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| -rw-r--r-- | bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst b/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst index b839e669cf..deb7afad43 100644 --- a/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst +++ b/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst | |||
| @@ -319,6 +319,10 @@ The variable ``D`` becomes "dvaladditional data". | |||
| 319 | 319 | ||
| 320 | You must control all spacing when you use the override syntax. | 320 | You must control all spacing when you use the override syntax. |
| 321 | 321 | ||
| 322 | .. note:: | ||
| 323 | |||
| 324 | The overrides are applied in this order, ":append", ":prepend", ":remove". | ||
| 325 | |||
| 322 | It is also possible to append and prepend to shell functions and | 326 | It is also possible to append and prepend to shell functions and |
| 323 | BitBake-style Python functions. See the ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:shell functions`" and ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:bitbake-style python functions`" | 327 | BitBake-style Python functions. See the ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:shell functions`" and ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:bitbake-style python functions`" |
| 324 | sections for examples. | 328 | sections for examples. |
| @@ -352,6 +356,28 @@ The variable ``FOO`` becomes | |||
| 352 | Like ":append" and ":prepend", ":remove" is applied at variable | 356 | Like ":append" and ":prepend", ":remove" is applied at variable |
| 353 | expansion time. | 357 | expansion time. |
| 354 | 358 | ||
| 359 | .. note:: | ||
| 360 | |||
| 361 | The overrides are applied in this order, ":append", ":prepend", ":remove". | ||
| 362 | This implies it is not possible to re-append previously removed strings. | ||
| 363 | However, one can undo a ":remove" by using an intermediate variable whose | ||
| 364 | content is passed to the ":remove" so that modifying the intermediate | ||
| 365 | variable equals to keeping the string in:: | ||
| 366 | |||
| 367 | FOOREMOVE = "123 456 789" | ||
| 368 | FOO:remove = "${FOOREMOVE}" | ||
| 369 | ... | ||
| 370 | FOOREMOVE = "123 789" | ||
| 371 | |||
| 372 | This expands to ``FOO:remove = "123 789"``. | ||
| 373 | |||
| 374 | .. note:: | ||
| 375 | |||
| 376 | Override application order may not match variable parse history, i.e. | ||
| 377 | the output of ``bitbake -e`` may contain ":remove" before ":append", | ||
| 378 | but the result will be removed string, because ":remove" is handled | ||
| 379 | last. | ||
| 380 | |||
| 355 | Override Style Operation Advantages | 381 | Override Style Operation Advantages |
| 356 | ----------------------------------- | 382 | ----------------------------------- |
| 357 | 383 | ||
