qt5base-lts/coin/instructions/README.md
Alexandru Croitor 440438092b coin: Use configure and qt-configure-module in instructions
We want to use configure and qt-configure-module when building in
Coin, rather than pure cmake and qt-cmake.

There are a few benefits:
- CI tests the scripts, making sure we don't introduce regressions
- CI uses the same scripts that we mention in our documentation for
developers to use
- The platform configurations become a bit less verbose and easier to
read due to less shouty-case CMake options

To ensure a more gradual porting, Coin will only use the new
instructions if the 'UseConfigure' feature is set on a platform
configuration in qt5.git. This allows going back to the old
instructions in case if something isn't working properly.

Due the opt-in, we need to support both old and new instructions in
the implementation.

The change strives to remove as much duplicate code as possible,
by moving it into common includes.

The README.md is updated to mention the overview of how the different
environment variables are used.

There are a few important things to point out.

1) Because during the porting we have to allow mixing of the old style
and new style, platform configs have to separate CMake-style options
from configure-style options in different environment variables.
Otherwise the instructions wouldn't be able to create a valid
configure call, where all CMake-style options have to go at the end
after a double dash --.

After all platform configs are ported to the new style, it should be
possible to combine all the options in a single environment variable
if that is desired, but it will require another round of porting to
remove all the '-D' prefixes in CMake-style options, and just use
regular variable assignment which configure supports.
e.g. -DQT_BUILD_EXAMPLES=ON becomes QT_BUILD_EXAMPLES=ON, which can be
mixed in-between configure-style args.

2) Configure is more strict in that it doesn't allow passing
unknown options. Due to that, we can't pass non-qtbase configure
options via NON_QTBASE_CONFIGURE_ARGS. qt-configure-module would
error out in the repos where the configure option is unknown.
Because we don't have a Coin configure variable for each repo,
we circumvent the issue by continuing to pass CMake-style options via
NON_QTBASE_CMAKE_ARGS instead, which does not do validation checks.
In the future, we could introduce a configure flag that disables
the validation checks.

Pick-to: 6.2 6.3
Task-number: QTQAINFRA-4357
Task-number: QTQAINFRA-4815
Change-Id: I72d8ba0b3a543b42982e22ae8d6566c0e885c446
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
Reviewed-by: Toni Saario <toni.saario@qt.io>
2022-03-17 17:14:36 +01:00

79 lines
4.2 KiB
Markdown

# Information about Coin instruction templates
## Build templates
* ``coin_qtbase_build_template_v2.yaml`` did not exist. The build instructions were directly embedded into
``module_config.yaml`` and did not support repos outside of qtbase, also no cross-compilation.
* ``coin_qtbase_build_template_v2`` introduced support for building other repos, and also enabled
build cross-compiling targets like ``Android`` and ``iOS``.
A bit later the template gained the ability to build ``qemu`` cross-compiling configurations.
The counterpart to qtbase to build other repositories is ``coin_module_build_template_v2``
## Test templates
* ``coin_module_test_template_v1`` did not exist. The test instructions were directly embedded into
``module_config.yaml`` and did not support repos outside of qtbase, also no cross-compilation.
* ``coin_module_test_template_v2`` introduced support for building tests for other repos, and made
sure not to build and run tests on cross-compiling configuration. A bit later the template gained
the ability to build and run tests for ``qemu`` cross-compiling configurations.
* ``coin_module_test_template_v3`` changed the run test instructions to not ignore the exit code
and thus enforce that tests pass in the CI.
# Environment variable description and usage
The following environment variables are used in Coin instructions when building Qt, tests, etc:
`CONFIGURE_ARGS` - contains platform-specific ``configure-style`` arguments
(e.g. `-shared`), that will be passed to a qtbase configure call
`CMAKE_ARGS` - contains platform-specific ``CMake-style`` arguments
(e.g. `-DOPENSSL_ROOT_DIR=Foo`) that will be passed to a qtbase
configure call
`NON_QTBASE_CONFIGURE_ARGS` - contains platform-specific ``configure-style`` arguments
that will be passed to a non-qtbase qt-configure-module call
`NON_QTBASE_CMAKE_ARGS` - contains platform-specific ``CMake-style`` arguments
that will be passed to a non-qtbase qt-configure-module call
`COMMON_CMAKE_ARGS` - platform-independent ``CMake-style`` args set in
`prepare_building_env.yaml` that apply to qtbase configurations
only.
`COMMON_NON_QTBASE_CMAKE_ARGS` - platform-independent ``CMake-style`` args set in
`prepare_building_env.yaml` that apply to
configuration of repos other than qtbase
`COMMON_TEST_CMAKE_ARGS` - platform-independent ``CMake-style`` args set in
`prepare_building_env.yaml` that apply to configuration of
all standalone tests
All of the above apply to host builds only.
There is a a set of environment variables that apply to target builds when cross-compiling which
mirror the ones above. They are:
`TARGET_CONFIGURE_ARGS`
`TARGET_CMAKE_ARGS`
`NON_QTBASE_TARGET_CONFIGURE_ARGS`
`NON_QTBASE_TARGET_CMAKE_ARGS`
`COMMON_TARGET_CMAKE_ARGS`
`COMMON_NON_QTBASE_TARGET_CMAKE_ARGS`
`COMMON_TARGET_TEST_CMAKE_ARGS`
Currently, there are no common ``configure-style`` variables for configuring
repos or tests, only ``CMake-style` ones.
`COIN_CMAKE_ARGS` contains the final set of cmake args that is passed to
`configure` / `qt-configure-module`, it is built up from the variables above + any additional values added
by custom instructions, like specification of `CMAKE_INSTALL_PREFIX` etc.
`INSTALL_DIR_SUFFIX` is used to append either `/host` or `/target` suffixes to install paths in
instructions when cross-building.
`CONFIGURE_EXECUTABLE` contains a platform-specific path to `configure` / `qt-configure-module`
or `cmake`/ `qt-cmake` depending on whether `UseConfigure` feature is enabled.
`CONFIGURE_ENV_PREFIX` contains the value of either `ENV_PREFIX` or `TARGET_ENV_PREFIX` depending on
whether it's a cross-build configure call. The values are used when configuring and building, to ensure
that things like compilers are found correctly.
We use `unixPathSeparators` to pass an install prefix with forward slashes even on Windows,
to avoid escaping issues when using configure.