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
|
//===--- Forest.cpp - Parse forest ------------------------------*- C++-*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "clang-pseudo/Forest.h"
#include "clang-pseudo/Token.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/None.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/FormatVariadic.h"
namespace clang {
namespace pseudo {
void ForestNode::RecursiveIterator::operator++() {
auto C = Cur->children();
// Try to find a child of the current node to descend into.
for (unsigned I = 0; I < C.size(); ++I) {
if (Seen.insert(C[I]).second) {
Stack.push_back({Cur, I});
Cur = C[I];
return;
}
}
// Try to find a sibling af an ancestor to advance to.
for (; !Stack.empty(); Stack.pop_back()) {
C = Stack.back().Parent->children();
unsigned &Index = Stack.back().ChildIndex;
while (++Index < C.size()) {
if (Seen.insert(C[Index]).second) {
Cur = C[Index];
return;
}
}
}
Cur = nullptr;
}
llvm::iterator_range<ForestNode::RecursiveIterator>
ForestNode::descendants() const {
return {RecursiveIterator(this), RecursiveIterator()};
}
std::string ForestNode::dump(const Grammar &G) const {
switch (kind()) {
case Ambiguous:
return llvm::formatv("{0} := <ambiguous>", G.symbolName(symbol()));
case Terminal:
return llvm::formatv("{0} := tok[{1}]", G.symbolName(symbol()),
startTokenIndex());
case Sequence:
return G.dumpRule(rule());
case Opaque:
return llvm::formatv("{0} := <opaque>", G.symbolName(symbol()));
}
llvm_unreachable("Unhandled node kind!");
}
std::string ForestNode::dumpRecursive(const Grammar &G,
bool Abbreviated) const {
using llvm::formatv;
Token::Index MaxToken = 0;
// Count visits of nodes so we can mark those seen multiple times.
llvm::DenseMap<const ForestNode *, /*VisitCount*/ unsigned> VisitCounts;
std::function<void(const ForestNode *)> CountVisits =
[&](const ForestNode *P) {
MaxToken = std::max(MaxToken, P->startTokenIndex());
if (VisitCounts[P]++ > 0)
return; // Don't count children as multiply visited.
if (P->kind() == Ambiguous)
llvm::for_each(P->alternatives(), CountVisits);
else if (P->kind() == Sequence)
llvm::for_each(P->elements(), CountVisits);
};
CountVisits(this);
unsigned IndexWidth = std::max(3, (int)std::to_string(MaxToken).size());
// e.g. "[{0,4}, {1,4})" if MaxToken is 5742.
std::string RangeFormat = formatv("[{{0,{0}}, {{1,{0}}) ", IndexWidth);
// The box-drawing characters that should be added as a child is rendered.
struct LineDecoration {
std::string Prefix; // Prepended to every line.
llvm::StringRef First; // added to the child's line.
llvm::StringRef Subsequent; // added to descendants' lines.
};
// We print a "#<id>" for nonterminal forest nodes that are being dumped
// multiple times.
llvm::DenseMap<const ForestNode *, size_t> ReferenceIds;
std::string Result;
constexpr Token::Index KEnd = std::numeric_limits<Token::Index>::max();
std::function<void(const ForestNode *, Token::Index, llvm::Optional<SymbolID>,
LineDecoration &LineDec)>
Dump = [&](const ForestNode *P, Token::Index End,
llvm::Optional<SymbolID> ElidedParent,
LineDecoration LineDec) {
bool SharedNode = VisitCounts.find(P)->getSecond() > 1;
llvm::ArrayRef<const ForestNode *> Children;
auto EndOfElement = [&](size_t ChildIndex) {
return ChildIndex + 1 == Children.size()
? End
: Children[ChildIndex + 1]->startTokenIndex();
};
if (P->kind() == Ambiguous) {
Children = P->alternatives();
} else if (P->kind() == Sequence) {
Children = P->elements();
if (Abbreviated) {
// Abbreviate chains of trivial sequence nodes.
// A := B, B := C, C := D, D := X Y Z
// becomes
// A~D := X Y Z
//
// We can't hide nodes that appear multiple times in the tree,
// because we need to call out their identity with IDs.
if (Children.size() == 1 && !SharedNode) {
assert(Children[0]->startTokenIndex() == P->startTokenIndex() &&
EndOfElement(0) == End);
return Dump(Children[0], End,
/*ElidedParent=*/ElidedParent.value_or(P->symbol()),
LineDec);
}
}
}
if (End == KEnd)
Result += formatv(RangeFormat.c_str(), P->startTokenIndex(), "end");
else
Result += formatv(RangeFormat.c_str(), P->startTokenIndex(), End);
Result += LineDec.Prefix;
Result += LineDec.First;
if (ElidedParent) {
Result += G.symbolName(*ElidedParent);
Result += "~";
}
if (SharedNode && P->kind() != ForestNode::Terminal) {
auto It = ReferenceIds.try_emplace(P, ReferenceIds.size() + 1);
bool First = It.second;
unsigned ID = It.first->second;
// The first time, print as #1. Later, =#1.
if (First) {
Result += formatv("{0} #{1}", P->dump(G), ID);
} else {
Result += formatv("{0} =#{1}", G.symbolName(P->symbol()), ID);
Children = {}; // Don't walk the children again.
}
} else {
Result.append(P->dump(G));
}
Result.push_back('\n');
auto OldPrefixSize = LineDec.Prefix.size();
LineDec.Prefix += LineDec.Subsequent;
for (size_t I = 0; I < Children.size(); ++I) {
if (I == Children.size() - 1) {
LineDec.First = "└─";
LineDec.Subsequent = " ";
} else {
LineDec.First = "├─";
LineDec.Subsequent = "│ ";
}
Dump(Children[I], P->kind() == Sequence ? EndOfElement(I) : End,
llvm::None, LineDec);
}
LineDec.Prefix.resize(OldPrefixSize);
};
LineDecoration LineDec;
Dump(this, KEnd, llvm::None, LineDec);
return Result;
}
llvm::ArrayRef<ForestNode>
ForestArena::createTerminals(const TokenStream &Code) {
ForestNode *Terminals = Arena.Allocate<ForestNode>(Code.tokens().size());
size_t Index = 0;
for (const auto &T : Code.tokens()) {
new (&Terminals[Index])
ForestNode(ForestNode::Terminal, tokenSymbol(T.Kind),
/*Start=*/Index, /*TerminalData*/ 0);
++Index;
}
NodeCount = Index;
return llvm::makeArrayRef(Terminals, Index);
}
} // namespace pseudo
} // namespace clang
|
