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
|
//===--- FunctionInputGenerator.h - Generator for formal params -*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2023 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file defines FunctionInputGenerator, which generates the sequence
// of formal parameters for a SIL function given its abstraction pattern,
// informing the caller of important information such as the orig and subst
// types and whether the parameter is passed as part of a pack. (It's this
// latter possibility that makes this relatively complicated.)
//
// The assumption is that this will be used as part of binding the parameters
// for a function and that the client of the traversal will claim those
// parameters one by one as the traversal goes on.
//
// In order to properly handle packs of parameters, and especially empty
// packs of parameters, this generator must claim the pack parameters
// as it goes. As a result, it's actually quite important that clients
// use the pattern above of claiming non-pack parameter values immediately
// while traversing a parameter and before advancing to the next parameter.
//
//===----------------------------------------------------------------------===//
#ifndef SWIFT_SILGEN_FUNCTIONINPUTGENERATOR_H
#define SWIFT_SILGEN_FUNCTIONINPUTGENERATOR_H
#include "ManagedValue.h"
#include "swift/SIL/AbstractionPatternGenerators.h"
#include "swift/AST/Types.h"
#include "swift/Basic/Generators.h"
namespace swift {
namespace Lowering {
/// A class for destructuring a list of formal input parameters given
/// an abstraction pattern for it.
class FunctionInputGenerator {
const ASTContext &ctx;
SimpleGeneratorRef<ManagedValue> inputs;
FunctionParamGenerator origParam;
/// If origParam.isPackExpansion(), this is the pack currently
/// being destructured. The cleanup on it is only for the components
/// starting at substParamIndex.
ManagedValue packValue;
/// If origParam.isPackExpansion(), this is the formal type
/// of the orig parameter pack.
CanPackType formalPackType;
/// The current index within origParam.getSubstParams().
unsigned substParamIndex;
/// Precondition: we aren't finished visiting orig parameters,
/// and we've already readied the current orig parameter.
///
/// Ready the next subst parameter (the one at inputSubstParamIndex)
/// from the current orig parameter. If we've exhausted the supply
/// of subst parameters from this orig parameter, advance to the
/// next orig parameter and repeat.
///
/// Postcondition: we're either finished or properly configured
/// with a subst parameter that hasn't been presented before.
void readyNextSubstParameter() {
while (true) {
assert(!origParam.isFinished());
assert(substParamIndex <= origParam.getSubstParams().size());
// If we haven't reached the limit of the current parameter yet,
// continue.
if (substParamIndex != origParam.getSubstParams().size())
return;
// Otherwise, advance, and ready the next orig parameter if we
// didn't finish.
origParam.advance();
if (origParam.isFinished()) return;
readyOrigParameter();
}
}
/// Ready the current orig parameter.
void readyOrigParameter() {
substParamIndex = 0;
if (origParam.isOrigPackExpansion()) {
// The pack value exists in the lowered parameters and must be
// claimed whether it contains formal parameters or not.
packValue = inputs.claimNext();
// We don't need to do any other set up if we're going to
// immediately move past it, though.
if (origParam.getSubstParams().empty())
return;
// Compute a formal pack type for the pack.
formalPackType = CanPackType::get(ctx, origParam.getSubstParams());
}
}
public:
FunctionInputGenerator(const ASTContext &ctx,
SimpleGeneratorRef<ManagedValue> inputs,
AbstractionPattern origFunctionType,
AnyFunctionType::CanParamArrayRef substParams,
bool ignoreFinalParam)
: ctx(ctx), inputs(inputs),
origParam(origFunctionType, substParams, ignoreFinalParam) {
if (!origParam.isFinished()) {
readyOrigParameter();
readyNextSubstParameter();
}
}
/// Is this generator finished? If so, the getters below may not be used.
bool isFinished() const {
return origParam.isFinished();
}
bool isOrigPackExpansion() const {
return origParam.isOrigPackExpansion();
}
AbstractionPattern getOrigType() const {
return origParam.getOrigType();
}
AnyFunctionType::CanParam getSubstParam() const {
return origParam.getSubstParams()[substParamIndex];
}
ManagedValue getPackValue() const {
assert(isOrigPackExpansion());
return packValue;
}
void updatePackValue(ManagedValue newPackValue) {
assert(isOrigPackExpansion());
packValue = newPackValue;
}
unsigned getPackComponentIndex() const {
assert(isOrigPackExpansion());
return substParamIndex;
}
CanPackType getFormalPackType() const {
assert(isOrigPackExpansion());
return formalPackType;
}
/// Given that we just processed an input, advance to the next,
/// if there is on.
///
/// Postcondition: either isFinished() or all of the invariants
/// for the mutable state have been established.
void advance() {
assert(!isFinished());
assert(substParamIndex < origParam.getSubstParams().size());
substParamIndex++;
readyNextSubstParameter();
}
void finish() {
origParam.finish();
}
/// Project out the current pack component. Do not call this multiple
/// times for the same component.
ManagedValue projectPackComponent(SILGenFunction &SGF, SILLocation loc);
};
} // end namespace Lowering
} // end namespace swift
#endif
|
