return Module['tempArguments'][$0] }, i) : (int32_t)0));
} else if (type == f32) {
arguments.push_back(Literal(i < seen ? (float)EM_ASM_DOUBLE({ return Module['tempArguments'][$0] }, i) : (float)0.0));
} else if (type == f64) {
arguments.push_back(Literal(i < seen ? EM_ASM_DOUBLE({ return Module['tempArguments'][$0] }, i) : (double)0.0));
} else {
abort();
}
}
Literal ret = instance->callExport(exportName, arguments);
#ifdef WASM_JS_DEBUG
std::cout << "call_from_js returning " << ret << '\n';
#endif
if (ret.type == none) return 0;
if (ret.type == i32) return ret.i32;
if (ret.type == f32) return ret.f32;
if (ret.type == f64) return ret.f64;
abort();
}
|
