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
|
/*
* Copyright 2016 WebAssembly Community Group participants
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Removes code from all functions but one, leaving a valid module with (mostly)
// just the code from that function, as best we can.
//
// This pass will run --remove-unused-module-elements automatically for you, in
// order to remove as many things as possible.
#include <cctype>
#include "pass.h"
#include "wasm-builder.h"
#include "wasm.h"
namespace wasm {
static void extract(PassRunner* runner, Module* module, Name name) {
std::cerr << "extracting " << name << "\n";
bool found = false;
for (auto& func : module->functions) {
if (func->name != name) {
// Turn it into an import.
func->module = "env";
func->base = func->name;
func->vars.clear();
func->body = nullptr;
} else {
found = true;
}
}
if (!found) {
Fatal() << "could not find the function to extract\n";
}
// Leave just one export, for the thing we want.
module->exports.clear();
module->updateMaps();
module->addExport(Builder::makeExport(name, name, ExternalKind::Function));
// Remove unneeded things.
PassRunner postRunner(runner);
postRunner.add("remove-unused-module-elements");
postRunner.run();
}
struct ExtractFunction : public Pass {
// Turns functions into imported functions.
bool addsEffects() override { return true; }
void run(Module* module) override {
Name name = getArgument(
"extract-function",
"ExtractFunction usage: wasm-opt --extract-function=FUNCTION_NAME");
extract(getPassRunner(), module, name);
}
};
struct ExtractFunctionIndex : public Pass {
// See above.
bool addsEffects() override { return true; }
void run(Module* module) override {
std::string index = getArgument("extract-function-index",
"ExtractFunctionIndex usage: wasm-opt "
"--extract-function-index=FUNCTION_INDEX");
for (char c : index) {
if (!std::isdigit(c)) {
Fatal() << "Expected numeric function index";
}
}
Index i = std::stoi(index);
if (i >= module->functions.size()) {
Fatal() << "Out of bounds function index " << i << "! (module has only "
<< module->functions.size() << " functions)";
}
// Assumes imports are at the beginning
Name name = module->functions[i]->name;
extract(getPassRunner(), module, name);
}
};
// declare passes
Pass* createExtractFunctionPass() { return new ExtractFunction(); }
Pass* createExtractFunctionIndexPass() { return new ExtractFunctionIndex(); }
} // namespace wasm
|
