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
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
# LLVM TableGen Kernel
This notebook is running `llvm-tblgen`.
```tablegen
%reset
// This is some tablegen
class Foo {}
```
------------- Classes -----------------
class Foo {
}
------------- Defs -----------------
Errors printed to stderr are shown.
```tablegen
%reset
This is not tablegen.
```
<stdin>:1:1: error: Unexpected token at top level
This is not tablegen.
^
Add some classes to get some output.
```tablegen
%reset
class Stuff {}
def thing : Stuff {}
```
------------- Classes -----------------
class Stuff {
}
------------- Defs -----------------
def thing { // Stuff
}
By default cells are connected. Meaning that we cache the code and magic directives from the previously run cells.
This means that the next cell still sees the `Stuff` class.
```tablegen
def other_thing : Stuff {}
```
------------- Classes -----------------
class Stuff {
}
------------- Defs -----------------
def other_thing { // Stuff
}
def thing { // Stuff
}
You can use the magic `%reset` to clear this cache and start fresh.
```tablegen
%reset
def other_thing : Stuff {}
```
<stdin>:1:19: error: Couldn't find class 'Stuff'
def other_thing : Stuff {}
^
You can also configure the default reset behaviour using the `%config` magic.
```tablegen
%config cellreset on
class Thing {}
```
------------- Classes -----------------
class Thing {
}
------------- Defs -----------------
```tablegen
// The cache is reset here so this is an error.
def AThing: Thing {}
```
<stdin>:2:13: error: Couldn't find class 'Thing'
def AThing: Thing {}
^
The default value is `off`, meaning cells are connected. If you want to override the default for one cell only, use the `%reset` or `%noreset` magic. These always override the default.
```tablegen
class Thing {}
```
------------- Classes -----------------
class Thing {
}
------------- Defs -----------------
```tablegen
%noreset
// This works because of the noreset above.
def AThing: Thing {}
```
------------- Classes -----------------
class Thing {
}
------------- Defs -----------------
def AThing { // Thing
}
```tablegen
// This does not because we're not changing the default.
def AnotherThing: Thing {}
```
<stdin>:2:19: error: Couldn't find class 'Thing'
def AnotherThing: Thing {}
^
```tablegen
%config cellreset off
%reset
// Here we have an empty cache and default reset behaviour.
```
------------- Classes -----------------
------------- Defs -----------------
It is not valid to have `%reset` and `%noreset` in the same cell.
```tablegen
%reset
%noreset
```
%reset and %noreset in the same cell is not allowed. Use only one, or neither.
Consider setting `cellreset` to the majority usecase for your notebook. For example a tutorial building a large example across many cells will likely want it `off`. One with many standalone examples, `on`.
There is a "magic" directive `%args` that you can use to send command line arguments to `llvm-tblgen`.
For example, here we have some code that shows a warning.
```tablegen
%reset
class Thing <int A, int B> {
int num = A;
}
```
<stdin>:1:25: warning: unused template argument: Thing:B
class Thing <int A, int B> {
^
We can pass an argument to ignore that warning.
```tablegen
%args --no-warn-on-unused-template-args
```
------------- Classes -----------------
class Thing<int Thing:A = ?, int Thing:B = ?> {
int num = Thing:A;
}
------------- Defs -----------------
If you have a run of cells without a `%reset`, the most recent `%args` is used.
```tablegen
// This passes --no-warn-on-unused-template-args
```
------------- Classes -----------------
class Thing<int Thing:A = ?, int Thing:B = ?> {
int num = Thing:A;
}
------------- Defs -----------------
```tablegen
%args
// Now we're not passing the argument so the warning comes back.
```
<stdin>:1:25: warning: unused template argument: Thing:B
class Thing <int A, int B> {
^
If there are many `%args` in a cell, the last one is used.
```tablegen
%reset
%args --no-warn-on-unused-template-args
%args
class Thing <int A, int B> {}
```
<stdin>:1:18: warning: unused template argument: Thing:A
class Thing <int A, int B> {}
^
<stdin>:1:25: warning: unused template argument: Thing:B
class Thing <int A, int B> {}
^
|
