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
|
use rustc_index::vec::{Idx, IndexVec};
use rustc_middle::mir::*;
use rustc_middle::ty::Ty;
use rustc_span::Span;
/// This struct represents a patch to MIR, which can add
/// new statements and basic blocks and patch over block
/// terminators.
pub struct MirPatch<'tcx> {
patch_map: IndexVec<BasicBlock, Option<TerminatorKind<'tcx>>>,
new_blocks: Vec<BasicBlockData<'tcx>>,
new_statements: Vec<(Location, StatementKind<'tcx>)>,
new_locals: Vec<LocalDecl<'tcx>>,
resume_block: Option<BasicBlock>,
body_span: Span,
next_local: usize,
}
impl<'tcx> MirPatch<'tcx> {
pub fn new(body: &Body<'tcx>) -> Self {
let mut result = MirPatch {
patch_map: IndexVec::from_elem(None, &body.basic_blocks),
new_blocks: vec![],
new_statements: vec![],
new_locals: vec![],
next_local: body.local_decls.len(),
resume_block: None,
body_span: body.span,
};
// Check if we already have a resume block
for (bb, block) in body.basic_blocks.iter_enumerated() {
if let TerminatorKind::Resume = block.terminator().kind && block.statements.is_empty() {
result.resume_block = Some(bb);
break;
}
}
result
}
pub fn resume_block(&mut self) -> BasicBlock {
if let Some(bb) = self.resume_block {
return bb;
}
let bb = self.new_block(BasicBlockData {
statements: vec![],
terminator: Some(Terminator {
source_info: SourceInfo::outermost(self.body_span),
kind: TerminatorKind::Resume,
}),
is_cleanup: true,
});
self.resume_block = Some(bb);
bb
}
pub fn is_patched(&self, bb: BasicBlock) -> bool {
self.patch_map[bb].is_some()
}
pub fn terminator_loc(&self, body: &Body<'tcx>, bb: BasicBlock) -> Location {
let offset = match bb.index().checked_sub(body.basic_blocks.len()) {
Some(index) => self.new_blocks[index].statements.len(),
None => body[bb].statements.len(),
};
Location { block: bb, statement_index: offset }
}
pub fn new_internal_with_info(
&mut self,
ty: Ty<'tcx>,
span: Span,
local_info: Option<Box<LocalInfo<'tcx>>>,
) -> Local {
let index = self.next_local;
self.next_local += 1;
let mut new_decl = LocalDecl::new(ty, span).internal();
new_decl.local_info = local_info;
self.new_locals.push(new_decl);
Local::new(index as usize)
}
pub fn new_temp(&mut self, ty: Ty<'tcx>, span: Span) -> Local {
let index = self.next_local;
self.next_local += 1;
self.new_locals.push(LocalDecl::new(ty, span));
Local::new(index as usize)
}
pub fn new_internal(&mut self, ty: Ty<'tcx>, span: Span) -> Local {
let index = self.next_local;
self.next_local += 1;
self.new_locals.push(LocalDecl::new(ty, span).internal());
Local::new(index as usize)
}
pub fn new_block(&mut self, data: BasicBlockData<'tcx>) -> BasicBlock {
let block = BasicBlock::new(self.patch_map.len());
debug!("MirPatch: new_block: {:?}: {:?}", block, data);
self.new_blocks.push(data);
self.patch_map.push(None);
block
}
pub fn patch_terminator(&mut self, block: BasicBlock, new: TerminatorKind<'tcx>) {
assert!(self.patch_map[block].is_none());
debug!("MirPatch: patch_terminator({:?}, {:?})", block, new);
self.patch_map[block] = Some(new);
}
pub fn add_statement(&mut self, loc: Location, stmt: StatementKind<'tcx>) {
debug!("MirPatch: add_statement({:?}, {:?})", loc, stmt);
self.new_statements.push((loc, stmt));
}
pub fn add_assign(&mut self, loc: Location, place: Place<'tcx>, rv: Rvalue<'tcx>) {
self.add_statement(loc, StatementKind::Assign(Box::new((place, rv))));
}
pub fn apply(self, body: &mut Body<'tcx>) {
debug!(
"MirPatch: {:?} new temps, starting from index {}: {:?}",
self.new_locals.len(),
body.local_decls.len(),
self.new_locals
);
debug!(
"MirPatch: {} new blocks, starting from index {}",
self.new_blocks.len(),
body.basic_blocks.len()
);
let bbs = if self.patch_map.is_empty() && self.new_blocks.is_empty() {
body.basic_blocks.as_mut_preserves_cfg()
} else {
body.basic_blocks.as_mut()
};
bbs.extend(self.new_blocks);
body.local_decls.extend(self.new_locals);
for (src, patch) in self.patch_map.into_iter_enumerated() {
if let Some(patch) = patch {
debug!("MirPatch: patching block {:?}", src);
bbs[src].terminator_mut().kind = patch;
}
}
let mut new_statements = self.new_statements;
new_statements.sort_by_key(|s| s.0);
let mut delta = 0;
let mut last_bb = START_BLOCK;
for (mut loc, stmt) in new_statements {
if loc.block != last_bb {
delta = 0;
last_bb = loc.block;
}
debug!("MirPatch: adding statement {:?} at loc {:?}+{}", stmt, loc, delta);
loc.statement_index += delta;
let source_info = Self::source_info_for_index(&body[loc.block], loc);
body[loc.block]
.statements
.insert(loc.statement_index, Statement { source_info, kind: stmt });
delta += 1;
}
}
pub fn source_info_for_index(data: &BasicBlockData<'_>, loc: Location) -> SourceInfo {
match data.statements.get(loc.statement_index) {
Some(stmt) => stmt.source_info,
None => data.terminator().source_info,
}
}
pub fn source_info_for_location(&self, body: &Body<'tcx>, loc: Location) -> SourceInfo {
let data = match loc.block.index().checked_sub(body.basic_blocks.len()) {
Some(new) => &self.new_blocks[new],
None => &body[loc.block],
};
Self::source_info_for_index(data, loc)
}
}
|
