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
|
name: custom_target
returns: custom_tgt
description: |
Create a custom top level build target. The only positional argument
is the name of this target and cannot contain path separators (`/` or `\`).
The name of custom target might not be used by every backends, for instance with
the Ninja backend, `subdir/meson.build` containing the example below,
`ninja -C builddir foo` or `ninja -C builddir subdir/foo` won't work,
it is instead `ninja -C builddir subdir/file.txt`. Howerver, `meson compile subdir/foo`
is accepted.
```meson
custom_target('foo', output: 'file.txt', ...)
```
*Since 0.60.0* the name argument is optional and defaults to the basename of the first
output (`file.txt` in the example above).
The list of strings passed to the `command` keyword argument accept
the following special string substitutions:
- `@INPUT@`: the full path to the input passed to `input`. If more than
one input is specified, all of them will be substituted as separate
arguments only if the command uses `'@INPUT@'` as a
standalone-argument. For instance, this would not work: `command :
['cp', './@INPUT@']`, but this would: `command : ['cp', '@INPUT@']`.
- `@OUTPUT@`: the full path to the output passed to `output`. If more
than one outputs are specified, the behavior is the same as
`@INPUT@`.
- `@INPUT0@` `@INPUT1@` `...`: the full path to the input with the specified array index in `input`
- `@OUTPUT0@` `@OUTPUT1@` `...`: the full path to the output with the specified array index in `output`
- `@OUTDIR@`: the full path to the directory where the output(s) must be written
- `@DEPFILE@`: the full path to the dependency file passed to `depfile`
- `@PLAINNAME@`: the input filename, without a path
- `@BASENAME@`: the input filename, with extension removed
- `@PRIVATE_DIR@` *(since 0.50.1)*: path to a directory where the custom target must store all its intermediate files.
- `@SOURCE_ROOT@`: the path to the root of the source tree. Depending on the backend,
this may be an absolute or a relative to current workdir path.
- `@BUILD_ROOT@`: the path to the root of the build tree. Depending on the backend,
this may be an absolute or a relative to current workdir path.
- `@CURRENT_SOURCE_DIR@`: this is the directory where the currently
processed meson.build is located in. Depending on the backend,
this may be an absolute or a relative to current workdir path.
*(since 0.47.0)* The `depfile` keyword argument also accepts the
`@BASENAME@` and `@PLAINNAME@` substitutions.
The returned object also has methods that are documented in [[@custom_tgt]].
notes:
- |
Assuming that `command:` is executed by a POSIX `sh` shell
is not portable, notably to Windows. Instead, consider using a
`native: true` [[executable]], or a python script.
optargs:
name:
type: str
description: |
The *unique* id of the custom target
This posarg is optional *since 0.60.0*. It defaults to the basename
of the first output.
kwargs:
build_by_default:
type: bool
since: 0.38.0
description: |
Causes, when set to true, to
have this target be built by default. This means it will be built when
`meson compile` is called without any arguments. The default value is `false`.
*(since 0.50.0)* If `build_by_default` is explicitly set to false, `install`
will no longer override it. If `build_by_default` is not set, `install` will
still determine its default.
build_always:
type: bool
deprecated: 0.47.0
description: |
If `true` this target is always considered out of
date and is rebuilt every time. Equivalent to setting both
`build_always_stale` and `build_by_default` to true.
build_always_stale:
type: bool
since: 0.47.0
default: false
description: |
If `true` the target is always considered out of date.
Useful for things such as build timestamps or revision control tags.
The associated command is run even if the outputs are up to date.
capture:
type: bool
default: false
description: |
There are some compilers that can't be told to write
their output to a file but instead write it to standard output. When
this argument is set to true, Meson captures `stdout` and writes it
to the target file. Note that your command argument list may not
contain `@OUTPUT@` when capture mode is active.
console:
type: bool
since: 0.48.0
description: |
Keyword argument conflicts with `capture`, and is meant
for commands that are resource-intensive and take a long time to
finish. With the Ninja backend, setting this will add this target
to [Ninja's `console` pool](https://ninja-build.org/manual.html#_the_literal_console_literal_pool),
which has special properties such as not buffering stdout and
serializing all targets in this pool.
command:
type: list[str | file | exe | external_program]
description: |
Command to run to create outputs from inputs. The command
may be strings or the return value of functions that return file-like
objects such as [[find_program]],
[[executable]], [[configure_file]],
[[files]], [[custom_target]], etc.
Meson will automatically insert the appropriate dependencies on
targets and files listed in this keyword argument.
Note: always specify commands in array form `['commandname',
'-arg1', '-arg2']` rather than as a string `'commandname -arg1
-arg2'` as the latter will *not* work.
depend_files:
type: list[str | file]
description: |
files ([[@str]],
[[@file]], or the return value of [[configure_file]] that
this target depends on but are not listed in the `command` keyword
argument. Useful for adding regen dependencies.
depends:
type: list[tgt]
description: |
Specifies that this target depends on the specified
target(s), even though it does not take any of them as a command
line argument. This is meant for cases where you have a tool that
e.g. does globbing internally. Usually you should just put the
generated sources as inputs and Meson will set up all dependencies
automatically.
depfile:
type: str
description: |
A dependency file that the command can write listing
all the additional files this target depends on, for example a C
compiler would list all the header files it included, and a change
in any one of these files triggers a recompilation.
*(since 0.47.0)* the `@BASENAME@` and `@PLAINNAME@` substitutions
are also accepted.
input:
type: list[str | file]
description: List of source files. *(since 0.41.0)* the list is flattened.
install:
type: bool
description: When true, this target is installed during the install step.
install_dir:
type: str | list[str]
description: |
If only one install_dir is provided, all outputs are installed there.
*Since 0.40.0* Allows you to specify the installation directory for each
corresponding output. For example:
```meson
custom_target('different-install-dirs',
output : ['first.file', 'second.file'],
install : true,
install_dir : ['somedir', 'otherdir'])
```
This would install `first.file` to `somedir` and `second.file` to `otherdir`.
To only install some outputs, pass `false` for the outputs that you
don't want installed. For example:
```meson
custom_target('only-install-second',
output : ['first.file', 'second.file'],
install : true,
install_dir : [false, 'otherdir'])
```
This would install `second.file` to `otherdir` and not install `first.file`.
install_mode:
type: list[str | int]
since: 0.47.0
description: |
The file mode and optionally the owner/uid and group/gid.
See the `install_mode` kwarg of [[install_data]] for more information.
install_tag:
type: list[str]
since: 0.60.0
description: |
A list of strings, one per output, used by the `meson install --tags` command
to install only a subset of the files.
By default all outputs have no install tag which means they are not being
installed when `--tags` argument is specified. If only one tag is specified,
it is assumed that all outputs have the same tag. `false` can be used for
outputs that have no tag or are not installed.
output:
type: list[str]
description: List of output files.
env:
since: 0.57.0
type: env | list[str] | dict[str]
description: |
environment variables to set, such as
`{'NAME1': 'value1', 'NAME2': 'value2'}` or `['NAME1=value1', 'NAME2=value2']`,
or an [[@env]] object which allows more
sophisticated environment juggling.
feed:
type: bool
since: 0.59.0
default: false
description: |
There are some compilers that can't be told to read
their input from a file and instead read it from standard input. When this
argument is set to `true`, Meson feeds the input file to `stdin`. Note that
your argument list may not contain `@INPUT@` when feed mode is active.
|
