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
use crate::std::string::String;
use crate::std::vec::Vec;
use crate::std::borrow::ToOwned;
use tetsy_wasm::{elements, builder};
use byteorder::{LittleEndian, ByteOrder};
use crate::optimizer::{import_section, export_section};
type Insertion = (usize, u32, u32, String);
pub fn update_call_index(instructions: &mut elements::Instructions, original_imports: usize, inserts: &[Insertion]) {
use tetsy_wasm::elements::Instruction::*;
for instruction in instructions.elements_mut().iter_mut() {
if let Call(call_index) = instruction {
if let Some(pos) = inserts.iter().position(|x| x.1 == *call_index) {
*call_index = (original_imports + pos) as u32;
} else if *call_index as usize > original_imports {
*call_index += inserts.len() as u32;
}
}
}
}
pub fn memory_section(module: &mut elements::Module) -> Option<&mut elements::MemorySection> {
for section in module.sections_mut() {
if let elements::Section::Memory(sect) = section {
return Some(sect);
}
}
None
}
pub fn externalize_mem(mut module: elements::Module, adjust_pages: Option<u32>, max_pages: u32) -> elements::Module {
let mut entry = memory_section(&mut module)
.expect("Memory section to exist")
.entries_mut()
.pop()
.expect("Own memory entry to exist in memory section");
if let Some(adjust_pages) = adjust_pages {
assert!(adjust_pages <= max_pages);
entry = elements::MemoryType::new(adjust_pages, Some(max_pages));
}
if entry.limits().maximum().is_none() {
entry = elements::MemoryType::new(entry.limits().initial(), Some(max_pages));
}
let mut builder = builder::from_module(module);
builder.push_import(
elements::ImportEntry::new(
"env".to_owned(),
"memory".to_owned(),
elements::External::Memory(entry),
)
);
builder.build()
}
fn foreach_public_func_name<F>(mut module: elements::Module, f: F) -> elements::Module
where F: Fn(&mut String)
{
if let Some(section) = import_section(&mut module) {
for entry in section.entries_mut() {
if let elements::External::Function(_) = *entry.external() {
f(entry.field_mut())
}
}
}
if let Some(section) = export_section(&mut module) {
for entry in section.entries_mut() {
if let elements::Internal::Function(_) = *entry.internal() {
f(entry.field_mut())
}
}
}
module
}
pub fn underscore_funcs(module: elements::Module) -> elements::Module {
foreach_public_func_name(module, |n| n.insert(0, '_'))
}
pub fn ununderscore_funcs(module: elements::Module) -> elements::Module {
foreach_public_func_name(module, |n| { n.remove(0); })
}
pub fn shrink_unknown_stack(
mut module: elements::Module,
shrink_amount: u32,
) -> (elements::Module, u32) {
let mut new_stack_top = 0;
for section in module.sections_mut() {
match section {
elements::Section::Data(data_section) => {
for data_segment in data_section.entries_mut() {
if *data_segment
.offset()
.as_ref()
.expect("tetsy-wasm is compiled without bulk-memory operations")
.code() == [elements::Instruction::I32Const(4), elements::Instruction::End]
{
assert_eq!(data_segment.value().len(), 4);
let current_val = LittleEndian::read_u32(data_segment.value());
let new_val = current_val - shrink_amount;
LittleEndian::write_u32(data_segment.value_mut(), new_val);
new_stack_top = new_val;
}
}
},
_ => continue
}
}
(module, new_stack_top)
}
pub fn externalize(
module: elements::Module,
replaced_funcs: Vec<&str>,
) -> elements::Module {
let import_funcs_total = module
.import_section().expect("Import section to exist")
.entries()
.iter()
.filter(|e| matches!(e.external(), &elements::External::Function(_)))
.count();
let mut replaces: Vec<Insertion> = replaced_funcs
.into_iter()
.filter_map(|f| {
let export = module
.export_section().expect("Export section to exist")
.entries().iter().enumerate()
.find(|&(_, entry)| entry.field() == f)
.expect("All functions of interest to exist");
if let elements::Internal::Function(func_idx) = *export.1.internal() {
let type_ref = module
.function_section().expect("Functions section to exist")
.entries()[func_idx as usize - import_funcs_total]
.type_ref();
Some((export.0, func_idx, type_ref, export.1.field().to_owned()))
} else {
None
}
})
.collect();
replaces.sort_by_key(|e| e.0);
let mut mbuilder = builder::from_module(module);
for (_, _, type_ref, field) in replaces.iter() {
mbuilder.push_import(
builder::import()
.module("env")
.field(field)
.external().func(*type_ref)
.build()
);
}
let mut module = mbuilder.build();
for section in module.sections_mut() {
match section {
elements::Section::Code(code_section) => {
for func_body in code_section.bodies_mut() {
update_call_index(func_body.code_mut(), import_funcs_total, &replaces);
}
},
elements::Section::Export(export_section) => {
for export in export_section.entries_mut() {
if let elements::Internal::Function(func_index) = export.internal_mut() {
if *func_index >= import_funcs_total as u32 { *func_index += replaces.len() as u32; }
}
}
},
elements::Section::Element(elements_section) => {
for segment in elements_section.entries_mut() {
for func_index in segment.members_mut() {
if *func_index >= import_funcs_total as u32 { *func_index += replaces.len() as u32; }
}
}
},
_ => { }
}
}
module
}